[libc++] Work around gcc/Power9 bug in `include/thread`
This fixes PR39696, which breaks the libcxx build with gcc (I tested
7.5.0) on Power9. This fix was suggested at
https://bugs.llvm.org/show_bug.cgi?id=39696#c38
but never applied. It just reverts 0583d9ea8d5e, which reverses
components of the original fix in 3bf63cf3b366, which is correct.
Fixes https://llvm.org/PR39696
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D81438
Cr-Mirrored-From: https://chromium.googlesource.com/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: d9a42ec98adcb1ebc0c3837715df4e5a50c7ccc0
diff --git a/include/thread b/include/thread
index 22aa4f2..6eff180 100644
--- a/include/thread
+++ b/include/thread
@@ -365,9 +365,9 @@
{
#if defined(_LIBCPP_COMPILER_GCC) && (__powerpc__ || __POWERPC__)
// GCC's long double const folding is incomplete for IBM128 long doubles.
- _LIBCPP_CONSTEXPR duration<long double> _Max = nanoseconds::max();
-#else
_LIBCPP_CONSTEXPR duration<long double> _Max = duration<long double>(ULLONG_MAX/1000000000ULL) ;
+#else
+ _LIBCPP_CONSTEXPR duration<long double> _Max = nanoseconds::max();
#endif
nanoseconds __ns;
if (__d < _Max)