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llvm-project/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
Jon Chesterfield 77579b99e9 [openmp][nfc] Replace OMPGridValues array with struct 
[nfc] Replaces enum indices into an array with a struct. Named the
fields to match the enum, leaves memory layout and initialization unchanged.

Motivation is to later safely remove dead fields and replace redundant ones
with (compile time) computation. It should also be possible to factor some
common fields into a base and introduce a gfx10 amdgpu instance with less
duplication than the arrays of integers require.

Reviewed By: ronlieb

Differential Revision: https://reviews.llvm.org/D108339
2021-08-19 13:25:42 +01:00

3937 lines
159 KiB
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//===---- CGOpenMPRuntimeGPU.cpp - Interface to OpenMP GPU Runtimes ----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This provides a generalized class for OpenMP runtime code generation
// specialized by GPU targets NVPTX and AMDGCN.
//
//===----------------------------------------------------------------------===//
#include "CGOpenMPRuntimeGPU.h"
#include "CGOpenMPRuntimeNVPTX.h"
#include "CodeGenFunction.h"
#include "clang/AST/Attr.h"
#include "clang/AST/DeclOpenMP.h"
#include "clang/AST/StmtOpenMP.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/Basic/Cuda.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Frontend/OpenMP/OMPGridValues.h"
#include "llvm/IR/IntrinsicsNVPTX.h"
using namespace clang;
using namespace CodeGen;
using namespace llvm::omp;
namespace {
/// Pre(post)-action for different OpenMP constructs specialized for NVPTX.
class NVPTXActionTy final : public PrePostActionTy {
llvm::FunctionCallee EnterCallee = nullptr;
ArrayRef<llvm::Value *> EnterArgs;
llvm::FunctionCallee ExitCallee = nullptr;
ArrayRef<llvm::Value *> ExitArgs;
bool Conditional = false;
llvm::BasicBlock *ContBlock = nullptr;
public:
NVPTXActionTy(llvm::FunctionCallee EnterCallee,
ArrayRef<llvm::Value *> EnterArgs,
llvm::FunctionCallee ExitCallee,
ArrayRef<llvm::Value *> ExitArgs, bool Conditional = false)
: EnterCallee(EnterCallee), EnterArgs(EnterArgs), ExitCallee(ExitCallee),
ExitArgs(ExitArgs), Conditional(Conditional) {}
void Enter(CodeGenFunction &CGF) override {
llvm::Value *EnterRes = CGF.EmitRuntimeCall(EnterCallee, EnterArgs);
if (Conditional) {
llvm::Value *CallBool = CGF.Builder.CreateIsNotNull(EnterRes);
auto *ThenBlock = CGF.createBasicBlock("omp_if.then");
ContBlock = CGF.createBasicBlock("omp_if.end");
// Generate the branch (If-stmt)
CGF.Builder.CreateCondBr(CallBool, ThenBlock, ContBlock);
CGF.EmitBlock(ThenBlock);
}
}
void Done(CodeGenFunction &CGF) {
// Emit the rest of blocks/branches
CGF.EmitBranch(ContBlock);
CGF.EmitBlock(ContBlock, true);
}
void Exit(CodeGenFunction &CGF) override {
CGF.EmitRuntimeCall(ExitCallee, ExitArgs);
}
};
/// A class to track the execution mode when codegening directives within
/// a target region. The appropriate mode (SPMD|NON-SPMD) is set on entry
/// to the target region and used by containing directives such as 'parallel'
/// to emit optimized code.
class ExecutionRuntimeModesRAII {
private:
CGOpenMPRuntimeGPU::ExecutionMode SavedExecMode =
CGOpenMPRuntimeGPU::EM_Unknown;
CGOpenMPRuntimeGPU::ExecutionMode &ExecMode;
bool SavedRuntimeMode = false;
bool *RuntimeMode = nullptr;
public:
/// Constructor for Non-SPMD mode.
ExecutionRuntimeModesRAII(CGOpenMPRuntimeGPU::ExecutionMode &ExecMode)
: ExecMode(ExecMode) {
SavedExecMode = ExecMode;
ExecMode = CGOpenMPRuntimeGPU::EM_NonSPMD;
}
/// Constructor for SPMD mode.
ExecutionRuntimeModesRAII(CGOpenMPRuntimeGPU::ExecutionMode &ExecMode,
bool &RuntimeMode, bool FullRuntimeMode)
: ExecMode(ExecMode), RuntimeMode(&RuntimeMode) {
SavedExecMode = ExecMode;
SavedRuntimeMode = RuntimeMode;
ExecMode = CGOpenMPRuntimeGPU::EM_SPMD;
RuntimeMode = FullRuntimeMode;
}
~ExecutionRuntimeModesRAII() {
ExecMode = SavedExecMode;
if (RuntimeMode)
*RuntimeMode = SavedRuntimeMode;
}
};
/// GPU Configuration: This information can be derived from cuda registers,
/// however, providing compile time constants helps generate more efficient
/// code. For all practical purposes this is fine because the configuration
/// is the same for all known NVPTX architectures.
enum MachineConfiguration : unsigned {
/// See "llvm/Frontend/OpenMP/OMPGridValues.h" for various related target
/// specific Grid Values like GV_Warp_Size, GV_Warp_Size_Log2,
/// and GV_Warp_Size_Log2_Mask.
/// Global memory alignment for performance.
GlobalMemoryAlignment = 128,
/// Maximal size of the shared memory buffer.
SharedMemorySize = 128,
};
static const ValueDecl *getPrivateItem(const Expr *RefExpr) {
RefExpr = RefExpr->IgnoreParens();
if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(RefExpr)) {
const Expr *Base = ASE->getBase()->IgnoreParenImpCasts();
while (const auto *TempASE = dyn_cast<ArraySubscriptExpr>(Base))
Base = TempASE->getBase()->IgnoreParenImpCasts();
RefExpr = Base;
} else if (auto *OASE = dyn_cast<OMPArraySectionExpr>(RefExpr)) {
const Expr *Base = OASE->getBase()->IgnoreParenImpCasts();
while (const auto *TempOASE = dyn_cast<OMPArraySectionExpr>(Base))
Base = TempOASE->getBase()->IgnoreParenImpCasts();
while (const auto *TempASE = dyn_cast<ArraySubscriptExpr>(Base))
Base = TempASE->getBase()->IgnoreParenImpCasts();
RefExpr = Base;
}
RefExpr = RefExpr->IgnoreParenImpCasts();
if (const auto *DE = dyn_cast<DeclRefExpr>(RefExpr))
return cast<ValueDecl>(DE->getDecl()->getCanonicalDecl());
const auto *ME = cast<MemberExpr>(RefExpr);
return cast<ValueDecl>(ME->getMemberDecl()->getCanonicalDecl());
}
static RecordDecl *buildRecordForGlobalizedVars(
ASTContext &C, ArrayRef<const ValueDecl *> EscapedDecls,
ArrayRef<const ValueDecl *> EscapedDeclsForTeams,
llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
&MappedDeclsFields, int BufSize) {
using VarsDataTy = std::pair<CharUnits /*Align*/, const ValueDecl *>;
if (EscapedDecls.empty() && EscapedDeclsForTeams.empty())
return nullptr;
SmallVector<VarsDataTy, 4> GlobalizedVars;
for (const ValueDecl *D : EscapedDecls)
GlobalizedVars.emplace_back(
CharUnits::fromQuantity(std::max(
C.getDeclAlign(D).getQuantity(),
static_cast<CharUnits::QuantityType>(GlobalMemoryAlignment))),
D);
for (const ValueDecl *D : EscapedDeclsForTeams)
GlobalizedVars.emplace_back(C.getDeclAlign(D), D);
llvm::stable_sort(GlobalizedVars, [](VarsDataTy L, VarsDataTy R) {
return L.first > R.first;
});
// Build struct _globalized_locals_ty {
// /* globalized vars */[WarSize] align (max(decl_align,
// GlobalMemoryAlignment))
// /* globalized vars */ for EscapedDeclsForTeams
// };
RecordDecl *GlobalizedRD = C.buildImplicitRecord("_globalized_locals_ty");
GlobalizedRD->startDefinition();
llvm::SmallPtrSet<const ValueDecl *, 16> SingleEscaped(
EscapedDeclsForTeams.begin(), EscapedDeclsForTeams.end());
for (const auto &Pair : GlobalizedVars) {
const ValueDecl *VD = Pair.second;
QualType Type = VD->getType();
if (Type->isLValueReferenceType())
Type = C.getPointerType(Type.getNonReferenceType());
else
Type = Type.getNonReferenceType();
SourceLocation Loc = VD->getLocation();
FieldDecl *Field;
if (SingleEscaped.count(VD)) {
Field = FieldDecl::Create(
C, GlobalizedRD, Loc, Loc, VD->getIdentifier(), Type,
C.getTrivialTypeSourceInfo(Type, SourceLocation()),
/*BW=*/nullptr, /*Mutable=*/false,
/*InitStyle=*/ICIS_NoInit);
Field->setAccess(AS_public);
if (VD->hasAttrs()) {
for (specific_attr_iterator<AlignedAttr> I(VD->getAttrs().begin()),
E(VD->getAttrs().end());
I != E; ++I)
Field->addAttr(*I);
}
} else {
llvm::APInt ArraySize(32, BufSize);
Type = C.getConstantArrayType(Type, ArraySize, nullptr, ArrayType::Normal,
0);
Field = FieldDecl::Create(
C, GlobalizedRD, Loc, Loc, VD->getIdentifier(), Type,
C.getTrivialTypeSourceInfo(Type, SourceLocation()),
/*BW=*/nullptr, /*Mutable=*/false,
/*InitStyle=*/ICIS_NoInit);
Field->setAccess(AS_public);
llvm::APInt Align(32, std::max(C.getDeclAlign(VD).getQuantity(),
static_cast<CharUnits::QuantityType>(
GlobalMemoryAlignment)));
Field->addAttr(AlignedAttr::CreateImplicit(
C, /*IsAlignmentExpr=*/true,
IntegerLiteral::Create(C, Align,
C.getIntTypeForBitwidth(32, /*Signed=*/0),
SourceLocation()),
{}, AttributeCommonInfo::AS_GNU, AlignedAttr::GNU_aligned));
}
GlobalizedRD->addDecl(Field);
MappedDeclsFields.try_emplace(VD, Field);
}
GlobalizedRD->completeDefinition();
return GlobalizedRD;
}
/// Get the list of variables that can escape their declaration context.
class CheckVarsEscapingDeclContext final
: public ConstStmtVisitor<CheckVarsEscapingDeclContext> {
CodeGenFunction &CGF;
llvm::SetVector<const ValueDecl *> EscapedDecls;
llvm::SetVector<const ValueDecl *> EscapedVariableLengthDecls;
llvm::SmallPtrSet<const Decl *, 4> EscapedParameters;
RecordDecl *GlobalizedRD = nullptr;
llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *> MappedDeclsFields;
bool AllEscaped = false;
bool IsForCombinedParallelRegion = false;
void markAsEscaped(const ValueDecl *VD) {
// Do not globalize declare target variables.
if (!isa<VarDecl>(VD) ||
OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD))
return;
VD = cast<ValueDecl>(VD->getCanonicalDecl());
// Use user-specified allocation.
if (VD->hasAttrs() && VD->hasAttr<OMPAllocateDeclAttr>())
return;
// Variables captured by value must be globalized.
if (auto *CSI = CGF.CapturedStmtInfo) {
if (const FieldDecl *FD = CSI->lookup(cast<VarDecl>(VD))) {
// Check if need to capture the variable that was already captured by
// value in the outer region.
if (!IsForCombinedParallelRegion) {
if (!FD->hasAttrs())
return;
const auto *Attr = FD->getAttr<OMPCaptureKindAttr>();
if (!Attr)
return;
if (((Attr->getCaptureKind() != OMPC_map) &&
!isOpenMPPrivate(Attr->getCaptureKind())) ||
((Attr->getCaptureKind() == OMPC_map) &&
!FD->getType()->isAnyPointerType()))
return;
}
if (!FD->getType()->isReferenceType()) {
assert(!VD->getType()->isVariablyModifiedType() &&
"Parameter captured by value with variably modified type");
EscapedParameters.insert(VD);
} else if (!IsForCombinedParallelRegion) {
return;
}
}
}
if ((!CGF.CapturedStmtInfo ||
(IsForCombinedParallelRegion && CGF.CapturedStmtInfo)) &&
VD->getType()->isReferenceType())
// Do not globalize variables with reference type.
return;
if (VD->getType()->isVariablyModifiedType())
EscapedVariableLengthDecls.insert(VD);
else
EscapedDecls.insert(VD);
}
void VisitValueDecl(const ValueDecl *VD) {
if (VD->getType()->isLValueReferenceType())
markAsEscaped(VD);
if (const auto *VarD = dyn_cast<VarDecl>(VD)) {
if (!isa<ParmVarDecl>(VarD) && VarD->hasInit()) {
const bool SavedAllEscaped = AllEscaped;
AllEscaped = VD->getType()->isLValueReferenceType();
Visit(VarD->getInit());
AllEscaped = SavedAllEscaped;
}
}
}
void VisitOpenMPCapturedStmt(const CapturedStmt *S,
ArrayRef<OMPClause *> Clauses,
bool IsCombinedParallelRegion) {
if (!S)
return;
for (const CapturedStmt::Capture &C : S->captures()) {
if (C.capturesVariable() && !C.capturesVariableByCopy()) {
const ValueDecl *VD = C.getCapturedVar();
bool SavedIsForCombinedParallelRegion = IsForCombinedParallelRegion;
if (IsCombinedParallelRegion) {
// Check if the variable is privatized in the combined construct and
// those private copies must be shared in the inner parallel
// directive.
IsForCombinedParallelRegion = false;
for (const OMPClause *C : Clauses) {
if (!isOpenMPPrivate(C->getClauseKind()) ||
C->getClauseKind() == OMPC_reduction ||
C->getClauseKind() == OMPC_linear ||
C->getClauseKind() == OMPC_private)
continue;
ArrayRef<const Expr *> Vars;
if (const auto *PC = dyn_cast<OMPFirstprivateClause>(C))
Vars = PC->getVarRefs();
else if (const auto *PC = dyn_cast<OMPLastprivateClause>(C))
Vars = PC->getVarRefs();
else
llvm_unreachable("Unexpected clause.");
for (const auto *E : Vars) {
const Decl *D =
cast<DeclRefExpr>(E)->getDecl()->getCanonicalDecl();
if (D == VD->getCanonicalDecl()) {
IsForCombinedParallelRegion = true;
break;
}
}
if (IsForCombinedParallelRegion)
break;
}
}
markAsEscaped(VD);
if (isa<OMPCapturedExprDecl>(VD))
VisitValueDecl(VD);
IsForCombinedParallelRegion = SavedIsForCombinedParallelRegion;
}
}
}
void buildRecordForGlobalizedVars(bool IsInTTDRegion) {
assert(!GlobalizedRD &&
"Record for globalized variables is built already.");
ArrayRef<const ValueDecl *> EscapedDeclsForParallel, EscapedDeclsForTeams;
unsigned WarpSize = CGF.getTarget().getGridValue().GV_Warp_Size;
if (IsInTTDRegion)
EscapedDeclsForTeams = EscapedDecls.getArrayRef();
else
EscapedDeclsForParallel = EscapedDecls.getArrayRef();
GlobalizedRD = ::buildRecordForGlobalizedVars(
CGF.getContext(), EscapedDeclsForParallel, EscapedDeclsForTeams,
MappedDeclsFields, WarpSize);
}
public:
CheckVarsEscapingDeclContext(CodeGenFunction &CGF,
ArrayRef<const ValueDecl *> TeamsReductions)
: CGF(CGF), EscapedDecls(TeamsReductions.begin(), TeamsReductions.end()) {
}
virtual ~CheckVarsEscapingDeclContext() = default;
void VisitDeclStmt(const DeclStmt *S) {
if (!S)
return;
for (const Decl *D : S->decls())
if (const auto *VD = dyn_cast_or_null<ValueDecl>(D))
VisitValueDecl(VD);
}
void VisitOMPExecutableDirective(const OMPExecutableDirective *D) {
if (!D)
return;
if (!D->hasAssociatedStmt())
return;
if (const auto *S =
dyn_cast_or_null<CapturedStmt>(D->getAssociatedStmt())) {
// Do not analyze directives that do not actually require capturing,
// like `omp for` or `omp simd` directives.
llvm::SmallVector<OpenMPDirectiveKind, 4> CaptureRegions;
getOpenMPCaptureRegions(CaptureRegions, D->getDirectiveKind());
if (CaptureRegions.size() == 1 && CaptureRegions.back() == OMPD_unknown) {
VisitStmt(S->getCapturedStmt());
return;
}
VisitOpenMPCapturedStmt(
S, D->clauses(),
CaptureRegions.back() == OMPD_parallel &&
isOpenMPDistributeDirective(D->getDirectiveKind()));
}
}
void VisitCapturedStmt(const CapturedStmt *S) {
if (!S)
return;
for (const CapturedStmt::Capture &C : S->captures()) {
if (C.capturesVariable() && !C.capturesVariableByCopy()) {
const ValueDecl *VD = C.getCapturedVar();
markAsEscaped(VD);
if (isa<OMPCapturedExprDecl>(VD))
VisitValueDecl(VD);
}
}
}
void VisitLambdaExpr(const LambdaExpr *E) {
if (!E)
return;
for (const LambdaCapture &C : E->captures()) {
if (C.capturesVariable()) {
if (C.getCaptureKind() == LCK_ByRef) {
const ValueDecl *VD = C.getCapturedVar();
markAsEscaped(VD);
if (E->isInitCapture(&C) || isa<OMPCapturedExprDecl>(VD))
VisitValueDecl(VD);
}
}
}
}
void VisitBlockExpr(const BlockExpr *E) {
if (!E)
return;
for (const BlockDecl::Capture &C : E->getBlockDecl()->captures()) {
if (C.isByRef()) {
const VarDecl *VD = C.getVariable();
markAsEscaped(VD);
if (isa<OMPCapturedExprDecl>(VD) || VD->isInitCapture())
VisitValueDecl(VD);
}
}
}
void VisitCallExpr(const CallExpr *E) {
if (!E)
return;
for (const Expr *Arg : E->arguments()) {
if (!Arg)
continue;
if (Arg->isLValue()) {
const bool SavedAllEscaped = AllEscaped;
AllEscaped = true;
Visit(Arg);
AllEscaped = SavedAllEscaped;
} else {
Visit(Arg);
}
}
Visit(E->getCallee());
}
void VisitDeclRefExpr(const DeclRefExpr *E) {
if (!E)
return;
const ValueDecl *VD = E->getDecl();
if (AllEscaped)
markAsEscaped(VD);
if (isa<OMPCapturedExprDecl>(VD))
VisitValueDecl(VD);
else if (const auto *VarD = dyn_cast<VarDecl>(VD))
if (VarD->isInitCapture())
VisitValueDecl(VD);
}
void VisitUnaryOperator(const UnaryOperator *E) {
if (!E)
return;
if (E->getOpcode() == UO_AddrOf) {
const bool SavedAllEscaped = AllEscaped;
AllEscaped = true;
Visit(E->getSubExpr());
AllEscaped = SavedAllEscaped;
} else {
Visit(E->getSubExpr());
}
}
void VisitImplicitCastExpr(const ImplicitCastExpr *E) {
if (!E)
return;
if (E->getCastKind() == CK_ArrayToPointerDecay) {
const bool SavedAllEscaped = AllEscaped;
AllEscaped = true;
Visit(E->getSubExpr());
AllEscaped = SavedAllEscaped;
} else {
Visit(E->getSubExpr());
}
}
void VisitExpr(const Expr *E) {
if (!E)
return;
bool SavedAllEscaped = AllEscaped;
if (!E->isLValue())
AllEscaped = false;
for (const Stmt *Child : E->children())
if (Child)
Visit(Child);
AllEscaped = SavedAllEscaped;
}
void VisitStmt(const Stmt *S) {
if (!S)
return;
for (const Stmt *Child : S->children())
if (Child)
Visit(Child);
}
/// Returns the record that handles all the escaped local variables and used
/// instead of their original storage.
const RecordDecl *getGlobalizedRecord(bool IsInTTDRegion) {
if (!GlobalizedRD)
buildRecordForGlobalizedVars(IsInTTDRegion);
return GlobalizedRD;
}
/// Returns the field in the globalized record for the escaped variable.
const FieldDecl *getFieldForGlobalizedVar(const ValueDecl *VD) const {
assert(GlobalizedRD &&
"Record for globalized variables must be generated already.");
auto I = MappedDeclsFields.find(VD);
if (I == MappedDeclsFields.end())
return nullptr;
return I->getSecond();
}
/// Returns the list of the escaped local variables/parameters.
