26455 Commits

Author SHA1 Message Date
Matt Arsenault
f29366b1f5 StackProtector: Use PointerMayBeCaptured
This was using its own, outdated list of possible captures. This was
at minimum not catching cmpxchg and addrspacecast captures.

One change is now any volatile access is treated as capturing. The
test coverage for this pass is quite inadequate, but this required
removing volatile in the lifetime capture test.

Also fixes some infrastructure issues to allow running just the IR
pass.

Fixes bug 42238.

llvm-svn: 363169
2019-06-12 14:23:33 +00:00
Anton Afanasyev
339b39b773 [MIR] Skip hoisting to basic block which may throw exception or return
Summary:
Fix hoisting to basic block which are not legal for hoisting cause
it can be terminated by exception or it is return block.

Reviewers: john.brawn, RKSimon, MatzeB

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63148

llvm-svn: 363164
2019-06-12 13:51:44 +00:00
Hsiangkai Wang
93be25b580 [NFC] Correct comments in RegisterCoalescer.
Differential Revision: https://reviews.llvm.org/D63124

llvm-svn: 363119
2019-06-12 02:58:04 +00:00
Amara Emerson
d133c15925 [GlobalISel] Add a G_JUMP_TABLE opcode.
This opcode generates a pointer to the address of the jump table
specified by the source operand, which is a jump table index.

It will be used in conjunction with an upcoming G_BRJT opcode to support
jump table codegen with GlobalISel.

Differential Revision: https://reviews.llvm.org/D63111

llvm-svn: 363096
2019-06-11 19:58:06 +00:00
Jinsong Ji
ef2d6d99c0 [PowerPC] Enable MachinePipeliner for P9 with -ppc-enable-pipeliner
Implement necessary target hooks to enable MachinePipeliner for P9 only.
The pass is off by default, can be enabled with -ppc-enable-pipeliner for P9.

Differential Revision: https://reviews.llvm.org/D62164

llvm-svn: 363085
2019-06-11 17:40:39 +00:00
Simon Pilgrim
266f43964e [TargetLowering] Add allowsMemoryAccess(MachineMemOperand) helper wrapper. NFCI.
As suggested by @arsenm on D63075 - this adds a TargetLowering::allowsMemoryAccess wrapper that takes a Load/Store node's MachineMemOperand to handle the AddressSpace/Alignment arguments and will also implicitly handle the MachineMemOperand::Flags change in D63075.

llvm-svn: 363048
2019-06-11 11:00:23 +00:00
Simon Pilgrim
287e78c82b [DAGCombine] GetNegatedExpression - constant float vector support (PR42105)
Add support for negation of constant build vectors.

Differential Revision: https://reviews.llvm.org/D62963

llvm-svn: 363040
2019-06-11 09:44:33 +00:00
Sander de Smalen
cbeb563cfb Change semantics of fadd/fmul vector reductions.
This patch changes how LLVM handles the accumulator/start value
in the reduction, by never ignoring it regardless of the presence of
fast-math flags on callsites. This change introduces the following
new intrinsics to replace the existing ones:

  llvm.experimental.vector.reduce.fadd -> llvm.experimental.vector.reduce.v2.fadd
  llvm.experimental.vector.reduce.fmul -> llvm.experimental.vector.reduce.v2.fmul

and adds functionality to auto-upgrade existing LLVM IR and bitcode.

Reviewers: RKSimon, greened, dmgreen, nikic, simoll, aemerson

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D60261

llvm-svn: 363035
2019-06-11 08:22:10 +00:00
Matt Arsenault
c5830f5f05 AtomicExpand: Don't crash on non-0 alloca
This now produces garbage on AMDGPU with a call to an nonexistent,
anonymous libcall but won't assert.

llvm-svn: 363022
2019-06-11 01:35:07 +00:00
Matt Arsenault
383e72fcfe AMDGPU: Expand < 32-bit atomics
Also fix AtomicExpand asserting on atomicrmw fadd/fsub.

llvm-svn: 363021
2019-06-11 01:35:00 +00:00
Puyan Lotfi
4d89462a1c [MIR-Canon] Fixing non-determinism that was breaking bots (NFC).
An earlier fix of a subtle iterator invalidation bug had uncovered a
nondeterminism that was present in the MultiUsers bag. Problem was that
MultiUsers was being looked up using pointers.

