llvm-6502/test/Transforms/InstCombine/bit-tracking.ll
2006-12-02 04:23:10 +00:00

27 lines
933 B
LLVM

; This file contains various testcases that require tracking whether bits are
; set or cleared by various instructions.
; RUN: llvm-upgrade < %s | llvm-as | opt -instcombine -instcombine -disable-output &&
; RUN: llvm-upgrade < %s | llvm-as | opt -instcombine -instcombine | llvm-dis | not grep %ELIM
; 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
}