ArrayRef<const ValueDecl *> getEscapedDecls() const {
return EscapedDecls.getArrayRef();
}
/// Checks if the escaped local variable is actually a parameter passed by
/// value.
const llvm::SmallPtrSetImpl<const Decl *> &getEscapedParameters() const {
return EscapedParameters;
}
/// Returns the list of the escaped variables with the variably modified
/// types.
ArrayRef<const ValueDecl *> getEscapedVariableLengthDecls() const {
return EscapedVariableLengthDecls.getArrayRef();
}
};
} // anonymous namespace
/// Get the id of the warp in the block.
/// We assume that the warp size is 32, which is always the case
/// on the NVPTX device, to generate more efficient code.
static llvm::Value *getNVPTXWarpID(CodeGenFunction &CGF) {
CGBuilderTy &Bld = CGF.Builder;
unsigned LaneIDBits = CGF.getTarget().getGridValue().GV_Warp_Size_Log2;
auto &RT = static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
return Bld.CreateAShr(RT.getGPUThreadID(CGF), LaneIDBits, "nvptx_warp_id");
}
/// Get the id of the current lane in the Warp.
/// We assume that the warp size is 32, which is always the case
/// on the NVPTX device, to generate more efficient code.
static llvm::Value *getNVPTXLaneID(CodeGenFunction &CGF) {
CGBuilderTy &Bld = CGF.Builder;
unsigned LaneIDMask =
CGF.getContext().getTargetInfo().getGridValue().GV_Warp_Size_Log2_Mask;
auto &RT = static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
return Bld.CreateAnd(RT.getGPUThreadID(CGF), Bld.getInt32(LaneIDMask),
"nvptx_lane_id");
}
CGOpenMPRuntimeGPU::ExecutionMode
CGOpenMPRuntimeGPU::getExecutionMode() const {
return CurrentExecutionMode;
}
static CGOpenMPRuntimeGPU::DataSharingMode
getDataSharingMode(CodeGenModule &CGM) {
return CGM.getLangOpts().OpenMPCUDAMode ? CGOpenMPRuntimeGPU::CUDA
: CGOpenMPRuntimeGPU::Generic;
}
/// Check for inner (nested) SPMD construct, if any
static bool hasNestedSPMDDirective(ASTContext &Ctx,
const OMPExecutableDirective &D) {
const auto *CS = D.getInnermostCapturedStmt();
const auto *Body =
CS->getCapturedStmt()->IgnoreContainers(/*IgnoreCaptured=*/true);
const Stmt *ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
if (const auto *NestedDir =
dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
OpenMPDirectiveKind DKind = NestedDir->getDirectiveKind();
switch (D.getDirectiveKind()) {
case OMPD_target:
if (isOpenMPParallelDirective(DKind))
return true;
if (DKind == OMPD_teams) {
Body = NestedDir->getInnermostCapturedStmt()->IgnoreContainers(
/*IgnoreCaptured=*/true);
if (!Body)
return false;
ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
if (const auto *NND =
dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
DKind = NND->getDirectiveKind();
if (isOpenMPParallelDirective(DKind))
return true;
}
}
return false;
case OMPD_target_teams:
return isOpenMPParallelDirective(DKind);
case OMPD_target_simd:
case OMPD_target_parallel:
case OMPD_target_parallel_for:
case OMPD_target_parallel_for_simd:
case OMPD_target_teams_distribute:
case OMPD_target_teams_distribute_simd:
case OMPD_target_teams_distribute_parallel_for:
case OMPD_target_teams_distribute_parallel_for_simd:
case OMPD_parallel:
case OMPD_for:
case OMPD_parallel_for:
case OMPD_parallel_master:
case OMPD_parallel_sections:
case OMPD_for_simd:
case OMPD_parallel_for_simd:
case OMPD_cancel:
case OMPD_cancellation_point:
case OMPD_ordered:
case OMPD_threadprivate:
case OMPD_allocate:
case OMPD_task:
case OMPD_simd:
case OMPD_sections:
case OMPD_section:
case OMPD_single:
case OMPD_master:
case OMPD_critical:
case OMPD_taskyield:
case OMPD_barrier:
case OMPD_taskwait:
case OMPD_taskgroup:
case OMPD_atomic:
case OMPD_flush:
case OMPD_depobj:
case OMPD_scan:
case OMPD_teams:
case OMPD_target_data:
case OMPD_target_exit_data:
case OMPD_target_enter_data:
case OMPD_distribute:
case OMPD_distribute_simd:
case OMPD_distribute_parallel_for:
case OMPD_distribute_parallel_for_simd:
case OMPD_teams_distribute:
case OMPD_teams_distribute_simd:
case OMPD_teams_distribute_parallel_for:
case OMPD_teams_distribute_parallel_for_simd:
case OMPD_target_update:
case OMPD_declare_simd:
case OMPD_declare_variant:
case OMPD_begin_declare_variant:
case OMPD_end_declare_variant:
case OMPD_declare_target:
case OMPD_end_declare_target:
case OMPD_declare_reduction:
case OMPD_declare_mapper:
case OMPD_taskloop:
case OMPD_taskloop_simd:
case OMPD_master_taskloop:
case OMPD_master_taskloop_simd:
case OMPD_parallel_master_taskloop:
case OMPD_parallel_master_taskloop_simd:
case OMPD_requires:
case OMPD_unknown:
default:
llvm_unreachable("Unexpected directive.");
}
}
return false;
}
static bool supportsSPMDExecutionMode(ASTContext &Ctx,
const OMPExecutableDirective &D) {
OpenMPDirectiveKind DirectiveKind = D.getDirectiveKind();
switch (DirectiveKind) {
case OMPD_target:
case OMPD_target_teams:
return hasNestedSPMDDirective(Ctx, D);
case OMPD_target_parallel:
case OMPD_target_parallel_for:
case OMPD_target_parallel_for_simd:
case OMPD_target_teams_distribute_parallel_for:
case OMPD_target_teams_distribute_parallel_for_simd:
case OMPD_target_simd:
case OMPD_target_teams_distribute_simd:
return true;
case OMPD_target_teams_distribute:
return false;
case OMPD_parallel:
case OMPD_for:
case OMPD_parallel_for:
case OMPD_parallel_master:
case OMPD_parallel_sections:
case OMPD_for_simd:
case OMPD_parallel_for_simd:
case OMPD_cancel:
case OMPD_cancellation_point:
case OMPD_ordered:
case OMPD_threadprivate:
case OMPD_allocate:
case OMPD_task:
case OMPD_simd:
case OMPD_sections:
case OMPD_section:
case OMPD_single:
case OMPD_master:
case OMPD_critical:
case OMPD_taskyield:
case OMPD_barrier:
case OMPD_taskwait:
case OMPD_taskgroup:
case OMPD_atomic:
case OMPD_flush:
case OMPD_depobj:
case OMPD_scan:
case OMPD_teams:
case OMPD_target_data:
case OMPD_target_exit_data:
case OMPD_target_enter_data:
case OMPD_distribute:
case OMPD_distribute_simd:
case OMPD_distribute_parallel_for:
case OMPD_distribute_parallel_for_simd:
case OMPD_teams_distribute:
case OMPD_teams_distribute_simd:
case OMPD_teams_distribute_parallel_for:
case OMPD_teams_distribute_parallel_for_simd:
case OMPD_target_update:
case OMPD_declare_simd:
case OMPD_declare_variant:
case OMPD_begin_declare_variant:
case OMPD_end_declare_variant:
case OMPD_declare_target:
case OMPD_end_declare_target:
case OMPD_declare_reduction:
case OMPD_declare_mapper:
case OMPD_taskloop:
case OMPD_taskloop_simd:
case OMPD_master_taskloop:
case OMPD_master_taskloop_simd:
case OMPD_parallel_master_taskloop:
case OMPD_parallel_master_taskloop_simd:
case OMPD_requires:
case OMPD_unknown:
default:
break;
}
llvm_unreachable(
"Unknown programming model for OpenMP directive on NVPTX target.");
}
/// Check if the directive is loops based and has schedule clause at all or has
/// static scheduling.
static bool hasStaticScheduling(const OMPExecutableDirective &D) {
assert(isOpenMPWorksharingDirective(D.getDirectiveKind()) &&
isOpenMPLoopDirective(D.getDirectiveKind()) &&
"Expected loop-based directive.");
return !D.hasClausesOfKind<OMPOrderedClause>() &&
(!D.hasClausesOfKind<OMPScheduleClause>() ||
llvm::any_of(D.getClausesOfKind<OMPScheduleClause>(),
[](const OMPScheduleClause *C) {
return C->getScheduleKind() == OMPC_SCHEDULE_static;
}));
}
/// Check for inner (nested) lightweight runtime construct, if any
static bool hasNestedLightweightDirective(ASTContext &Ctx,
const OMPExecutableDirective &D) {
assert(supportsSPMDExecutionMode(Ctx, D) && "Expected SPMD mode directive.");
const auto *CS = D.getInnermostCapturedStmt();
const auto *Body =
CS->getCapturedStmt()->IgnoreContainers(/*IgnoreCaptured=*/true);
const Stmt *ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
if (const auto *NestedDir =
dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
OpenMPDirectiveKind DKind = NestedDir->getDirectiveKind();
switch (D.getDirectiveKind()) {
case OMPD_target:
if (isOpenMPParallelDirective(DKind) &&
isOpenMPWorksharingDirective(DKind) && isOpenMPLoopDirective(DKind) &&
hasStaticScheduling(*NestedDir))
return true;
if (DKind == OMPD_teams_distribute_simd || DKind == OMPD_simd)
return true;
if (DKind == OMPD_parallel) {
Body = NestedDir->getInnermostCapturedStmt()->IgnoreContainers(
/*IgnoreCaptured=*/true);
if (!Body)
return false;
ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
if (const auto *NND =
dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
DKind = NND->getDirectiveKind();
if (isOpenMPWorksharingDirective(DKind) &&
isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NND))
return true;
}
} else if (DKind == OMPD_teams) {
Body = NestedDir->getInnermostCapturedStmt()->IgnoreContainers(
/*IgnoreCaptured=*/true);
if (!Body)
return false;
ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
if (const auto *NND =
dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
DKind = NND->getDirectiveKind();
if (isOpenMPParallelDirective(DKind) &&
isOpenMPWorksharingDirective(DKind) &&
isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NND))
return true;
if (DKind == OMPD_parallel) {
Body = NND->getInnermostCapturedStmt()->IgnoreContainers(
/*IgnoreCaptured=*/true);
if (!Body)
return false;
ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
if (const auto *NND =
dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
DKind = NND->getDirectiveKind();
if (isOpenMPWorksharingDirective(DKind) &&
isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NND))
return true;
}
}
}
}
return false;
case OMPD_target_teams:
if (isOpenMPParallelDirective(DKind) &&
isOpenMPWorksharingDirective(DKind) && isOpenMPLoopDirective(DKind) &&
hasStaticScheduling(*NestedDir))
return true;
if (DKind == OMPD_distribute_simd || DKind == OMPD_simd)
return true;
if (DKind == OMPD_parallel) {
Body = NestedDir->getInnermostCapturedStmt()->IgnoreContainers(
/*IgnoreCaptured=*/true);
if (!Body)
return false;
ChildStmt = CGOpenMPRuntime::getSingleCompoundChild(Ctx, Body);
if (const auto *NND =
dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
DKind = NND->getDirectiveKind();
if (isOpenMPWorksharingDirective(DKind) &&
isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NND))
return true;
}
}
return false;
case OMPD_target_parallel:
if (DKind == OMPD_simd)
return true;
return isOpenMPWorksharingDirective(DKind) &&
isOpenMPLoopDirective(DKind) && hasStaticScheduling(*NestedDir);
case OMPD_target_teams_distribute:
case OMPD_target_simd:
case OMPD_target_parallel_for:
case OMPD_target_parallel_for_simd:
case OMPD_target_teams_distribute_simd:
case OMPD_target_teams_distribute_parallel_for:
case OMPD_target_teams_distribute_parallel_for_simd:
case OMPD_parallel:
case OMPD_for:
case OMPD_parallel_for:
case OMPD_parallel_master:
case OMPD_parallel_sections:
case OMPD_for_simd:
case OMPD_parallel_for_simd:
case OMPD_cancel:
case OMPD_cancellation_point:
case OMPD_ordered:
case OMPD_threadprivate:
case OMPD_allocate:
case OMPD_task:
case OMPD_simd:
case OMPD_sections:
case OMPD_section:
case OMPD_single:
case OMPD_master:
case OMPD_critical:
case OMPD_taskyield:
case OMPD_barrier:
case OMPD_taskwait:
case OMPD_taskgroup:
case OMPD_atomic:
case OMPD_flush:
case OMPD_depobj:
case OMPD_scan:
case OMPD_teams:
case OMPD_target_data:
case OMPD_target_exit_data:
case OMPD_target_enter_data:
case OMPD_distribute:
case OMPD_distribute_simd:
case OMPD_distribute_parallel_for:
case OMPD_distribute_parallel_for_simd:
case OMPD_teams_distribute:
case OMPD_teams_distribute_simd:
case OMPD_teams_distribute_parallel_for:
case OMPD_teams_distribute_parallel_for_simd:
case OMPD_target_update:
case OMPD_declare_simd:
case OMPD_declare_variant:
case OMPD_begin_declare_variant:
case OMPD_end_declare_variant:
case OMPD_declare_target:
case OMPD_end_declare_target:
case OMPD_declare_reduction:
case OMPD_declare_mapper:
case OMPD_taskloop:
case OMPD_taskloop_simd:
case OMPD_master_taskloop:
case OMPD_master_taskloop_simd:
case OMPD_parallel_master_taskloop:
case OMPD_parallel_master_taskloop_simd:
case OMPD_requires:
case OMPD_unknown:
default:
llvm_unreachable("Unexpected directive.");
}
}
return false;
}
/// Checks if the construct supports lightweight runtime. It must be SPMD
/// construct + inner loop-based construct with static scheduling.
static bool supportsLightweightRuntime(ASTContext &Ctx,
const OMPExecutableDirective &D) {
if (!supportsSPMDExecutionMode(Ctx, D))
return false;
OpenMPDirectiveKind DirectiveKind = D.getDirectiveKind();
switch (DirectiveKind) {
case OMPD_target:
case OMPD_target_teams:
case OMPD_target_parallel:
return hasNestedLightweightDirective(Ctx, D);
case OMPD_target_parallel_for:
case OMPD_target_parallel_for_simd:
case OMPD_target_teams_distribute_parallel_for:
case OMPD_target_teams_distribute_parallel_for_simd:
// (Last|First)-privates must be shared in parallel region.
return hasStaticScheduling(D);
case OMPD_target_simd:
case OMPD_target_teams_distribute_simd:
return true;
case OMPD_target_teams_distribute:
return false;
case OMPD_parallel:
case OMPD_for:
case OMPD_parallel_for:
case OMPD_parallel_master:
case OMPD_parallel_sections:
case OMPD_for_simd:
case OMPD_parallel_for_simd:
case OMPD_cancel:
case OMPD_cancellation_point:
case OMPD_ordered:
case OMPD_threadprivate:
case OMPD_allocate:
case OMPD_task:
case OMPD_simd:
case OMPD_sections:
case OMPD_section:
case OMPD_single:
case OMPD_master:
case OMPD_critical:
case OMPD_taskyield:
case OMPD_barrier:
case OMPD_taskwait:
case OMPD_taskgroup:
case OMPD_atomic:
case OMPD_flush:
case OMPD_depobj:
case OMPD_scan:
case OMPD_teams:
case OMPD_target_data:
case OMPD_target_exit_data:
case OMPD_target_enter_data:
case OMPD_distribute:
case OMPD_distribute_simd:
case OMPD_distribute_parallel_for:
case OMPD_distribute_parallel_for_simd:
case OMPD_teams_distribute:
case OMPD_teams_distribute_simd:
case OMPD_teams_distribute_parallel_for:
case OMPD_teams_distribute_parallel_for_simd:
case OMPD_target_update:
case OMPD_declare_simd:
case OMPD_declare_variant:
case OMPD_begin_declare_variant:
case OMPD_end_declare_variant:
case OMPD_declare_target:
case OMPD_end_declare_target:
case OMPD_declare_reduction:
case OMPD_declare_mapper:
case OMPD_taskloop:
case OMPD_taskloop_simd:
case OMPD_master_taskloop:
case OMPD_master_taskloop_simd:
case OMPD_parallel_master_taskloop:
case OMPD_parallel_master_taskloop_simd:
case OMPD_requires:
case OMPD_unknown:
default:
break;
}
llvm_unreachable(
"Unknown programming model for OpenMP directive on NVPTX target.");
}
void CGOpenMPRuntimeGPU::emitNonSPMDKernel(const OMPExecutableDirective &D,
StringRef ParentName,
llvm::Function *&OutlinedFn,
llvm::Constant *&OutlinedFnID,
bool IsOffloadEntry,
const RegionCodeGenTy &CodeGen) {
ExecutionRuntimeModesRAII ModeRAII(CurrentExecutionMode);
EntryFunctionState EST;
WrapperFunctionsMap.clear();
// Emit target region as a standalone region.
class NVPTXPrePostActionTy : public PrePostActionTy {
CGOpenMPRuntimeGPU::EntryFunctionState &EST;
public:
NVPTXPrePostActionTy(CGOpenMPRuntimeGPU::EntryFunctionState &EST)
: EST(EST) {}
void Enter(CodeGenFunction &CGF) override {
auto &RT =
static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
RT.emitKernelInit(CGF, EST, /* IsSPMD */ false);
// Skip target region initialization.
RT.setLocThreadIdInsertPt(CGF, /*AtCurrentPoint=*/true);
}
void Exit(CodeGenFunction &CGF) override {
auto &RT =
static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
RT.clearLocThreadIdInsertPt(CGF);
RT.emitKernelDeinit(CGF, EST, /* IsSPMD */ false);
}
} Action(EST);
CodeGen.setAction(Action);
IsInTTDRegion = true;
emitTargetOutlinedFunctionHelper(D, ParentName, OutlinedFn, OutlinedFnID,
IsOffloadEntry, CodeGen);
IsInTTDRegion = false;
}
void CGOpenMPRuntimeGPU::emitKernelInit(CodeGenFunction &CGF,
EntryFunctionState &EST, bool IsSPMD) {
CGBuilderTy &Bld = CGF.Builder;
Bld.restoreIP(OMPBuilder.createTargetInit(Bld, IsSPMD, requiresFullRuntime()));
IsInTargetMasterThreadRegion = IsSPMD;
if (!IsSPMD)
emitGenericVarsProlog(CGF, EST.Loc);
}
void CGOpenMPRuntimeGPU::emitKernelDeinit(CodeGenFunction &CGF,
EntryFunctionState &EST,
bool IsSPMD) {
if (!IsSPMD)
emitGenericVarsEpilog(CGF);
CGBuilderTy &Bld = CGF.Builder;
OMPBuilder.createTargetDeinit(Bld, IsSPMD, requiresFullRuntime());
}
void CGOpenMPRuntimeGPU::emitSPMDKernel(const OMPExecutableDirective &D,
StringRef ParentName,
llvm::Function *&OutlinedFn,
llvm::Constant *&OutlinedFnID,
bool IsOffloadEntry,
const RegionCodeGenTy &CodeGen) {
ExecutionRuntimeModesRAII ModeRAII(
CurrentExecutionMode, RequiresFullRuntime,
CGM.getLangOpts().OpenMPCUDAForceFullRuntime ||
!supportsLightweightRuntime(CGM.getContext(), D));
EntryFunctionState EST;
// Emit target region as a standalone region.
class NVPTXPrePostActionTy : public PrePostActionTy {
CGOpenMPRuntimeGPU &RT;
CGOpenMPRuntimeGPU::EntryFunctionState &EST;
public:
NVPTXPrePostActionTy(CGOpenMPRuntimeGPU &RT,
CGOpenMPRuntimeGPU::EntryFunctionState &EST)
: RT(RT), EST(EST) {}
void Enter(CodeGenFunction &CGF) override {
RT.emitKernelInit(CGF, EST, /* IsSPMD */ true);
// Skip target region initialization.
