mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-25 12:12:47 +01:00
8749d297f5
the Transforms library. This reduces debug library size by 132 KB, debug binary size by 376 KB, and reduces link time for llvm tools slightly. llvm-svn: 33939
88 lines
3.0 KiB
C++
88 lines
3.0 KiB
C++
//===- Reg2Mem.cpp - Convert registers to allocas -------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by the LLVM research group and is distributed under
|
|
// the University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file demotes all registers to memory references. It is intented to be
|
|
// the inverse of PromoteMemoryToRegister. By converting to loads, the only
|
|
// values live accross basic blocks are allocas and loads before phi nodes.
|
|
// It is intended that this should make CFG hacking much easier.
|
|
// To make later hacking easier, the entry block is split into two, such that
|
|
// all introduced allocas and nothing else are in the entry block.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#define DEBUG_TYPE "reg2mem"
|
|
#include "llvm/Transforms/Scalar.h"
|
|
#include "llvm/Transforms/Utils/Local.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Function.h"
|
|
#include "llvm/Module.h"
|
|
#include "llvm/BasicBlock.h"
|
|
#include "llvm/Instructions.h"
|
|
#include "llvm/ADT/Statistic.h"
|
|
#include "llvm/Support/Compiler.h"
|
|
#include <list>
|
|
using namespace llvm;
|
|
|
|
STATISTIC(NumDemoted, "Number of registers demoted");
|
|
|
|
namespace {
|
|
struct VISIBILITY_HIDDEN RegToMem : public FunctionPass {
|
|
|
|
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
|
|
AU.addRequiredID(BreakCriticalEdgesID);
|
|
AU.addPreservedID(BreakCriticalEdgesID);
|
|
}
|
|
|
|
bool valueEscapes(Instruction* i) {
|
|
BasicBlock* bb = i->getParent();
|
|
for(Value::use_iterator ii = i->use_begin(), ie = i->use_end();
|
|
ii != ie; ++ii)
|
|
if (cast<Instruction>(*ii)->getParent() != bb ||
|
|
isa<PHINode>(*ii))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
virtual bool runOnFunction(Function &F) {
|
|
if (!F.isDeclaration()) {
|
|
//give us a clean block
|
|
BasicBlock* bbold = &F.getEntryBlock();
|
|
BasicBlock* bbnew = new BasicBlock("allocablock", &F, &F.getEntryBlock());
|
|
new BranchInst(bbold, bbnew);
|
|
|
|
//find the instructions
|
|
std::list<Instruction*> worklist;
|
|
for (Function::iterator ibb = F.begin(), ibe = F.end();
|
|
ibb != ibe; ++ibb)
|
|
for (BasicBlock::iterator iib = ibb->begin(), iie = ibb->end();
|
|
iib != iie; ++iib) {
|
|
if(valueEscapes(iib))
|
|
worklist.push_front(&*iib);
|
|
}
|
|
//demote escaped instructions
|
|
NumDemoted += worklist.size();
|
|
for (std::list<Instruction*>::iterator ilb = worklist.begin(),
|
|
ile = worklist.end(); ilb != ile; ++ilb)
|
|
DemoteRegToStack(**ilb, false);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
};
|
|
|
|
RegisterPass<RegToMem> X("reg2mem", "Demote all values to stack slots");
|
|
}
|
|
|
|
// createDemoteRegisterToMemory - Provide an entry point to create this pass.
|
|
//
|
|
const PassInfo *llvm::DemoteRegisterToMemoryID = X.getPassInfo();
|
|
FunctionPass *llvm::createDemoteRegisterToMemoryPass() {
|
|
return new RegToMem();
|
|
}
|