Another test to exercise APInt divide step D6.

This is divrem_big7 since divrem_big6 is used in Pawel upcoming patch.

llvm-svn: 235536

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index acdc1ecbbde..a8fc3629cdb 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -409,6 +409,19 @@ TEST(APIntTest, divrem_big5) {
   EXPECT_EQ(r, c);
 }
 
+TEST(APIntTest, divrem_big7) {
+  // Yet another test for KnuthDiv rare step D6.
+  APInt a{224, "800000008000000200000005", 16};
+  APInt b{224, "fffffffd", 16};
+  APInt c{224, "80000000800000010000000f", 16};
+
+  auto p = a * b + c;
+  auto q = p.udiv(a);
+  auto r = p.urem(a);
+  EXPECT_EQ(q, b);
+  EXPECT_EQ(r, c);
+}
+
 TEST(APIntTest, fromString) {
   EXPECT_EQ(APInt(32, 0), APInt(32,   "0", 2));
   EXPECT_EQ(APInt(32, 1), APInt(32,   "1", 2));