21 lines
573 B
LLVM
21 lines
573 B
LLVM
; RUN: opt -S -instcombine < %s | FileCheck %s
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; https://llvm.org/bugs/show_bug.cgi?id=25900
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; An arithmetic shift right of a power of two is not a power
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; of two if the original value is the sign bit. Therefore,
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; we can't transform the sdiv into a udiv.
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define i32 @pr25900(i32 %d) {
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%and = and i32 %d, -2147483648
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; The next 3 lines prevent another fold from masking the bug.
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%ext = zext i32 %and to i64
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%or = or i64 %ext, 4294967296
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%trunc = trunc i64 %or to i32
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%ashr = ashr exact i32 %trunc, 31
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%div = sdiv i32 4, %ashr
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ret i32 %div
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; CHECK: sdiv
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}
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