RT.setLocThreadIdInsertPt(CGF, /*AtCurrentPoint=*/true);
}
void Exit(CodeGenFunction &CGF) override {
RT.clearLocThreadIdInsertPt(CGF);
RT.emitKernelDeinit(CGF, EST, /* IsSPMD */ true);
}
} Action(*this, EST);
CodeGen.setAction(Action);
IsInTTDRegion = true;
emitTargetOutlinedFunctionHelper(D, ParentName, OutlinedFn, OutlinedFnID,
IsOffloadEntry, CodeGen);
IsInTTDRegion = false;
}
// Create a unique global variable to indicate the execution mode of this target
// region. The execution mode is either 'generic', or 'spmd' depending on the
// target directive. This variable is picked up by the offload library to setup
// the device appropriately before kernel launch. If the execution mode is
// 'generic', the runtime reserves one warp for the master, otherwise, all
// warps participate in parallel work.
static void setPropertyExecutionMode(CodeGenModule &CGM, StringRef Name,
bool Mode) {
auto *GVMode =
new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, /*isConstant=*/true,
llvm::GlobalValue::WeakAnyLinkage,
llvm::ConstantInt::get(CGM.Int8Ty, Mode ? 0 : 1),
Twine(Name, "_exec_mode"));
CGM.addCompilerUsedGlobal(GVMode);
}
void CGOpenMPRuntimeGPU::createOffloadEntry(llvm::Constant *ID,
llvm::Constant *Addr,
uint64_t Size, int32_t,
llvm::GlobalValue::LinkageTypes) {
// TODO: Add support for global variables on the device after declare target
// support.
if (!isa<llvm::Function>(Addr))
return;
llvm::Module &M = CGM.getModule();
llvm::LLVMContext &Ctx = CGM.getLLVMContext();
// Get "nvvm.annotations" metadata node
llvm::NamedMDNode *MD = M.getOrInsertNamedMetadata("nvvm.annotations");
llvm::Metadata *MDVals[] = {
llvm::ConstantAsMetadata::get(Addr), llvm::MDString::get(Ctx, "kernel"),
llvm::ConstantAsMetadata::get(
llvm::ConstantInt::get(llvm::Type::getInt32Ty(Ctx), 1))};
// Append metadata to nvvm.annotations
MD->addOperand(llvm::MDNode::get(Ctx, MDVals));
}
void CGOpenMPRuntimeGPU::emitTargetOutlinedFunction(
const OMPExecutableDirective &D, StringRef ParentName,
llvm::Function *&OutlinedFn, llvm::Constant *&OutlinedFnID,
bool IsOffloadEntry, const RegionCodeGenTy &CodeGen) {
if (!IsOffloadEntry) // Nothing to do.
return;
assert(!ParentName.empty() && "Invalid target region parent name!");
bool Mode = supportsSPMDExecutionMode(CGM.getContext(), D);
if (Mode)
emitSPMDKernel(D, ParentName, OutlinedFn, OutlinedFnID, IsOffloadEntry,
CodeGen);
else
emitNonSPMDKernel(D, ParentName, OutlinedFn, OutlinedFnID, IsOffloadEntry,
CodeGen);
setPropertyExecutionMode(CGM, OutlinedFn->getName(), Mode);
}
namespace {
LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();
/// Enum for accesseing the reserved_2 field of the ident_t struct.
enum ModeFlagsTy : unsigned {
/// Bit set to 1 when in SPMD mode.
KMP_IDENT_SPMD_MODE = 0x01,
/// Bit set to 1 when a simplified runtime is used.
KMP_IDENT_SIMPLE_RT_MODE = 0x02,
LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/KMP_IDENT_SIMPLE_RT_MODE)
};
/// Special mode Undefined. Is the combination of Non-SPMD mode + SimpleRuntime.
static const ModeFlagsTy UndefinedMode =
(~KMP_IDENT_SPMD_MODE) & KMP_IDENT_SIMPLE_RT_MODE;
} // anonymous namespace
unsigned CGOpenMPRuntimeGPU::getDefaultLocationReserved2Flags() const {
switch (getExecutionMode()) {
case EM_SPMD:
if (requiresFullRuntime())
return KMP_IDENT_SPMD_MODE & (~KMP_IDENT_SIMPLE_RT_MODE);
return KMP_IDENT_SPMD_MODE | KMP_IDENT_SIMPLE_RT_MODE;
case EM_NonSPMD:
assert(requiresFullRuntime() && "Expected full runtime.");
return (~KMP_IDENT_SPMD_MODE) & (~KMP_IDENT_SIMPLE_RT_MODE);
case EM_Unknown:
return UndefinedMode;
}
llvm_unreachable("Unknown flags are requested.");
}
CGOpenMPRuntimeGPU::CGOpenMPRuntimeGPU(CodeGenModule &CGM)
: CGOpenMPRuntime(CGM, "_", "$") {
if (!CGM.getLangOpts().OpenMPIsDevice)
llvm_unreachable("OpenMP NVPTX can only handle device code.");
}
void CGOpenMPRuntimeGPU::emitProcBindClause(CodeGenFunction &CGF,
ProcBindKind ProcBind,
SourceLocation Loc) {
// Do nothing in case of SPMD mode and L0 parallel.
if (getExecutionMode() == CGOpenMPRuntimeGPU::EM_SPMD)
return;
CGOpenMPRuntime::emitProcBindClause(CGF, ProcBind, Loc);
}
void CGOpenMPRuntimeGPU::emitNumThreadsClause(CodeGenFunction &CGF,
llvm::Value *NumThreads,
SourceLocation Loc) {
// Do nothing in case of SPMD mode and L0 parallel.
if (getExecutionMode() == CGOpenMPRuntimeGPU::EM_SPMD)
return;
CGOpenMPRuntime::emitNumThreadsClause(CGF, NumThreads, Loc);
}
void CGOpenMPRuntimeGPU::emitNumTeamsClause(CodeGenFunction &CGF,
const Expr *NumTeams,
const Expr *ThreadLimit,
SourceLocation Loc) {}
llvm::Function *CGOpenMPRuntimeGPU::emitParallelOutlinedFunction(
const OMPExecutableDirective &D, const VarDecl *ThreadIDVar,
OpenMPDirectiveKind InnermostKind, const RegionCodeGenTy &CodeGen) {
// Emit target region as a standalone region.
class NVPTXPrePostActionTy : public PrePostActionTy {
bool &IsInParallelRegion;
bool PrevIsInParallelRegion;
public:
NVPTXPrePostActionTy(bool &IsInParallelRegion)
: IsInParallelRegion(IsInParallelRegion) {}
void Enter(CodeGenFunction &CGF) override {
PrevIsInParallelRegion = IsInParallelRegion;
IsInParallelRegion = true;
}
void Exit(CodeGenFunction &CGF) override {
IsInParallelRegion = PrevIsInParallelRegion;
}
} Action(IsInParallelRegion);
CodeGen.setAction(Action);
bool PrevIsInTTDRegion = IsInTTDRegion;
IsInTTDRegion = false;
bool PrevIsInTargetMasterThreadRegion = IsInTargetMasterThreadRegion;
IsInTargetMasterThreadRegion = false;
auto *OutlinedFun =
cast<llvm::Function>(CGOpenMPRuntime::emitParallelOutlinedFunction(
D, ThreadIDVar, InnermostKind, CodeGen));
IsInTargetMasterThreadRegion = PrevIsInTargetMasterThreadRegion;
IsInTTDRegion = PrevIsInTTDRegion;
if (getExecutionMode() != CGOpenMPRuntimeGPU::EM_SPMD &&
!IsInParallelRegion) {
llvm::Function *WrapperFun =
createParallelDataSharingWrapper(OutlinedFun, D);
WrapperFunctionsMap[OutlinedFun] = WrapperFun;
}
return OutlinedFun;
}
/// Get list of lastprivate variables from the teams distribute ... or
/// teams {distribute ...} directives.
static void
getDistributeLastprivateVars(ASTContext &Ctx, const OMPExecutableDirective &D,
llvm::SmallVectorImpl<const ValueDecl *> &Vars) {
assert(isOpenMPTeamsDirective(D.getDirectiveKind()) &&
"expected teams directive.");
const OMPExecutableDirective *Dir = &D;
if (!isOpenMPDistributeDirective(D.getDirectiveKind())) {
if (const Stmt *S = CGOpenMPRuntime::getSingleCompoundChild(
Ctx,
D.getInnermostCapturedStmt()->getCapturedStmt()->IgnoreContainers(
/*IgnoreCaptured=*/true))) {
Dir = dyn_cast_or_null<OMPExecutableDirective>(S);
if (Dir && !isOpenMPDistributeDirective(Dir->getDirectiveKind()))
Dir = nullptr;
}
}
if (!Dir)
return;
for (const auto *C : Dir->getClausesOfKind<OMPLastprivateClause>()) {
for (const Expr *E : C->getVarRefs())
Vars.push_back(getPrivateItem(E));
}
}
/// Get list of reduction variables from the teams ... directives.
static void
getTeamsReductionVars(ASTContext &Ctx, const OMPExecutableDirective &D,
llvm::SmallVectorImpl<const ValueDecl *> &Vars) {
assert(isOpenMPTeamsDirective(D.getDirectiveKind()) &&
"expected teams directive.");
for (const auto *C : D.getClausesOfKind<OMPReductionClause>()) {
for (const Expr *E : C->privates())
Vars.push_back(getPrivateItem(E));
}
}
llvm::Function *CGOpenMPRuntimeGPU::emitTeamsOutlinedFunction(
const OMPExecutableDirective &D, const VarDecl *ThreadIDVar,
OpenMPDirectiveKind InnermostKind, const RegionCodeGenTy &CodeGen) {
SourceLocation Loc = D.getBeginLoc();
const RecordDecl *GlobalizedRD = nullptr;
llvm::SmallVector<const ValueDecl *, 4> LastPrivatesReductions;
llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *> MappedDeclsFields;
unsigned WarpSize = CGM.getTarget().getGridValue().GV_Warp_Size;
// Globalize team reductions variable unconditionally in all modes.
if (getExecutionMode() != CGOpenMPRuntimeGPU::EM_SPMD)
getTeamsReductionVars(CGM.getContext(), D, LastPrivatesReductions);
if (getExecutionMode() == CGOpenMPRuntimeGPU::EM_SPMD) {
getDistributeLastprivateVars(CGM.getContext(), D, LastPrivatesReductions);
if (!LastPrivatesReductions.empty()) {
GlobalizedRD = ::buildRecordForGlobalizedVars(
CGM.getContext(), llvm::None, LastPrivatesReductions,
MappedDeclsFields, WarpSize);
}
} else if (!LastPrivatesReductions.empty()) {
assert(!TeamAndReductions.first &&
"Previous team declaration is not expected.");
TeamAndReductions.first = D.getCapturedStmt(OMPD_teams)->getCapturedDecl();
std::swap(TeamAndReductions.second, LastPrivatesReductions);
}
// Emit target region as a standalone region.
class NVPTXPrePostActionTy : public PrePostActionTy {
SourceLocation &Loc;
const RecordDecl *GlobalizedRD;
llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
&MappedDeclsFields;
public:
NVPTXPrePostActionTy(
SourceLocation &Loc, const RecordDecl *GlobalizedRD,
llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
&MappedDeclsFields)
: Loc(Loc), GlobalizedRD(GlobalizedRD),
MappedDeclsFields(MappedDeclsFields) {}
void Enter(CodeGenFunction &CGF) override {
auto &Rt =
static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
if (GlobalizedRD) {
auto I = Rt.FunctionGlobalizedDecls.try_emplace(CGF.CurFn).first;
I->getSecond().MappedParams =
std::make_unique<CodeGenFunction::OMPMapVars>();
DeclToAddrMapTy &Data = I->getSecond().LocalVarData;
for (const auto &Pair : MappedDeclsFields) {
assert(Pair.getFirst()->isCanonicalDecl() &&
"Expected canonical declaration");
Data.insert(std::make_pair(Pair.getFirst(), MappedVarData()));
}
}
Rt.emitGenericVarsProlog(CGF, Loc);
}
void Exit(CodeGenFunction &CGF) override {
static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime())
.emitGenericVarsEpilog(CGF);
}
} Action(Loc, GlobalizedRD, MappedDeclsFields);
CodeGen.setAction(Action);
llvm::Function *OutlinedFun = CGOpenMPRuntime::emitTeamsOutlinedFunction(
D, ThreadIDVar, InnermostKind, CodeGen);
return OutlinedFun;
}
void CGOpenMPRuntimeGPU::emitGenericVarsProlog(CodeGenFunction &CGF,
SourceLocation Loc,
bool WithSPMDCheck) {
if (getDataSharingMode(CGM) != CGOpenMPRuntimeGPU::Generic &&
getExecutionMode() != CGOpenMPRuntimeGPU::EM_SPMD)
return;
CGBuilderTy &Bld = CGF.Builder;
const auto I = FunctionGlobalizedDecls.find(CGF.CurFn);
if (I == FunctionGlobalizedDecls.end())
return;
for (auto &Rec : I->getSecond().LocalVarData) {
const auto *VD = cast<VarDecl>(Rec.first);
bool EscapedParam = I->getSecond().EscapedParameters.count(Rec.first);
QualType VarTy = VD->getType();
// Get the local allocation of a firstprivate variable before sharing
llvm::Value *ParValue;
if (EscapedParam) {
LValue ParLVal =
CGF.MakeAddrLValue(CGF.GetAddrOfLocalVar(VD), VD->getType());
ParValue = CGF.EmitLoadOfScalar(ParLVal, Loc);
}
// Allocate space for the variable to be globalized
llvm::Value *AllocArgs[] = {CGF.getTypeSize(VD->getType())};
llvm::Instruction *VoidPtr =
CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_alloc_shared),
AllocArgs, VD->getName());
// Cast the void pointer and get the address of the globalized variable.
llvm::PointerType *VarPtrTy = CGF.ConvertTypeForMem(VarTy)->getPointerTo();
llvm::Value *CastedVoidPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
VoidPtr, VarPtrTy, VD->getName() + "_on_stack");
LValue VarAddr = CGF.MakeNaturalAlignAddrLValue(CastedVoidPtr, VarTy);
Rec.second.PrivateAddr = VarAddr.getAddress(CGF);
Rec.second.GlobalizedVal = VoidPtr;
// Assign the local allocation to the newly globalized location.
if (EscapedParam) {
CGF.EmitStoreOfScalar(ParValue, VarAddr);
I->getSecond().MappedParams->setVarAddr(CGF, VD, VarAddr.getAddress(CGF));
}
if (auto *DI = CGF.getDebugInfo())
VoidPtr->setDebugLoc(DI->SourceLocToDebugLoc(VD->getLocation()));
}
for (const auto *VD : I->getSecond().EscapedVariableLengthDecls) {
// Use actual memory size of the VLA object including the padding
// for alignment purposes.
llvm::Value *Size = CGF.getTypeSize(VD->getType());
CharUnits Align = CGM.getContext().getDeclAlign(VD);
Size = Bld.CreateNUWAdd(
Size, llvm::ConstantInt::get(CGF.SizeTy, Align.getQuantity() - 1));
llvm::Value *AlignVal =
llvm::ConstantInt::get(CGF.SizeTy, Align.getQuantity());
Size = Bld.CreateUDiv(Size, AlignVal);
Size = Bld.CreateNUWMul(Size, AlignVal);
// Allocate space for this VLA object to be globalized.
llvm::Value *AllocArgs[] = {CGF.getTypeSize(VD->getType())};
llvm::Instruction *VoidPtr =
CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_alloc_shared),
AllocArgs, VD->getName());
I->getSecond().EscapedVariableLengthDeclsAddrs.emplace_back(
std::pair<llvm::Value *, llvm::Value *>(
{VoidPtr, CGF.getTypeSize(VD->getType())}));
LValue Base = CGF.MakeAddrLValue(VoidPtr, VD->getType(),
CGM.getContext().getDeclAlign(VD),
AlignmentSource::Decl);
I->getSecond().MappedParams->setVarAddr(CGF, cast<VarDecl>(VD),
Base.getAddress(CGF));
}
I->getSecond().MappedParams->apply(CGF);
}
void CGOpenMPRuntimeGPU::emitGenericVarsEpilog(CodeGenFunction &CGF,
bool WithSPMDCheck) {
if (getDataSharingMode(CGM) != CGOpenMPRuntimeGPU::Generic &&
getExecutionMode() != CGOpenMPRuntimeGPU::EM_SPMD)
return;
const auto I = FunctionGlobalizedDecls.find(CGF.CurFn);
if (I != FunctionGlobalizedDecls.end()) {
// Deallocate the memory for each globalized VLA object
for (auto AddrSizePair :
llvm::reverse(I->getSecond().EscapedVariableLengthDeclsAddrs)) {
CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_free_shared),
{AddrSizePair.first, AddrSizePair.second});
}
// Deallocate the memory for each globalized value
for (auto &Rec : llvm::reverse(I->getSecond().LocalVarData)) {
const auto *VD = cast<VarDecl>(Rec.first);
I->getSecond().MappedParams->restore(CGF);
llvm::Value *FreeArgs[] = {Rec.second.GlobalizedVal,
CGF.getTypeSize(VD->getType())};
CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_free_shared),
FreeArgs);
}
}
}
void CGOpenMPRuntimeGPU::emitTeamsCall(CodeGenFunction &CGF,
const OMPExecutableDirective &D,
SourceLocation Loc,
llvm::Function *OutlinedFn,
ArrayRef<llvm::Value *> CapturedVars) {
if (!CGF.HaveInsertPoint())
return;
Address ZeroAddr = CGF.CreateDefaultAlignTempAlloca(CGF.Int32Ty,
/*Name=*/".zero.addr");
CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
llvm::SmallVector<llvm::Value *, 16> OutlinedFnArgs;
OutlinedFnArgs.push_back(emitThreadIDAddress(CGF, Loc).getPointer());
OutlinedFnArgs.push_back(ZeroAddr.getPointer());
OutlinedFnArgs.append(CapturedVars.begin(), CapturedVars.end());
emitOutlinedFunctionCall(CGF, Loc, OutlinedFn, OutlinedFnArgs);
}
void CGOpenMPRuntimeGPU::emitParallelCall(CodeGenFunction &CGF,
SourceLocation Loc,
llvm::Function *OutlinedFn,
ArrayRef<llvm::Value *> CapturedVars,
const Expr *IfCond) {
if (!CGF.HaveInsertPoint())
return;
auto &&ParallelGen = [this, Loc, OutlinedFn, CapturedVars,
IfCond](CodeGenFunction &CGF, PrePostActionTy &Action) {
CGBuilderTy &Bld = CGF.Builder;
llvm::Function *WFn = WrapperFunctionsMap[OutlinedFn];
llvm::Value *ID = llvm::ConstantPointerNull::get(CGM.Int8PtrTy);
if (WFn)
ID = Bld.CreateBitOrPointerCast(WFn, CGM.Int8PtrTy);
llvm::Value *FnPtr = Bld.CreateBitOrPointerCast(OutlinedFn, CGM.Int8PtrTy);
// Create a private scope that will globalize the arguments
// passed from the outside of the target region.
// TODO: Is that needed?
CodeGenFunction::OMPPrivateScope PrivateArgScope(CGF);
Address CapturedVarsAddrs = CGF.CreateDefaultAlignTempAlloca(
llvm::ArrayType::get(CGM.VoidPtrTy, CapturedVars.size()),
"captured_vars_addrs");
// There's something to share.
if (!CapturedVars.empty()) {
// Prepare for parallel region. Indicate the outlined function.
ASTContext &Ctx = CGF.getContext();
unsigned Idx = 0;
for (llvm::Value *V : CapturedVars) {
Address Dst = Bld.CreateConstArrayGEP(CapturedVarsAddrs, Idx);
llvm::Value *PtrV;
if (V->getType()->isIntegerTy())
PtrV = Bld.CreateIntToPtr(V, CGF.VoidPtrTy);
else
PtrV = Bld.CreatePointerBitCastOrAddrSpaceCast(V, CGF.VoidPtrTy);
CGF.EmitStoreOfScalar(PtrV, Dst, /*Volatile=*/false,
Ctx.getPointerType(Ctx.VoidPtrTy));
++Idx;
}
}
llvm::Value *IfCondVal = nullptr;
if (IfCond)
IfCondVal = Bld.CreateIntCast(CGF.EvaluateExprAsBool(IfCond), CGF.Int32Ty,
/* isSigned */ false);
else
IfCondVal = llvm::ConstantInt::get(CGF.Int32Ty, 1);
assert(IfCondVal && "Expected a value");
llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
llvm::Value *Args[] = {
RTLoc,
getThreadID(CGF, Loc),
IfCondVal,
llvm::ConstantInt::get(CGF.Int32Ty, -1),
llvm::ConstantInt::get(CGF.Int32Ty, -1),
FnPtr,
ID,
Bld.CreateBitOrPointerCast(CapturedVarsAddrs.getPointer(),
CGF.VoidPtrPtrTy),
llvm::ConstantInt::get(CGM.SizeTy, CapturedVars.size())};
CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_parallel_51),
Args);
};
RegionCodeGenTy RCG(ParallelGen);
RCG(CGF);
}
void CGOpenMPRuntimeGPU::syncCTAThreads(CodeGenFunction &CGF) {
// Always emit simple barriers!
if (!CGF.HaveInsertPoint())
return;
// Build call __kmpc_barrier_simple_spmd(nullptr, 0);
// This function does not use parameters, so we can emit just default values.
llvm::Value *Args[] = {
llvm::ConstantPointerNull::get(
cast<llvm::PointerType>(getIdentTyPointerTy())),
llvm::ConstantInt::get(CGF.Int32Ty, /*V=*/0, /*isSigned=*/true)};
CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_barrier_simple_spmd),
Args);
}
void CGOpenMPRuntimeGPU::emitBarrierCall(CodeGenFunction &CGF,
SourceLocation Loc,
OpenMPDirectiveKind Kind, bool,
bool) {
// Always emit simple barriers!
if (!CGF.HaveInsertPoint())
return;
// Build call __kmpc_cancel_barrier(loc, thread_id);
unsigned Flags = getDefaultFlagsForBarriers(Kind);
llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc, Flags),
getThreadID(CGF, Loc)};
CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_barrier),
Args);
}
void CGOpenMPRuntimeGPU::emitCriticalRegion(
CodeGenFunction &CGF, StringRef CriticalName,
const RegionCodeGenTy &CriticalOpGen, SourceLocation Loc,
const Expr *Hint) {
llvm::BasicBlock *LoopBB = CGF.createBasicBlock("omp.critical.loop");
llvm::BasicBlock *TestBB = CGF.createBasicBlock("omp.critical.test");
llvm::BasicBlock *SyncBB = CGF.createBasicBlock("omp.critical.sync");
llvm::BasicBlock *BodyBB = CGF.createBasicBlock("omp.critical.body");
llvm::BasicBlock *ExitBB = CGF.createBasicBlock("omp.critical.exit");
auto &RT = static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
// Get the mask of active threads in the warp.
llvm::Value *Mask = CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_warp_active_thread_mask));
// Fetch team-local id of the thread.
llvm::Value *ThreadID = RT.getGPUThreadID(CGF);
// Get the width of the team.
llvm::Value *TeamWidth = RT.getGPUNumThreads(CGF);
// Initialize the counter variable for the loop.
