commit 157c86913a5d0a9ff9257455600689dc96333321
author Stephen Canon <scanon@apple.com> Fri Mar 31 20:31:33 2017 +0000
committer Stephen Canon <scanon@apple.com> Fri Mar 31 20:31:33 2017 +0000
tree a1d4575e6a5e1a32c309ad387e38668c11cf6c93
parent 34da36e74f1f5ab5874f825074f04ecde2be50f4

Fix APFloat mod (committing for simonbyrne)

The previous version was prone to intermediate rounding or overflow.

Differential Revision: https://reviews.llvm.org/D29346

llvm-svn: 299256

llvm/unittests/ADT/APFloatTest.cpp

diff --git a/llvm/unittests/ADT/APFloatTest.cpp b/llvm/unittests/ADT/APFloatTest.cpp
index 1cd9847..60a920b 100644
--- a/llvm/unittests/ADT/APFloatTest.cpp
+++ b/llvm/unittests/ADT/APFloatTest.cpp
@@ -3192,10 +3192,73 @@
   EXPECT_TRUE(APFloat(APFloat::IEEEdouble(), "0x1.c60f120d9f87cp-1").bitwiseIsEqual(Frac));
 }
 
+TEST(APFloatTest, mod) {
+  {
+    APFloat f1(APFloat::IEEEdouble(), "1.5");
+    APFloat f2(APFloat::IEEEdouble(), "1.0");
+    APFloat expected(APFloat::IEEEdouble(), "0.5");
+    EXPECT_EQ(f1.mod(f2), APFloat::opOK);
+    EXPECT_TRUE(f1.bitwiseIsEqual(expected));
+  }
+  {
+    APFloat f1(APFloat::IEEEdouble(), "0.5");
+    APFloat f2(APFloat::IEEEdouble(), "1.0");
+    APFloat expected(APFloat::IEEEdouble(), "0.5");
+    EXPECT_EQ(f1.mod(f2), APFloat::opOK);
+    EXPECT_TRUE(f1.bitwiseIsEqual(expected));
+  }
+  {
+    APFloat f1(APFloat::IEEEdouble(), "0x1.3333333333333p-2"); // 0.3
+    APFloat f2(APFloat::IEEEdouble(), "0x1.47ae147ae147bp-7"); // 0.01
+    APFloat expected(APFloat::IEEEdouble(),
+                     "0x1.47ae147ae1471p-7"); // 0.009999999999999983
+    EXPECT_EQ(f1.mod(f2), APFloat::opOK);
+    EXPECT_TRUE(f1.bitwiseIsEqual(expected));
+  }
+  {
+    APFloat f1(APFloat::IEEEdouble(), "0x1p64"); // 1.8446744073709552e19
+    APFloat f2(APFloat::IEEEdouble(), "1.5");
+    APFloat expected(APFloat::IEEEdouble(), "1.0");
+    EXPECT_EQ(f1.mod(f2), APFloat::opOK);
+    EXPECT_TRUE(f1.bitwiseIsEqual(expected));
+  }
+  {
+    APFloat f1(APFloat::IEEEdouble(), "0x1p1000");
+    APFloat f2(APFloat::IEEEdouble(), "0x1p-1000");
+    APFloat expected(APFloat::IEEEdouble(), "0.0");
+    EXPECT_EQ(f1.mod(f2), APFloat::opOK);
+    EXPECT_TRUE(f1.bitwiseIsEqual(expected));
+  }
+  {
+    APFloat f1(APFloat::IEEEdouble(), "0.0");
+    APFloat f2(APFloat::IEEEdouble(), "1.0");
+    APFloat expected(APFloat::IEEEdouble(), "0.0");
+    EXPECT_EQ(f1.mod(f2), APFloat::opOK);
+    EXPECT_TRUE(f1.bitwiseIsEqual(expected));
+  }
+  {
+    APFloat f1(APFloat::IEEEdouble(), "1.0");
+    APFloat f2(APFloat::IEEEdouble(), "0.0");
+    EXPECT_EQ(f1.mod(f2), APFloat::opInvalidOp);
+    EXPECT_TRUE(f1.isNaN());
+  }
+  {
+    APFloat f1(APFloat::IEEEdouble(), "0.0");
+    APFloat f2(APFloat::IEEEdouble(), "0.0");
+    EXPECT_EQ(f1.mod(f2), APFloat::opInvalidOp);
+    EXPECT_TRUE(f1.isNaN());
+  }
+  {
+    APFloat f1 = APFloat::getInf(APFloat::IEEEdouble(), false);
+    APFloat f2(APFloat::IEEEdouble(), "1.0");
+    EXPECT_EQ(f1.mod(f2), APFloat::opInvalidOp);
+    EXPECT_TRUE(f1.isNaN());
+  }
+}
+
 TEST(APFloatTest, PPCDoubleDoubleAddSpecial) {
   using DataType = std::tuple<uint64_t, uint64_t, uint64_t, uint64_t,
-                              APFloat::fltCategory, APFloat::roundingMode>;
-  DataType Data[] = {
+                              APFloat::fltCategory, APFloat::roundingMode>;  DataType Data[] = {
       // (1 + 0) + (-1 + 0) = fcZero
       std::make_tuple(0x3ff0000000000000ull, 0, 0xbff0000000000000ull, 0,
                       APFloat::fcZero, APFloat::rmNearestTiesToEven),