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From: "malat at debian dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/110622] x87: Miscompilation at O2 level (O1 is working)
Date: Thu, 21 Sep 2023 09:51:16 +0000	[thread overview]
Message-ID: <bug-110622-4-KfQVIoG8ke@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-110622-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110622

--- Comment #11 from Mathieu Malaterre <malat at debian dot org> ---
Typical setup:

g++ -fno-asynchronous-unwind-tables -fno-exceptions -fno-rtti -DHIDESYMPTOM
-std=c++11 -g -m32 -fexcess-precision=fast -O2 -o works math_test.cc
-Wfatal-errors -Wall -Wextra -Wpedantic -Wconversion -Werror

and:

g++ -fno-asynchronous-unwind-tables -fno-exceptions -fno-rtti -std=c++11 -g
-m32 -fexcess-precision=fast -O2 -o fails math_test.cc -Wfatal-errors -Wall
-Wextra -Wpedantic -Wconversion -Werror

You can observe that the only difference is that I am preventing an elision :

```
% grep -A2 HIDE math_test.cc
#ifdef HIDESYMPTOM
  asm volatile("" : "+r"(y.raw[0]) : : "memory");
#endif
```

  parent reply	other threads:[~2023-09-21  9:51 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-11  6:28 [Bug c++/110622] New: x86: Miscompilation at O1 level (O0 " malat at debian dot org
2023-07-11  6:29 ` [Bug c++/110622] " malat at debian dot org
2023-07-11  6:30 ` malat at debian dot org
2023-07-11  6:31 ` pinskia at gcc dot gnu.org
2023-07-11  6:33 ` malat at debian dot org
2023-07-11  6:33 ` malat at debian dot org
2023-07-11  6:38 ` pinskia at gcc dot gnu.org
2023-07-11  6:44 ` [Bug target/110622] " malat at debian dot org
2023-07-11  8:25 ` malat at debian dot org
2023-09-21  9:44 ` malat at debian dot org
2023-09-21  9:48 ` [Bug target/110622] x87: Miscompilation at O2 level (O1 " malat at debian dot org
2023-09-21  9:51 ` malat at debian dot org [this message]
2023-09-21  9:56 ` malat at debian dot org
2023-09-21 13:33 ` pinskia at gcc dot gnu.org
2023-09-21 13:42 ` malat at debian dot org
2023-09-21 13:45 ` xry111 at gcc dot gnu.org
2023-09-21 14:29 ` malat at debian dot org

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