From: Jonathan Wakely <jwakely@redhat.com>
Date: Tue, 8 Mar 2022 12:15:55 +0000 (+0000)
Subject: libstdc++: Support VAX floats in std::strong_order
X-Git-Tag: basepoints/gcc-13~724
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cfaa2fac42f6f4bddb197dc1fc601f2ba136f9f0;p=thirdparty%2Fgcc.git

libstdc++: Support VAX floats in std::strong_order

The VAX float and double format does not support NaN, so the
std::partial_ordering returned by <=> will never be 'unordered'. We can
just use the partial_ordering value as the strong_ordering.

libstdc++-v3/ChangeLog:

	* libsupc++/compare (_Strong_ordering::_S_fp_cmp) [__vax__]: Use
	<=> comparison.
---

diff --git a/libstdc++-v3/libsupc++/compare b/libstdc++-v3/libsupc++/compare
index 050cf7ed20d1..3c22d9addf17 100644
--- a/libstdc++-v3/libsupc++/compare
+++ b/libstdc++-v3/libsupc++/compare
@@ -843,6 +843,11 @@ namespace std
 	static constexpr strong_ordering
 	_S_fp_cmp(_Tp __x, _Tp __y) noexcept
 	{
+#ifdef __vax__
+	  // VAX format has no NaN, only "excess" for Inf, so totally ordered.
+	  return __builtin_bit_cast(strong_ordering, __x <=> __y);
+#endif
+
 	  auto __ix = _S_fp_bits(__x);
 	  auto __iy = _S_fp_bits(__y);