Fix APFloat from string conversion for Inf

The method IEEEFloat::convertFromStringSpecials() does not recognize
the "+Inf" and "-Inf" strings but these strings are printed for
the double Infinities by the IEEEFloat::toString().

This patch adds the "+Inf" and "-Inf" strings to the list of recognized
patterns in IEEEFloat::convertFromStringSpecials().

Re-landing after fix.

Reviewers: sberg, bogner, majnemer, timshen, rnk, skatkov, gottesmm, bkramer, scanon, anna
Reviewed By: anna
Subscribers: mkazantsev, FlameTop, llvm-commits, reames, apilipenko
Differential Revision: https://reviews.llvm.org/D38030

llvm-svn: 321054

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/unittests/ADT/StringRefTest.cpp b/llvm/unittests/ADT/StringRefTest.cpp
index 0684afe678f..0e0b5957f02 100644
--- a/llvm/unittests/ADT/StringRefTest.cpp
+++ b/llvm/unittests/ADT/StringRefTest.cpp
@@ -875,7 +875,12 @@ struct GetDoubleStrings {
                      {"0.0", false, false, 0.0},
                      {"-0.0", false, false, -0.0},
                      {"123.45", false, true, 123.45},
-                     {"123.45", true, false, 123.45}};
+                     {"123.45", true, false, 123.45},
+                     {"1.8e308", true, false, std::numeric_limits<double>::infinity()},
+                     {"1.8e308", false, true, std::numeric_limits<double>::infinity()},
+                     {"0x0.0000000000001P-1023", false, true, 0.0},
+                     {"0x0.0000000000001P-1023", true, false, 0.0},
+                    };
 
 TEST(StringRefTest, getAsDouble) {
   for (const auto &Entry : DoubleStrings) {