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Change the RaiseAllocations pass to be a Pass instead of a BasicBlock pass.

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This makes it more efficient: it doesn't have to scan the whole program, so
it performs work proportional to the number of malloc/free calls in the
program, not the size of the program.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8280 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-09-01 03:14:56 +00:00
parent 2757af2d47
commit 2dbfa03fd8
1 changed files with 74 additions and 53 deletions
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127
lib/Transforms/IPO/RaiseAllocations.cpp
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@ -5,13 +5,13 @@
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/iMemory.h"
#include "llvm/iOther.h"
#include "llvm/Pass.h"
#include "llvm/Support/CallSite.h"
#include "Support/Statistic.h"
namespace {
@ -20,7 +20,7 @@ namespace {
// RaiseAllocations - Turn %malloc and %free calls into the appropriate
// instruction.
//
class RaiseAllocations : public BasicBlockPass {
class RaiseAllocations : public Pass {
Function *MallocFunc; // Functions in the module we are processing
Function *FreeFunc; // Initialized by doPassInitializationVirt
public:
@ -29,12 +29,11 @@ namespace {
// doPassInitialization - For the raise allocations pass, this finds a
// declaration for malloc and free if they exist.
//
bool doInitialization(Module &M);
void doInitialization(Module &M);
// runOnBasicBlock - This method does the actual work of converting
// instructions over, assuming that the pass has already been initialized.
// run - This method does the actual work of converting instructions over.
//
bool runOnBasicBlock(BasicBlock &BB);
bool run(Module &M);
};
RegisterOpt<RaiseAllocations>
@ -48,15 +47,15 @@ Pass *createRaiseAllocationsPass() {
}
bool RaiseAllocations::doInitialization(Module &M) {
// If the module has a symbol table, they might be referring to the malloc
// and free functions. If this is the case, grab the method pointers that
// the module is using.
//
// Lookup %malloc and %free in the symbol table, for later use. If they
// don't exist, or are not external, we do not worry about converting calls
// to that function into the appropriate instruction.
//
// If the module has a symbol table, they might be referring to the malloc and
// free functions. If this is the case, grab the method pointers that the
// module is using.
//
// Lookup %malloc and %free in the symbol table, for later use. If they don't
// exist, or are not external, we do not worry about converting calls to that
// function into the appropriate instruction.
//
void RaiseAllocations::doInitialization(Module &M) {
const FunctionType *MallocType = // Get the type for malloc
FunctionType::get(PointerType::get(Type::SByteTy),
std::vector<const Type*>(1, Type::ULongTy), false);
@ -100,52 +99,74 @@ bool RaiseAllocations::doInitialization(Module &M) {
FreeFunc = M.getFunction("free", FreeType);
}
// Don't mess with locally defined versions of these functions...
if (MallocFunc && !MallocFunc->isExternal()) MallocFunc = 0;
if (FreeFunc && !FreeFunc->isExternal()) FreeFunc = 0;
return false;
}
// runOnBasicBlock - Process a basic block, fixing it up...
// run - Transform calls into instructions...
//
bool RaiseAllocations::runOnBasicBlock(BasicBlock &BB) {
bool RaiseAllocations::run(Module &M) {
// Find the malloc/free prototypes...
doInitialization(M);
bool Changed = false;
BasicBlock::InstListType &BIL = BB.getInstList();
for (BasicBlock::iterator BI = BB.begin(); BI != BB.end(); ++BI) {
Instruction *I = BI;
if (CallInst *CI = dyn_cast<CallInst>(I)) {
if (CI->getCalledValue() == MallocFunc) { // Replace call to malloc?
Value *Source = CI->getOperand(1);
// If no prototype was provided for malloc, we may need to cast the
// source size.
if (Source->getType() != Type::UIntTy)
Source = new CastInst(Source, Type::UIntTy, "MallocAmtCast", BI);
std::string Name(CI->getName()); CI->setName("");
BI = new MallocInst(Type::SByteTy, Source, Name, BI);
CI->replaceAllUsesWith(BI);
BIL.erase(I);
Changed = true;
++NumRaised;
} else if (CI->getCalledValue() == FreeFunc) { // Replace call to free?
// If no prototype was provided for free, we may need to cast the
// source pointer. This should be really uncommon, but it's necessary
// just in case we are dealing with wierd code like this:
// free((long)ptr);
//
Value *Source = CI->getOperand(1);
if (!isa<PointerType>(Source->getType()))
Source = new CastInst(Source, PointerType::get(Type::SByteTy),
"FreePtrCast", BI);
BI = new FreeInst(Source, BI);
BIL.erase(I);
Changed = true;
++NumRaised;
// First, process all of the malloc calls...
if (MallocFunc) {
std::vector<User*> Users(MallocFunc->use_begin(), MallocFunc->use_end());
while (!Users.empty()) {
if (Instruction *I = dyn_cast<Instruction>(Users.back())) {
CallSite CS = CallSite::get(I);
if (CS.getInstruction() && CS.getCalledFunction() == MallocFunc &&
CS.arg_begin() != CS.arg_end()) {
Value *Source = *CS.arg_begin();
// If no prototype was provided for malloc, we may need to cast the
// source size.
if (Source->getType() != Type::UIntTy)
Source = new CastInst(Source, Type::UIntTy, "MallocAmtCast", I);
std::string Name(I->getName()); I->setName("");
MallocInst *MI = new MallocInst(Type::SByteTy, Source, Name, I);
I->replaceAllUsesWith(MI);
MI->getParent()->getInstList().erase(I);
Changed = true;
++NumRaised;
}
}
Users.pop_back();
}
}
// Next, process all free calls...
if (FreeFunc) {
std::vector<User*> Users(FreeFunc->use_begin(), FreeFunc->use_end());
while (!Users.empty()) {
if (Instruction *I = dyn_cast<Instruction>(Users.back())) {
CallSite CS = CallSite::get(I);
if (CS.getInstruction() && CS.getCalledFunction() == FreeFunc &&
CS.arg_begin() != CS.arg_end()) {
// If no prototype was provided for free, we may need to cast the
// source pointer. This should be really uncommon, but it's necessary
// just in case we are dealing with wierd code like this:
// free((long)ptr);
//
Value *Source = *CS.arg_begin();
if (!isa<PointerType>(Source->getType()))
Source = new CastInst(Source, PointerType::get(Type::SByteTy),
"FreePtrCast", I);
new FreeInst(Source, I);
I->getParent()->getInstList().erase(I);
Changed = true;
++NumRaised;
}
}
Users.pop_back();
}
}