Add X86FastISel support for return statements. This entails refactoring

a bunch of stuff, to allow the target-independent calling convention
logic to be employed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107800 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman
2010-07-07 18:32:53 +00:00
parent ced9ec9bac
commit f423a69839
11 changed files with 165 additions and 97 deletions

View File

@@ -20,6 +20,7 @@
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/GlobalVariable.h"
#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
@@ -838,6 +839,65 @@ unsigned TargetLowering::getVectorTypeBreakdown(LLVMContext &Context, EVT VT,
return 1;
}
/// Get the EVTs and ArgFlags collections that represent the legalized return
/// type of the given function. This does not require a DAG or a return value,
/// and is suitable for use before any DAGs for the function are constructed.
/// TODO: Move this out of TargetLowering.cpp.
void llvm::GetReturnInfo(const Type* ReturnType, Attributes attr,
SmallVectorImpl<ISD::OutputArg> &Outs,
const TargetLowering &TLI,
SmallVectorImpl<uint64_t> *Offsets) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, ReturnType, ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0) return;
unsigned Offset = 0;
for (unsigned j = 0, f = NumValues; j != f; ++j) {
EVT VT = ValueVTs[j];
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
if (attr & Attribute::SExt)
ExtendKind = ISD::SIGN_EXTEND;
else if (attr & Attribute::ZExt)
ExtendKind = ISD::ZERO_EXTEND;
// FIXME: C calling convention requires the return type to be promoted to
// at least 32-bit. But this is not necessary for non-C calling
// conventions. The frontend should mark functions whose return values
// require promoting with signext or zeroext attributes.
if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) {
EVT MinVT = TLI.getRegisterType(ReturnType->getContext(), MVT::i32);
if (VT.bitsLT(MinVT))
VT = MinVT;
}
unsigned NumParts = TLI.getNumRegisters(ReturnType->getContext(), VT);
EVT PartVT = TLI.getRegisterType(ReturnType->getContext(), VT);
unsigned PartSize = TLI.getTargetData()->getTypeAllocSize(
PartVT.getTypeForEVT(ReturnType->getContext()));
// 'inreg' on function refers to return value
ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
if (attr & Attribute::InReg)
Flags.setInReg();
// Propagate extension type if any
if (attr & Attribute::SExt)
Flags.setSExt();
else if (attr & Attribute::ZExt)
Flags.setZExt();
for (unsigned i = 0; i < NumParts; ++i) {
Outs.push_back(ISD::OutputArg(Flags, PartVT, /*isFixed=*/true));
if (Offsets) {
Offsets->push_back(Offset);
Offset += PartSize;
}
}
}
}
/// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
/// function arguments in the caller parameter area. This is the actual
/// alignment, not its logarithm.