[llvm] r314579 - Recommi r314561 after fixing over-debug assertion
Xinliang David Li via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 29 17:46:32 PDT 2017
Author: davidxl
Date: Fri Sep 29 17:46:32 2017
New Revision: 314579
URL: http://llvm.org/viewvc/llvm-project?rev=314579&view=rev
Log:
Recommi r314561 after fixing over-debug assertion
Added:
llvm/trunk/test/Transforms/InstCombine/intptr1.ll
- copied unchanged from r314562, llvm/trunk/test/Transforms/InstCombine/intptr1.ll
llvm/trunk/test/Transforms/InstCombine/intptr2.ll
- copied unchanged from r314562, llvm/trunk/test/Transforms/InstCombine/intptr2.ll
llvm/trunk/test/Transforms/InstCombine/intptr3.ll
- copied unchanged from r314562, llvm/trunk/test/Transforms/InstCombine/intptr3.ll
llvm/trunk/test/Transforms/InstCombine/intptr4.ll
- copied unchanged from r314562, llvm/trunk/test/Transforms/InstCombine/intptr4.ll
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h
llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h?rev=314579&r1=314578&r2=314579&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h Fri Sep 29 17:46:32 2017
@@ -670,6 +670,10 @@ private:
Instruction *FoldPHIArgGEPIntoPHI(PHINode &PN);
Instruction *FoldPHIArgLoadIntoPHI(PHINode &PN);
Instruction *FoldPHIArgZextsIntoPHI(PHINode &PN);
+ /// If an integer typed PHI has only one use which is an IntToPtr operation,
+ /// replace the PHI with an existing pointer typed PHI if it exists. Otherwise
+ /// insert a new pointer typed PHI and replace the original one.
+ Instruction *FoldIntegerTypedPHI(PHINode &PN);
/// Helper function for FoldPHIArgXIntoPHI() to get debug location for the
/// folded operation.
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp?rev=314579&r1=314578&r2=314579&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp Fri Sep 29 17:46:32 2017
@@ -39,6 +39,224 @@ DebugLoc InstCombiner::PHIArgMergedDebug
return Loc;
}
+// Replace Integer typed PHI PN if the PHI's value is used as a pointer value.
+// If there is an existing pointer typed PHI that produces the same value as PN,
+// replace PN and the IntToPtr operation with it. Otherwise, synthesize a new
+// PHI node:
+//
+// Case-1:
+// bb1:
+// int_init = PtrToInt(ptr_init)
+// br label %bb2
+// bb2:
+// int_val = PHI([int_init, %bb1], [int_val_inc, %bb2]
+// ptr_val = PHI([ptr_init, %bb1], [ptr_val_inc, %bb2]
+// ptr_val2 = IntToPtr(int_val)
+// ...
+// use(ptr_val2)
+// ptr_val_inc = ...
+// inc_val_inc = PtrToInt(ptr_val_inc)
+//
+// ==>
+// bb1:
+// br label %bb2
+// bb2:
+// ptr_val = PHI([ptr_init, %bb1], [ptr_val_inc, %bb2]
+// ...
+// use(ptr_val)
+// ptr_val_inc = ...
+//
+// Case-2:
+// bb1:
+// int_ptr = BitCast(ptr_ptr)
+// int_init = Load(int_ptr)
+// br label %bb2
+// bb2:
+// int_val = PHI([int_init, %bb1], [int_val_inc, %bb2]
+// ptr_val2 = IntToPtr(int_val)
+// ...
+// use(ptr_val2)
+// ptr_val_inc = ...
+// inc_val_inc = PtrToInt(ptr_val_inc)
+// ==>
+// bb1:
+// ptr_init = Load(ptr_ptr)
+// br label %bb2
+// bb2:
+// ptr_val = PHI([ptr_init, %bb1], [ptr_val_inc, %bb2]
+// ...
+// use(ptr_val)
+// ptr_val_inc = ...
+// ...
