* Documentation patch related to PR42376
@ 2010-01-07 15:44 Martin Reinecke
2010-01-11 8:54 ` Gerald Pfeifer
0 siblings, 1 reply; 6+ messages in thread
From: Martin Reinecke @ 2010-01-07 15:44 UTC (permalink / raw)
To: GCC Patches; +Cc: rguenth
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Hi,
here is a proposed patch to gcc-4.5/changes.html, which mentions the apparent
performance regression mentioned in PR42376 (and describes how to avoid it)
in the "Caveats" section.
The FSF should have my copyright assignment; in any case I think this patch is
trivial enough.
Cheers,
Martin
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Index: changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.5/changes.html,v
retrieving revision 1.58
diff -u -3 -r1.58 changes.html
--- changes.html 24 Dec 2009 10:49:56 -0000 1.58
+++ changes.html 7 Jan 2010 15:10:56 -0000
@@ -39,6 +39,13 @@
<code>-gdwarf-2 -gstrict-dwarf</code> restrict GCC to just DWARF2
standard, but epilogue unwind info is emitted unconditionally whenever
unwind info is emitted. </li>
+
+ <li>On i386 targets, codes containing floating-point calculations may run
+ significantly more slowly when compiled with GCC 4.5.x in strict C99
+ conformance mode than they did with earlier GCC versions. This is due
+ to stricter standard conformance of the compiler and can be avoided by
+ using the flag <code>-fexcess-precision=fast</code>; see also
+ <a href="#ia32_x86_64">below</a>.</li>
</ul>
<h2>General Optimizer Improvements</h2>
@@ -460,7 +467,7 @@
</li>
</ul>
-<h3>IA-32/x86-64</h3>
+<h3 id=ia32_x86_64>IA-32/x86-64</h3>
<ul>
<li>GCC now supports handling floating-point excess precision
arising from use of the x87 floating-point unit in a way that
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Documentation patch related to PR42376
2010-01-07 15:44 Documentation patch related to PR42376 Martin Reinecke
@ 2010-01-11 8:54 ` Gerald Pfeifer
2010-01-11 10:08 ` Martin Reinecke
0 siblings, 1 reply; 6+ messages in thread
From: Gerald Pfeifer @ 2010-01-11 8:54 UTC (permalink / raw)
To: Martin Reinecke; +Cc: GCC Patches, rguenth
On Thu, 7 Jan 2010, Martin Reinecke wrote:
> here is a proposed patch to gcc-4.5/changes.html, which mentions the
> apparent performance regression mentioned in PR42376 (and describes how
> to avoid it) in the "Caveats" section.
Thanks, Martin.
> The FSF should have my copyright assignment; in any case I think this
> patch is trivial enough.
I checked, and indeed did find your assignment on file with the FSF.
There are some minor changes I made to your patch, specifically I
replaced "i386 targets" by "x86 targets" and id=ia32_x86_64 by id="x86".
See below for the patch as I committed it now
Gerald
Index: changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.5/changes.html,v
retrieving revision 1.63
diff -u -3 -p -r1.63 changes.html
--- changes.html 11 Jan 2010 08:44:28 -0000 1.63
+++ changes.html 11 Jan 2010 08:47:41 -0000
@@ -39,6 +39,13 @@
<code>-gdwarf-2 -gstrict-dwarf</code> restrict GCC to just DWARF2
standard, but epilogue unwind info is emitted unconditionally whenever
unwind info is emitted. </li>
+
+ <li>On x86 targets, code containing floating-point calculations may
+ run significantly slower when compiled with GCC 4.5 in strict C99
+ conformance mode than they did with earlier GCC versions. This is due
+ to stricter standard conformance of the compiler and can be avoided by
+ using the flag <code>-fexcess-precision=fast</code>; also see
+ <a href="#x86">below</a>.</li>
</ul>
<h2>General Optimizer Improvements</h2>
@@ -530,7 +537,7 @@ transformed via the <code>-D_GLIBCXX_PRO
</li>
</ul>
-<h3>IA-32/x86-64</h3>
+<h3 id="x86">IA-32/x86-64</h3>
<ul>
<li>GCC now supports handling floating-point excess precision
arising from use of the x87 floating-point unit in a way that
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Documentation patch related to PR42376
2010-01-11 8:54 ` Gerald Pfeifer
@ 2010-01-11 10:08 ` Martin Reinecke
2017-02-27 22:34 ` Gerald Pfeifer
0 siblings, 1 reply; 6+ messages in thread
From: Martin Reinecke @ 2010-01-11 10:08 UTC (permalink / raw)
To: Gerald Pfeifer; +Cc: GCC Patches, rguenth
Hi Gerald,
thanks for applying the patch!
