Ian Lance Taylor - Re: Change to gcc/config/i386/emmintrin.h (original) (raw)

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• From: Ian Lance Taylor
• To: "Jagasia, Harsha"
• Cc: "Jakub Jelinek" , gcc-patches at gcc dot gnu dot org
• Date: 07 Feb 2007 07🔞55 -0800
• Subject: Re: Change to gcc/config/i386/emmintrin.h
• References: <D5B24B5251882048AD03DDFA431BB79059CF69@SAUSEXMB3.amd.com>

Your mailer is not threading properly. It is not inserting appropriate References headers.

"Jagasia, Harsha" harsha.jagasia@amd.com writes:

Hi Jakub,

On Tue, Feb 06, 2007 at 12:11:17PM -0600, Jagasia, Harsha wrote:

From what I can see, xmmintrin.h (SSE header) includes emmintrin.h (SSE2 header) at the end of the file.

/* For backward source compatibility.  */
#include <emmintrin.h>

Then perhaps you can do there: /* For backward source compatibility. */ #ifdef SSE2

include <emmintrin.h>

#endif

Jakub

Sure, that's the easy fix. I suspect any code base that Ian or others are running outside of the testsuite, which relies on this behavior, will have to change the makefiles etc accordingly.

That #include was added when emmintrin.h was introduced, here:

http://gcc.gnu.org/ml/gcc-patches/2003-06/msg00229.html

It was introduced for backward compatibility. Your change breaks that backward compatibility. This should have been handled separately from the amdfam10 patches. It has nothing to do with amdfam10, and it was quite easy to miss the change in the patch, especially without the ChangeLog entry. In the future, please send unrelated patches in separate e-mail messages. Thanks.

In order to acheive the two goals of backward compatibility (insofar as that is important) and correctness, Jakub's patch looks right to me. I don't see why it would require any changes to Makefiles. The intrinsic functions in emmintrin.h were ineffective without -msse2.

So I will preapprove that patch. Harsha, please test it with a bootstrap and testsuite run for the target i686-pc-linux-gnu--i.e., a target which does not natively support any form of SSE. If it passes, please commit it with an appropriate ChangeLog entry. If you have any questions or concerns, please ask. Thanks.

Ian

• References:
  • RE: Change to gcc/config/i386/emmintrin.h
    * From: Jagasia, Harsha