This patch is an NFC change that numbers each multiuser and processes each in
numbered order. This fixes the test failure on netbsd and will likely fix the
green-dragon bot too.

llvm-svn: 363012
2019-06-11 00:00:25 +00:00
Jessica Paquette
b22954384e [GlobalISel] Translate memset/memmove/memcpy from undef ptrs into nops
If the source is undef, then just don't do anything.

This matches SelectionDAG's behaviour in SelectionDAG.cpp.

Also add a test showing that we do the right thing here.
(irtranslator-memfunc-undef.ll)

Differential Revision: https://reviews.llvm.org/D63095

llvm-svn: 362989
2019-06-10 21:53:56 +00:00
Francis Visoiu Mistrih
a438432acc [FastISel] Skip creating unnecessary vregs for arguments
This behavior was added in r130928 for both FastISel and SD, and then
disabled in r131156 for FastISel.

This re-enables it for FastISel with the corresponding fix.

This is triggered only when FastISel can't lower the arguments and falls
back to SelectionDAG for it.

FastISel contains a map of "register fixups" where at the end of the
selection phase it replaces all uses of a register with another
register that FastISel sometimes pre-assigned. Code at the end of
SelectionDAGISel::runOnMachineFunction is doing the replacement at the
very end of the function, while other pieces that come in before that
look through the MachineFunction and assume everything is done. In this
case, the real issue is that the code emitting COPY instructions for the
liveins (physreg to vreg) (EmitLiveInCopies) is checking if the vreg
assigned to the physreg is used, and if it's not, it will skip the COPY.
If a register wasn't replaced with its assigned fixup yet, the copy will
be skipped and we'll end up with uses of undefined registers.

This fix moves the replacement of registers before the emission of
copies for the live-ins.

The initial motivation for this fix is to enable tail calls for
swiftself functions, which were blocked because we couldn't prove that
the swiftself argument (which is callee-save) comes from a function
argument (live-in), because there was an extra copy (vreg to vreg).

A few tests are affected by this:

* llvm/test/CodeGen/AArch64/swifterror.ll: we used to spill x21
(callee-save) but never reload it because it's attached to the return.
We now don't even spill it anymore.
* llvm/test/CodeGen/*/swiftself.ll: we tail-call now.
* llvm/test/CodeGen/AMDGPU/mubuf-legalize-operands.ll: I believe this
test was not really testing the right thing, but it worked because the
same registers were re-used.
* llvm/test/CodeGen/ARM/cmpxchg-O0.ll: regalloc changes
* llvm/test/CodeGen/ARM/swifterror.ll: get rid of a copy
* llvm/test/CodeGen/Mips/*: get rid of spills and copies
* llvm/test/CodeGen/SystemZ/swift-return.ll: smaller stack
* llvm/test/CodeGen/X86/atomic-unordered.ll: smaller stack
* llvm/test/CodeGen/X86/swifterror.ll: same as AArch64
* llvm/test/DebugInfo/X86/dbg-declare-arg.ll: stack size changed

Differential Revision: https://reviews.llvm.org/D62361

llvm-svn: 362963
2019-06-10 16:53:37 +00:00
Jeremy Morse
bcff417292 [DebugInfo] Terminate all location-lists at end of block
This commit reapplies r359426 (which was reverted in r360301 due to
performance problems) and rolls in D61940 to address the performance problem.
I've combined the two to avoid creating a span of slow-performance, and to
ease reverting if more problems crop up.

The summary of D61940: This patch removes the "ChangingRegs" facility in
DbgEntityHistoryCalculator, as its overapproximate nature can produce incorrect
variable locations. An unchanging register doesn't mean a variable doesn't
change its location.

