From: Jonathan Wakely <jwakely@redhat.com>
To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: [PATCH][risc-v] libstdc++: Preserve signbit of nan when converting float to double [PR113578]
Date: Tue, 7 May 2024 14:49:33 +0100 [thread overview]
Message-ID: <20240507135019.3821031-1-jwakely@redhat.com> (raw)
Do we want this change for RISC-V, to fix PR113578?
I haven't tested it on RISC-V, only on x86_64-linux (where it doesn't do
anything).
-- >8 --
libstdc++-v3/ChangeLog:
PR libstdc++/113578
* include/std/ostream (operator<<(basic_ostream&, float)):
Restore signbit after converting to double.
---
libstdc++-v3/include/std/ostream | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/libstdc++-v3/include/std/ostream b/libstdc++-v3/include/std/ostream
index 8a21758d0a3..d492168ca0e 100644
--- a/libstdc++-v3/include/std/ostream
+++ b/libstdc++-v3/include/std/ostream
@@ -233,7 +233,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 117. basic_ostream uses nonexistent num_put member functions.
+#ifdef __riscv
+ return _M_insert(__builtin_copysign((double)__f,
+ (double)-__builtin_signbit(__f));
+#else
return _M_insert(static_cast<double>(__f));
+#endif
}
__ostream_type&
--
2.44.0
next reply other threads:[~2024-05-07 13:50 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 13:49 Jonathan Wakely [this message]
2024-05-07 13:57 ` Jeff Law
2024-05-07 14:06 ` Jonathan Wakely
2024-05-07 14:11 ` Jonathan Wakely
2024-05-07 16:24 ` Palmer Dabbelt
2024-05-10 10:58 ` Jonathan Wakely
2024-05-07 15:25 ` Jeff Law
2024-05-07 15:36 ` Andreas Schwab
2024-05-07 16:31 ` Jeff Law
2024-05-07 16:39 ` Jonathan Wakely
2024-05-07 16:45 ` Jonathan Wakely
2024-05-08 10:32 ` Andrew Waterman
2024-05-08 10:40 ` Jonathan Wakely
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