mirror of
https://github.com/RPCSX/llvm.git
synced 2024-12-05 18:37:17 +00:00
83c39d2edb
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6901 91177308-0d34-0410-b5e6-96231b3b80d8
70 lines
2.1 KiB
C++
70 lines
2.1 KiB
C++
//===- Mem2Reg.cpp - The -mem2reg pass, a wrapper around the Utils lib ----===//
|
|
//
|
|
// This pass is a simple pass wrapper around the PromoteMemToReg function call
|
|
// exposed by the Utils library.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Transforms/Scalar.h"
|
|
#include "llvm/Transforms/Utils/PromoteMemToReg.h"
|
|
#include "llvm/Analysis/Dominators.h"
|
|
#include "llvm/iMemory.h"
|
|
#include "llvm/Function.h"
|
|
#include "llvm/Target/TargetData.h"
|
|
#include "Support/Statistic.h"
|
|
|
|
namespace {
|
|
Statistic<> NumPromoted("mem2reg", "Number of alloca's promoted");
|
|
|
|
struct PromotePass : public FunctionPass {
|
|
// runOnFunction - To run this pass, first we calculate the alloca
|
|
// instructions that are safe for promotion, then we promote each one.
|
|
//
|
|
virtual bool runOnFunction(Function &F);
|
|
|
|
// getAnalysisUsage - We need dominance frontiers
|
|
//
|
|
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
|
|
AU.addRequired<DominanceFrontier>();
|
|
AU.addRequired<TargetData>();
|
|
AU.setPreservesCFG();
|
|
}
|
|
};
|
|
|
|
RegisterOpt<PromotePass> X("mem2reg", "Promote Memory to Register");
|
|
} // end of anonymous namespace
|
|
|
|
bool PromotePass::runOnFunction(Function &F) {
|
|
std::vector<AllocaInst*> Allocas;
|
|
const TargetData &TD = getAnalysis<TargetData>();
|
|
|
|
BasicBlock &BB = F.getEntryNode(); // Get the entry node for the function
|
|
|
|
bool Changed = false;
|
|
|
|
while (1) {
|
|
Allocas.clear();
|
|
|
|
// Find allocas that are safe to promote, by looking at all instructions in
|
|
// the entry node
|
|
for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I)
|
|
if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca?
|
|
if (isAllocaPromotable(AI, TD))
|
|
Allocas.push_back(AI);
|
|
|
|
if (Allocas.empty()) break;
|
|
|
|
PromoteMemToReg(Allocas, getAnalysis<DominanceFrontier>(), TD);
|
|
NumPromoted += Allocas.size();
|
|
Changed = true;
|
|
}
|
|
|
|
return Changed;
|
|
}
|
|
|
|
// createPromoteMemoryToRegister - Provide an entry point to create this pass.
|
|
//
|
|
Pass *createPromoteMemoryToRegister() {
|
|
return new PromotePass();
|
|
}
|