The patch kills off everything that calculates the ChangingRegs vector.
Previously ChangingRegs spotted epilogues and marked registers as unchanging if
they weren't modified outside the epilogue, increasing the chance that we can
emit a single-location variable record. Without this feature,
debug-loc-offset.mir and pr19307.mir become temporarily XFAIL. They'll be
re-enabled by D62314, using the FrameDestroy flag to identify epilogues, I've
split this into two steps as FrameDestroy isn't necessarily supported by all
backends.

The logic for terminating variable locations at the end of a basic block now
becomes much more enjoyably simple: we just terminate them all.

Other test changes: inlined-argument.ll becomes XFAIL, but for a longer term.
The current algorithm for detecting that a variable has a single-location
doesn't work in this scenario (inlined function in multiple blocks), only other
bugs were making this test work. fission-ranges.ll gets slightly refreshed too,
as the location of "p" is now correctly determined to be a single location.

Differential Revision: https://reviews.llvm.org/D61940

llvm-svn: 362951
2019-06-10 15:23:46 +00:00
Nikola Prica
abc1dff7e4 [DebugInfo] More strict debug range for stack variables
Variable's stack location can stretch longer than it should. If a
variable is placed at the stack in a some nested basic block its range
can be calculated to be up to the next occurrence of the variable's
DBG_VALUE, or up to the end of the function, thus covering a basic
blocks that should not be included in the variable’s location range.
This happens because the DbgEntityHistoryCalculator ends register
locations at the end of a basic block only if the variable’s location
register has been changed throughout the function, which is not the
case for the register used to reference stack objects.

This patch also tries to produce a single value location if the location
list builder managed to merge all the locations into one.

Reviewers: aprantl, dstenb, jmorse

Reviewed By: aprantl, dstenb, jmorse

Subscribers: djtodoro, ivanbaev, asowda

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D61600

llvm-svn: 362923
2019-06-10 08:41:06 +00:00
QingShan Zhang
ab846da7e8 [DAGCombine] Match a pattern where a wide type scalar value is stored by several narrow stores
This opportunity is found from spec 2017 557.xz_r. And it is used by the sha encrypt/decrypt. See sha-2/sha512.c

static void store64(u64 x, unsigned char* y)
{
    for(int i = 0; i != 8; ++i)
        y[i] = (x >> ((7-i) * 8)) & 255;
}

static u64 load64(const unsigned char* y)
{
    u64 res = 0;
    for(int i = 0; i != 8; ++i)
        res |= (u64)(y[i]) << ((7-i) * 8);
    return res;
}
The load64 has been implemented by https://reviews.llvm.org/D26149
This patch is trying to implement the store pattern.

Match a pattern where a wide type scalar value is stored by several narrow
stores. Fold it into a single store or a BSWAP and a store if the targets
supports it.

Assuming little endian target:
i8 *p = ...
i32 val = ...
p[0] = (val >> 0) & 0xFF;
p[1] = (val >> 8) & 0xFF;
p[2] = (val >> 16) & 0xFF;
p[3] = (val >> 24) & 0xFF;

>
*((i32)p) = val;

i8 *p = ...
i32 val = ...
p[0] = (val >> 24) & 0xFF;
p[1] = (val >> 16) & 0xFF;
p[2] = (val >> 8) & 0xFF;
p[3] = (val >> 0) & 0xFF;

>
*((i32)p) = BSWAP(val);

Differential Revision: https://reviews.llvm.org/D62897

llvm-svn: 362921
2019-06-10 05:40:21 +00:00
David Bolvansky
dcf5e6abdf [TargetLowering] Simplify (ctpop x) == 1
Reviewers: craig.topper, spatel, RKSimon, bkramer

Reviewed By: spatel

Subscribers: javed.absar, lebedev.ri, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63004

llvm-svn: 362912
2019-06-09 18:18:57 +00:00
Anton Afanasyev
623d9ba068 [MIR] Add simple PRE pass to MachineCSE
This is the second part of the commit fixing PR38917 (hoisting
partitially redundant machine instruction). Most of PRE (partitial
redundancy elimination) and CSE work is done on LLVM IR, but some of
redundancy arises during DAG legalization. Machine CSE is not enough
to deal with it. This simple PRE implementation works a little bit
intricately: it passes before CSE, looking for partitial redundancy
and transforming it to fully redundancy, anticipating that the next
CSE step will eliminate this created redundancy. If CSE doesn't
eliminate this, than created instruction will remain dead and eliminated
later by Remove Dead Machine Instructions pass.

