More testcases

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9675 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/bit-tracking.ll b/test/Transforms/InstCombine/bit-tracking.ll
index 10d1cc2ed61e5c25ef842e33a6b55b16876b1efe..06cf65ccc941fad1e2360e15c05323281ec83d6c 100644 (file)
--- 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
+}
+