; 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
-; RUN: llvm-as < %s | opt -instcombine | llvm-dis | 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
+}
-; 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
+; 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
}