diff options
| -rw-r--r-- | test/Transforms/InstCombine/bit-tracking.ll | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/bit-tracking.ll b/test/Transforms/InstCombine/bit-tracking.ll index 10d1cc2ed6..06cf65ccc9 100644 --- a/test/Transforms/InstCombine/bit-tracking.ll +++ b/test/Transforms/InstCombine/bit-tracking.ll @@ -16,3 +16,32 @@ bool %test1(int %A, int %B) { ret bool %ELIM3 } +; See if we can eliminate the shifts... +int %test2(int %B) { + %ELIM1 = shl int %B, ubyte 31 + %ELIM2 = shr int %ELIM1, ubyte 31 + %inc = add int %ELIM2, 1 ; == xor int %B, 1 + ret int %inc +} + +; Reduce down to a single XOR +int %test3(int %B) { + %ELIMinc = and int %B, 1 + %tmp.5 = xor int %ELIMinc, 1 + %ELIM7 = and int %B, -2 + %tmp.8 = or int %tmp.5, %ELIM7 + ret int %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. +int %test4(int %B) { + %ELIM3 = shl int %B, ubyte 31 + %ELIM4 = shr int %ELIM3, ubyte 31 + %inc = add int %ELIM4, 1 + %ELIM5 = and int %inc, 1 + %ELIM7 = and int %B, -2 + %tmp.8 = or int %ELIM5, %ELIM7 + ret int %tmp.8 +} + |