QualType Int32Ty =
CGF.getContext().getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/0);
Address Counter = CGF.CreateMemTemp(Int32Ty, "critical_counter");
LValue CounterLVal = CGF.MakeAddrLValue(Counter, Int32Ty);
CGF.EmitStoreOfScalar(llvm::Constant::getNullValue(CGM.Int32Ty), CounterLVal,
/*isInit=*/true);
// Block checks if loop counter exceeds upper bound.
CGF.EmitBlock(LoopBB);
llvm::Value *CounterVal = CGF.EmitLoadOfScalar(CounterLVal, Loc);
llvm::Value *CmpLoopBound = CGF.Builder.CreateICmpSLT(CounterVal, TeamWidth);
CGF.Builder.CreateCondBr(CmpLoopBound, TestBB, ExitBB);
// Block tests which single thread should execute region, and which threads
// should go straight to synchronisation point.
CGF.EmitBlock(TestBB);
CounterVal = CGF.EmitLoadOfScalar(CounterLVal, Loc);
llvm::Value *CmpThreadToCounter =
CGF.Builder.CreateICmpEQ(ThreadID, CounterVal);
CGF.Builder.CreateCondBr(CmpThreadToCounter, BodyBB, SyncBB);
// Block emits the body of the critical region.
CGF.EmitBlock(BodyBB);
// Output the critical statement.
CGOpenMPRuntime::emitCriticalRegion(CGF, CriticalName, CriticalOpGen, Loc,
Hint);
// After the body surrounded by the critical region, the single executing
// thread will jump to the synchronisation point.
// Block waits for all threads in current team to finish then increments the
// counter variable and returns to the loop.
CGF.EmitBlock(SyncBB);
// Reconverge active threads in the warp.
(void)CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_syncwarp),
Mask);
llvm::Value *IncCounterVal =
CGF.Builder.CreateNSWAdd(CounterVal, CGF.Builder.getInt32(1));
CGF.EmitStoreOfScalar(IncCounterVal, CounterLVal);
CGF.EmitBranch(LoopBB);
// Block that is reached when all threads in the team complete the region.
CGF.EmitBlock(ExitBB, /*IsFinished=*/true);
}
/// Cast value to the specified type.
static llvm::Value *castValueToType(CodeGenFunction &CGF, llvm::Value *Val,
QualType ValTy, QualType CastTy,
SourceLocation Loc) {
assert(!CGF.getContext().getTypeSizeInChars(CastTy).isZero() &&
"Cast type must sized.");
assert(!CGF.getContext().getTypeSizeInChars(ValTy).isZero() &&
"Val type must sized.");
llvm::Type *LLVMCastTy = CGF.ConvertTypeForMem(CastTy);
if (ValTy == CastTy)
return Val;
if (CGF.getContext().getTypeSizeInChars(ValTy) ==
CGF.getContext().getTypeSizeInChars(CastTy))
return CGF.Builder.CreateBitCast(Val, LLVMCastTy);
if (CastTy->isIntegerType() && ValTy->isIntegerType())
return CGF.Builder.CreateIntCast(Val, LLVMCastTy,
CastTy->hasSignedIntegerRepresentation());
Address CastItem = CGF.CreateMemTemp(CastTy);
Address ValCastItem = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
CastItem, Val->getType()->getPointerTo(CastItem.getAddressSpace()));
CGF.EmitStoreOfScalar(Val, ValCastItem, /*Volatile=*/false, ValTy,
LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo());
return CGF.EmitLoadOfScalar(CastItem, /*Volatile=*/false, CastTy, Loc,
LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo());
}
/// This function creates calls to one of two shuffle functions to copy
/// variables between lanes in a warp.
static llvm::Value *createRuntimeShuffleFunction(CodeGenFunction &CGF,
llvm::Value *Elem,
QualType ElemType,
llvm::Value *Offset,
SourceLocation Loc) {
CodeGenModule &CGM = CGF.CGM;
CGBuilderTy &Bld = CGF.Builder;
CGOpenMPRuntimeGPU &RT =
*(static_cast<CGOpenMPRuntimeGPU *>(&CGM.getOpenMPRuntime()));
llvm::OpenMPIRBuilder &OMPBuilder = RT.getOMPBuilder();
CharUnits Size = CGF.getContext().getTypeSizeInChars(ElemType);
assert(Size.getQuantity() <= 8 &&
"Unsupported bitwidth in shuffle instruction.");
RuntimeFunction ShuffleFn = Size.getQuantity() <= 4
? OMPRTL___kmpc_shuffle_int32
: OMPRTL___kmpc_shuffle_int64;
// Cast all types to 32- or 64-bit values before calling shuffle routines.
QualType CastTy = CGF.getContext().getIntTypeForBitwidth(
Size.getQuantity() <= 4 ? 32 : 64, /*Signed=*/1);
llvm::Value *ElemCast = castValueToType(CGF, Elem, ElemType, CastTy, Loc);
llvm::Value *WarpSize =
Bld.CreateIntCast(RT.getGPUWarpSize(CGF), CGM.Int16Ty, /*isSigned=*/true);
llvm::Value *ShuffledVal = CGF.EmitRuntimeCall(
OMPBuilder.getOrCreateRuntimeFunction(CGM.getModule(), ShuffleFn),
{ElemCast, Offset, WarpSize});
return castValueToType(CGF, ShuffledVal, CastTy, ElemType, Loc);
}
static void shuffleAndStore(CodeGenFunction &CGF, Address SrcAddr,
Address DestAddr, QualType ElemType,
llvm::Value *Offset, SourceLocation Loc) {
CGBuilderTy &Bld = CGF.Builder;
CharUnits Size = CGF.getContext().getTypeSizeInChars(ElemType);
// Create the loop over the big sized data.
// ptr = (void*)Elem;
// ptrEnd = (void*) Elem + 1;
// Step = 8;
// while (ptr + Step < ptrEnd)
// shuffle((int64_t)*ptr);
// Step = 4;
// while (ptr + Step < ptrEnd)
// shuffle((int32_t)*ptr);
// ...
Address ElemPtr = DestAddr;
Address Ptr = SrcAddr;
Address PtrEnd = Bld.CreatePointerBitCastOrAddrSpaceCast(
Bld.CreateConstGEP(SrcAddr, 1), CGF.VoidPtrTy);
for (int IntSize = 8; IntSize >= 1; IntSize /= 2) {
if (Size < CharUnits::fromQuantity(IntSize))
continue;
QualType IntType = CGF.getContext().getIntTypeForBitwidth(
CGF.getContext().toBits(CharUnits::fromQuantity(IntSize)),
/*Signed=*/1);
llvm::Type *IntTy = CGF.ConvertTypeForMem(IntType);
Ptr = Bld.CreatePointerBitCastOrAddrSpaceCast(Ptr, IntTy->getPointerTo());
ElemPtr =
Bld.CreatePointerBitCastOrAddrSpaceCast(ElemPtr, IntTy->getPointerTo());
if (Size.getQuantity() / IntSize > 1) {
llvm::BasicBlock *PreCondBB = CGF.createBasicBlock(".shuffle.pre_cond");
llvm::BasicBlock *ThenBB = CGF.createBasicBlock(".shuffle.then");
llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".shuffle.exit");
llvm::BasicBlock *CurrentBB = Bld.GetInsertBlock();
CGF.EmitBlock(PreCondBB);
llvm::PHINode *PhiSrc =
Bld.CreatePHI(Ptr.getType(), /*NumReservedValues=*/2);
PhiSrc->addIncoming(Ptr.getPointer(), CurrentBB);
llvm::PHINode *PhiDest =
Bld.CreatePHI(ElemPtr.getType(), /*NumReservedValues=*/2);
PhiDest->addIncoming(ElemPtr.getPointer(), CurrentBB);
Ptr = Address(PhiSrc, Ptr.getAlignment());
ElemPtr = Address(PhiDest, ElemPtr.getAlignment());
llvm::Value *PtrDiff = Bld.CreatePtrDiff(
PtrEnd.getPointer(), Bld.CreatePointerBitCastOrAddrSpaceCast(
Ptr.getPointer(), CGF.VoidPtrTy));
Bld.CreateCondBr(Bld.CreateICmpSGT(PtrDiff, Bld.getInt64(IntSize - 1)),
ThenBB, ExitBB);
CGF.EmitBlock(ThenBB);
llvm::Value *Res = createRuntimeShuffleFunction(
CGF,
CGF.EmitLoadOfScalar(Ptr, /*Volatile=*/false, IntType, Loc,
LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo()),
IntType, Offset, Loc);
CGF.EmitStoreOfScalar(Res, ElemPtr, /*Volatile=*/false, IntType,
LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo());
Address LocalPtr = Bld.CreateConstGEP(Ptr, 1);
Address LocalElemPtr = Bld.CreateConstGEP(ElemPtr, 1);
PhiSrc->addIncoming(LocalPtr.getPointer(), ThenBB);
PhiDest->addIncoming(LocalElemPtr.getPointer(), ThenBB);
CGF.EmitBranch(PreCondBB);
CGF.EmitBlock(ExitBB);
} else {
llvm::Value *Res = createRuntimeShuffleFunction(
CGF,
CGF.EmitLoadOfScalar(Ptr, /*Volatile=*/false, IntType, Loc,
LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo()),
IntType, Offset, Loc);
CGF.EmitStoreOfScalar(Res, ElemPtr, /*Volatile=*/false, IntType,
LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo());
Ptr = Bld.CreateConstGEP(Ptr, 1);
ElemPtr = Bld.CreateConstGEP(ElemPtr, 1);
}
Size = Size % IntSize;
}
}
namespace {
enum CopyAction : unsigned {
// RemoteLaneToThread: Copy over a Reduce list from a remote lane in
// the warp using shuffle instructions.
RemoteLaneToThread,
// ThreadCopy: Make a copy of a Reduce list on the thread's stack.
ThreadCopy,
// ThreadToScratchpad: Copy a team-reduced array to the scratchpad.
ThreadToScratchpad,
// ScratchpadToThread: Copy from a scratchpad array in global memory
// containing team-reduced data to a thread's stack.
ScratchpadToThread,
};
} // namespace
struct CopyOptionsTy {
llvm::Value *RemoteLaneOffset;
llvm::Value *ScratchpadIndex;
llvm::Value *ScratchpadWidth;
};
/// Emit instructions to copy a Reduce list, which contains partially
/// aggregated values, in the specified direction.
static void emitReductionListCopy(
CopyAction Action, CodeGenFunction &CGF, QualType ReductionArrayTy,
ArrayRef<const Expr *> Privates, Address SrcBase, Address DestBase,
CopyOptionsTy CopyOptions = {nullptr, nullptr, nullptr}) {
CodeGenModule &CGM = CGF.CGM;
ASTContext &C = CGM.getContext();
CGBuilderTy &Bld = CGF.Builder;
llvm::Value *RemoteLaneOffset = CopyOptions.RemoteLaneOffset;
llvm::Value *ScratchpadIndex = CopyOptions.ScratchpadIndex;
llvm::Value *ScratchpadWidth = CopyOptions.ScratchpadWidth;
// Iterates, element-by-element, through the source Reduce list and
// make a copy.
unsigned Idx = 0;
unsigned Size = Privates.size();
for (const Expr *Private : Privates) {
Address SrcElementAddr = Address::invalid();
Address DestElementAddr = Address::invalid();
Address DestElementPtrAddr = Address::invalid();
// Should we shuffle in an element from a remote lane?
bool ShuffleInElement = false;
// Set to true to update the pointer in the dest Reduce list to a
// newly created element.
bool UpdateDestListPtr = false;
// Increment the src or dest pointer to the scratchpad, for each
// new element.
bool IncrScratchpadSrc = false;
bool IncrScratchpadDest = false;
switch (Action) {
case RemoteLaneToThread: {
// Step 1.1: Get the address for the src element in the Reduce list.
Address SrcElementPtrAddr = Bld.CreateConstArrayGEP(SrcBase, Idx);
SrcElementAddr = CGF.EmitLoadOfPointer(
SrcElementPtrAddr,
C.getPointerType(Private->getType())->castAs<PointerType>());
// Step 1.2: Create a temporary to store the element in the destination
// Reduce list.
DestElementPtrAddr = Bld.CreateConstArrayGEP(DestBase, Idx);
DestElementAddr =
CGF.CreateMemTemp(Private->getType(), ".omp.reduction.element");
ShuffleInElement = true;
UpdateDestListPtr = true;
break;
}
case ThreadCopy: {
// Step 1.1: Get the address for the src element in the Reduce list.
Address SrcElementPtrAddr = Bld.CreateConstArrayGEP(SrcBase, Idx);
SrcElementAddr = CGF.EmitLoadOfPointer(
SrcElementPtrAddr,
C.getPointerType(Private->getType())->castAs<PointerType>());
// Step 1.2: Get the address for dest element. The destination
// element has already been created on the thread's stack.
DestElementPtrAddr = Bld.CreateConstArrayGEP(DestBase, Idx);
DestElementAddr = CGF.EmitLoadOfPointer(
DestElementPtrAddr,
C.getPointerType(Private->getType())->castAs<PointerType>());
break;
}
case ThreadToScratchpad: {
// Step 1.1: Get the address for the src element in the Reduce list.
Address SrcElementPtrAddr = Bld.CreateConstArrayGEP(SrcBase, Idx);
SrcElementAddr = CGF.EmitLoadOfPointer(
SrcElementPtrAddr,
C.getPointerType(Private->getType())->castAs<PointerType>());
// Step 1.2: Get the address for dest element:
// address = base + index * ElementSizeInChars.
llvm::Value *ElementSizeInChars = CGF.getTypeSize(Private->getType());
llvm::Value *CurrentOffset =
Bld.CreateNUWMul(ElementSizeInChars, ScratchpadIndex);
llvm::Value *ScratchPadElemAbsolutePtrVal =
Bld.CreateNUWAdd(DestBase.getPointer(), CurrentOffset);
ScratchPadElemAbsolutePtrVal =
Bld.CreateIntToPtr(ScratchPadElemAbsolutePtrVal, CGF.VoidPtrTy);
DestElementAddr = Address(ScratchPadElemAbsolutePtrVal,
C.getTypeAlignInChars(Private->getType()));
IncrScratchpadDest = true;
break;
}
case ScratchpadToThread: {
// Step 1.1: Get the address for the src element in the scratchpad.
// address = base + index * ElementSizeInChars.
llvm::Value *ElementSizeInChars = CGF.getTypeSize(Private->getType());
llvm::Value *CurrentOffset =
Bld.CreateNUWMul(ElementSizeInChars, ScratchpadIndex);
llvm::Value *ScratchPadElemAbsolutePtrVal =
Bld.CreateNUWAdd(SrcBase.getPointer(), CurrentOffset);
ScratchPadElemAbsolutePtrVal =
Bld.CreateIntToPtr(ScratchPadElemAbsolutePtrVal, CGF.VoidPtrTy);
SrcElementAddr = Address(ScratchPadElemAbsolutePtrVal,
C.getTypeAlignInChars(Private->getType()));
IncrScratchpadSrc = true;
// Step 1.2: Create a temporary to store the element in the destination
// Reduce list.
DestElementPtrAddr = Bld.CreateConstArrayGEP(DestBase, Idx);
DestElementAddr =
CGF.CreateMemTemp(Private->getType(), ".omp.reduction.element");
UpdateDestListPtr = true;
break;
}
}
// Regardless of src and dest of copy, we emit the load of src
// element as this is required in all directions
SrcElementAddr = Bld.CreateElementBitCast(
SrcElementAddr, CGF.ConvertTypeForMem(Private->getType()));
DestElementAddr = Bld.CreateElementBitCast(DestElementAddr,
SrcElementAddr.getElementType());
// Now that all active lanes have read the element in the
// Reduce list, shuffle over the value from the remote lane.
if (ShuffleInElement) {
shuffleAndStore(CGF, SrcElementAddr, DestElementAddr, Private->getType(),
RemoteLaneOffset, Private->getExprLoc());
} else {
switch (CGF.getEvaluationKind(Private->getType())) {
case TEK_Scalar: {
llvm::Value *Elem = CGF.EmitLoadOfScalar(
SrcElementAddr, /*Volatile=*/false, Private->getType(),
Private->getExprLoc(), LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo());
// Store the source element value to the dest element address.
CGF.EmitStoreOfScalar(
Elem, DestElementAddr, /*Volatile=*/false, Private->getType(),
LValueBaseInfo(AlignmentSource::Type), TBAAAccessInfo());
break;
}
case TEK_Complex: {
CodeGenFunction::ComplexPairTy Elem = CGF.EmitLoadOfComplex(
CGF.MakeAddrLValue(SrcElementAddr, Private->getType()),
Private->getExprLoc());
CGF.EmitStoreOfComplex(
Elem, CGF.MakeAddrLValue(DestElementAddr, Private->getType()),
/*isInit=*/false);
break;
}
case TEK_Aggregate:
CGF.EmitAggregateCopy(
CGF.MakeAddrLValue(DestElementAddr, Private->getType()),
CGF.MakeAddrLValue(SrcElementAddr, Private->getType()),
Private->getType(), AggValueSlot::DoesNotOverlap);
break;
}
}
// Step 3.1: Modify reference in dest Reduce list as needed.
// Modifying the reference in Reduce list to point to the newly
// created element. The element is live in the current function
// scope and that of functions it invokes (i.e., reduce_function).
// RemoteReduceData[i] = (void*)&RemoteElem
if (UpdateDestListPtr) {
CGF.EmitStoreOfScalar(Bld.CreatePointerBitCastOrAddrSpaceCast(
DestElementAddr.getPointer(), CGF.VoidPtrTy),
DestElementPtrAddr, /*Volatile=*/false,
C.VoidPtrTy);
}
// Step 4.1: Increment SrcBase/DestBase so that it points to the starting
// address of the next element in scratchpad memory, unless we're currently
// processing the last one. Memory alignment is also taken care of here.
if ((IncrScratchpadDest || IncrScratchpadSrc) && (Idx + 1 < Size)) {
llvm::Value *ScratchpadBasePtr =
IncrScratchpadDest ? DestBase.getPointer() : SrcBase.getPointer();
llvm::Value *ElementSizeInChars = CGF.getTypeSize(Private->getType());
ScratchpadBasePtr = Bld.CreateNUWAdd(
ScratchpadBasePtr,
Bld.CreateNUWMul(ScratchpadWidth, ElementSizeInChars));
// Take care of global memory alignment for performance
ScratchpadBasePtr = Bld.CreateNUWSub(
ScratchpadBasePtr, llvm::ConstantInt::get(CGM.SizeTy, 1));
ScratchpadBasePtr = Bld.CreateUDiv(
ScratchpadBasePtr,
llvm::ConstantInt::get(CGM.SizeTy, GlobalMemoryAlignment));
ScratchpadBasePtr = Bld.CreateNUWAdd(
ScratchpadBasePtr, llvm::ConstantInt::get(CGM.SizeTy, 1));
ScratchpadBasePtr = Bld.CreateNUWMul(
ScratchpadBasePtr,
llvm::ConstantInt::get(CGM.SizeTy, GlobalMemoryAlignment));
if (IncrScratchpadDest)
DestBase = Address(ScratchpadBasePtr, CGF.getPointerAlign());
else /* IncrScratchpadSrc = true */
SrcBase = Address(ScratchpadBasePtr, CGF.getPointerAlign());
}
++Idx;
}
}
/// This function emits a helper that gathers Reduce lists from the first
/// lane of every active warp to lanes in the first warp.
