[APInt] Keep the original bit width in quotient and remainder
Some trivial cases in udivrem were handled by directly assigning 0 or 1
to APInt objects. This would set the bit width to 1, instead of the bit
width of the inputs. A potentially undesirable side effect of that is
that with the bit width of 1, 1 equals -1.
Differential Revision: https://reviews.llvm.org/D49554
llvm-svn: 337478
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index 4eb6d67..48f9119 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -1060,6 +1060,38 @@
APInt{1024, 1});
}
+TEST(APIntTest, divrem_simple) {
+ // Test simple cases.
+ APInt A(65, 2), B(65, 2);
+ APInt Q, R;
+
+ // X / X
+ APInt::sdivrem(A, B, Q, R);
+ EXPECT_EQ(Q, APInt(65, 1));
+ EXPECT_EQ(R, APInt(65, 0));
+ APInt::udivrem(A, B, Q, R);
+ EXPECT_EQ(Q, APInt(65, 1));
+ EXPECT_EQ(R, APInt(65, 0));
+
+ // 0 / X
+ APInt O(65, 0);
+ APInt::sdivrem(O, B, Q, R);
+ EXPECT_EQ(Q, APInt(65, 0));
+ EXPECT_EQ(R, APInt(65, 0));
+ APInt::udivrem(O, B, Q, R);
+ EXPECT_EQ(Q, APInt(65, 0));
+ EXPECT_EQ(R, APInt(65, 0));
+
+ // X / 1
+ APInt I(65, 1);
+ APInt::sdivrem(A, I, Q, R);
+ EXPECT_EQ(Q, A);
+ EXPECT_EQ(R, APInt(65, 0));
+ APInt::udivrem(A, I, Q, R);
+ EXPECT_EQ(Q, A);
+ EXPECT_EQ(R, APInt(65, 0));
+}
+
TEST(APIntTest, fromString) {
EXPECT_EQ(APInt(32, 0), APInt(32, "0", 2));
EXPECT_EQ(APInt(32, 1), APInt(32, "1", 2));