1 ; This file contains various testcases that require tracking whether bits are 2 ; set or cleared by various instructions. 3 ; RUN: opt < %s -instcombine -instcombine -S |\ 4 ; RUN: not grep %ELIM 5 6 ; Reduce down to a single XOR 7 define i32 @test3(i32 %B) { 8 %ELIMinc = and i32 %B, 1 ; <i32> [#uses=1] 9 %tmp.5 = xor i32 %ELIMinc, 1 ; <i32> [#uses=1] 10 %ELIM7 = and i32 %B, -2 ; <i32> [#uses=1] 11 %tmp.8 = or i32 %tmp.5, %ELIM7 ; <i32> [#uses=1] 12 ret i32 %tmp.8 13 } 14 15 ; Finally, a bigger case where we chain things together. This corresponds to 16 ; incrementing a single-bit bitfield, which should become just an xor. 17 define i32 @test4(i32 %B) { 18 %ELIM3 = shl i32 %B, 31 ; <i32> [#uses=1] 19 %ELIM4 = ashr i32 %ELIM3, 31 ; <i32> [#uses=1] 20 %inc = add i32 %ELIM4, 1 ; <i32> [#uses=1] 21 %ELIM5 = and i32 %inc, 1 ; <i32> [#uses=1] 22 %ELIM7 = and i32 %B, -2 ; <i32> [#uses=1] 23 %tmp.8 = or i32 %ELIM5, %ELIM7 ; <i32> [#uses=1] 24 ret i32 %tmp.8 25 } 26 27