///
/// void inter_warp_copy_func(void* reduce_data, num_warps)
/// shared smem[warp_size];
/// For all data entries D in reduce_data:
/// sync
/// If (I am the first lane in each warp)
/// Copy my local D to smem[warp_id]
/// sync
/// if (I am the first warp)
/// Copy smem[thread_id] to my local D
static llvm::Value *emitInterWarpCopyFunction(CodeGenModule &CGM,
ArrayRef<const Expr *> Privates,
QualType ReductionArrayTy,
SourceLocation Loc) {
ASTContext &C = CGM.getContext();
llvm::Module &M = CGM.getModule();
// ReduceList: thread local Reduce list.
// At the stage of the computation when this function is called, partially
// aggregated values reside in the first lane of every active warp.
ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
// NumWarps: number of warps active in the parallel region. This could
// be smaller than 32 (max warps in a CTA) for partial block reduction.
ImplicitParamDecl NumWarpsArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.getIntTypeForBitwidth(32, /* Signed */ true),
ImplicitParamDecl::Other);
FunctionArgList Args;
Args.push_back(&ReduceListArg);
Args.push_back(&NumWarpsArg);
const CGFunctionInfo &CGFI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
auto *Fn = llvm::Function::Create(CGM.getTypes().GetFunctionType(CGFI),
llvm::GlobalValue::InternalLinkage,
"_omp_reduction_inter_warp_copy_func", &M);
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
Fn->setDoesNotRecurse();
CodeGenFunction CGF(CGM);
CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
CGBuilderTy &Bld = CGF.Builder;
// This array is used as a medium to transfer, one reduce element at a time,
// the data from the first lane of every warp to lanes in the first warp
// in order to perform the final step of a reduction in a parallel region
// (reduction across warps). The array is placed in NVPTX __shared__ memory
// for reduced latency, as well as to have a distinct copy for concurrently
// executing target regions. The array is declared with common linkage so
// as to be shared across compilation units.
StringRef TransferMediumName =
"__openmp_nvptx_data_transfer_temporary_storage";
llvm::GlobalVariable *TransferMedium =
M.getGlobalVariable(TransferMediumName);
unsigned WarpSize = CGF.getTarget().getGridValue().GV_Warp_Size;
if (!TransferMedium) {
auto *Ty = llvm::ArrayType::get(CGM.Int32Ty, WarpSize);
unsigned SharedAddressSpace = C.getTargetAddressSpace(LangAS::cuda_shared);
TransferMedium = new llvm::GlobalVariable(
M, Ty, /*isConstant=*/false, llvm::GlobalVariable::WeakAnyLinkage,
llvm::UndefValue::get(Ty), TransferMediumName,
/*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal,
SharedAddressSpace);
CGM.addCompilerUsedGlobal(TransferMedium);
}
auto &RT = static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
// Get the CUDA thread id of the current OpenMP thread on the GPU.
llvm::Value *ThreadID = RT.getGPUThreadID(CGF);
// nvptx_lane_id = nvptx_id % warpsize
llvm::Value *LaneID = getNVPTXLaneID(CGF);
// nvptx_warp_id = nvptx_id / warpsize
llvm::Value *WarpID = getNVPTXWarpID(CGF);
Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
Address LocalReduceList(
Bld.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLoadOfScalar(
AddrReduceListArg, /*Volatile=*/false, C.VoidPtrTy, Loc,
LValueBaseInfo(AlignmentSource::Type), TBAAAccessInfo()),
CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo()),
CGF.getPointerAlign());
unsigned Idx = 0;
for (const Expr *Private : Privates) {
//
// Warp master copies reduce element to transfer medium in __shared__
// memory.
//
unsigned RealTySize =
C.getTypeSizeInChars(Private->getType())
.alignTo(C.getTypeAlignInChars(Private->getType()))
.getQuantity();
for (unsigned TySize = 4; TySize > 0 && RealTySize > 0; TySize /=2) {
unsigned NumIters = RealTySize / TySize;
if (NumIters == 0)
continue;
QualType CType = C.getIntTypeForBitwidth(
C.toBits(CharUnits::fromQuantity(TySize)), /*Signed=*/1);
llvm::Type *CopyType = CGF.ConvertTypeForMem(CType);
CharUnits Align = CharUnits::fromQuantity(TySize);
llvm::Value *Cnt = nullptr;
Address CntAddr = Address::invalid();
llvm::BasicBlock *PrecondBB = nullptr;
llvm::BasicBlock *ExitBB = nullptr;
if (NumIters > 1) {
CntAddr = CGF.CreateMemTemp(C.IntTy, ".cnt.addr");
CGF.EmitStoreOfScalar(llvm::Constant::getNullValue(CGM.IntTy), CntAddr,
/*Volatile=*/false, C.IntTy);
PrecondBB = CGF.createBasicBlock("precond");
ExitBB = CGF.createBasicBlock("exit");
llvm::BasicBlock *BodyBB = CGF.createBasicBlock("body");
// There is no need to emit line number for unconditional branch.
(void)ApplyDebugLocation::CreateEmpty(CGF);
CGF.EmitBlock(PrecondBB);
Cnt = CGF.EmitLoadOfScalar(CntAddr, /*Volatile=*/false, C.IntTy, Loc);
llvm::Value *Cmp =
Bld.CreateICmpULT(Cnt, llvm::ConstantInt::get(CGM.IntTy, NumIters));
Bld.CreateCondBr(Cmp, BodyBB, ExitBB);
CGF.EmitBlock(BodyBB);
}
// kmpc_barrier.
CGM.getOpenMPRuntime().emitBarrierCall(CGF, Loc, OMPD_unknown,
/*EmitChecks=*/false,
/*ForceSimpleCall=*/true);
llvm::BasicBlock *ThenBB = CGF.createBasicBlock("then");
llvm::BasicBlock *ElseBB = CGF.createBasicBlock("else");
llvm::BasicBlock *MergeBB = CGF.createBasicBlock("ifcont");
// if (lane_id == 0)
llvm::Value *IsWarpMaster = Bld.CreateIsNull(LaneID, "warp_master");
Bld.CreateCondBr(IsWarpMaster, ThenBB, ElseBB);
CGF.EmitBlock(ThenBB);
// Reduce element = LocalReduceList[i]
Address ElemPtrPtrAddr = Bld.CreateConstArrayGEP(LocalReduceList, Idx);
llvm::Value *ElemPtrPtr = CGF.EmitLoadOfScalar(
ElemPtrPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
// elemptr = ((CopyType*)(elemptrptr)) + I
Address ElemPtr = Address(ElemPtrPtr, Align);
ElemPtr = Bld.CreateElementBitCast(ElemPtr, CopyType);
if (NumIters > 1) {
ElemPtr = Address(Bld.CreateGEP(ElemPtr.getElementType(),
ElemPtr.getPointer(), Cnt),
ElemPtr.getAlignment());
}
// Get pointer to location in transfer medium.
// MediumPtr = &medium[warp_id]
llvm::Value *MediumPtrVal = Bld.CreateInBoundsGEP(
TransferMedium->getValueType(), TransferMedium,
{llvm::Constant::getNullValue(CGM.Int64Ty), WarpID});
Address MediumPtr(MediumPtrVal, Align);
// Casting to actual data type.
// MediumPtr = (CopyType*)MediumPtrAddr;
MediumPtr = Bld.CreateElementBitCast(MediumPtr, CopyType);
// elem = *elemptr
//*MediumPtr = elem
llvm::Value *Elem = CGF.EmitLoadOfScalar(
ElemPtr, /*Volatile=*/false, CType, Loc,
LValueBaseInfo(AlignmentSource::Type), TBAAAccessInfo());
// Store the source element value to the dest element address.
CGF.EmitStoreOfScalar(Elem, MediumPtr, /*Volatile=*/true, CType,
LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo());
Bld.CreateBr(MergeBB);
CGF.EmitBlock(ElseBB);
Bld.CreateBr(MergeBB);
CGF.EmitBlock(MergeBB);
// kmpc_barrier.
CGM.getOpenMPRuntime().emitBarrierCall(CGF, Loc, OMPD_unknown,
/*EmitChecks=*/false,
/*ForceSimpleCall=*/true);
//
// Warp 0 copies reduce element from transfer medium.
//
llvm::BasicBlock *W0ThenBB = CGF.createBasicBlock("then");
llvm::BasicBlock *W0ElseBB = CGF.createBasicBlock("else");
llvm::BasicBlock *W0MergeBB = CGF.createBasicBlock("ifcont");
Address AddrNumWarpsArg = CGF.GetAddrOfLocalVar(&NumWarpsArg);
llvm::Value *NumWarpsVal = CGF.EmitLoadOfScalar(
AddrNumWarpsArg, /*Volatile=*/false, C.IntTy, Loc);
// Up to 32 threads in warp 0 are active.
llvm::Value *IsActiveThread =
Bld.CreateICmpULT(ThreadID, NumWarpsVal, "is_active_thread");
Bld.CreateCondBr(IsActiveThread, W0ThenBB, W0ElseBB);
CGF.EmitBlock(W0ThenBB);
// SrcMediumPtr = &medium[tid]
llvm::Value *SrcMediumPtrVal = Bld.CreateInBoundsGEP(
TransferMedium->getValueType(), TransferMedium,
{llvm::Constant::getNullValue(CGM.Int64Ty), ThreadID});
Address SrcMediumPtr(SrcMediumPtrVal, Align);
// SrcMediumVal = *SrcMediumPtr;
SrcMediumPtr = Bld.CreateElementBitCast(SrcMediumPtr, CopyType);
// TargetElemPtr = (CopyType*)(SrcDataAddr[i]) + I
Address TargetElemPtrPtr = Bld.CreateConstArrayGEP(LocalReduceList, Idx);
llvm::Value *TargetElemPtrVal = CGF.EmitLoadOfScalar(
TargetElemPtrPtr, /*Volatile=*/false, C.VoidPtrTy, Loc);
Address TargetElemPtr = Address(TargetElemPtrVal, Align);
TargetElemPtr = Bld.CreateElementBitCast(TargetElemPtr, CopyType);
if (NumIters > 1) {
TargetElemPtr = Address(Bld.CreateGEP(TargetElemPtr.getElementType(),
TargetElemPtr.getPointer(), Cnt),
TargetElemPtr.getAlignment());
}
// *TargetElemPtr = SrcMediumVal;
llvm::Value *SrcMediumValue =
CGF.EmitLoadOfScalar(SrcMediumPtr, /*Volatile=*/true, CType, Loc);
CGF.EmitStoreOfScalar(SrcMediumValue, TargetElemPtr, /*Volatile=*/false,
CType);
Bld.CreateBr(W0MergeBB);
CGF.EmitBlock(W0ElseBB);
Bld.CreateBr(W0MergeBB);
CGF.EmitBlock(W0MergeBB);
if (NumIters > 1) {
Cnt = Bld.CreateNSWAdd(Cnt, llvm::ConstantInt::get(CGM.IntTy, /*V=*/1));
CGF.EmitStoreOfScalar(Cnt, CntAddr, /*Volatile=*/false, C.IntTy);
CGF.EmitBranch(PrecondBB);
(void)ApplyDebugLocation::CreateEmpty(CGF);
CGF.EmitBlock(ExitBB);
}
RealTySize %= TySize;
}
++Idx;
}
CGF.FinishFunction();
return Fn;
}
/// Emit a helper that reduces data across two OpenMP threads (lanes)
/// in the same warp. It uses shuffle instructions to copy over data from
/// a remote lane's stack. The reduction algorithm performed is specified
/// by the fourth parameter.
///
/// Algorithm Versions.
/// Full Warp Reduce (argument value 0):
/// This algorithm assumes that all 32 lanes are active and gathers
/// data from these 32 lanes, producing a single resultant value.
/// Contiguous Partial Warp Reduce (argument value 1):
/// This algorithm assumes that only a *contiguous* subset of lanes
/// are active. This happens for the last warp in a parallel region
/// when the user specified num_threads is not an integer multiple of
/// 32. This contiguous subset always starts with the zeroth lane.
/// Partial Warp Reduce (argument value 2):
/// This algorithm gathers data from any number of lanes at any position.
/// All reduced values are stored in the lowest possible lane. The set
/// of problems every algorithm addresses is a super set of those
/// addressable by algorithms with a lower version number. Overhead
/// increases as algorithm version increases.
///
/// Terminology
/// Reduce element:
/// Reduce element refers to the individual data field with primitive
/// data types to be combined and reduced across threads.
/// Reduce list:
/// Reduce list refers to a collection of local, thread-private
/// reduce elements.
/// Remote Reduce list:
/// Remote Reduce list refers to a collection of remote (relative to
/// the current thread) reduce elements.
///
/// We distinguish between three states of threads that are important to
/// the implementation of this function.
/// Alive threads:
/// Threads in a warp executing the SIMT instruction, as distinguished from
/// threads that are inactive due to divergent control flow.
/// Active threads:
/// The minimal set of threads that has to be alive upon entry to this
/// function. The computation is correct iff active threads are alive.
/// Some threads are alive but they are not active because they do not
/// contribute to the computation in any useful manner. Turning them off
/// may introduce control flow overheads without any tangible benefits.
/// Effective threads:
/// In order to comply with the argument requirements of the shuffle
/// function, we must keep all lanes holding data alive. But at most
/// half of them perform value aggregation; we refer to this half of
/// threads as effective. The other half is simply handing off their
/// data.
///
/// Procedure
/// Value shuffle:
/// In this step active threads transfer data from higher lane positions
/// in the warp to lower lane positions, creating Remote Reduce list.
/// Value aggregation:
/// In this step, effective threads combine their thread local Reduce list
/// with Remote Reduce list and store the result in the thread local
/// Reduce list.
/// Value copy:
/// In this step, we deal with the assumption made by algorithm 2
/// (i.e. contiguity assumption). When we have an odd number of lanes
/// active, say 2k+1, only k threads will be effective and therefore k
/// new values will be produced. However, the Reduce list owned by the
/// (2k+1)th thread is ignored in the value aggregation. Therefore
/// we copy the Reduce list from the (2k+1)th lane to (k+1)th lane so
/// that the contiguity assumption still holds.
static llvm::Function *emitShuffleAndReduceFunction(
CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
QualType ReductionArrayTy, llvm::Function *ReduceFn, SourceLocation Loc) {
ASTContext &C = CGM.getContext();
// Thread local Reduce list used to host the values of data to be reduced.
ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
// Current lane id; could be logical.
ImplicitParamDecl LaneIDArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.ShortTy,
ImplicitParamDecl::Other);
// Offset of the remote source lane relative to the current lane.
ImplicitParamDecl RemoteLaneOffsetArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.ShortTy, ImplicitParamDecl::Other);
// Algorithm version. This is expected to be known at compile time.
ImplicitParamDecl AlgoVerArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.ShortTy, ImplicitParamDecl::Other);
FunctionArgList Args;
Args.push_back(&ReduceListArg);
Args.push_back(&LaneIDArg);
Args.push_back(&RemoteLaneOffsetArg);
Args.push_back(&AlgoVerArg);
const CGFunctionInfo &CGFI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
auto *Fn = llvm::Function::Create(
CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
"_omp_reduction_shuffle_and_reduce_func", &CGM.getModule());
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
Fn->setDoesNotRecurse();
CodeGenFunction CGF(CGM);
CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
CGBuilderTy &Bld = CGF.Builder;
Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
Address LocalReduceList(
Bld.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLoadOfScalar(AddrReduceListArg, /*Volatile=*/false,
C.VoidPtrTy, SourceLocation()),
CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo()),
CGF.getPointerAlign());
Address AddrLaneIDArg = CGF.GetAddrOfLocalVar(&LaneIDArg);
llvm::Value *LaneIDArgVal = CGF.EmitLoadOfScalar(
AddrLaneIDArg, /*Volatile=*/false, C.ShortTy, SourceLocation());
Address AddrRemoteLaneOffsetArg = CGF.GetAddrOfLocalVar(&RemoteLaneOffsetArg);
llvm::Value *RemoteLaneOffsetArgVal = CGF.EmitLoadOfScalar(
AddrRemoteLaneOffsetArg, /*Volatile=*/false, C.ShortTy, SourceLocation());
Address AddrAlgoVerArg = CGF.GetAddrOfLocalVar(&AlgoVerArg);
llvm::Value *AlgoVerArgVal = CGF.EmitLoadOfScalar(
AddrAlgoVerArg, /*Volatile=*/false, C.ShortTy, SourceLocation());
// Create a local thread-private variable to host the Reduce list
// from a remote lane.
Address RemoteReduceList =
CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.remote_reduce_list");
// This loop iterates through the list of reduce elements and copies,
// element by element, from a remote lane in the warp to RemoteReduceList,
// hosted on the thread's stack.
emitReductionListCopy(RemoteLaneToThread, CGF, ReductionArrayTy, Privates,
LocalReduceList, RemoteReduceList,
{/*RemoteLaneOffset=*/RemoteLaneOffsetArgVal,
/*ScratchpadIndex=*/nullptr,
/*ScratchpadWidth=*/nullptr});
// The actions to be performed on the Remote Reduce list is dependent
// on the algorithm version.
//
// if (AlgoVer==0) || (AlgoVer==1 && (LaneId < Offset)) || (AlgoVer==2 &&
// LaneId % 2 == 0 && Offset > 0):
// do the reduction value aggregation
//
// The thread local variable Reduce list is mutated in place to host the
// reduced data, which is the aggregated value produced from local and
// remote lanes.
//
// Note that AlgoVer is expected to be a constant integer known at compile
// time.
// When AlgoVer==0, the first conjunction evaluates to true, making
// the entire predicate true during compile time.
// When AlgoVer==1, the second conjunction has only the second part to be
// evaluated during runtime. Other conjunctions evaluates to false
// during compile time.
// When AlgoVer==2, the third conjunction has only the second part to be
// evaluated during runtime. Other conjunctions evaluates to false
// during compile time.
llvm::Value *CondAlgo0 = Bld.CreateIsNull(AlgoVerArgVal);
llvm::Value *Algo1 = Bld.CreateICmpEQ(AlgoVerArgVal, Bld.getInt16(1));
llvm::Value *CondAlgo1 = Bld.CreateAnd(
Algo1, Bld.CreateICmpULT(LaneIDArgVal, RemoteLaneOffsetArgVal));
llvm::Value *Algo2 = Bld.CreateICmpEQ(AlgoVerArgVal, Bld.getInt16(2));
llvm::Value *CondAlgo2 = Bld.CreateAnd(
Algo2, Bld.CreateIsNull(Bld.CreateAnd(LaneIDArgVal, Bld.getInt16(1))));
CondAlgo2 = Bld.CreateAnd(
CondAlgo2, Bld.CreateICmpSGT(RemoteLaneOffsetArgVal, Bld.getInt16(0)));
llvm::Value *CondReduce = Bld.CreateOr(CondAlgo0, CondAlgo1);
CondReduce = Bld.CreateOr(CondReduce, CondAlgo2);
llvm::BasicBlock *ThenBB = CGF.createBasicBlock("then");
llvm::BasicBlock *ElseBB = CGF.createBasicBlock("else");
llvm::BasicBlock *MergeBB = CGF.createBasicBlock("ifcont");
Bld.CreateCondBr(CondReduce, ThenBB, ElseBB);
CGF.EmitBlock(ThenBB);
// reduce_function(LocalReduceList, RemoteReduceList)
llvm::Value *LocalReduceListPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
LocalReduceList.getPointer(), CGF.VoidPtrTy);
llvm::Value *RemoteReduceListPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
RemoteReduceList.getPointer(), CGF.VoidPtrTy);
CGM.getOpenMPRuntime().emitOutlinedFunctionCall(
CGF, Loc, ReduceFn, {LocalReduceListPtr, RemoteReduceListPtr});
Bld.CreateBr(MergeBB);
CGF.EmitBlock(ElseBB);
Bld.CreateBr(MergeBB);
CGF.EmitBlock(MergeBB);
// if (AlgoVer==1 && (LaneId >= Offset)) copy Remote Reduce list to local
// Reduce list.
Algo1 = Bld.CreateICmpEQ(AlgoVerArgVal, Bld.getInt16(1));
llvm::Value *CondCopy = Bld.CreateAnd(
Algo1, Bld.CreateICmpUGE(LaneIDArgVal, RemoteLaneOffsetArgVal));
llvm::BasicBlock *CpyThenBB = CGF.createBasicBlock("then");
llvm::BasicBlock *CpyElseBB = CGF.createBasicBlock("else");
llvm::BasicBlock *CpyMergeBB = CGF.createBasicBlock("ifcont");
Bld.CreateCondBr(CondCopy, CpyThenBB, CpyElseBB);
CGF.EmitBlock(CpyThenBB);
emitReductionListCopy(ThreadCopy, CGF, ReductionArrayTy, Privates,
RemoteReduceList, LocalReduceList);
Bld.CreateBr(CpyMergeBB);
CGF.EmitBlock(CpyElseBB);
Bld.CreateBr(CpyMergeBB);
CGF.EmitBlock(CpyMergeBB);
CGF.FinishFunction();
return Fn;
}
/// This function emits a helper that copies all the reduction variables from
/// the team into the provided global buffer for the reduction variables.
