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Initial implementation of ARM ABI. Mostly untested. Note that I'm not

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really intending to take ownership of this; I wrote this mostly because 
I was curious about how the ARM ABI works.  It should be a decent start, 
though.

llvm-svn: 67969
This commit is contained in:
Eli Friedman 2009-03-29 00:15:25 +00:00
parent a59a3e2d10
commit bbcf49e410
1 changed files with 88 additions and 0 deletions
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88
clang/lib/CodeGen/CGCall.cpp
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@ -1157,6 +1157,91 @@ llvm::Value *X86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
return ResAddr;
}
class ARMABIInfo : public ABIInfo {
ABIArgInfo classifyReturnType(QualType RetTy,
ASTContext &Context) const;
ABIArgInfo classifyArgumentType(QualType RetTy,
ASTContext &Context) const;
virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context) const;
virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const;
};
void ARMABIInfo::computeInfo(CGFunctionInfo &FI, ASTContext &Context) const {
FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), Context);
for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
it != ie; ++it) {
it->info = classifyArgumentType(it->type, Context);
}
}
ABIArgInfo ARMABIInfo::classifyArgumentType(QualType Ty,
ASTContext &Context) const {
if (!CodeGenFunction::hasAggregateLLVMType(Ty)) {
return ABIArgInfo::getDirect();
}
// FIXME: This is kind of nasty... but there isn't much choice
// because the ARM backend doesn't support byval.
// FIXME: This doesn't handle alignment > 64 bits.
const llvm::Type* ElemTy;
unsigned SizeRegs;
if (Context.getTypeAlign(Ty) > 32) {
ElemTy = llvm::Type::Int64Ty;
SizeRegs = (Context.getTypeSize(Ty) + 63) / 64;
} else {
ElemTy = llvm::Type::Int32Ty;
SizeRegs = (Context.getTypeSize(Ty) + 31) / 32;
}
std::vector<const llvm::Type*> LLVMFields;
LLVMFields.push_back(llvm::ArrayType::get(ElemTy, SizeRegs));
const llvm::Type* STy = llvm::StructType::get(LLVMFields, true);
return ABIArgInfo::getCoerce(STy);
}
ABIArgInfo ARMABIInfo::classifyReturnType(QualType RetTy,
ASTContext &Context) const {
if (RetTy->isVoidType()) {
return ABIArgInfo::getIgnore();
} else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) {
// Aggregates <= 4 bytes are returned in r0; other aggregates
// are returned indirectly.
uint64_t Size = Context.getTypeSize(RetTy);
if (Size <= 32)
return ABIArgInfo::getCoerce(llvm::Type::Int32Ty);
return ABIArgInfo::getIndirect(0);
} else {
return ABIArgInfo::getDirect();
}
}
llvm::Value *ARMABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGenFunction &CGF) const {
// FIXME: Need to handle alignment
const llvm::Type *BP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
const llvm::Type *BPP = llvm::PointerType::getUnqual(BP);
CGBuilderTy &Builder = CGF.Builder;
llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP,
"ap");
llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
llvm::Type *PTy =
llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy);
uint64_t Offset =
llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4);
llvm::Value *NextAddr =
Builder.CreateGEP(Addr,
llvm::ConstantInt::get(llvm::Type::Int32Ty, Offset),
"ap.next");
Builder.CreateStore(NextAddr, VAListAddrAsBPP);
return AddrTyped;
}
ABIArgInfo DefaultABIInfo::classifyReturnType(QualType RetTy,
ASTContext &Context) const {
if (RetTy->isVoidType()) {
@ -1197,6 +1282,9 @@ const ABIInfo &CodeGenTypes::getABIInfo() const {
case 64:
return *(TheABIInfo = new X86_64ABIInfo());
}
} else if (strcmp(TargetPrefix, "arm") == 0) {
// FIXME: Support for OABI?
return *(TheABIInfo = new ARMABIInfo());
}
return *(TheABIInfo = new DefaultABIInfo);