+//
+Instruction *InstCombiner::FoldIntegerTypedPHI(PHINode &PN) {
+ if (!PN.getType()->isIntegerTy())
+ return nullptr;
+ if (!PN.hasOneUse())
+ return nullptr;
+
+ auto *IntToPtr = dyn_cast<IntToPtrInst>(PN.user_back());
+ if (!IntToPtr)
+ return nullptr;
+
+ // Check if the pointer is actually used as pointer:
+ auto HasPointerUse = [](Instruction *IIP) {
+ for (User *U : IIP->users()) {
+ Value *Ptr = nullptr;
+ if (LoadInst *LoadI = dyn_cast<LoadInst>(U)) {
+ Ptr = LoadI->getPointerOperand();
+ } else if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
+ Ptr = SI->getPointerOperand();
+ } else if (GetElementPtrInst *GI = dyn_cast<GetElementPtrInst>(U)) {
+ Ptr = GI->getPointerOperand();
+ }
+
+ if (Ptr && Ptr == IIP)
+ return true;
+ }
+ return false;
+ };
+
+ if (!HasPointerUse(IntToPtr))
+ return nullptr;
+
+ if (DL.getPointerSizeInBits(IntToPtr->getAddressSpace()) !=
+ DL.getTypeSizeInBits(IntToPtr->getOperand(0)->getType()))
+ return nullptr;
+
+ SmallVector<Value *, 4> AvailablePtrVals;
+ for (unsigned i = 0; i != PN.getNumIncomingValues(); ++i) {
+ Value *Arg = PN.getIncomingValue(i);
+
+ // First look backward:
+ if (auto *PI = dyn_cast<PtrToIntInst>(Arg)) {
+ AvailablePtrVals.emplace_back(PI->getOperand(0));
+ continue;
+ }
+
+ // Next look forward:
+ Value *ArgIntToPtr = nullptr;
+ for (User *U : Arg->users()) {
+ if (isa<IntToPtrInst>(U) && U->getType() == IntToPtr->getType() &&
+ (DT.dominates(cast<Instruction>(U), PN.getIncomingBlock(i)) ||
+ cast<Instruction>(U)->getParent() == PN.getIncomingBlock(i))) {
+ ArgIntToPtr = U;
+ break;
+ }
+ }
+
+ if (ArgIntToPtr) {
+ AvailablePtrVals.emplace_back(ArgIntToPtr);
+ continue;
+ }
+
+ // If Arg is defined by a PHI, allow it. This will also create
+ // more opportunities iteratively.
+ if (isa<PHINode>(Arg)) {
+ AvailablePtrVals.emplace_back(Arg);
+ continue;
+ }
+
+ // For a single use integer load:
+ auto *LoadI = dyn_cast<LoadInst>(Arg);
+ if (!LoadI)
+ return nullptr;
+
+ if (!LoadI->hasOneUse())
+ return nullptr;
+
+ // Push the integer typed Load instruction into the available
+ // value set, and fix it up later when the pointer typed PHI
+ // is synthesized.
+ AvailablePtrVals.emplace_back(LoadI);
+ }
+
+ // Now search for a matching PHI
+ auto *BB = PN.getParent();
+ assert(AvailablePtrVals.size() == PN.getNumIncomingValues() &&
+ "Not enough available ptr typed incoming values");
+ PHINode *MatchingPtrPHI = nullptr;
+ for (auto II = BB->begin(), EI = BasicBlock::iterator(BB->getFirstNonPHI());
+ II != EI; II++) {
+ PHINode *PtrPHI = dyn_cast<PHINode>(II);
+ if (!PtrPHI || PtrPHI == &PN)
+ continue;
+ MatchingPtrPHI = PtrPHI;
+ for (unsigned i = 0; i != PtrPHI->getNumIncomingValues(); ++i) {
+ if (AvailablePtrVals[i] != PtrPHI->getIncomingValue(i)) {
+ MatchingPtrPHI = nullptr;
+ break;
+ }
+ }
+
+ if (MatchingPtrPHI)
+ break;
+ }
+
+ if (MatchingPtrPHI) {
+ assert(MatchingPtrPHI->getType() == IntToPtr->getType() &&
+ "Phi's Type does not match with IntToPtr");
+ // The PtrToCast + IntToPtr will be simplified later
+ return CastInst::CreateBitOrPointerCast(MatchingPtrPHI,
+ IntToPtr->getOperand(0)->getType());
+ }
+
+ // If it requires a conversion for every PHI operand, do not do it.
