41 lines
1.2 KiB
LLVM
41 lines
1.2 KiB
LLVM
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; RUN: opt -S < %s -instcombine | FileCheck %s
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target datalayout = "e-p1:16:16-p2:32:32-p3:64:64"
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@G1 = global i32 42, align 1
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@G2 = global i32 42
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@G3 = global [4 x i8] zeroinitializer, align 1
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@A1 = alias i32, bitcast (i8* getelementptr inbounds ([4 x i8], [4 x i8]* @G3, i32 0, i32 2) to i32*)
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@A2 = alias i32, inttoptr (i64 and (i64 ptrtoint (i8* getelementptr inbounds ([4 x i8], [4 x i8]* @G3, i32 0, i32 3) to i64), i64 -4) to i32*)
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define i64 @f1() {
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; This cannot be constant folded because G1 is underaligned.
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; CHECK-LABEL: @f1(
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; CHECK: ret i64 and
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ret i64 and (i64 ptrtoint (i32* @G1 to i64), i64 1)
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}
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define i64 @f2() {
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; The preferred alignment for G2 allows this one to foled to zero.
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; CHECK-LABEL: @f2(
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; CHECK: ret i64 0
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ret i64 and (i64 ptrtoint (i32* @G2 to i64), i64 1)
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}
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define i64 @g1() {
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; This cannot be constant folded because A1 aliases G3 which is underalaigned.
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; CHECK-LABEL: @g1(
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; CHECK: ret i64 and
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ret i64 and (i64 ptrtoint (i32* @A1 to i64), i64 1)
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}
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define i64 @g2() {
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; While A2 also aliases G3 which is underaligned, the math of A2 forces a
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; certain alignment allowing this to fold to zero.
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; CHECK-LABEL: @g2(
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; CHECK: ret i64 0
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ret i64 and (i64 ptrtoint (i32* @A2 to i64), i64 1)
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}
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