///
/// void list_to_global_copy_func(void *buffer, int Idx, void *reduce_data)
/// For all data entries D in reduce_data:
/// Copy local D to buffer.D[Idx]
static llvm::Value *emitListToGlobalCopyFunction(
CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
QualType ReductionArrayTy, SourceLocation Loc,
const RecordDecl *TeamReductionRec,
const llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
&VarFieldMap) {
ASTContext &C = CGM.getContext();
// Buffer: global reduction buffer.
ImplicitParamDecl BufferArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
// Idx: index of the buffer.
ImplicitParamDecl IdxArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.IntTy,
ImplicitParamDecl::Other);
// ReduceList: thread local Reduce list.
ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
FunctionArgList Args;
Args.push_back(&BufferArg);
Args.push_back(&IdxArg);
Args.push_back(&ReduceListArg);
const CGFunctionInfo &CGFI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
auto *Fn = llvm::Function::Create(
CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
"_omp_reduction_list_to_global_copy_func", &CGM.getModule());
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
Fn->setDoesNotRecurse();
CodeGenFunction CGF(CGM);
CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
CGBuilderTy &Bld = CGF.Builder;
Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
Address AddrBufferArg = CGF.GetAddrOfLocalVar(&BufferArg);
Address LocalReduceList(
Bld.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLoadOfScalar(AddrReduceListArg, /*Volatile=*/false,
C.VoidPtrTy, Loc),
CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo()),
CGF.getPointerAlign());
QualType StaticTy = C.getRecordType(TeamReductionRec);
llvm::Type *LLVMReductionsBufferTy =
CGM.getTypes().ConvertTypeForMem(StaticTy);
llvm::Value *BufferArrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLoadOfScalar(AddrBufferArg, /*Volatile=*/false, C.VoidPtrTy, Loc),
LLVMReductionsBufferTy->getPointerTo());
llvm::Value *Idxs[] = {llvm::ConstantInt::getNullValue(CGF.Int32Ty),
CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(&IdxArg),
/*Volatile=*/false, C.IntTy,
Loc)};
unsigned Idx = 0;
for (const Expr *Private : Privates) {
// Reduce element = LocalReduceList[i]
Address ElemPtrPtrAddr = Bld.CreateConstArrayGEP(LocalReduceList, Idx);
llvm::Value *ElemPtrPtr = CGF.EmitLoadOfScalar(
ElemPtrPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
// elemptr = ((CopyType*)(elemptrptr)) + I
ElemPtrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
ElemPtrPtr, CGF.ConvertTypeForMem(Private->getType())->getPointerTo());
Address ElemPtr =
Address(ElemPtrPtr, C.getTypeAlignInChars(Private->getType()));
const ValueDecl *VD = cast<DeclRefExpr>(Private)->getDecl();
// Global = Buffer.VD[Idx];
const FieldDecl *FD = VarFieldMap.lookup(VD);
LValue GlobLVal = CGF.EmitLValueForField(
CGF.MakeNaturalAlignAddrLValue(BufferArrPtr, StaticTy), FD);
Address GlobAddr = GlobLVal.getAddress(CGF);
llvm::Value *BufferPtr = Bld.CreateInBoundsGEP(
GlobAddr.getElementType(), GlobAddr.getPointer(), Idxs);
GlobLVal.setAddress(Address(BufferPtr, GlobAddr.getAlignment()));
switch (CGF.getEvaluationKind(Private->getType())) {
case TEK_Scalar: {
llvm::Value *V = CGF.EmitLoadOfScalar(
ElemPtr, /*Volatile=*/false, Private->getType(), Loc,
LValueBaseInfo(AlignmentSource::Type), TBAAAccessInfo());
CGF.EmitStoreOfScalar(V, GlobLVal);
break;
}
case TEK_Complex: {
CodeGenFunction::ComplexPairTy V = CGF.EmitLoadOfComplex(
CGF.MakeAddrLValue(ElemPtr, Private->getType()), Loc);
CGF.EmitStoreOfComplex(V, GlobLVal, /*isInit=*/false);
break;
}
case TEK_Aggregate:
CGF.EmitAggregateCopy(GlobLVal,
CGF.MakeAddrLValue(ElemPtr, Private->getType()),
Private->getType(), AggValueSlot::DoesNotOverlap);
break;
}
++Idx;
}
CGF.FinishFunction();
return Fn;
}
/// This function emits a helper that reduces all the reduction variables from
/// the team into the provided global buffer for the reduction variables.
///
/// void list_to_global_reduce_func(void *buffer, int Idx, void *reduce_data)
/// void *GlobPtrs[];
/// GlobPtrs[0] = (void*)&buffer.D0[Idx];
/// ...
/// GlobPtrs[N] = (void*)&buffer.DN[Idx];
/// reduce_function(GlobPtrs, reduce_data);
static llvm::Value *emitListToGlobalReduceFunction(
CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
QualType ReductionArrayTy, SourceLocation Loc,
const RecordDecl *TeamReductionRec,
const llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
&VarFieldMap,
llvm::Function *ReduceFn) {
ASTContext &C = CGM.getContext();
// Buffer: global reduction buffer.
ImplicitParamDecl BufferArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
// Idx: index of the buffer.
ImplicitParamDecl IdxArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.IntTy,
ImplicitParamDecl::Other);
// ReduceList: thread local Reduce list.
ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
FunctionArgList Args;
Args.push_back(&BufferArg);
Args.push_back(&IdxArg);
Args.push_back(&ReduceListArg);
const CGFunctionInfo &CGFI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
auto *Fn = llvm::Function::Create(
CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
"_omp_reduction_list_to_global_reduce_func", &CGM.getModule());
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
Fn->setDoesNotRecurse();
CodeGenFunction CGF(CGM);
CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
CGBuilderTy &Bld = CGF.Builder;
Address AddrBufferArg = CGF.GetAddrOfLocalVar(&BufferArg);
QualType StaticTy = C.getRecordType(TeamReductionRec);
llvm::Type *LLVMReductionsBufferTy =
CGM.getTypes().ConvertTypeForMem(StaticTy);
llvm::Value *BufferArrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLoadOfScalar(AddrBufferArg, /*Volatile=*/false, C.VoidPtrTy, Loc),
LLVMReductionsBufferTy->getPointerTo());
// 1. Build a list of reduction variables.
// void *RedList[<n>] = {<ReductionVars>[0], ..., <ReductionVars>[<n>-1]};
Address ReductionList =
CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.red_list");
auto IPriv = Privates.begin();
llvm::Value *Idxs[] = {llvm::ConstantInt::getNullValue(CGF.Int32Ty),
CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(&IdxArg),
/*Volatile=*/false, C.IntTy,
Loc)};
unsigned Idx = 0;
for (unsigned I = 0, E = Privates.size(); I < E; ++I, ++IPriv, ++Idx) {
Address Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
// Global = Buffer.VD[Idx];
const ValueDecl *VD = cast<DeclRefExpr>(*IPriv)->getDecl();
const FieldDecl *FD = VarFieldMap.lookup(VD);
LValue GlobLVal = CGF.EmitLValueForField(
CGF.MakeNaturalAlignAddrLValue(BufferArrPtr, StaticTy), FD);
Address GlobAddr = GlobLVal.getAddress(CGF);
llvm::Value *BufferPtr = Bld.CreateInBoundsGEP(
GlobAddr.getElementType(), GlobAddr.getPointer(), Idxs);
llvm::Value *Ptr = CGF.EmitCastToVoidPtr(BufferPtr);
CGF.EmitStoreOfScalar(Ptr, Elem, /*Volatile=*/false, C.VoidPtrTy);
if ((*IPriv)->getType()->isVariablyModifiedType()) {
// Store array size.
++Idx;
Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
llvm::Value *Size = CGF.Builder.CreateIntCast(
CGF.getVLASize(
CGF.getContext().getAsVariableArrayType((*IPriv)->getType()))
.NumElts,
CGF.SizeTy, /*isSigned=*/false);
CGF.Builder.CreateStore(CGF.Builder.CreateIntToPtr(Size, CGF.VoidPtrTy),
Elem);
}
}
// Call reduce_function(GlobalReduceList, ReduceList)
llvm::Value *GlobalReduceList =
CGF.EmitCastToVoidPtr(ReductionList.getPointer());
Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
llvm::Value *ReducedPtr = CGF.EmitLoadOfScalar(
AddrReduceListArg, /*Volatile=*/false, C.VoidPtrTy, Loc);
CGM.getOpenMPRuntime().emitOutlinedFunctionCall(
CGF, Loc, ReduceFn, {GlobalReduceList, ReducedPtr});
CGF.FinishFunction();
return Fn;
}
/// This function emits a helper that copies all the reduction variables from
/// the team into the provided global buffer for the reduction variables.
///
/// void list_to_global_copy_func(void *buffer, int Idx, void *reduce_data)
/// For all data entries D in reduce_data:
/// Copy buffer.D[Idx] to local D;
static llvm::Value *emitGlobalToListCopyFunction(
CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
QualType ReductionArrayTy, SourceLocation Loc,
const RecordDecl *TeamReductionRec,
const llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
&VarFieldMap) {
ASTContext &C = CGM.getContext();
// Buffer: global reduction buffer.
ImplicitParamDecl BufferArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
// Idx: index of the buffer.
ImplicitParamDecl IdxArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.IntTy,
ImplicitParamDecl::Other);
// ReduceList: thread local Reduce list.
ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
FunctionArgList Args;
Args.push_back(&BufferArg);
Args.push_back(&IdxArg);
Args.push_back(&ReduceListArg);
const CGFunctionInfo &CGFI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
auto *Fn = llvm::Function::Create(
CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
"_omp_reduction_global_to_list_copy_func", &CGM.getModule());
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
Fn->setDoesNotRecurse();
CodeGenFunction CGF(CGM);
CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
CGBuilderTy &Bld = CGF.Builder;
Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
Address AddrBufferArg = CGF.GetAddrOfLocalVar(&BufferArg);
Address LocalReduceList(
Bld.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLoadOfScalar(AddrReduceListArg, /*Volatile=*/false,
C.VoidPtrTy, Loc),
CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo()),
CGF.getPointerAlign());
QualType StaticTy = C.getRecordType(TeamReductionRec);
llvm::Type *LLVMReductionsBufferTy =
CGM.getTypes().ConvertTypeForMem(StaticTy);
llvm::Value *BufferArrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLoadOfScalar(AddrBufferArg, /*Volatile=*/false, C.VoidPtrTy, Loc),
LLVMReductionsBufferTy->getPointerTo());
llvm::Value *Idxs[] = {llvm::ConstantInt::getNullValue(CGF.Int32Ty),
CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(&IdxArg),
/*Volatile=*/false, C.IntTy,
Loc)};
unsigned Idx = 0;
for (const Expr *Private : Privates) {
// Reduce element = LocalReduceList[i]
Address ElemPtrPtrAddr = Bld.CreateConstArrayGEP(LocalReduceList, Idx);
llvm::Value *ElemPtrPtr = CGF.EmitLoadOfScalar(
ElemPtrPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
// elemptr = ((CopyType*)(elemptrptr)) + I
ElemPtrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
ElemPtrPtr, CGF.ConvertTypeForMem(Private->getType())->getPointerTo());
Address ElemPtr =
Address(ElemPtrPtr, C.getTypeAlignInChars(Private->getType()));
const ValueDecl *VD = cast<DeclRefExpr>(Private)->getDecl();
// Global = Buffer.VD[Idx];
const FieldDecl *FD = VarFieldMap.lookup(VD);
LValue GlobLVal = CGF.EmitLValueForField(
CGF.MakeNaturalAlignAddrLValue(BufferArrPtr, StaticTy), FD);
Address GlobAddr = GlobLVal.getAddress(CGF);
llvm::Value *BufferPtr = Bld.CreateInBoundsGEP(
GlobAddr.getElementType(), GlobAddr.getPointer(), Idxs);
GlobLVal.setAddress(Address(BufferPtr, GlobAddr.getAlignment()));
switch (CGF.getEvaluationKind(Private->getType())) {
case TEK_Scalar: {
llvm::Value *V = CGF.EmitLoadOfScalar(GlobLVal, Loc);
CGF.EmitStoreOfScalar(V, ElemPtr, /*Volatile=*/false, Private->getType(),
LValueBaseInfo(AlignmentSource::Type),
TBAAAccessInfo());
break;
}
case TEK_Complex: {
CodeGenFunction::ComplexPairTy V = CGF.EmitLoadOfComplex(GlobLVal, Loc);
CGF.EmitStoreOfComplex(V, CGF.MakeAddrLValue(ElemPtr, Private->getType()),
/*isInit=*/false);
break;
}
case TEK_Aggregate:
CGF.EmitAggregateCopy(CGF.MakeAddrLValue(ElemPtr, Private->getType()),
GlobLVal, Private->getType(),
AggValueSlot::DoesNotOverlap);
break;
}
++Idx;
}
CGF.FinishFunction();
return Fn;
}
/// This function emits a helper that reduces all the reduction variables from
/// the team into the provided global buffer for the reduction variables.
///
/// void global_to_list_reduce_func(void *buffer, int Idx, void *reduce_data)
/// void *GlobPtrs[];
/// GlobPtrs[0] = (void*)&buffer.D0[Idx];
/// ...
/// GlobPtrs[N] = (void*)&buffer.DN[Idx];
/// reduce_function(reduce_data, GlobPtrs);
static llvm::Value *emitGlobalToListReduceFunction(
CodeGenModule &CGM, ArrayRef<const Expr *> Privates,
QualType ReductionArrayTy, SourceLocation Loc,
const RecordDecl *TeamReductionRec,
const llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *>
&VarFieldMap,
llvm::Function *ReduceFn) {
ASTContext &C = CGM.getContext();
// Buffer: global reduction buffer.
ImplicitParamDecl BufferArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
// Idx: index of the buffer.
ImplicitParamDecl IdxArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, C.IntTy,
ImplicitParamDecl::Other);
// ReduceList: thread local Reduce list.
ImplicitParamDecl ReduceListArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr,
C.VoidPtrTy, ImplicitParamDecl::Other);
FunctionArgList Args;
Args.push_back(&BufferArg);
Args.push_back(&IdxArg);
Args.push_back(&ReduceListArg);
const CGFunctionInfo &CGFI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, Args);
auto *Fn = llvm::Function::Create(
CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
"_omp_reduction_global_to_list_reduce_func", &CGM.getModule());
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
Fn->setDoesNotRecurse();
CodeGenFunction CGF(CGM);
CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args, Loc, Loc);
CGBuilderTy &Bld = CGF.Builder;
Address AddrBufferArg = CGF.GetAddrOfLocalVar(&BufferArg);
QualType StaticTy = C.getRecordType(TeamReductionRec);
llvm::Type *LLVMReductionsBufferTy =
CGM.getTypes().ConvertTypeForMem(StaticTy);
llvm::Value *BufferArrPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLoadOfScalar(AddrBufferArg, /*Volatile=*/false, C.VoidPtrTy, Loc),
LLVMReductionsBufferTy->getPointerTo());
// 1. Build a list of reduction variables.
// void *RedList[<n>] = {<ReductionVars>[0], ..., <ReductionVars>[<n>-1]};
Address ReductionList =
CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.red_list");
auto IPriv = Privates.begin();
llvm::Value *Idxs[] = {llvm::ConstantInt::getNullValue(CGF.Int32Ty),
CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(&IdxArg),
/*Volatile=*/false, C.IntTy,
Loc)};
unsigned Idx = 0;
for (unsigned I = 0, E = Privates.size(); I < E; ++I, ++IPriv, ++Idx) {
Address Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
// Global = Buffer.VD[Idx];
const ValueDecl *VD = cast<DeclRefExpr>(*IPriv)->getDecl();
const FieldDecl *FD = VarFieldMap.lookup(VD);
LValue GlobLVal = CGF.EmitLValueForField(
CGF.MakeNaturalAlignAddrLValue(BufferArrPtr, StaticTy), FD);
Address GlobAddr = GlobLVal.getAddress(CGF);
llvm::Value *BufferPtr = Bld.CreateInBoundsGEP(
GlobAddr.getElementType(), GlobAddr.getPointer(), Idxs);
llvm::Value *Ptr = CGF.EmitCastToVoidPtr(BufferPtr);
CGF.EmitStoreOfScalar(Ptr, Elem, /*Volatile=*/false, C.VoidPtrTy);
if ((*IPriv)->getType()->isVariablyModifiedType()) {
// Store array size.
++Idx;
Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
llvm::Value *Size = CGF.Builder.CreateIntCast(
CGF.getVLASize(
CGF.getContext().getAsVariableArrayType((*IPriv)->getType()))
.NumElts,
CGF.SizeTy, /*isSigned=*/false);
CGF.Builder.CreateStore(CGF.Builder.CreateIntToPtr(Size, CGF.VoidPtrTy),
Elem);
}
}
// Call reduce_function(ReduceList, GlobalReduceList)
llvm::Value *GlobalReduceList =
CGF.EmitCastToVoidPtr(ReductionList.getPointer());
Address AddrReduceListArg = CGF.GetAddrOfLocalVar(&ReduceListArg);
llvm::Value *ReducedPtr = CGF.EmitLoadOfScalar(
AddrReduceListArg, /*Volatile=*/false, C.VoidPtrTy, Loc);
CGM.getOpenMPRuntime().emitOutlinedFunctionCall(
CGF, Loc, ReduceFn, {ReducedPtr, GlobalReduceList});
CGF.FinishFunction();
return Fn;
}
///
/// Design of OpenMP reductions on the GPU
///
/// Consider a typical OpenMP program with one or more reduction
/// clauses:
///
/// float foo;
/// double bar;
/// #pragma omp target teams distribute parallel for \
/// reduction(+:foo) reduction(*:bar)
/// for (int i = 0; i < N; i++) {
/// foo += A[i]; bar *= B[i];
/// }
///
/// where 'foo' and 'bar' are reduced across all OpenMP threads in
/// all teams. In our OpenMP implementation on the NVPTX device an
/// OpenMP team is mapped to a CUDA threadblock and OpenMP threads
/// within a team are mapped to CUDA threads within a threadblock.
/// Our goal is to efficiently aggregate values across all OpenMP
/// threads such that:
///
/// - the compiler and runtime are logically concise, and
/// - the reduction is performed efficiently in a hierarchical
/// manner as follows: within OpenMP threads in the same warp,
/// across warps in a threadblock, and finally across teams on
/// the NVPTX device.
///
/// Introduction to Decoupling
///
/// We would like to decouple the compiler and the runtime so that the
/// latter is ignorant of the reduction variables (number, data types)
/// and the reduction operators. This allows a simpler interface
/// and implementation while still attaining good performance.
///
/// Pseudocode for the aforementioned OpenMP program generated by the
/// compiler is as follows:
///
/// 1. Create private copies of reduction variables on each OpenMP
/// thread: 'foo_private', 'bar_private'
/// 2. Each OpenMP thread reduces the chunk of 'A' and 'B' assigned
/// to it and writes the result in 'foo_private' and 'bar_private'
/// respectively.
/// 3. Call the OpenMP runtime on the GPU to reduce within a team
/// and store the result on the team master:
///
/// __kmpc_nvptx_parallel_reduce_nowait_v2(...,
/// reduceData, shuffleReduceFn, interWarpCpyFn)
///
/// where:
/// struct ReduceData {
/// double *foo;
/// double *bar;
/// } reduceData
/// reduceData.foo = &foo_private
/// reduceData.bar = &bar_private
///
/// 'shuffleReduceFn' and 'interWarpCpyFn' are pointers to two
/// auxiliary functions generated by the compiler that operate on
/// variables of type 'ReduceData'. They aid the runtime perform
/// algorithmic steps in a data agnostic manner.
///
/// 'shuffleReduceFn' is a pointer to a function that reduces data
/// of type 'ReduceData' across two OpenMP threads (lanes) in the
/// same warp. It takes the following arguments as input:
///
/// a. variable of type 'ReduceData' on the calling lane,
/// b. its lane_id,
/// c. an offset relative to the current lane_id to generate a
/// remote_lane_id. The remote lane contains the second
/// variable of type 'ReduceData' that is to be reduced.
/// d. an algorithm version parameter determining which reduction
/// algorithm to use.
///
/// 'shuffleReduceFn' retrieves data from the remote lane using
/// efficient GPU shuffle intrinsics and reduces, using the
/// algorithm specified by the 4th parameter, the two operands
/// element-wise. The result is written to the first operand.
