[PATCH] D70425: [APFloat] Fix construction of APFloat with FP value instead of integer

[Ehud Katz via Phabricator via llvm-commits]

ekatz created this revision.
ekatz added reviewers: scanon, chandlerc, arsenm, efriedma.
ekatz added a project: LLVM.
Herald added subscribers: llvm-commits, dexonsmith, wdng.

Constructor invocations such as `APFloat(APFloat::IEEEdouble(), 0.0)` have a float literal (only `0.0`, `1.0` and `3.0` in all the unit tests) in the source but the overload they reach is actually the `integerPart` one, not a `float` or `double` overload (which only exists when `fltSemantics` isn't passed).

This may lead to possible loss of data, by the conversion from `float` or `double` to 'integerPart'. The tests just happen to pass, as the FP values used are all without fraction.

Fix PR34095.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D70425

Files:
  llvm/unittests/ADT/APFloatTest.cpp


Index: llvm/unittests/ADT/APFloatTest.cpp
===================================================================
--- llvm/unittests/ADT/APFloatTest.cpp
+++ llvm/unittests/ADT/APFloatTest.cpp
@@ -520,9 +520,9 @@
 
   // Test x87 extended precision case from http://llvm.org/PR20728.
   {
-    APFloat M1(APFloat::x87DoubleExtended(), 1.0);
-    APFloat M2(APFloat::x87DoubleExtended(), 1.0);
-    APFloat A(APFloat::x87DoubleExtended(), 3.0);
+    APFloat M1(APFloat::x87DoubleExtended(), 1);
+    APFloat M2(APFloat::x87DoubleExtended(), 1);
+    APFloat A(APFloat::x87DoubleExtended(), 3);
 
     bool losesInfo = false;
     M1.fusedMultiplyAdd(M1, A, APFloat::rmNearestTiesToEven);
@@ -591,9 +591,9 @@
   {
     const char *MinNormalStr = "1.17549435082228750797e-38";
     EXPECT_FALSE(APFloat(APFloat::IEEEsingle(), MinNormalStr).isDenormal());
-    EXPECT_FALSE(APFloat(APFloat::IEEEsingle(), 0.0).isDenormal());
+    EXPECT_FALSE(APFloat(APFloat::IEEEsingle(), 0).isDenormal());
 
-    APFloat Val2(APFloat::IEEEsingle(), 2.0e0);
+    APFloat Val2(APFloat::IEEEsingle(), 2);
     APFloat T(APFloat::IEEEsingle(), MinNormalStr);
     T.divide(Val2, rdmd);
     EXPECT_TRUE(T.isDenormal());
@@ -603,9 +603,9 @@
   {
     const char *MinNormalStr = "2.22507385850720138309e-308";
     EXPECT_FALSE(APFloat(APFloat::IEEEdouble(), MinNormalStr).isDenormal());
-    EXPECT_FALSE(APFloat(APFloat::IEEEdouble(), 0.0).isDenormal());
+    EXPECT_FALSE(APFloat(APFloat::IEEEdouble(), 0).isDenormal());
 
-    APFloat Val2(APFloat::IEEEdouble(), 2.0e0);
+    APFloat Val2(APFloat::IEEEdouble(), 2);
     APFloat T(APFloat::IEEEdouble(), MinNormalStr);
     T.divide(Val2, rdmd);
     EXPECT_TRUE(T.isDenormal());
@@ -615,9 +615,9 @@
   {
     const char *MinNormalStr = "3.36210314311209350626e-4932";
     EXPECT_FALSE(APFloat(APFloat::x87DoubleExtended(), MinNormalStr).isDenormal());
-    EXPECT_FALSE(APFloat(APFloat::x87DoubleExtended(), 0.0).isDenormal());
+    EXPECT_FALSE(APFloat(APFloat::x87DoubleExtended(), 0).isDenormal());
 
-    APFloat Val2(APFloat::x87DoubleExtended(), 2.0e0);
+    APFloat Val2(APFloat::x87DoubleExtended(), 2);
     APFloat T(APFloat::x87DoubleExtended(), MinNormalStr);
     T.divide(Val2, rdmd);
     EXPECT_TRUE(T.isDenormal());
@@ -627,9 +627,9 @@
   {
     const char *MinNormalStr = "3.36210314311209350626267781732175260e-4932";
     EXPECT_FALSE(APFloat(APFloat::IEEEquad(), MinNormalStr).isDenormal());
-    EXPECT_FALSE(APFloat(APFloat::IEEEquad(), 0.0).isDenormal());
+    EXPECT_FALSE(APFloat(APFloat::IEEEquad(), 0).isDenormal());
 
-    APFloat Val2(APFloat::IEEEquad(), 2.0e0);
+    APFloat Val2(APFloat::IEEEquad(), 2);
     APFloat T(APFloat::IEEEquad(), MinNormalStr);
     T.divide(Val2, rdmd);
     EXPECT_TRUE(T.isDenormal());
@@ -1144,8 +1144,8 @@
 #ifdef GTEST_HAS_DEATH_TEST
 #ifndef NDEBUG
 TEST(APFloatTest, SemanticsDeath) {
-  EXPECT_DEATH(APFloat(APFloat::IEEEsingle(), 0.0f).convertToDouble(), "Float semantics are not IEEEdouble");
-  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), 0.0 ).convertToFloat(),  "Float semantics are not IEEEsingle");
+  EXPECT_DEATH(APFloat(APFloat::IEEEsingle(), 0).convertToDouble(), "Float semantics are not IEEEdouble");
+  EXPECT_DEATH(APFloat(APFloat::IEEEdouble(), 0).convertToFloat(),  "Float semantics are not IEEEsingle");
 }
 
 TEST(APFloatTest, StringDecimalDeath) {


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