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Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."

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Yes, there are other types than i8* and GEPs on them can produce an add+multiply.
We don't consider that cheap enough to be speculatively executed.

llvm-svn: 126481
This commit is contained in:
Benjamin Kramer 2011-02-25 10:33:33 +00:00
parent ed7f556f44
commit 39a5d8596c
2 changed files with 4 additions and 6 deletions
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8
lib/Transforms/Utils/SimplifyCFG.cpp
View File

@ -247,13 +247,11 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB,
if (PBB->getFirstNonPHIOrDbg() != I)
return false;
break;
case Instruction::GetElementPtr: {
// GEPs are cheap if all indices are constant or if there's only one index.
GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
if (!GEP->hasAllConstantIndices() && GEP->getNumIndices() > 1)
case Instruction::GetElementPtr:
// GEPs are cheap if all indices are constant.
if (!cast<GetElementPtrInst>(I)->hasAllConstantIndices())
return false;
break;
}
case Instruction::Add:
case Instruction::Sub:
case Instruction::And:

2
test/Transforms/SimplifyCFG/select-gep.ll
View File

@ -15,7 +15,7 @@ if.end:
ret i8* %x.addr
; CHECK: @test1
; CHECK: %x.addr = select i1 %cmp, i8* %incdec.ptr, i8* %x
; CHECK-NOT: select
; CHECK: ret i8* %x.addr
}