///
/// Different reduction algorithms are implemented in different
/// runtime functions, all calling 'shuffleReduceFn' to perform
/// the essential reduction step. Therefore, based on the 4th
/// parameter, this function behaves slightly differently to
/// cooperate with the runtime to ensure correctness under
/// different circumstances.
///
/// 'InterWarpCpyFn' is a pointer to a function that transfers
/// reduced variables across warps. It tunnels, through CUDA
/// shared memory, the thread-private data of type 'ReduceData'
/// from lane 0 of each warp to a lane in the first warp.
/// 4. Call the OpenMP runtime on the GPU to reduce across teams.
/// The last team writes the global reduced value to memory.
///
/// ret = __kmpc_nvptx_teams_reduce_nowait(...,
/// reduceData, shuffleReduceFn, interWarpCpyFn,
/// scratchpadCopyFn, loadAndReduceFn)
///
/// 'scratchpadCopyFn' is a helper that stores reduced
/// data from the team master to a scratchpad array in
/// global memory.
///
/// 'loadAndReduceFn' is a helper that loads data from
/// the scratchpad array and reduces it with the input
/// operand.
///
/// These compiler generated functions hide address
/// calculation and alignment information from the runtime.
/// 5. if ret == 1:
/// The team master of the last team stores the reduced
/// result to the globals in memory.
/// foo += reduceData.foo; bar *= reduceData.bar
///
///
/// Warp Reduction Algorithms
///
/// On the warp level, we have three algorithms implemented in the
/// OpenMP runtime depending on the number of active lanes:
///
/// Full Warp Reduction
///
/// The reduce algorithm within a warp where all lanes are active
/// is implemented in the runtime as follows:
///
/// full_warp_reduce(void *reduce_data,
/// kmp_ShuffleReductFctPtr ShuffleReduceFn) {
/// for (int offset = WARPSIZE/2; offset > 0; offset /= 2)
/// ShuffleReduceFn(reduce_data, 0, offset, 0);
/// }
///
/// The algorithm completes in log(2, WARPSIZE) steps.
///
/// 'ShuffleReduceFn' is used here with lane_id set to 0 because it is
/// not used therefore we save instructions by not retrieving lane_id
/// from the corresponding special registers. The 4th parameter, which
/// represents the version of the algorithm being used, is set to 0 to
/// signify full warp reduction.
///
/// In this version, 'ShuffleReduceFn' behaves, per element, as follows:
///
/// #reduce_elem refers to an element in the local lane's data structure
/// #remote_elem is retrieved from a remote lane
/// remote_elem = shuffle_down(reduce_elem, offset, WARPSIZE);
/// reduce_elem = reduce_elem REDUCE_OP remote_elem;
///
/// Contiguous Partial Warp Reduction
///
/// This reduce algorithm is used within a warp where only the first
/// 'n' (n <= WARPSIZE) lanes are active. It is typically used when the
/// number of OpenMP threads in a parallel region is not a multiple of
/// WARPSIZE. The algorithm is implemented in the runtime as follows:
///
/// void
/// contiguous_partial_reduce(void *reduce_data,
/// kmp_ShuffleReductFctPtr ShuffleReduceFn,
/// int size, int lane_id) {
/// int curr_size;
/// int offset;
/// curr_size = size;
/// mask = curr_size/2;
/// while (offset>0) {
/// ShuffleReduceFn(reduce_data, lane_id, offset, 1);
/// curr_size = (curr_size+1)/2;
/// offset = curr_size/2;
/// }
/// }
///
/// In this version, 'ShuffleReduceFn' behaves, per element, as follows:
///
/// remote_elem = shuffle_down(reduce_elem, offset, WARPSIZE);
/// if (lane_id < offset)
/// reduce_elem = reduce_elem REDUCE_OP remote_elem
/// else
/// reduce_elem = remote_elem
///
/// This algorithm assumes that the data to be reduced are located in a
/// contiguous subset of lanes starting from the first. When there is
/// an odd number of active lanes, the data in the last lane is not
/// aggregated with any other lane's dat but is instead copied over.
///
/// Dispersed Partial Warp Reduction
///
/// This algorithm is used within a warp when any discontiguous subset of
/// lanes are active. It is used to implement the reduction operation
/// across lanes in an OpenMP simd region or in a nested parallel region.
///
/// void
/// dispersed_partial_reduce(void *reduce_data,
/// kmp_ShuffleReductFctPtr ShuffleReduceFn) {
/// int size, remote_id;
/// int logical_lane_id = number_of_active_lanes_before_me() * 2;
/// do {
/// remote_id = next_active_lane_id_right_after_me();
/// # the above function returns 0 of no active lane
/// # is present right after the current lane.
/// size = number_of_active_lanes_in_this_warp();
/// logical_lane_id /= 2;
/// ShuffleReduceFn(reduce_data, logical_lane_id,
/// remote_id-1-threadIdx.x, 2);
/// } while (logical_lane_id % 2 == 0 && size > 1);
/// }
///
/// There is no assumption made about the initial state of the reduction.
/// Any number of lanes (>=1) could be active at any position. The reduction
/// result is returned in the first active lane.
///
/// In this version, 'ShuffleReduceFn' behaves, per element, as follows:
///
/// remote_elem = shuffle_down(reduce_elem, offset, WARPSIZE);
/// if (lane_id % 2 == 0 && offset > 0)
/// reduce_elem = reduce_elem REDUCE_OP remote_elem
/// else
/// reduce_elem = remote_elem
///
///
/// Intra-Team Reduction
///
/// This function, as implemented in the runtime call
/// '__kmpc_nvptx_parallel_reduce_nowait_v2', aggregates data across OpenMP
/// threads in a team. It first reduces within a warp using the
/// aforementioned algorithms. We then proceed to gather all such
/// reduced values at the first warp.
///
/// The runtime makes use of the function 'InterWarpCpyFn', which copies
/// data from each of the "warp master" (zeroth lane of each warp, where
/// warp-reduced data is held) to the zeroth warp. This step reduces (in
/// a mathematical sense) the problem of reduction across warp masters in
/// a block to the problem of warp reduction.
///
///
/// Inter-Team Reduction
///
/// Once a team has reduced its data to a single value, it is stored in
/// a global scratchpad array. Since each team has a distinct slot, this
/// can be done without locking.
///
/// The last team to write to the scratchpad array proceeds to reduce the
/// scratchpad array. One or more workers in the last team use the helper
/// 'loadAndReduceDataFn' to load and reduce values from the array, i.e.,
/// the k'th worker reduces every k'th element.
///
/// Finally, a call is made to '__kmpc_nvptx_parallel_reduce_nowait_v2' to
/// reduce across workers and compute a globally reduced value.
///
void CGOpenMPRuntimeGPU::emitReduction(
CodeGenFunction &CGF, SourceLocation Loc, ArrayRef<const Expr *> Privates,
ArrayRef<const Expr *> LHSExprs, ArrayRef<const Expr *> RHSExprs,
ArrayRef<const Expr *> ReductionOps, ReductionOptionsTy Options) {
if (!CGF.HaveInsertPoint())
return;
bool ParallelReduction = isOpenMPParallelDirective(Options.ReductionKind);
#ifndef NDEBUG
bool TeamsReduction = isOpenMPTeamsDirective(Options.ReductionKind);
#endif
if (Options.SimpleReduction) {
assert(!TeamsReduction && !ParallelReduction &&
"Invalid reduction selection in emitReduction.");
CGOpenMPRuntime::emitReduction(CGF, Loc, Privates, LHSExprs, RHSExprs,
ReductionOps, Options);
return;
}
assert((TeamsReduction || ParallelReduction) &&
"Invalid reduction selection in emitReduction.");
// Build res = __kmpc_reduce{_nowait}(<gtid>, <n>, sizeof(RedList),
// RedList, shuffle_reduce_func, interwarp_copy_func);
// or
// Build res = __kmpc_reduce_teams_nowait_simple(<loc>, <gtid>, <lck>);
llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
llvm::Value *ThreadId = getThreadID(CGF, Loc);
llvm::Value *Res;
ASTContext &C = CGM.getContext();
// 1. Build a list of reduction variables.
// void *RedList[<n>] = {<ReductionVars>[0], ..., <ReductionVars>[<n>-1]};
auto Size = RHSExprs.size();
for (const Expr *E : Privates) {
if (E->getType()->isVariablyModifiedType())
// Reserve place for array size.
++Size;
}
llvm::APInt ArraySize(/*unsigned int numBits=*/32, Size);
QualType ReductionArrayTy =
C.getConstantArrayType(C.VoidPtrTy, ArraySize, nullptr, ArrayType::Normal,
/*IndexTypeQuals=*/0);
Address ReductionList =
CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.red_list");
auto IPriv = Privates.begin();
unsigned Idx = 0;
for (unsigned I = 0, E = RHSExprs.size(); I < E; ++I, ++IPriv, ++Idx) {
Address Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
CGF.Builder.CreateStore(
CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
CGF.EmitLValue(RHSExprs[I]).getPointer(CGF), CGF.VoidPtrTy),
Elem);
if ((*IPriv)->getType()->isVariablyModifiedType()) {
// Store array size.
++Idx;
Elem = CGF.Builder.CreateConstArrayGEP(ReductionList, Idx);
llvm::Value *Size = CGF.Builder.CreateIntCast(
CGF.getVLASize(
CGF.getContext().getAsVariableArrayType((*IPriv)->getType()))
.NumElts,
CGF.SizeTy, /*isSigned=*/false);
CGF.Builder.CreateStore(CGF.Builder.CreateIntToPtr(Size, CGF.VoidPtrTy),
Elem);
}
}
llvm::Value *RL = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
ReductionList.getPointer(), CGF.VoidPtrTy);
llvm::Function *ReductionFn = emitReductionFunction(
Loc, CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo(), Privates,
LHSExprs, RHSExprs, ReductionOps);
llvm::Value *ReductionArrayTySize = CGF.getTypeSize(ReductionArrayTy);
llvm::Function *ShuffleAndReduceFn = emitShuffleAndReduceFunction(
CGM, Privates, ReductionArrayTy, ReductionFn, Loc);
llvm::Value *InterWarpCopyFn =
emitInterWarpCopyFunction(CGM, Privates, ReductionArrayTy, Loc);
if (ParallelReduction) {
llvm::Value *Args[] = {RTLoc,
ThreadId,
CGF.Builder.getInt32(RHSExprs.size()),
ReductionArrayTySize,
RL,
ShuffleAndReduceFn,
InterWarpCopyFn};
Res = CGF.EmitRuntimeCall(
OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_nvptx_parallel_reduce_nowait_v2),
Args);
} else {
assert(TeamsReduction && "expected teams reduction.");
llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *> VarFieldMap;
llvm::SmallVector<const ValueDecl *, 4> PrivatesReductions(Privates.size());
int Cnt = 0;
for (const Expr *DRE : Privates) {
PrivatesReductions[Cnt] = cast<DeclRefExpr>(DRE)->getDecl();
++Cnt;
}
const RecordDecl *TeamReductionRec = ::buildRecordForGlobalizedVars(
CGM.getContext(), PrivatesReductions, llvm::None, VarFieldMap,
C.getLangOpts().OpenMPCUDAReductionBufNum);
TeamsReductions.push_back(TeamReductionRec);
if (!KernelTeamsReductionPtr) {
KernelTeamsReductionPtr = new llvm::GlobalVariable(
CGM.getModule(), CGM.VoidPtrTy, /*isConstant=*/true,
llvm::GlobalValue::InternalLinkage, nullptr,
"_openmp_teams_reductions_buffer_$_$ptr");
}
llvm::Value *GlobalBufferPtr = CGF.EmitLoadOfScalar(
Address(KernelTeamsReductionPtr, CGM.getPointerAlign()),
/*Volatile=*/false, C.getPointerType(C.VoidPtrTy), Loc);
llvm::Value *GlobalToBufferCpyFn = ::emitListToGlobalCopyFunction(
CGM, Privates, ReductionArrayTy, Loc, TeamReductionRec, VarFieldMap);
llvm::Value *GlobalToBufferRedFn = ::emitListToGlobalReduceFunction(
CGM, Privates, ReductionArrayTy, Loc, TeamReductionRec, VarFieldMap,
ReductionFn);
llvm::Value *BufferToGlobalCpyFn = ::emitGlobalToListCopyFunction(
CGM, Privates, ReductionArrayTy, Loc, TeamReductionRec, VarFieldMap);
llvm::Value *BufferToGlobalRedFn = ::emitGlobalToListReduceFunction(
CGM, Privates, ReductionArrayTy, Loc, TeamReductionRec, VarFieldMap,
ReductionFn);
llvm::Value *Args[] = {
RTLoc,
ThreadId,
GlobalBufferPtr,
CGF.Builder.getInt32(C.getLangOpts().OpenMPCUDAReductionBufNum),
RL,
ShuffleAndReduceFn,
InterWarpCopyFn,
GlobalToBufferCpyFn,
GlobalToBufferRedFn,
BufferToGlobalCpyFn,
BufferToGlobalRedFn};
Res = CGF.EmitRuntimeCall(
OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_nvptx_teams_reduce_nowait_v2),
Args);
}
// 5. Build if (res == 1)
llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".omp.reduction.done");
llvm::BasicBlock *ThenBB = CGF.createBasicBlock(".omp.reduction.then");
llvm::Value *Cond = CGF.Builder.CreateICmpEQ(
Res, llvm::ConstantInt::get(CGM.Int32Ty, /*V=*/1));
CGF.Builder.CreateCondBr(Cond, ThenBB, ExitBB);
// 6. Build then branch: where we have reduced values in the master
// thread in each team.
// __kmpc_end_reduce{_nowait}(<gtid>);
// break;
CGF.EmitBlock(ThenBB);
// Add emission of __kmpc_end_reduce{_nowait}(<gtid>);
auto &&CodeGen = [Privates, LHSExprs, RHSExprs, ReductionOps,
this](CodeGenFunction &CGF, PrePostActionTy &Action) {
auto IPriv = Privates.begin();
auto ILHS = LHSExprs.begin();
auto IRHS = RHSExprs.begin();
for (const Expr *E : ReductionOps) {
emitSingleReductionCombiner(CGF, E, *IPriv, cast<DeclRefExpr>(*ILHS),
cast<DeclRefExpr>(*IRHS));
++IPriv;
++ILHS;
++IRHS;
}
};
llvm::Value *EndArgs[] = {ThreadId};
RegionCodeGenTy RCG(CodeGen);
NVPTXActionTy Action(
nullptr, llvm::None,
OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_nvptx_end_reduce_nowait),
EndArgs);
RCG.setAction(Action);
RCG(CGF);
// There is no need to emit line number for unconditional branch.
(void)ApplyDebugLocation::CreateEmpty(CGF);
CGF.EmitBlock(ExitBB, /*IsFinished=*/true);
}
const VarDecl *
CGOpenMPRuntimeGPU::translateParameter(const FieldDecl *FD,
const VarDecl *NativeParam) const {
if (!NativeParam->getType()->isReferenceType())
return NativeParam;
QualType ArgType = NativeParam->getType();
QualifierCollector QC;
const Type *NonQualTy = QC.strip(ArgType);
QualType PointeeTy = cast<ReferenceType>(NonQualTy)->getPointeeType();
if (const auto *Attr = FD->getAttr<OMPCaptureKindAttr>()) {
if (Attr->getCaptureKind() == OMPC_map) {
PointeeTy = CGM.getContext().getAddrSpaceQualType(PointeeTy,
LangAS::opencl_global);
}
}
ArgType = CGM.getContext().getPointerType(PointeeTy);
QC.addRestrict();
enum { NVPTX_local_addr = 5 };
QC.addAddressSpace(getLangASFromTargetAS(NVPTX_local_addr));
ArgType = QC.apply(CGM.getContext(), ArgType);
if (isa<ImplicitParamDecl>(NativeParam))
return ImplicitParamDecl::Create(
CGM.getContext(), /*DC=*/nullptr, NativeParam->getLocation(),
NativeParam->getIdentifier(), ArgType, ImplicitParamDecl::Other);
return ParmVarDecl::Create(
CGM.getContext(),
const_cast<DeclContext *>(NativeParam->getDeclContext()),
NativeParam->getBeginLoc(), NativeParam->getLocation(),
NativeParam->getIdentifier(), ArgType,
/*TInfo=*/nullptr, SC_None, /*DefArg=*/nullptr);
}
Address
CGOpenMPRuntimeGPU::getParameterAddress(CodeGenFunction &CGF,
const VarDecl *NativeParam,
const VarDecl *TargetParam) const {
assert(NativeParam != TargetParam &&
NativeParam->getType()->isReferenceType() &&
"Native arg must not be the same as target arg.");
Address LocalAddr = CGF.GetAddrOfLocalVar(TargetParam);
QualType NativeParamType = NativeParam->getType();
QualifierCollector QC;
const Type *NonQualTy = QC.strip(NativeParamType);
QualType NativePointeeTy = cast<ReferenceType>(NonQualTy)->getPointeeType();
unsigned NativePointeeAddrSpace =
CGF.getContext().getTargetAddressSpace(NativePointeeTy);
QualType TargetTy = TargetParam->getType();
llvm::Value *TargetAddr = CGF.EmitLoadOfScalar(
LocalAddr, /*Volatile=*/false, TargetTy, SourceLocation());
// First cast to generic.
TargetAddr = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
TargetAddr, TargetAddr->getType()->getPointerElementType()->getPointerTo(
/*AddrSpace=*/0));
// Cast from generic to native address space.
TargetAddr = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
TargetAddr, TargetAddr->getType()->getPointerElementType()->getPointerTo(
NativePointeeAddrSpace));
Address NativeParamAddr = CGF.CreateMemTemp(NativeParamType);
CGF.EmitStoreOfScalar(TargetAddr, NativeParamAddr, /*Volatile=*/false,
NativeParamType);
return NativeParamAddr;
}
void CGOpenMPRuntimeGPU::emitOutlinedFunctionCall(
CodeGenFunction &CGF, SourceLocation Loc, llvm::FunctionCallee OutlinedFn,
ArrayRef<llvm::Value *> Args) const {
SmallVector<llvm::Value *, 4> TargetArgs;
TargetArgs.reserve(Args.size());
auto *FnType = OutlinedFn.getFunctionType();
for (unsigned I = 0, E = Args.size(); I < E; ++I) {
if (FnType->isVarArg() && FnType->getNumParams() <= I) {
TargetArgs.append(std::next(Args.begin(), I), Args.end());
break;
}
llvm::Type *TargetType = FnType->getParamType(I);
llvm::Value *NativeArg = Args[I];
if (!TargetType->isPointerTy()) {
TargetArgs.emplace_back(NativeArg);
continue;
}
llvm::Value *TargetArg = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
NativeArg,
NativeArg->getType()->getPointerElementType()->getPointerTo());
TargetArgs.emplace_back(
CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(TargetArg, TargetType));
}
CGOpenMPRuntime::emitOutlinedFunctionCall(CGF, Loc, OutlinedFn, TargetArgs);
}
/// Emit function which wraps the outline parallel region
/// and controls the arguments which are passed to this function.
/// The wrapper ensures that the outlined function is called
/// with the correct arguments when data is shared.
llvm::Function *CGOpenMPRuntimeGPU::createParallelDataSharingWrapper(
llvm::Function *OutlinedParallelFn, const OMPExecutableDirective &D) {
ASTContext &Ctx = CGM.getContext();
const auto &CS = *D.getCapturedStmt(OMPD_parallel);
// Create a function that takes as argument the source thread.
FunctionArgList WrapperArgs;
QualType Int16QTy =
Ctx.getIntTypeForBitwidth(/*DestWidth=*/16, /*Signed=*/false);
QualType Int32QTy =
Ctx.getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/false);
ImplicitParamDecl ParallelLevelArg(Ctx, /*DC=*/nullptr, D.getBeginLoc(),
/*Id=*/nullptr, Int16QTy,
ImplicitParamDecl::Other);
ImplicitParamDecl WrapperArg(Ctx, /*DC=*/nullptr, D.getBeginLoc(),
/*Id=*/nullptr, Int32QTy,
ImplicitParamDecl::Other);
WrapperArgs.emplace_back(&ParallelLevelArg);
WrapperArgs.emplace_back(&WrapperArg);
const CGFunctionInfo &CGFI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, WrapperArgs);
auto *Fn = llvm::Function::Create(
CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
Twine(OutlinedParallelFn->getName(), "_wrapper"), &CGM.getModule());
// Ensure we do not inline the function. This is trivially true for the ones
// passed to __kmpc_fork_call but the ones calles in serialized regions
// could be inlined. This is not a perfect but it is closer to the invariant
// we want, namely, every data environment starts with a new function.
// TODO: We should pass the if condition to the runtime function and do the
// handling there. Much cleaner code.