The third part of the commit is supposed to refactor MachineCSE,
to make it more clear and to merge MachinePRE with MachineCSE,
so one need no rely on further Remove Dead pass to clear instrs
not eliminated by CSE.

First step: https://reviews.llvm.org/D54839

Fixes llvm.org/PR38917

This is fixed recommit of r361356 after PowerPC64 multistage build failure.

llvm-svn: 362901
2019-06-09 12:15:47 +00:00
Simon Pilgrim
5f337149fa Use for-range loop. NFCI.
llvm-svn: 362897
2019-06-09 09:07:30 +00:00
Simon Pilgrim
6bae6d5a5d [DAGCombine] visitAND - merge (zext_inreg ((s)extload x)) -> (zextload x) combines. NFCI.
Same codegen, only differ by the oneuse limit for the sextload case.

llvm-svn: 362880
2019-06-08 17:02:00 +00:00
Jonas Paulsson
fdc4ea34e3 [SystemZ, RegAlloc] Favor 3-address instructions during instruction selection.
This patch aims to reduce spilling and register moves by using the 3-address
versions of instructions per default instead of the 2-address equivalent
ones. It seems that both spilling and register moves are improved noticeably
generally.

Regalloc hints are passed to increase conversions to 2-address instructions
which are done in SystemZShortenInst.cpp (after regalloc).

Since the SystemZ reg/mem instructions are 2-address (dst and lhs regs are
the same), foldMemoryOperandImpl() can no longer trivially fold a spilled
source register since the reg/reg instruction is now 3-address. In order to
remedy this, new 3-address pseudo memory instructions are used to perform the
folding only when the dst and lhs virtual registers are known to be allocated
to the same physreg. In order to not let MachineCopyPropagation run and
change registers on these transformed instructions (making it 3-address), a
new target pass called SystemZPostRewrite.cpp is run just after
VirtRegRewriter, that immediately lowers the pseudo to a target instruction.

If it would have been possibe to insert a COPY instruction and change a
register operand (convert to 2-address) in foldMemoryOperandImpl() while
trusting that the caller (e.g. InlineSpiller) would update/repair the
involved LiveIntervals, the solution involving pseudo instructions would not
have been needed. This is perhaps a potential improvement (see Phabricator
post).

Common code changes:

* A new hook TargetPassConfig::addPostRewrite() is utilized to be able to run a
target pass immediately before MachineCopyPropagation.

* VirtRegMap is passed as an argument to foldMemoryOperand().

Review: Ulrich Weigand, Quentin Colombet
https://reviews.llvm.org/D60888

llvm-svn: 362868
2019-06-08 06:19:15 +00:00
Amara Emerson
829037a914 Factor out SelectionDAG's switch analysis and lowering into a separate component.
In order for GlobalISel to re-use the significant amount of analysis and
optimization code in SDAG's switch lowering, we first have to extract it and
create an interface to be used by both frameworks.

No test changes as it's NFC.

Differential Revision: https://reviews.llvm.org/D62745

llvm-svn: 362857
2019-06-08 00:05:17 +00:00
Volkan Keles
97204a6788 [GlobalISel] IRTranslator: Translate the intrinsics ignored by CodeGen
Summary:
Translate `llvm.assume`, `llvm.var.annotation` and `llvm.sideeffect` to nothing
as they have no effect on CodeGen.