+ if (std::all_of(AvailablePtrVals.begin(), AvailablePtrVals.end(),
+ [&](Value *V) {
+ return (V->getType() != IntToPtr->getType()) ||
+ isa<IntToPtrInst>(V);
+ }))
+ return nullptr;
+
+ PHINode *NewPtrPHI = PHINode::Create(
+ IntToPtr->getType(), PN.getNumIncomingValues(), PN.getName() + ".ptr");
+
+ InsertNewInstBefore(NewPtrPHI, PN);
+ for (unsigned i = 0; i != PN.getNumIncomingValues(); ++i) {
+ auto *IncomingBB = PN.getIncomingBlock(i);
+ auto *IncomingVal = AvailablePtrVals[i];
+
+ if (IncomingVal->getType() == IntToPtr->getType()) {
+ NewPtrPHI->addIncoming(IncomingVal, IncomingBB);
+ continue;
+ }
+
+#ifndef NDEBUG
+ LoadInst *LoadI = dyn_cast<LoadInst>(IncomingVal);
+ assert((isa<PHINode>(IncomingVal) ||
+ IncomingVal->getType()->isPointerTy() ||
+ (LoadI && LoadI->hasOneUse())) &&
+ "Can not replace LoadInst with multiple uses");
+#endif
+ // Need to insert a BitCast.
+ // For an integer Load instruction with a single use, the load + IntToPtr
+ // cast will be simplified into a pointer load:
+ // %v = load i64, i64* %a.ip, align 8
+ // %v.cast = inttoptr i64 %v to float **
+ // ==>
+ // %v.ptrp = bitcast i64 * %a.ip to float **
+ // %v.cast = load float *, float ** %v.ptrp, align 8
+ auto *CI = CastInst::CreateBitOrPointerCast(
+ IncomingVal, IntToPtr->getType(), IncomingVal->getName() + ".ptr");
+ if (auto *IncomingI = dyn_cast<Instruction>(IncomingVal)) {
+ BasicBlock::iterator InsertPos(IncomingI);
+ InsertPos++;
+ if (isa<PHINode>(IncomingI))
+ InsertPos = IncomingI->getParent()->getFirstInsertionPt();
+ InsertNewInstBefore(CI, *InsertPos);
+ } else {
+ auto *InsertBB = &IncomingBB->getParent()->getEntryBlock();
+ InsertNewInstBefore(CI, *InsertBB->getFirstInsertionPt());
+ }
+ NewPtrPHI->addIncoming(CI, IncomingBB);
+ }
+
+ // The PtrToCast + IntToPtr will be simplified later
+ return CastInst::CreateBitOrPointerCast(NewPtrPHI,
+ IntToPtr->getOperand(0)->getType());
+}
+
/// If we have something like phi [add (a,b), add(a,c)] and if a/b/c and the
/// adds all have a single use, turn this into a phi and a single binop.
Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) {
@@ -902,6 +1120,9 @@ Instruction *InstCombiner::visitPHINode(
// this PHI only has a single use (a PHI), and if that PHI only has one use (a
// PHI)... break the cycle.
if (PN.hasOneUse()) {
+ if (Instruction *Result = FoldIntegerTypedPHI(PN))
+ return Result;
+
Instruction *PHIUser = cast<Instruction>(PN.user_back());
if (PHINode *PU = dyn_cast<PHINode>(PHIUser)) {
SmallPtrSet<PHINode*, 16> PotentiallyDeadPHIs;
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