llvm-6502/lib/Target/Hexagon/HexagonRemoveSZExtArgs.cpp
Bill Wendling 6765834754 Create enums for the different attributes.
We use the enums to query whether an Attributes object has that attribute. The
opaque layer is responsible for knowing where that specific attribute is stored.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165488 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 07:45:08 +00:00

83 lines
2.5 KiB
C++

//===- HexagonRemoveExtendArgs.cpp - Remove unnecessary argument sign extends //
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Pass that removes sign extends for function parameters. These parameters
// are already sign extended by the caller per Hexagon's ABI
//
//===----------------------------------------------------------------------===//
#include "HexagonTargetMachine.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/CodeGen/MachineFunctionAnalysis.h"
#include "llvm/Transforms/Scalar.h"
using namespace llvm;
namespace {
struct HexagonRemoveExtendArgs : public FunctionPass {
public:
static char ID;
HexagonRemoveExtendArgs() : FunctionPass(ID) {}
virtual bool runOnFunction(Function &F);
const char *getPassName() const {
return "Remove sign extends";
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<MachineFunctionAnalysis>();
AU.addPreserved<MachineFunctionAnalysis>();
FunctionPass::getAnalysisUsage(AU);
}
};
}
char HexagonRemoveExtendArgs::ID = 0;
RegisterPass<HexagonRemoveExtendArgs> X("reargs",
"Remove Sign and Zero Extends for Args"
);
bool HexagonRemoveExtendArgs::runOnFunction(Function &F) {
unsigned Idx = 1;
for (Function::arg_iterator AI = F.arg_begin(), AE = F.arg_end(); AI != AE;
++AI, ++Idx) {
if (F.getParamAttributes(Idx).hasAttribute(Attributes::SExt)) {
Argument* Arg = AI;
if (!isa<PointerType>(Arg->getType())) {
for (Instruction::use_iterator UI = Arg->use_begin();
UI != Arg->use_end();) {
if (isa<SExtInst>(*UI)) {
Instruction* Use = cast<Instruction>(*UI);
SExtInst* SI = new SExtInst(Arg, Use->getType());
assert (EVT::getEVT(SI->getType()) ==
(EVT::getEVT(Use->getType())));
++UI;
Use->replaceAllUsesWith(SI);
Instruction* First = F.getEntryBlock().begin();
SI->insertBefore(First);
Use->eraseFromParent();
} else {
++UI;
}
}
}
}
}
return true;
}
FunctionPass *llvm::createHexagonRemoveExtendOps(HexagonTargetMachine &TM) {
return new HexagonRemoveExtendArgs();
}