Reviewers: qcolombet, aditya_nandakumar, dsanders, paquette, aemerson, arsenm

Reviewed By: arsenm

Subscribers: hiraditya, wdng, rovka, kristof.beyls, javed.absar, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63022

llvm-svn: 362834
2019-06-07 20:19:27 +00:00
Simon Pilgrim
f0240ee76d [DAGCombine] visitAND - fix local shadow variable warnings. NFCI.
llvm-svn: 362825
2019-06-07 18:36:43 +00:00
Simon Pilgrim
4c9db2045a [DAGCombine] Use APInt::extractBits in "sub-splat" constant mask detection. NFCI.
llvm-svn: 362820
2019-06-07 18:07:06 +00:00
Jinsong Ji
7aafdef627 [MachineScheduler] checkResourceLimit boundary condition update
When we call checkResourceLimit in bumpCycle or bumpNode, and we
know the resource count has just reached the limit (the equations
 are equal). We should return true to mark that we are resource
limited for next schedule, or else we might continue to schedule
in favor of latency for 1 more schedule and create a schedule that
 actually overbook the resource.

When we call checkResourceLimit to estimate the resource limite before
scheduling, we don't need to return true even if the equations are
equal, as it shouldn't limit the schedule for it .

Differential Revision: https://reviews.llvm.org/D62345

llvm-svn: 362805
2019-06-07 14:54:47 +00:00
Matt Arsenault
94a609e343 TailDuplicator: Remove no-op analyzeBranch call
This could fail, which looked concerning. However nothing was actually
using the results of this. I assume this was intended to use the
anti-feature of analyzeBranch of removing instructions, but wasn't
actually calling it with AllowModify = true.

Fixes bug 42162.

llvm-svn: 362800
2019-06-07 13:33:34 +00:00
Sam Parker
67f9dc60b8 Fix for lld buildbot
Removed unused (in non-debug builds) variable.

llvm-svn: 362775
2019-06-07 08:04:18 +00:00
Sam Parker
c5ef502ee8 [CodeGen] Generic Hardware Loop Support
Patch which introduces a target-independent framework for generating
hardware loops at the IR level. Most of the code has been taken from
PowerPC CTRLoops and PowerPC has been ported over to use this generic
pass. The target dependent parts have been moved into
TargetTransformInfo, via isHardwareLoopProfitable, with
HardwareLoopInfo introduced to transfer information from the backend.
    
Three generic intrinsics have been introduced:
- void @llvm.set_loop_iterations
  Takes as a single operand, the number of iterations to be executed.
- i1 @llvm.loop_decrement(anyint)
  Takes the maximum number of elements processed in an iteration of
  the loop body and subtracts this from the total count. Returns
  false when the loop should exit.
- anyint @llvm.loop_decrement_reg(anyint, anyint)
  Takes the number of elements remaining to be processed as well as
  the maximum numbe of elements processed in an iteration of the loop
  body. Returns the updated number of elements remaining.

llvm-svn: 362774
2019-06-07 07:35:30 +00:00
Alexey Lapshin
b9f1e7b16e [DebugInfo] Incorrect debug info record generated for loop counter.
Incorrect Debug Variable Range was calculated while "COMPUTING LIVE DEBUG VARIABLES" stage.
Range for Debug Variable("i") computed according to current state of instructions
inside of basic block. But Register Allocator creates new instructions which were not taken
into account when Live Debug Variables computed. In the result DBG_VALUE instruction for
the "i" variable was put after these newly inserted instructions. This is incorrect.
Debug Value for the loop counter should be inserted before any loop instruction.

Differential Revision: https://reviews.llvm.org/D62650

llvm-svn: 362750
2019-06-06 21:19:39 +00:00
Jason Liu
60ec248148 [AIX] Implement function descriptor on SDAG
Summary:
(1) Function descriptor on AIX
On AIX, a called routine may have 2 distinct symbols associated with it:
 * A function descriptor (Name)
 * A function entry point (.Name)

The descriptor structure on AIX is the same as those in the ELF V1 ABI:
 * The address of the entry point of the function.
 * The TOC base address for the function.
 * The environment pointer.

