New testcase for masking operation that frequently occurs in the pool allocator

for converting a number that is a power of two into a mask

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9706 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/xor.ll b/test/Transforms/InstCombine/xor.ll
index 6082e0c9a1b73086bfb851a6fd63ac489b5af8c7..0e6550c23337da4ef04e4d513a8a2bf106c30a17 100644 (file)
--- a/test/Transforms/InstCombine/xor.ll
+++ b/test/Transforms/InstCombine/xor.ll
@@ -98,3 +98,9 @@ bool %test14(ubyte %A, ubyte %B) {
        %E = xor bool %C, %D        ; E = true
        ret bool %E
 }
+
+uint %test15(uint %A) {             ; ~(X-1) == -X
+       %B = add uint %A, 4294967295
+       %C = xor uint %B, 4294967295
+       ret uint %C
+}