//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "ipconstprop"
#include "llvm/Transforms/IPO.h"
-#include "llvm/Constants.h"
-#include "llvm/Instructions.h"
-#include "llvm/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/Support/CallSite.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
using namespace llvm;
+#define DEBUG_TYPE "ipconstprop"
+
STATISTIC(NumArgumentsProped, "Number of args turned into constants");
STATISTIC(NumReturnValProped, "Number of return values turned into constants");
namespace {
/// IPCP - The interprocedural constant propagation pass
///
- struct VISIBILITY_HIDDEN IPCP : public ModulePass {
+ struct IPCP : public ModulePass {
static char ID; // Pass identification, replacement for typeid
- IPCP() : ModulePass(&ID) {}
+ IPCP() : ModulePass(ID) {
+ initializeIPCPPass(*PassRegistry::getPassRegistry());
+ }
- bool runOnModule(Module &M);
+ bool runOnModule(Module &M) override;
private:
bool PropagateConstantsIntoArguments(Function &F);
bool PropagateConstantReturn(Function &F);
}
char IPCP::ID = 0;
-static RegisterPass<IPCP>
-X("ipconstprop", "Interprocedural constant propagation");
+INITIALIZE_PASS(IPCP, "ipconstprop",
+ "Interprocedural constant propagation", false, false)
ModulePass *llvm::createIPConstantPropagationPass() { return new IPCP(); }
if (!I->isDeclaration()) {
// Delete any klingons.
I->removeDeadConstantUsers();
- if (I->hasInternalLinkage())
+ if (I->hasLocalLinkage())
LocalChange |= PropagateConstantsIntoArguments(*I);
Changed |= PropagateConstantReturn(*I);
}
ArgumentConstants.resize(F.arg_size());
unsigned NumNonconstant = 0;
- for (Value::use_iterator UI = F.use_begin(), E = F.use_end(); UI != E; ++UI) {
+ for (Use &U : F.uses()) {
+ User *UR = U.getUser();
+ // Ignore blockaddress uses.
+ if (isa<BlockAddress>(UR)) continue;
+
// Used by a non-instruction, or not the callee of a function, do not
// transform.
- if (UI.getOperandNo() != 0 ||
- (!isa<CallInst>(*UI) && !isa<InvokeInst>(*UI)))
+ if (!isa<CallInst>(UR) && !isa<InvokeInst>(UR))
return false;
- CallSite CS = CallSite::get(cast<Instruction>(*UI));
+ CallSite CS(cast<Instruction>(UR));
+ if (!CS.isCallee(&U))
+ return false;
// Check out all of the potentially constant arguments. Note that we don't
// inspect varargs here.
continue;
Constant *C = dyn_cast<Constant>(*AI);
- if (C && ArgumentConstants[i].first == 0) {
+ if (C && ArgumentConstants[i].first == nullptr) {
ArgumentConstants[i].first = C; // First constant seen.
} else if (C && ArgumentConstants[i].first == C) {
// Still the constant value we think it is.
Function::arg_iterator AI = F.arg_begin();
for (unsigned i = 0, e = ArgumentConstants.size(); i != e; ++i, ++AI) {
// Do we have a constant argument?
- if (ArgumentConstants[i].second || AI->use_empty())
+ if (ArgumentConstants[i].second || AI->use_empty() ||
+ AI->hasInAllocaAttr() || (AI->hasByValAttr() && !F.onlyReadsMemory()))
continue;
Value *V = ArgumentConstants[i].first;
- if (V == 0) V = UndefValue::get(AI->getType());
+ if (!V) V = UndefValue::get(AI->getType());
AI->replaceAllUsesWith(V);
++NumArgumentsProped;
MadeChange = true;
// callers will be updated to use the value they pass in directly instead of
// using the return value.
bool IPCP::PropagateConstantReturn(Function &F) {
- if (F.getReturnType() == Type::VoidTy)
+ if (F.getReturnType()->isVoidTy())
return false; // No return value.
// If this function could be overridden later in the link stage, we can't
// propagate information about its results into callers.
- if (F.hasLinkOnceLinkage() || F.mayBeOverridden())
+ if (F.mayBeOverridden())
return false;
-
+
// Check to see if this function returns a constant.
SmallVector<Value *,4> RetVals;
- const StructType *STy = dyn_cast<StructType>(F.getReturnType());
+ StructType *STy = dyn_cast<StructType>(F.getReturnType());
if (STy)
for (unsigned i = 0, e = STy->getNumElements(); i < e; ++i)
RetVals.push_back(UndefValue::get(STy->getElementType(i)));
unsigned NumNonConstant = 0;
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
- // Return type does not match operand type, this is an old style multiple
- // return
- bool OldReturn = (F.getReturnType() != RI->getOperand(0)->getType());
-
for (unsigned i = 0, e = RetVals.size(); i != e; ++i) {
// Already found conflicting return values?
Value *RV = RetVals[i];
// Find the returned value
Value *V;
- if (!STy || OldReturn)
- V = RI->getOperand(i);
+ if (!STy)
+ V = RI->getOperand(0);
else
V = FindInsertedValue(RI->getOperand(0), i);
}
// Different or no known return value? Don't propagate this return
// value.
- RetVals[i] = 0;
- // All values non constant? Stop looking.
+ RetVals[i] = nullptr;
+ // All values non-constant? Stop looking.
if (++NumNonConstant == RetVals.size())
return false;
}
// over all users, replacing any uses of the return value with the returned
// constant.
bool MadeChange = false;
- for (Value::use_iterator UI = F.use_begin(), E = F.use_end(); UI != E; ++UI) {
- CallSite CS = CallSite::get(*UI);
+ for (Use &U : F.uses()) {
+ CallSite CS(U.getUser());
Instruction* Call = CS.getInstruction();
// Not a call instruction or a call instruction that's not calling F
// directly?
- if (!Call || UI.getOperandNo() != 0)
+ if (!Call || !CS.isCallee(&U))
continue;
// Call result not used?
MadeChange = true;
- if (STy == 0) {
+ if (!STy) {
Value* New = RetVals[0];
if (Argument *A = dyn_cast<Argument>(New))
// Was an argument returned? Then find the corresponding argument in
Call->replaceAllUsesWith(New);
continue;
}
-
- for (Value::use_iterator I = Call->use_begin(), E = Call->use_end();
- I != E;) {
- Instruction *Ins = dyn_cast<Instruction>(*I);
+
+ for (auto I = Call->user_begin(), E = Call->user_end(); I != E;) {
+ Instruction *Ins = cast<Instruction>(*I);
// Increment now, so we can remove the use
++I;
- // Not an instruction? Ignore
- if (!Ins)
- continue;
-
// Find the index of the retval to replace with
int index = -1;
if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Ins))