[APIntTest] multiplicativeInverse(): clarify test

Clarify that multiplicative inverse exists for all odd numbers,
and does not exist for all even numbers (including 0).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364920 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/unittests/ADT/APIntTest.cpp b/unittests/ADT/APIntTest.cpp
index 64560669342a1aa76b894386edddfebbf5d1aac3..4ab79e4b32f4afa2e573f525f1948730ab3bf59a 100644 (file)
--- a/unittests/ADT/APIntTest.cpp
+++ b/unittests/ADT/APIntTest.cpp
@@ -2527,10 +2527,13 @@ TEST(APIntTest, MultiplicativeInverseExaustive) {
               .multiplicativeInverse(APInt::getSignedMinValue(BitWidth + 1))
               .trunc(BitWidth);
       APInt One = V * MulInv;
-      EXPECT_TRUE(MulInv.isNullValue() || One.isOneValue())
-          << " bitwidth = " << BitWidth << ", value = " << Value
-          << ", computed multiplicative inverse = " << MulInv
-          << ", value * multiplicative inverse = " << One << " (should be 1)";
+      if (!V.isNullValue() && V.countTrailingZeros() == 0) {
+        // Multiplicative inverse exists for all odd numbers.
+        EXPECT_TRUE(One.isOneValue());
+      } else {
+        // Multiplicative inverse does not exist for even numbers (and 0).
+        EXPECT_TRUE(MulInv.isNullValue());
+      }
     }
   }
 }