teach ConstantRange that zero times X is always zero

[oota-llvm.git] / unittests / Support / ConstantRangeTest.cpp

diff --git a/unittests/Support/ConstantRangeTest.cpp b/unittests/Support/ConstantRangeTest.cpp
index 6d2510ced5656a9155fed7c64b2226ca7e9b1570..7d4055f889f55cfab10f15b1467fc45ddf3b472c 100644 (file)
--- a/unittests/Support/ConstantRangeTest.cpp
+++ b/unittests/Support/ConstantRangeTest.cpp
@@ -382,6 +382,14 @@ TEST_F(ConstantRangeTest, Multiply) {
   EXPECT_EQ(Some.multiply(Wrap), Full);
   EXPECT_EQ(Wrap.multiply(Wrap), Full);
 
+  ConstantRange Zero(APInt(16, 0));
+  EXPECT_EQ(Zero.multiply(Full), Zero);
+  EXPECT_EQ(Zero.multiply(Some), Zero);
+  EXPECT_EQ(Zero.multiply(Wrap), Zero);
+  EXPECT_EQ(Full.multiply(Zero), Zero);
+  EXPECT_EQ(Some.multiply(Zero), Zero);
+  EXPECT_EQ(Wrap.multiply(Zero), Zero);
+
   // http://llvm.org/PR4545
   EXPECT_EQ(ConstantRange(APInt(4, 1), APInt(4, 6)).multiply(
                 ConstantRange(APInt(4, 6), APInt(4, 2))),