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* [Bug target/45365] X86 SSE FP add and multiply aren't commutative with 2 NaNs
[not found] <bug-45365-4@http.gcc.gnu.org/bugzilla/>
@ 2010-11-14 15:55 ` hjl.tools at gmail dot com
2010-11-14 16:17 ` hjl.tools at gmail dot com
2021-11-26 17:58 ` roger at nextmovesoftware dot com
2 siblings, 0 replies; 4+ messages in thread
From: hjl.tools at gmail dot com @ 2010-11-14 15:55 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45365
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |REOPENED
Last reconfirmed| |2010.11.14 15:51:37
CC| |ubizjak at gmail dot com
Resolution|WONTFIX |
Ever Confirmed|0 |1
--- Comment #6 from H.J. Lu <hjl.tools at gmail dot com> 2010-11-14 15:51:37 UTC ---
i386 backend should define HONOR_SNANS.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/45365] X86 SSE FP add and multiply aren't commutative with 2 NaNs
[not found] <bug-45365-4@http.gcc.gnu.org/bugzilla/>
2010-11-14 15:55 ` [Bug target/45365] X86 SSE FP add and multiply aren't commutative with 2 NaNs hjl.tools at gmail dot com
@ 2010-11-14 16:17 ` hjl.tools at gmail dot com
2021-11-26 17:58 ` roger at nextmovesoftware dot com
2 siblings, 0 replies; 4+ messages in thread
From: hjl.tools at gmail dot com @ 2010-11-14 16:17 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45365
--- Comment #7 from H.J. Lu <hjl.tools at gmail dot com> 2010-11-14 15:53:28 UTC ---
Does -fsignaling-nans work here?
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/45365] X86 SSE FP add and multiply aren't commutative with 2 NaNs
[not found] <bug-45365-4@http.gcc.gnu.org/bugzilla/>
2010-11-14 15:55 ` [Bug target/45365] X86 SSE FP add and multiply aren't commutative with 2 NaNs hjl.tools at gmail dot com
2010-11-14 16:17 ` hjl.tools at gmail dot com
@ 2021-11-26 17:58 ` roger at nextmovesoftware dot com
2 siblings, 0 replies; 4+ messages in thread
From: roger at nextmovesoftware dot com @ 2021-11-26 17:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=45365
Roger Sayle <roger at nextmovesoftware dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |shaohua.li at inf dot ethz.ch
--- Comment #8 from Roger Sayle <roger at nextmovesoftware dot com> ---
*** Bug 103406 has been marked as a duplicate of this bug. ***
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/45365] X86 SSE FP add and multiply aren't commutative with 2 NaNs
2010-08-21 3:42 [Bug target/45365] New: X86 FP add and multiply aren't commutative hjl dot tools at gmail dot com
@ 2010-08-23 16:30 ` hjl dot tools at gmail dot com
0 siblings, 0 replies; 4+ messages in thread
From: hjl dot tools at gmail dot com @ 2010-08-23 16:30 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from hjl dot tools at gmail dot com 2010-08-23 16:29 -------
ICC people say
--
In my opinion, FP multiplication and addition should be considered commutative
at both the C and intrinsic level. The only case where the underlying
instructions behave in a non-commutative manner is when both operands are NaN.
And in that case, even the IEEE-754 floating-point standard does not specify
which operand NaN should be returned as the result. The C standard doesn't
distinguish between different NaN values at all.
If the programmer cares about this very subtle detail in the handling of NaNs,
I think inline assembly is the right option.
---
Closing as WONTFIX.
--
hjl dot tools at gmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |WONTFIX
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45365
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-11-26 17:58 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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[not found] <bug-45365-4@http.gcc.gnu.org/bugzilla/>
2010-11-14 15:55 ` [Bug target/45365] X86 SSE FP add and multiply aren't commutative with 2 NaNs hjl.tools at gmail dot com
2010-11-14 16:17 ` hjl.tools at gmail dot com
2021-11-26 17:58 ` roger at nextmovesoftware dot com
2010-08-21 3:42 [Bug target/45365] New: X86 FP add and multiply aren't commutative hjl dot tools at gmail dot com
2010-08-23 16:30 ` [Bug target/45365] X86 SSE FP add and multiply aren't commutative with 2 NaNs hjl dot tools at gmail dot com
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