Regression is gone, don't try to find it on clean target.

llvm-svn: 33296

1 files changed, 26 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/bit-tracking.ll b/llvm/test/Transforms/InstCombine/bit-tracking.ll
new file mode 100644
index 00000000000..f6654738d7f
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/bit-tracking.ll
@@ -0,0 +1,26 @@
+; 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
+}
+