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This was removed upstream.

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This commit is contained in:
Roman Divacky 2009-10-23 15:58:05 +00:00
parent bd3c9c2e3e
commit f9666f9b3a
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/vendor/llvm/dist/; revision=198413
1 changed files with 0 additions and 90 deletions
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lib/Transforms/IPO/IndMemRemoval.cpp
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@ -1,90 +0,0 @@
//===-- IndMemRemoval.cpp - Remove indirect allocations and frees ---------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This pass finds places where memory allocation functions may escape into
// indirect land. Some transforms are much easier (aka possible) only if free
// or malloc are not called indirectly.
// Thus find places where the address of memory functions are taken and
// construct bounce functions with direct calls of those functions.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "indmemrem"
#include "llvm/Transforms/IPO.h"
#include "llvm/Pass.h"
#include "llvm/Module.h"
#include "llvm/Instructions.h"
#include "llvm/Type.h"
#include "llvm/DerivedTypes.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Compiler.h"
using namespace llvm;
STATISTIC(NumBounceSites, "Number of sites modified");
STATISTIC(NumBounce , "Number of bounce functions created");
namespace {
class VISIBILITY_HIDDEN IndMemRemPass : public ModulePass {
public:
static char ID; // Pass identification, replacement for typeid
IndMemRemPass() : ModulePass(&ID) {}
virtual bool runOnModule(Module &M);
};
} // end anonymous namespace
char IndMemRemPass::ID = 0;
static RegisterPass<IndMemRemPass>
X("indmemrem","Indirect Malloc and Free Removal");
bool IndMemRemPass::runOnModule(Module &M) {
// In theory, all direct calls of malloc and free should be promoted
// to intrinsics. Therefore, this goes through and finds where the
// address of free or malloc are taken and replaces those with bounce
// functions, ensuring that all malloc and free that might happen
// happen through intrinsics.
bool changed = false;
if (Function* F = M.getFunction("free")) {
if (F->isDeclaration() && F->arg_size() == 1 && !F->use_empty()) {
Function* FN = Function::Create(F->getFunctionType(),
GlobalValue::LinkOnceAnyLinkage,
"free_llvm_bounce", &M);
BasicBlock* bb = BasicBlock::Create(M.getContext(), "entry",FN);
Instruction* R = ReturnInst::Create(M.getContext(), bb);
new FreeInst(FN->arg_begin(), R);
++NumBounce;
NumBounceSites += F->getNumUses();
F->replaceAllUsesWith(FN);
changed = true;
}
}
if (Function* F = M.getFunction("malloc")) {
if (F->isDeclaration() && F->arg_size() == 1 && !F->use_empty()) {
Function* FN = Function::Create(F->getFunctionType(),
GlobalValue::LinkOnceAnyLinkage,
"malloc_llvm_bounce", &M);
FN->setDoesNotAlias(0);
BasicBlock* bb = BasicBlock::Create(M.getContext(), "entry",FN);
Instruction* c = CastInst::CreateIntegerCast(
FN->arg_begin(), Type::getInt32Ty(M.getContext()), false, "c", bb);
Instruction* a = new MallocInst(Type::getInt8Ty(M.getContext()),
c, "m", bb);
ReturnInst::Create(M.getContext(), a, bb);
++NumBounce;
NumBounceSites += F->getNumUses();
F->replaceAllUsesWith(FN);
changed = true;
}
}
return changed;
}
ModulePass *llvm::createIndMemRemPass() {
return new IndMemRemPass();
}