//
//===----------------------------------------------------------------------===//
//
-// This file demotes all registers to memory references. It is intented to be
+// This file demotes all registers to memory references. It is intended to be
// the inverse of PromoteMemoryToRegister. By converting to loads, the only
-// values live accross basic blocks are allocas and loads before phi nodes.
+// values live across 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/LLVMContext.h"
-#include "llvm/Module.h"
-#include "llvm/BasicBlock.h"
-#include "llvm/Instructions.h"
#include "llvm/ADT/Statistic.h"
-#include "llvm/Support/CFG.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Transforms/Utils/Local.h"
#include <list>
using namespace llvm;
+#define DEBUG_TYPE "reg2mem"
+
STATISTIC(NumRegsDemoted, "Number of registers demoted");
STATISTIC(NumPhisDemoted, "Number of phi-nodes demoted");
namespace {
struct RegToMem : public FunctionPass {
static char ID; // Pass identification, replacement for typeid
- RegToMem() : FunctionPass(&ID) {}
+ RegToMem() : FunctionPass(ID) {
+ initializeRegToMemPass(*PassRegistry::getPassRegistry());
+ }
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequiredID(BreakCriticalEdgesID);
AU.addPreservedID(BreakCriticalEdgesID);
}
- bool valueEscapes(const Instruction *Inst) const {
- const BasicBlock *BB = Inst->getParent();
- for (Value::const_use_iterator UI = Inst->use_begin(),E = Inst->use_end();
- UI != E; ++UI) {
- const Instruction *I = cast<Instruction>(*UI);
- if (I->getParent() != BB || isa<PHINode>(I))
+ bool valueEscapes(const Instruction *Inst) const {
+ const BasicBlock *BB = Inst->getParent();
+ for (const User *U : Inst->users()) {
+ const Instruction *UI = cast<Instruction>(U);
+ if (UI->getParent() != BB || isa<PHINode>(UI))
return true;
}
return false;
}
- virtual bool runOnFunction(Function &F);
+ bool runOnFunction(Function &F) override;
};
}
-
-char RegToMem::ID = 0;
-static RegisterPass<RegToMem>
-X("reg2mem", "Demote all values to stack slots");
+char RegToMem::ID = 0;
+INITIALIZE_PASS_BEGIN(RegToMem, "reg2mem", "Demote all values to stack slots",
+ false, false)
+INITIALIZE_PASS_DEPENDENCY(BreakCriticalEdges)
+INITIALIZE_PASS_END(RegToMem, "reg2mem", "Demote all values to stack slots",
+ false, false)
bool RegToMem::runOnFunction(Function &F) {
- if (F.isDeclaration())
+ if (F.isDeclaration())
return false;
-
+
// Insert all new allocas into entry block.
BasicBlock *BBEntry = &F.getEntryBlock();
- assert(pred_begin(BBEntry) == pred_end(BBEntry) &&
+ assert(pred_empty(BBEntry) &&
"Entry block to function must not have predecessors!");
-
+
// Find first non-alloca instruction and create insertion point. This is
// safe if block is well-formed: it always have terminator, otherwise
// we'll get and assertion.
BasicBlock::iterator I = BBEntry->begin();
while (isa<AllocaInst>(I)) ++I;
-
+
CastInst *AllocaInsertionPoint =
new BitCastInst(Constant::getNullValue(Type::getInt32Ty(F.getContext())),
Type::getInt32Ty(F.getContext()),
"reg2mem alloca point", I);
-
+
// Find the escaped instructions. But don't create stack slots for
// allocas in entry block.
std::list<Instruction*> WorkList;
WorkList.push_front(&*iib);
}
}
-
+
// Demote escaped instructions
NumRegsDemoted += WorkList.size();
- for (std::list<Instruction*>::iterator ilb = WorkList.begin(),
+ for (std::list<Instruction*>::iterator ilb = WorkList.begin(),
ile = WorkList.end(); ilb != ile; ++ilb)
DemoteRegToStack(**ilb, false, AllocaInsertionPoint);
-
+
WorkList.clear();
-
+
// Find all phi's
for (Function::iterator ibb = F.begin(), ibe = F.end();
ibb != ibe; ++ibb)
iib != iie; ++iib)
if (isa<PHINode>(iib))
WorkList.push_front(&*iib);
-
+
// Demote phi nodes
NumPhisDemoted += WorkList.size();
- for (std::list<Instruction*>::iterator ilb = WorkList.begin(),
+ for (std::list<Instruction*>::iterator ilb = WorkList.begin(),
ile = WorkList.end(); ilb != ile; ++ilb)
DemotePHIToStack(cast<PHINode>(*ilb), AllocaInsertionPoint);
-
+
return true;
}
// createDemoteRegisterToMemory - Provide an entry point to create this pass.
-//
-const PassInfo *const llvm::DemoteRegisterToMemoryID = &X;
+char &llvm::DemoteRegisterToMemoryID = RegToMem::ID;
FunctionPass *llvm::createDemoteRegisterToMemoryPass() {
return new RegToMem();
}