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d32daec92c
Bitwise arithmetic can obscure a simple sign-test. If replacing the mask with a truncate is preferable if the type is legal because it permits us to rephrase the comparison more explicitly. llvm-svn: 245171
39 lines
1.1 KiB
LLVM
39 lines
1.1 KiB
LLVM
; RUN: opt < %s -instcombine -S | \
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; RUN: FileCheck %s
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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-unknown-linux-gnu"
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; Should be optimized to one and.
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define i1 @test1(i32 %a, i32 %b) {
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; CHECK-LABEL: @test1(
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; CHECK-NEXT: %1 = xor i32 %a, %b
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; CHECK-NEXT: %2 = and i32 %1, 65280
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; CHECK-NEXT: %tmp = icmp ne i32 %2, 0
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; CHECK-NEXT: ret i1 %tmp
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%tmp1 = and i32 %a, 65280 ; <i32> [#uses=1]
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%tmp3 = and i32 %b, 65280 ; <i32> [#uses=1]
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%tmp = icmp ne i32 %tmp1, %tmp3 ; <i1> [#uses=1]
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ret i1 %tmp
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}
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define zeroext i1 @test2(i64 %A) {
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; CHECK-LABEL: @test2(
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; CHECK-NEXT: %[[trunc:.*]] = trunc i64 %A to i8
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; CHECK-NEXT: %[[icmp:.*]] = icmp sgt i8 %[[trunc]], -1
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; CHECK-NEXT: ret i1 %[[icmp]]
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%and = and i64 %A, 128
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%cmp = icmp eq i64 %and, 0
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ret i1 %cmp
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}
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define zeroext i1 @test3(i64 %A) {
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; CHECK-LABEL: @test3(
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; CHECK-NEXT: %[[trunc:.*]] = trunc i64 %A to i8
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; CHECK-NEXT: %[[icmp:.*]] = icmp slt i8 %[[trunc]], 0
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; CHECK-NEXT: ret i1 %[[icmp]]
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%and = and i64 %A, 128
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%cmp = icmp ne i64 %and, 0
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ret i1 %cmp
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}
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