Fn->addFnAttr(llvm::Attribute::NoInline);
CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, CGFI);
Fn->setLinkage(llvm::GlobalValue::InternalLinkage);
Fn->setDoesNotRecurse();
CodeGenFunction CGF(CGM, /*suppressNewContext=*/true);
CGF.StartFunction(GlobalDecl(), Ctx.VoidTy, Fn, CGFI, WrapperArgs,
D.getBeginLoc(), D.getBeginLoc());
const auto *RD = CS.getCapturedRecordDecl();
auto CurField = RD->field_begin();
Address ZeroAddr = CGF.CreateDefaultAlignTempAlloca(CGF.Int32Ty,
/*Name=*/".zero.addr");
CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
// Get the array of arguments.
SmallVector<llvm::Value *, 8> Args;
Args.emplace_back(CGF.GetAddrOfLocalVar(&WrapperArg).getPointer());
Args.emplace_back(ZeroAddr.getPointer());
CGBuilderTy &Bld = CGF.Builder;
auto CI = CS.capture_begin();
// Use global memory for data sharing.
// Handle passing of global args to workers.
Address GlobalArgs =
CGF.CreateDefaultAlignTempAlloca(CGF.VoidPtrPtrTy, "global_args");
llvm::Value *GlobalArgsPtr = GlobalArgs.getPointer();
llvm::Value *DataSharingArgs[] = {GlobalArgsPtr};
CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
CGM.getModule(), OMPRTL___kmpc_get_shared_variables),
DataSharingArgs);
// Retrieve the shared variables from the list of references returned
// by the runtime. Pass the variables to the outlined function.
Address SharedArgListAddress = Address::invalid();
if (CS.capture_size() > 0 ||
isOpenMPLoopBoundSharingDirective(D.getDirectiveKind())) {
SharedArgListAddress = CGF.EmitLoadOfPointer(
GlobalArgs, CGF.getContext()
.getPointerType(CGF.getContext().getPointerType(
CGF.getContext().VoidPtrTy))
.castAs<PointerType>());
}
unsigned Idx = 0;
if (isOpenMPLoopBoundSharingDirective(D.getDirectiveKind())) {
Address Src = Bld.CreateConstInBoundsGEP(SharedArgListAddress, Idx);
Address TypedAddress = Bld.CreatePointerBitCastOrAddrSpaceCast(
Src, CGF.SizeTy->getPointerTo());
llvm::Value *LB = CGF.EmitLoadOfScalar(
TypedAddress,
/*Volatile=*/false,
CGF.getContext().getPointerType(CGF.getContext().getSizeType()),
cast<OMPLoopDirective>(D).getLowerBoundVariable()->getExprLoc());
Args.emplace_back(LB);
++Idx;
Src = Bld.CreateConstInBoundsGEP(SharedArgListAddress, Idx);
TypedAddress = Bld.CreatePointerBitCastOrAddrSpaceCast(
Src, CGF.SizeTy->getPointerTo());
llvm::Value *UB = CGF.EmitLoadOfScalar(
TypedAddress,
/*Volatile=*/false,
CGF.getContext().getPointerType(CGF.getContext().getSizeType()),
cast<OMPLoopDirective>(D).getUpperBoundVariable()->getExprLoc());
Args.emplace_back(UB);
++Idx;
}
if (CS.capture_size() > 0) {
ASTContext &CGFContext = CGF.getContext();
for (unsigned I = 0, E = CS.capture_size(); I < E; ++I, ++CI, ++CurField) {
QualType ElemTy = CurField->getType();
Address Src = Bld.CreateConstInBoundsGEP(SharedArgListAddress, I + Idx);
Address TypedAddress = Bld.CreatePointerBitCastOrAddrSpaceCast(
Src, CGF.ConvertTypeForMem(CGFContext.getPointerType(ElemTy)));
llvm::Value *Arg = CGF.EmitLoadOfScalar(TypedAddress,
/*Volatile=*/false,
CGFContext.getPointerType(ElemTy),
CI->getLocation());
if (CI->capturesVariableByCopy() &&
!CI->getCapturedVar()->getType()->isAnyPointerType()) {
Arg = castValueToType(CGF, Arg, ElemTy, CGFContext.getUIntPtrType(),
CI->getLocation());
}
Args.emplace_back(Arg);
}
}
emitOutlinedFunctionCall(CGF, D.getBeginLoc(), OutlinedParallelFn, Args);
CGF.FinishFunction();
return Fn;
}
void CGOpenMPRuntimeGPU::emitFunctionProlog(CodeGenFunction &CGF,
const Decl *D) {
if (getDataSharingMode(CGM) != CGOpenMPRuntimeGPU::Generic)
return;
assert(D && "Expected function or captured|block decl.");
assert(FunctionGlobalizedDecls.count(CGF.CurFn) == 0 &&
"Function is registered already.");
assert((!TeamAndReductions.first || TeamAndReductions.first == D) &&
"Team is set but not processed.");
const Stmt *Body = nullptr;
bool NeedToDelayGlobalization = false;
if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
Body = FD->getBody();
} else if (const auto *BD = dyn_cast<BlockDecl>(D)) {
Body = BD->getBody();
} else if (const auto *CD = dyn_cast<CapturedDecl>(D)) {
Body = CD->getBody();
NeedToDelayGlobalization = CGF.CapturedStmtInfo->getKind() == CR_OpenMP;
if (NeedToDelayGlobalization &&
getExecutionMode() == CGOpenMPRuntimeGPU::EM_SPMD)
return;
}
if (!Body)
return;
CheckVarsEscapingDeclContext VarChecker(CGF, TeamAndReductions.second);
VarChecker.Visit(Body);
const RecordDecl *GlobalizedVarsRecord =
VarChecker.getGlobalizedRecord(IsInTTDRegion);
TeamAndReductions.first = nullptr;
TeamAndReductions.second.clear();
ArrayRef<const ValueDecl *> EscapedVariableLengthDecls =
VarChecker.getEscapedVariableLengthDecls();
if (!GlobalizedVarsRecord && EscapedVariableLengthDecls.empty())
return;
auto I = FunctionGlobalizedDecls.try_emplace(CGF.CurFn).first;
I->getSecond().MappedParams =
std::make_unique<CodeGenFunction::OMPMapVars>();
I->getSecond().EscapedParameters.insert(
VarChecker.getEscapedParameters().begin(),
VarChecker.getEscapedParameters().end());
I->getSecond().EscapedVariableLengthDecls.append(
EscapedVariableLengthDecls.begin(), EscapedVariableLengthDecls.end());
DeclToAddrMapTy &Data = I->getSecond().LocalVarData;
for (const ValueDecl *VD : VarChecker.getEscapedDecls()) {
assert(VD->isCanonicalDecl() && "Expected canonical declaration");
Data.insert(std::make_pair(VD, MappedVarData()));
}
if (!IsInTTDRegion && !NeedToDelayGlobalization && !IsInParallelRegion) {
CheckVarsEscapingDeclContext VarChecker(CGF, llvm::None);
VarChecker.Visit(Body);
I->getSecond().SecondaryLocalVarData.emplace();
DeclToAddrMapTy &Data = I->getSecond().SecondaryLocalVarData.getValue();
for (const ValueDecl *VD : VarChecker.getEscapedDecls()) {
assert(VD->isCanonicalDecl() && "Expected canonical declaration");
Data.insert(std::make_pair(VD, MappedVarData()));
}
}
if (!NeedToDelayGlobalization) {
emitGenericVarsProlog(CGF, D->getBeginLoc(), /*WithSPMDCheck=*/true);
struct GlobalizationScope final : EHScopeStack::Cleanup {
GlobalizationScope() = default;
void Emit(CodeGenFunction &CGF, Flags flags) override {
static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime())
.emitGenericVarsEpilog(CGF, /*WithSPMDCheck=*/true);
}
};
CGF.EHStack.pushCleanup<GlobalizationScope>(NormalAndEHCleanup);
}
}
Address CGOpenMPRuntimeGPU::getAddressOfLocalVariable(CodeGenFunction &CGF,
const VarDecl *VD) {
if (VD && VD->hasAttr<OMPAllocateDeclAttr>()) {
const auto *A = VD->getAttr<OMPAllocateDeclAttr>();
auto AS = LangAS::Default;
switch (A->getAllocatorType()) {
// Use the default allocator here as by default local vars are
// threadlocal.
case OMPAllocateDeclAttr::OMPNullMemAlloc:
case OMPAllocateDeclAttr::OMPDefaultMemAlloc:
case OMPAllocateDeclAttr::OMPThreadMemAlloc:
case OMPAllocateDeclAttr::OMPHighBWMemAlloc:
case OMPAllocateDeclAttr::OMPLowLatMemAlloc:
// Follow the user decision - use default allocation.
return Address::invalid();
case OMPAllocateDeclAttr::OMPUserDefinedMemAlloc:
// TODO: implement aupport for user-defined allocators.
return Address::invalid();
case OMPAllocateDeclAttr::OMPConstMemAlloc:
AS = LangAS::cuda_constant;
break;
case OMPAllocateDeclAttr::OMPPTeamMemAlloc:
AS = LangAS::cuda_shared;
break;
case OMPAllocateDeclAttr::OMPLargeCapMemAlloc:
case OMPAllocateDeclAttr::OMPCGroupMemAlloc:
break;
}
llvm::Type *VarTy = CGF.ConvertTypeForMem(VD->getType());
auto *GV = new llvm::GlobalVariable(
CGM.getModule(), VarTy, /*isConstant=*/false,
llvm::GlobalValue::InternalLinkage, llvm::Constant::getNullValue(VarTy),
VD->getName(),
/*InsertBefore=*/nullptr, llvm::GlobalValue::NotThreadLocal,
CGM.getContext().getTargetAddressSpace(AS));
CharUnits Align = CGM.getContext().getDeclAlign(VD);
GV->setAlignment(Align.getAsAlign());
return Address(
CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
GV, VarTy->getPointerTo(CGM.getContext().getTargetAddressSpace(
VD->getType().getAddressSpace()))),
Align);
}
if (getDataSharingMode(CGM) != CGOpenMPRuntimeGPU::Generic)
return Address::invalid();
VD = VD->getCanonicalDecl();
auto I = FunctionGlobalizedDecls.find(CGF.CurFn);
if (I == FunctionGlobalizedDecls.end())
return Address::invalid();
auto VDI = I->getSecond().LocalVarData.find(VD);
if (VDI != I->getSecond().LocalVarData.end())
return VDI->second.PrivateAddr;
if (VD->hasAttrs()) {
for (specific_attr_iterator<OMPReferencedVarAttr> IT(VD->attr_begin()),
E(VD->attr_end());
IT != E; ++IT) {
auto VDI = I->getSecond().LocalVarData.find(
cast<VarDecl>(cast<DeclRefExpr>(IT->getRef())->getDecl())
->getCanonicalDecl());
if (VDI != I->getSecond().LocalVarData.end())
return VDI->second.PrivateAddr;
}
}
return Address::invalid();
}
void CGOpenMPRuntimeGPU::functionFinished(CodeGenFunction &CGF) {
FunctionGlobalizedDecls.erase(CGF.CurFn);
CGOpenMPRuntime::functionFinished(CGF);
}
void CGOpenMPRuntimeGPU::getDefaultDistScheduleAndChunk(
CodeGenFunction &CGF, const OMPLoopDirective &S,
OpenMPDistScheduleClauseKind &ScheduleKind,
llvm::Value *&Chunk) const {
auto &RT = static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
if (getExecutionMode() == CGOpenMPRuntimeGPU::EM_SPMD) {
ScheduleKind = OMPC_DIST_SCHEDULE_static;
Chunk = CGF.EmitScalarConversion(
RT.getGPUNumThreads(CGF),
CGF.getContext().getIntTypeForBitwidth(32, /*Signed=*/0),
S.getIterationVariable()->getType(), S.getBeginLoc());
return;
}
CGOpenMPRuntime::getDefaultDistScheduleAndChunk(
CGF, S, ScheduleKind, Chunk);
}
void CGOpenMPRuntimeGPU::getDefaultScheduleAndChunk(
CodeGenFunction &CGF, const OMPLoopDirective &S,
OpenMPScheduleClauseKind &ScheduleKind,
const Expr *&ChunkExpr) const {
ScheduleKind = OMPC_SCHEDULE_static;
// Chunk size is 1 in this case.
llvm::APInt ChunkSize(32, 1);
ChunkExpr = IntegerLiteral::Create(CGF.getContext(), ChunkSize,
CGF.getContext().getIntTypeForBitwidth(32, /*Signed=*/0),
SourceLocation());
}
void CGOpenMPRuntimeGPU::adjustTargetSpecificDataForLambdas(
CodeGenFunction &CGF, const OMPExecutableDirective &D) const {
assert(isOpenMPTargetExecutionDirective(D.getDirectiveKind()) &&
" Expected target-based directive.");
const CapturedStmt *CS = D.getCapturedStmt(OMPD_target);
for (const CapturedStmt::Capture &C : CS->captures()) {
// Capture variables captured by reference in lambdas for target-based
// directives.
if (!C.capturesVariable())
continue;
const VarDecl *VD = C.getCapturedVar();
const auto *RD = VD->getType()
.getCanonicalType()
.getNonReferenceType()
->getAsCXXRecordDecl();
if (!RD || !RD->isLambda())
continue;
Address VDAddr = CGF.GetAddrOfLocalVar(VD);
LValue VDLVal;
if (VD->getType().getCanonicalType()->isReferenceType())
VDLVal = CGF.EmitLoadOfReferenceLValue(VDAddr, VD->getType());
else
VDLVal = CGF.MakeAddrLValue(
VDAddr, VD->getType().getCanonicalType().getNonReferenceType());
llvm::DenseMap<const VarDecl *, FieldDecl *> Captures;
FieldDecl *ThisCapture = nullptr;
RD->getCaptureFields(Captures, ThisCapture);
if (ThisCapture && CGF.CapturedStmtInfo->isCXXThisExprCaptured()) {
LValue ThisLVal =
CGF.EmitLValueForFieldInitialization(VDLVal, ThisCapture);
llvm::Value *CXXThis = CGF.LoadCXXThis();
CGF.EmitStoreOfScalar(CXXThis, ThisLVal);
}
for (const LambdaCapture &LC : RD->captures()) {
if (LC.getCaptureKind() != LCK_ByRef)
continue;
const VarDecl *VD = LC.getCapturedVar();
if (!CS->capturesVariable(VD))
continue;
auto It = Captures.find(VD);
assert(It != Captures.end() && "Found lambda capture without field.");
LValue VarLVal = CGF.EmitLValueForFieldInitialization(VDLVal, It->second);
Address VDAddr = CGF.GetAddrOfLocalVar(VD);
if (VD->getType().getCanonicalType()->isReferenceType())
VDAddr = CGF.EmitLoadOfReferenceLValue(VDAddr,
VD->getType().getCanonicalType())
.getAddress(CGF);
CGF.EmitStoreOfScalar(VDAddr.getPointer(), VarLVal);
}
}
}
bool CGOpenMPRuntimeGPU::hasAllocateAttributeForGlobalVar(const VarDecl *VD,
LangAS &AS) {
if (!VD || !VD->hasAttr<OMPAllocateDeclAttr>())
return false;
const auto *A = VD->getAttr<OMPAllocateDeclAttr>();
switch(A->getAllocatorType()) {
case OMPAllocateDeclAttr::OMPNullMemAlloc:
case OMPAllocateDeclAttr::OMPDefaultMemAlloc:
// Not supported, fallback to the default mem space.
case OMPAllocateDeclAttr::OMPThreadMemAlloc:
case OMPAllocateDeclAttr::OMPLargeCapMemAlloc:
case OMPAllocateDeclAttr::OMPCGroupMemAlloc:
case OMPAllocateDeclAttr::OMPHighBWMemAlloc:
case OMPAllocateDeclAttr::OMPLowLatMemAlloc:
AS = LangAS::Default;
return true;
case OMPAllocateDeclAttr::OMPConstMemAlloc:
AS = LangAS::cuda_constant;
return true;
case OMPAllocateDeclAttr::OMPPTeamMemAlloc:
AS = LangAS::cuda_shared;
return true;
case OMPAllocateDeclAttr::OMPUserDefinedMemAlloc:
llvm_unreachable("Expected predefined allocator for the variables with the "
"static storage.");
}
return false;
}
// Get current CudaArch and ignore any unknown values
static CudaArch getCudaArch(CodeGenModule &CGM) {
if (!CGM.getTarget().hasFeature("ptx"))
return CudaArch::UNKNOWN;
for (const auto &Feature : CGM.getTarget().getTargetOpts().FeatureMap) {
if (Feature.getValue()) {
CudaArch Arch = StringToCudaArch(Feature.getKey());
if (Arch != CudaArch::UNKNOWN)
return Arch;
}
}
return CudaArch::UNKNOWN;
}
/// Check to see if target architecture supports unified addressing which is
/// a restriction for OpenMP requires clause "unified_shared_memory".
void CGOpenMPRuntimeGPU::processRequiresDirective(
const OMPRequiresDecl *D) {
for (const OMPClause *Clause : D->clauselists()) {
if (Clause->getClauseKind() == OMPC_unified_shared_memory) {
CudaArch Arch = getCudaArch(CGM);
switch (Arch) {
case CudaArch::SM_20:
case CudaArch::SM_21:
case CudaArch::SM_30:
case CudaArch::SM_32:
case CudaArch::SM_35:
case CudaArch::SM_37:
case CudaArch::SM_50:
case CudaArch::SM_52:
case CudaArch::SM_53: {
SmallString<256> Buffer;
llvm::raw_svector_ostream Out(Buffer);
Out << "Target architecture " << CudaArchToString(Arch)
<< " does not support unified addressing";
CGM.Error(Clause->getBeginLoc(), Out.str());
return;
}
case CudaArch::SM_60:
case CudaArch::SM_61:
case CudaArch::SM_62:
case CudaArch::SM_70:
case CudaArch::SM_72:
case CudaArch::SM_75:
case CudaArch::SM_80:
case CudaArch::SM_86:
case CudaArch::GFX600:
case CudaArch::GFX601:
case CudaArch::GFX602:
case CudaArch::GFX700:
case CudaArch::GFX701:
case CudaArch::GFX702:
case CudaArch::GFX703:
case CudaArch::GFX704:
case CudaArch::GFX705:
case CudaArch::GFX801:
case CudaArch::GFX802:
case CudaArch::GFX803:
case CudaArch::GFX805:
case CudaArch::GFX810:
case CudaArch::GFX900:
case CudaArch::GFX902:
case CudaArch::GFX904:
case CudaArch::GFX906:
case CudaArch::GFX908:
case CudaArch::GFX909:
case CudaArch::GFX90a:
case CudaArch::GFX90c:
case CudaArch::GFX1010:
case CudaArch::GFX1011:
case CudaArch::GFX1012:
case CudaArch::GFX1013:
case CudaArch::GFX1030:
case CudaArch::GFX1031:
case CudaArch::GFX1032:
case CudaArch::GFX1033:
case CudaArch::GFX1034:
case CudaArch::GFX1035:
case CudaArch::UNUSED:
case CudaArch::UNKNOWN:
break;
case CudaArch::LAST:
llvm_unreachable("Unexpected Cuda arch.");
}
}
}
CGOpenMPRuntime::processRequiresDirective(D);
}
void CGOpenMPRuntimeGPU::clear() {
if (!TeamsReductions.empty()) {
ASTContext &C = CGM.getContext();
RecordDecl *StaticRD = C.buildImplicitRecord(
"_openmp_teams_reduction_type_$_", RecordDecl::TagKind::TTK_Union);
StaticRD->startDefinition();
for (const RecordDecl *TeamReductionRec : TeamsReductions) {
QualType RecTy = C.getRecordType(TeamReductionRec);
auto *Field = FieldDecl::Create(
C, StaticRD, SourceLocation(), SourceLocation(), nullptr, RecTy,
C.getTrivialTypeSourceInfo(RecTy, SourceLocation()),
/*BW=*/nullptr, /*Mutable=*/false,
/*InitStyle=*/ICIS_NoInit);
Field->setAccess(AS_public);
StaticRD->addDecl(Field);
}
StaticRD->completeDefinition();
QualType StaticTy = C.getRecordType(StaticRD);
llvm::Type *LLVMReductionsBufferTy =
CGM.getTypes().ConvertTypeForMem(StaticTy);
// FIXME: nvlink does not handle weak linkage correctly (object with the
// different size are reported as erroneous).
// Restore CommonLinkage as soon as nvlink is fixed.
auto *GV = new llvm::GlobalVariable(
CGM.getModule(), LLVMReductionsBufferTy,
/*isConstant=*/false, llvm::GlobalValue::InternalLinkage,
llvm::Constant::getNullValue(LLVMReductionsBufferTy),
"_openmp_teams_reductions_buffer_$_");
KernelTeamsReductionPtr->setInitializer(
llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV,
CGM.VoidPtrTy));
}
CGOpenMPRuntime::clear();
}
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