commit 9d6b222c3ab0d56eb71e1feb1b578d87b3e51360
author Peter Klausler <35819229+klausler@users.noreply.github.com> Fri Mar 01 14:15:48 2024 -0800
committer Copybara-Service <copybara-worker@google.com> Fri Mar 01 14:19:13 2024 -0800
tree bb10a08dd8775be72308d719133ae7ad06d6acc6
parent c2b7c00d2a08029009216cdfde4e437176e4d838

[flang][runtime] Underflow real input to -0. when negative (#82443)

When the result of real input editing underflows to zero, return -0.
when the input field had a minus sign.

GitOrigin-RevId: 4762c6557d15ba45594793749fea8df6c911f0a8

lib/Decimal/decimal-to-binary.cpp

diff --git a/lib/Decimal/decimal-to-binary.cpp b/lib/Decimal/decimal-to-binary.cpp
index d38af0f..c5cdb72 100644
--- a/lib/Decimal/decimal-to-binary.cpp
+++ b/lib/Decimal/decimal-to-binary.cpp
@@ -14,6 +14,7 @@
 #include <cinttypes>
 #include <cstring>
 #include <ctype.h>
+#include <utility>
 
 namespace Fortran::decimal {
 
@@ -275,7 +276,12 @@
         if (guard != 0) {
           flags |= Underflow;
         }
-        return {Binary{}, static_cast<enum ConversionResultFlags>(flags)};
+        Binary zero;
+        if (isNegative) {
+          zero.Negate();
+        }
+        return {
+            std::move(zero), static_cast<enum ConversionResultFlags>(flags)};
       }
     }
   } else {

unittests/Runtime/NumericalFormatTest.cpp

diff --git a/unittests/Runtime/NumericalFormatTest.cpp b/unittests/Runtime/NumericalFormatTest.cpp
index 03a2be3..37eecd7 100644
--- a/unittests/Runtime/NumericalFormatTest.cpp
+++ b/unittests/Runtime/NumericalFormatTest.cpp
@@ -916,7 +916,7 @@
       {"(RU,F7.0)", "-1.e999", 0xffefffffffffffff, 0}, // -HUGE()
       {"(E9.1)", " 1.0E-325", 0x0, 0},
       {"(RU,E9.1)", " 1.0E-325", 0x1, 0},
-      {"(E9.1)", "-1.0E-325", 0x0, 0},
+      {"(E9.1)", "-1.0E-325", 0x8000000000000000, 0},
       {"(RD,E9.1)", "-1.0E-325", 0x8000000000000001, 0},
   };
   for (auto const &[format, data, want, iostat] : testCases) {