The descriptor symbol uses the same name as the source level function in C.
The function entry point is analogous to the symbol we would generate for a
 function in a non-descriptor-based ABI, except that it is renamed by
prepending a ".".

Which symbol gets referenced depends on the context:
 * Taking the address of the function references the descriptor symbol.
 * Calling the function references the entry point symbol.

(2) Speaking of implementation on AIX, for direct function call target, we
 create proper MCSymbol SDNode(e.g . ".foo") while constructing SDAG to
 replace original TargetGlobalAddress SDNode. Then down the path, we can
 take advantage of this MCSymbol.

Patch by: Xiangling_L

Reviewed by: sfertile, hubert.reinterpretcast, jasonliu, syzaara

Differential Revision: https://reviews.llvm.org/D62532

llvm-svn: 362735
2019-06-06 19:13:36 +00:00
Simon Pilgrim
842c7792aa [DAGCombine] MergeConsecutiveStores - improve non-temporal load\store handling (PR42123)
This patch is the first step towards ensuring MergeConsecutiveStores correctly handles non-temporal loads\stores:

1 - When merging load\stores we must ensure that they all have the same non-temporal flag. This is unlikely to occur, but can in strange cases where we're storing at the end of one page and the beginning of another.

2 - The merged load\store node must retain the non-temporal flag.

Differential Revision: https://reviews.llvm.org/D62910

llvm-svn: 362723
2019-06-06 17:04:13 +00:00
Simon Pilgrim
da993d08c8 [DAGCombine] Cleanup isNegatibleForFree/GetNegatedExpression. NFCI.
Prep work for PR42105 - clang-format, use auto for cast and merge nested if()s

llvm-svn: 362695
2019-06-06 10:21:18 +00:00
Petar Avramovic
faaa2b5d21 [MIPS GlobalISel] Select floor and ceil
Select G_FFLOOR and G_FCEIL for MIPS32.

Differential Revision: https://reviews.llvm.org/D62901

llvm-svn: 362688
2019-06-06 09:02:24 +00:00
Ulrich Weigand
6c5d5ce551 Allow target to handle STRICT floating-point nodes
The ISD::STRICT_ nodes used to implement the constrained floating-point
intrinsics are currently never passed to the target back-end, which makes
it impossible to handle them correctly (e.g. mark instructions are depending
on a floating-point status and control register, or mark instructions as
possibly trapping).

This patch allows the target to use setOperationAction to switch the action
on ISD::STRICT_ nodes to Legal. If this is done, the SelectionDAG common code
will stop converting the STRICT nodes to regular floating-point nodes, but
instead pass the STRICT nodes to the target using normal SelectionDAG
matching rules.

To avoid having the back-end duplicate all the floating-point instruction
patterns to handle both strict and non-strict variants, we make the MI
codegen explicitly aware of the floating-point exceptions by introducing
two new concepts:

- A new MCID flag "mayRaiseFPException" that the target should set on any
  instruction that possibly can raise FP exception according to the
  architecture definition.
- A new MI flag FPExcept that CodeGen/SelectionDAG will set on any MI
  instruction resulting from expansion of any constrained FP intrinsic.

Any MI instruction that is *both* marked as mayRaiseFPException *and*
FPExcept then needs to be considered as raising exceptions by MI-level
codegen (e.g. scheduling).

Setting those two new flags is straightforward. The mayRaiseFPException
flag is simply set via TableGen by marking all relevant instruction
patterns in the .td files.

The FPExcept flag is set in SDNodeFlags when creating the STRICT_ nodes
in the SelectionDAG, and gets inherited in the MachineSDNode nodes created
from it during instruction selection. The flag is then transfered to an
MIFlag when creating the MI from the MachineSDNode. This is handled just
like fast-math flags like no-nans are handled today.

This patch includes both common code changes required to implement the
new features, and the SystemZ implementation.

