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Stop folding constant adds into GEP when the type size doesn't match. Otherwise, the adds' operands are effectively being promoted, changing the conditions of an overflow. Results are different when: sext(a) + sext(b) != sext(a + b) Problem originally found on x86-64, but also fixed issues with ARM and PPC, which used similar code. <rdar://problem/15292280> Patch by Duncan Exon Smith! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194840 91177308-0d34-0410-b5e6-96231b3b80d8
19 lines
519 B
LLVM
19 lines
519 B
LLVM
; fastisel should not fold add with non-pointer bitwidth
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; sext(a) + sext(b) != sext(a + b)
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; RUN: llc -mtriple=armv7-apple-ios %s -O0 -o - | FileCheck %s
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define zeroext i8 @gep_promotion(i8* %ptr) nounwind uwtable ssp {
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entry:
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%ptr.addr = alloca i8*, align 8
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%add = add i8 64, 64 ; 0x40 + 0x40
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%0 = load i8** %ptr.addr, align 8
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; CHECK-LABEL: _gep_promotion:
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; CHECK: ldrb {{r[0-9]+}}, {{\[r[0-9]+\]}}
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%arrayidx = getelementptr inbounds i8* %0, i8 %add
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%1 = load i8* %arrayidx, align 1
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ret i8 %1
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}
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