[llvm] r209775 - Revert "Add support for combining GEPs across PHI nodes"
Rafael Espindola
rafael.espindola at gmail.com
Wed May 28 14:41:21 PDT 2014
Author: rafael
Date: Wed May 28 16:41:21 2014
New Revision: 209775
URL: http://llvm.org/viewvc/llvm-project?rev=209775&view=rev
Log:
Revert "Add support for combining GEPs across PHI nodes"
This reverts commit r209755.
it was the real cause of the libc++ build failure.
Removed:
llvm/trunk/test/Transforms/InstCombine/gepphigep.ll
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
Modified: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp?rev=209775&r1=209774&r2=209775&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp Wed May 28 16:41:21 2014
@@ -1220,85 +1220,6 @@ Instruction *InstCombiner::visitGetEleme
if (MadeChange) return &GEP;
}
- // Check to see if the inputs to the PHI node are getelementptr instructions.
- if (PHINode *PN = dyn_cast<PHINode>(PtrOp)) {
- GetElementPtrInst *Op1 = dyn_cast<GetElementPtrInst>(PN->getOperand(0));
- if (!Op1)
- return nullptr;
-
- signed DI = -1;
-
- for (auto I = PN->op_begin()+1, E = PN->op_end(); I !=E; ++I) {
- GetElementPtrInst *Op2 = dyn_cast<GetElementPtrInst>(*I);
- if (!Op2 || Op1->getNumOperands() != Op2->getNumOperands())
- return nullptr;
-
- for (unsigned J = 0, F = Op1->getNumOperands(); J != F; ++J) {
- if (Op1->getOperand(J)->getType() != Op2->getOperand(J)->getType())
- return nullptr;
-
- if (Op1->getOperand(J) != Op2->getOperand(J)) {
- if (DI == -1) {
- // We have not seen any differences yet in the GEPs feeding the
- // PHI yet, so we record this one if it is allowed to be a
- // variable.
-
- // The first two arguments can vary for any GEP, the rest have to be
- // static for struct slots
- if (J > 1) {
- SmallVector<Value*, 8> Idxs(GEP.idx_begin(), GEP.idx_begin()+J);
- Type *Ty =
- GetElementPtrInst::getIndexedType(Op1->getOperand(0)->getType(),
- Idxs);
- if (Ty->isStructTy())
- return nullptr;
- }
-
- DI = J;
- } else {
- // The GEP is different by more than one input. While this could be
- // extended to support GEPs that vary by more than one variable it
- // doesn't make sense since it greatly increases the complexity and
- // would result in an R+R+R addressing mode which no backend
- // directly supports and would need to be broken into several
- // simpler instructions anyway.
- return nullptr;
- }
- }
- }
- }
-
- GetElementPtrInst *NewGEP = cast<GetElementPtrInst>(Op1->clone());
-
- if (DI == -1) {
- // All the GEPs feeding the PHI are identical. Clone one down into our
- // BB so that it can be merged with the current GEP.
- GEP.getParent()->getInstList().insert(GEP.getParent()->getFirstNonPHI(),
- NewGEP);
- } else {
- // All the GEPs feeding the PHI differ at a single offset. Clone a GEP
- // into the current block so it can be merged, and create a new PHI to
- // set that index.
- Instruction *InsertPt = Builder->GetInsertPoint();
- Builder->SetInsertPoint(PN);
- PHINode *NewPN = Builder->CreatePHI(Op1->getOperand(DI)->getType(),
- PN->getNumOperands());
- Builder->SetInsertPoint(InsertPt);
-
- for (auto &I : PN->operands())
- NewPN->addIncoming(cast<GEPOperator>(I)->getOperand(DI),
- PN->getIncomingBlock(I));
-
- NewGEP->setOperand(DI, NewPN);
- GEP.getParent()->getInstList().insert(GEP.getParent()->getFirstNonPHI(),
- NewGEP);
- NewGEP->setOperand(DI, NewPN);
- }
-
- GEP.setOperand(0, NewGEP);
- PtrOp = NewGEP;
- }
-
// Combine Indices - If the source pointer to this getelementptr instruction
// is a getelementptr instruction, combine the indices of the two
// getelementptr instructions into a single instruction.
Removed: llvm/trunk/test/Transforms/InstCombine/gepphigep.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/gepphigep.ll?rev=209774&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/gepphigep.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/gepphigep.ll (removed)
@@ -1,56 +0,0 @@
-; RUN: opt -instcombine -S < %s | FileCheck %s
-
-%struct1 = type { %struct2*, i32, i32, i32 }
-%struct2 = type { i32, i32 }
-
-define i32 @test1(%struct1* %dm, i1 %tmp4, i64 %tmp9, i64 %tmp19) {
-bb:
- %tmp = getelementptr inbounds %struct1* %dm, i64 0, i32 0
- %tmp1 = load %struct2** %tmp, align 8
- br i1 %tmp4, label %bb1, label %bb2
-
-bb1:
- %tmp10 = getelementptr inbounds %struct2* %tmp1, i64 %tmp9
- %tmp11 = getelementptr inbounds %struct2* %tmp10, i64 0, i32 0
- store i32 0, i32* %tmp11, align 4
- br label %bb3
-
-bb2:
- %tmp20 = getelementptr inbounds %struct2* %tmp1, i64 %tmp19
- %tmp21 = getelementptr inbounds %struct2* %tmp20, i64 0, i32 0
- store i32 0, i32* %tmp21, align 4
- br label %bb3
-
-bb3:
- %phi = phi %struct2* [ %tmp10, %bb1 ], [ %tmp20, %bb2 ]
- %tmp24 = getelementptr inbounds %struct2* %phi, i64 0, i32 1
- %tmp25 = load i32* %tmp24, align 4
- ret i32 %tmp25
-
-; CHECK-LABEL: @test1(
-; CHECK: getelementptr inbounds %struct2* %tmp1, i64 %tmp9, i32 0
-; CHECK: getelementptr inbounds %struct2* %tmp1, i64 %tmp19, i32 0
-; CHECK: %[[PHI:[0-9A-Za-z]+]] = phi i64 [ %tmp9, %bb1 ], [ %tmp19, %bb2 ]
-; CHECK: getelementptr inbounds %struct2* %tmp1, i64 %[[PHI]], i32 1
-
-}
-
-define i32 @test2(%struct1* %dm, i1 %tmp4, i64 %tmp9, i64 %tmp19) {
-bb:
- %tmp = getelementptr inbounds %struct1* %dm, i64 0, i32 0
- %tmp1 = load %struct2** %tmp, align 8
- %tmp10 = getelementptr inbounds %struct2* %tmp1, i64 %tmp9
- %tmp11 = getelementptr inbounds %struct2* %tmp10, i64 0, i32 0
- store i32 0, i32* %tmp11, align 4
- %tmp20 = getelementptr inbounds %struct2* %tmp1, i64 %tmp19
- %tmp21 = getelementptr inbounds %struct2* %tmp20, i64 0, i32 0
- store i32 0, i32* %tmp21, align 4
- %tmp24 = getelementptr inbounds %struct2* %tmp10, i64 0, i32 1
- %tmp25 = load i32* %tmp24, align 4
- ret i32 %tmp25
-
-; CHECK-LABEL: @test2(
-; CHECK: getelementptr inbounds %struct2* %tmp1, i64 %tmp9, i32 0
-; CHECK: getelementptr inbounds %struct2* %tmp1, i64 %tmp19, i32 0
-; CHECK: getelementptr inbounds %struct2* %tmp1, i64 %tmp9, i32 1
-}
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