forked from OSchip/llvm-project
Revert r209049 and r209065, "Add support for combining GEPs across PHI nodes"
It broke clang selfhosting even after r209065. llvm-svn: 209067
This commit is contained in:
NAKAMURA Takumi
parent
41d7dfe46a
commit
7ef81a4f98
|
|
@ -1220,72 +1220,6 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
|
||||||
if (MadeChange) return &GEP;
|
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.
|
|
||||||
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 = dyn_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(dyn_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
|
// Combine Indices - If the source pointer to this getelementptr instruction
|
||||||
// is a getelementptr instruction, combine the indices of the two
|
// is a getelementptr instruction, combine the indices of the two
|
||||||
// getelementptr instructions into a single instruction.
|
// getelementptr instructions into a single instruction.
|
||||||
|
|
|
||||||
|
|
@ -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
|
|
||||||
}
|
|
||||||
|
|
||||||
Loading…
Reference in New Issue