blob: 34bf4eacfdc0cf410851109a3325644aac7436af [file] [log] [blame]
//===- 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 "Hexagon.h"
#include "HexagonTargetMachine.h"
#include "llvm/CodeGen/MachineFunctionAnalysis.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/Pass.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.getAttributes().hasAttribute(Idx, Attribute::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();
}