Reviewed By: andrew.w.kaylor

Differential Revision: https://reviews.llvm.org/D55506

llvm-svn: 362663
2019-06-05 22:33:10 +00:00
Tim Northover
607c8a9d14 IR: make getParamByValType Just Work. NFC.
Most parts of LLVM don't care whether the byval type is derived from an
explicit Attribute or from the parameter's pointee type, so it makes
sense for the main access function to just return the right value.

The very few users who do care (only BitcodeReader so far) can find out
how it's specified by accessing the Attribute directly.

llvm-svn: 362642
2019-06-05 20:37:47 +00:00
Simon Pilgrim
77d6adc491 Fix shadow local variable warning. NFCI.
llvm-svn: 362622
2019-06-05 17:26:29 +00:00
Sanjay Patel
ad62a3a299 [LoopUtils][SLPVectorizer] clean up management of fast-math-flags
Instead of passing around fast-math-flags as a parameter, we can set those
using an IRBuilder guard object. This is no-functional-change-intended.

The motivation is to eventually fix the vectorizers to use and set the
correct fast-math-flags for reductions. Examples of that not behaving as
expected are:
https://bugs.llvm.org/show_bug.cgi?id=23116 (should be able to reduce with less than 'fast')
https://bugs.llvm.org/show_bug.cgi?id=35538 (possible miscompile for -0.0)
D61802 (should be able to reduce with IR-level FMF)

Differential Revision: https://reviews.llvm.org/D62272

llvm-svn: 362612
2019-06-05 14:58:04 +00:00
Simon Pilgrim
5a81af547c [TargetLowering] SimplifyDemandedBits - pull out shift value type. NFCI.
Will be used more in an upcoming patch.

llvm-svn: 362595
2019-06-05 10:59:04 +00:00
Johannes Doerfert
6b432dca5d [SelectionDAG][FIX] Allow "returned" arguments to be bit-casted
Summary:
An argument that is return by a function but bit-casted before can still
be annotated as "returned". Make sure we do not crash for this case.

Reviewers: sunfish, stephenwlin, niravd, arsenm

Subscribers: wdng, hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59917

llvm-svn: 362546
2019-06-04 20:34:43 +00:00
Nemanja Ivanovic
aed7227b71 Revert r362472 as it is breaking PPC build bots
The patch https://reviews.llvm.org/rL362472 broke PPC LNT buildbots.
Reverting it to bring the bots back to green.

llvm-svn: 362539
2019-06-04 18:48:43 +00:00
Craig Topper
09a4415803 [DAGCombiner][X86] Fold (not (neg X)) -> (add X, -1)
This is a special case of a more general transform (not (sub Y, X)) -> (add X, ~Y). InstCombine knows the general form. I've restricted to the special case to fix the motivating case PR42118. I tried handling any case where Y was constant, but got some changes on some Mips tests that I couldn't quickly prove where beneficial.

Fixes PR42118

Differential Revision: https://reviews.llvm.org/D62828

llvm-svn: 362533
2019-06-04 17:44:18 +00:00
Sanjay Patel
1e63dd0b44 [SelectionDAG][x86] limit post-legalization store merging by type
The proposal in D62498 showed that x86 would benefit from vector
store splitting, but that may conflict with the generic DAG
combiner's store merging transforms.

Add memory type to the existing TLI hook that enables the merging
transforms, so we can limit those changes to scalars only for x86.

llvm-svn: 362507
2019-06-04 15:15:59 +00:00
Roman Lebedev
3dce0326fe [DAGCombine][X86][AArch64][MIPS][LANAI] (C - x) - y -> C - (x + y) fold (PR41952)
Summary:
This *might* be the last fold for `sink-addsub-of-const.ll`, but i'm not sure yet.

As far as i can tell, there are no regressions here (ignoring x86-32),
all changes are either good or neutral.

