Commit afb3aea9 authored by Tom Stellard's avatar Tom Stellard
Browse files

Merging r281650: 

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r281650 | david.majnemer | 2016-09-15 13:10:09 -0700 (Thu, 15 Sep 2016) | 6 lines

[InstCombine] Do not RAUW a constant GEP

canRewriteGEPAsOffset expects to process instructions, not constants.

This fixes PR30342.

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llvm-svn: 288066
parent 75fa61d2

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

+1 −1
Original line number Diff line number Diff line
@@ -634,7 +634,7 @@ static bool canRewriteGEPAsOffset(Value *Start, Value *Base, 
      }



      if (!isa<IntToPtrInst>(V) && !isa<PtrToIntInst>(V) &&

          !isa<GEPOperator>(V) && !isa<PHINode>(V))

          !isa<GetElementPtrInst>(V) && !isa<PHINode>(V))

        // We've found some value that we can't explore which is different from

        // the base. Therefore we can't do this transformation.

        return false;

llvm/test/Transforms/InstCombine/indexed-gep-compares.ll

+20 −0
Original line number Diff line number Diff line
@@ -167,4 +167,24 @@ lpad: 
; CHECK:  ret i32* %[[PTR]]

}





@pr30402 = constant i64 3

define i1 @test7() {

entry:

  br label %bb7



bb7:                                              ; preds = %bb10, %entry-block

  %phi = phi i64* [ @pr30402, %entry ], [ getelementptr inbounds (i64, i64* @pr30402, i32 1), %bb7 ]

  %cmp = icmp eq i64* %phi, getelementptr inbounds (i64, i64* @pr30402, i32 1)

  br i1 %cmp, label %bb10, label %bb7



bb10:

  ret i1 %cmp

}

; CHECK-LABEL: @test7(

; CHECK:  %[[phi:.*]] = phi i64* [ @pr30402, %entry ], [ getelementptr inbounds (i64, i64* @pr30402, i32 1), %bb7 ]

; CHECK:  %[[cmp:.*]] = icmp eq i64* %[[phi]], getelementptr inbounds (i64, i64* @pr30402, i32 1)

; CHECK: ret i1 %[[cmp]]





declare i32 @__gxx_personality_v0(...)