llvm/test/Transforms/InstCombine/bit-tracking.ll
Dan Gohman f2f6ce65b7 Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81537 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-11 18:01:28 +00:00

27 lines
1.1 KiB
LLVM

; This file contains various testcases that require tracking whether bits are
; set or cleared by various instructions.
; RUN: opt < %s -instcombine -instcombine -S |\
; RUN: not grep %ELIM
; Reduce down to a single XOR
define i32 @test3(i32 %B) {
%ELIMinc = and i32 %B, 1 ; <i32> [#uses=1]
%tmp.5 = xor i32 %ELIMinc, 1 ; <i32> [#uses=1]
%ELIM7 = and i32 %B, -2 ; <i32> [#uses=1]
%tmp.8 = or i32 %tmp.5, %ELIM7 ; <i32> [#uses=1]
ret i32 %tmp.8
}
; Finally, a bigger case where we chain things together. This corresponds to
; incrementing a single-bit bitfield, which should become just an xor.
define i32 @test4(i32 %B) {
%ELIM3 = shl i32 %B, 31 ; <i32> [#uses=1]
%ELIM4 = ashr i32 %ELIM3, 31 ; <i32> [#uses=1]
%inc = add i32 %ELIM4, 1 ; <i32> [#uses=1]
%ELIM5 = and i32 %inc, 1 ; <i32> [#uses=1]
%ELIM7 = and i32 %B, -2 ; <i32> [#uses=1]
%tmp.8 = or i32 %ELIM5, %ELIM7 ; <i32> [#uses=1]
ret i32 %tmp.8
}