; This file contains various testcases that require tracking whether bits are ; set or cleared by various instructions. ; XFAIL: * ; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep %ELIM ; test1 - Eliminating the casts in this testcase (by narrowing the AND ; operation) allows instcombine to realize the function always returns false. ; bool %test1(int %A, int %B) { %C1 = setlt int %A, %B %ELIM1 = cast bool %C1 to uint %C2 = setgt int %A, %B %ELIM2 = cast bool %C2 to uint %C3 = and uint %ELIM1, %ELIM2 %ELIM3 = cast uint %C3 to bool 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 }