This, almost surprisingly to me, fixes the motivational tests (in `shift-amount-mod.ll`)
`@reg32_lshr_by_sub_from_negated` from [[ https://bugs.llvm.org/show_bug.cgi?id=41952 | PR41952 ]].

https://rise4fun.com/Alive/vMd3

Reviewers: RKSimon, t.p.northover, craig.topper, spatel, efriedma

Reviewed By: RKSimon

Subscribers: sdardis, javed.absar, arichardson, kristof.beyls, jrtc27, atanasyan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62774

llvm-svn: 362488
2019-06-04 11:06:21 +00:00
Roman Lebedev
be6ce7b3f2 [DAGCombine][X86][AArch64][ARM] (C - x) + y -> (y - x) + C fold
Summary:
All changes except ARM look **great**.
https://rise4fun.com/Alive/R2M

The regression `test/CodeGen/ARM/addsubcarry-promotion.ll`
is recovered fully by D62392 + D62450.

Reviewers: RKSimon, craig.topper, spatel, rogfer01, efriedma

Reviewed By: efriedma

Subscribers: dmgreen, javed.absar, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62266

llvm-svn: 362487
2019-06-04 11:06:08 +00:00
Simon Pilgrim
ad298f86b7 [SelectionDAG] ComputeNumSignBits - support constant pool values from target
As I mentioned on D61887 we don't get many hits on ComputeNumSignBits as we did on computeKnownBits.

The case we do get is interesting though - it allows us to use the 'ConditionalNegate' combine in combineLogicBlendIntoPBLENDV to remove a select.

It comes too late for SSE41 (BLENDV) cases, but SSE2 tests can hit it now. We should probably try to make use of this for SSE41+ targets as well - avoiding variable blends is usually a good idea. I'll investigate as a followup.

Differential Revision: https://reviews.llvm.org/D62777

llvm-svn: 362486
2019-06-04 10:49:06 +00:00
Simon Pilgrim
3178546a27 [SelectionDAG] ComputeNumSignBits - clang-format + improve *EXTLOAD comments. NFCI.
Pre-commit requested for D62777.

llvm-svn: 362485
2019-06-04 10:17:56 +00:00
Simon Pilgrim
3018d505a3 [SelectionDAG] Add fpto[us]i(undef) --> undef constant fold
Follow up to D62807.

Differential Revision: https://reviews.llvm.org/D62811

llvm-svn: 362483
2019-06-04 10:04:55 +00:00
QingShan Zhang
11de0e71b0 [DAGCombine] Match a pattern where a wide type scalar value is stored by several narrow stores
This opportunity is found from spec 2017 557.xz_r. And it is used by the sha encrypt/decrypt. See sha-2/sha512.c

static void store64(u64 x, unsigned char* y)
{
    for(int i = 0; i != 8; ++i)
        y[i] = (x >> ((7-i) * 8)) & 255;
}

static u64 load64(const unsigned char* y)
{
    u64 res = 0;
    for(int i = 0; i != 8; ++i)
        res |= (u64)(y[i]) << ((7-i) * 8);
    return res;
}
The load64 has been implemented by https://reviews.llvm.org/D26149
This patch is trying to implement the store pattern.

Match a pattern where a wide type scalar value is stored by several narrow
stores. Fold it into a single store or a BSWAP and a store if the targets
supports it.

Assuming little endian target:
i8 *p = ...
i32 val = ...
p[0] = (val >> 0) & 0xFF;
p[1] = (val >> 8) & 0xFF;
p[2] = (val >> 16) & 0xFF;
p[3] = (val >> 24) & 0xFF;

>
*((i32)p) = val;

i8 *p = ...
i32 val = ...
p[0] = (val >> 24) & 0xFF;
p[1] = (val >> 16) & 0xFF;
p[2] = (val >> 8) & 0xFF;
p[3] = (val >> 0) & 0xFF;

>
*((i32)p) = BSWAP(val);

Differential Revision: https://reviews.llvm.org/D61843

llvm-svn: 362472
2019-06-04 08:53:53 +00:00
Michael Berg
6ff978ee05 Propagate fmf for setcc in SDAG for select folds
llvm-svn: 362448
2019-06-03 21:53:26 +00:00