Unfortunately I just noticed some mistakes in my wording :(
Currently the sentence says
"code [...] may run significantly slower [...] than they did [...]"
I'm not a native speaker, but I guess it would be more correct
to write
"code [...] may run significantly more slowly [...] than it did [...]"
Sorry for noticing this so late.
Cheers,
Martin
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Documentation patch related to PR42376
2010-01-11 10:08 ` Martin Reinecke
@ 2017-02-27 22:34 ` Gerald Pfeifer
2017-02-28 2:52 ` Sandra Loosemore
0 siblings, 1 reply; 6+ messages in thread
From: Gerald Pfeifer @ 2017-02-27 22:34 UTC (permalink / raw)
To: Martin Reinecke, Sandra Loosemore; +Cc: gcc-patches
On Mon, 11 Jan 2010, Martin Reinecke wrote:
> thanks for applying the patch!
> Unfortunately I just noticed some mistakes in my wording :(
> Currently the sentence says
> "code [...] may run significantly slower [...] than they did [...]"
> I'm not a native speaker, but I guess it would be more correct
> to write
> "code [...] may run significantly more slowly [...] than it did [...]"
I realized that we did not actually update this back then, and
will admit that "significantly more slowly" feels less natural
than "significantly slower" to me, but then I am not a native
speaker either. ;-)
Sandra, what is your take on the patch below?
Gerald
Index: changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.5/changes.html,v
retrieving revision 1.115
diff -u -r1.115 changes.html
--- changes.html 28 May 2016 20:40:35 -0000 1.115
+++ changes.html 27 Feb 2017 22:23:27 -0000
@@ -68,7 +68,7 @@
unwind info is emitted.</li>
<li>On x86 targets, code containing floating-point calculations may
- run significantly slower when compiled with GCC 4.5 in strict C99
+ run significantly more slowly when compiled with GCC 4.5 in strict C99
conformance mode than they did with earlier GCC versions. This is due
to stricter standard conformance of the compiler and can be avoided by
using the option <code>-fexcess-precision=fast</code>; also see
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Documentation patch related to PR42376
2017-02-27 22:34 ` Gerald Pfeifer
@ 2017-02-28 2:52 ` Sandra Loosemore
2017-02-28 10:10 ` Gerald Pfeifer
0 siblings, 1 reply; 6+ messages in thread
From: Sandra Loosemore @ 2017-02-28 2:52 UTC (permalink / raw)
To: Gerald Pfeifer, Martin Reinecke; +Cc: gcc-patches
On 02/27/2017 03:26 PM, Gerald Pfeifer wrote:
> On Mon, 11 Jan 2010, Martin Reinecke wrote:
>> thanks for applying the patch!
>> Unfortunately I just noticed some mistakes in my wording :(
>> Currently the sentence says
>> "code [...] may run significantly slower [...] than they did [...]"
>> I'm not a native speaker, but I guess it would be more correct
>> to write
>> "code [...] may run significantly more slowly [...] than it did [...]"
>
> I realized that we did not actually update this back then, and
> will admit that "significantly more slowly" feels less natural
> than "significantly slower" to me, but then I am not a native
> speaker either. ;-)
>
> Sandra, what is your take on the patch below?
Errrr.... I would have written "more slowly" (since this is an adverb
modifying "run"), but apparently both usages are correct.
https://www.grammarly.com/answers/questions/79959-comparing-with-adverbs/
-Sandra
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Documentation patch related to PR42376
2017-02-28 2:52 ` Sandra Loosemore
@ 2017-02-28 10:10 ` Gerald Pfeifer
0 siblings, 0 replies; 6+ messages in thread
From: Gerald Pfeifer @ 2017-02-28 10:10 UTC (permalink / raw)
To: Sandra Loosemore; +Cc: Martin Reinecke, gcc-patches
On Mon, 27 Feb 2017, Sandra Loosemore wrote:
> Errrr.... I would have written "more slowly" (since this is an adverb
> modifying "run"), but apparently both usages are correct.
>
> https://www.grammarly.com/answers/questions/79959-comparing-with-adverbs/
Thank you, Sandra!
Since both are viable, and you prefer "more slowly", and so did
Martin by submitting his patch, I went ahead and committed this
change.
Ger "learned something new" ald
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-02-28 10:09 UTC | newest]
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2010-01-07 15:44 Documentation patch related to PR42376 Martin Reinecke
2010-01-11 8:54 ` Gerald Pfeifer
2010-01-11 10:08 ` Martin Reinecke
2017-02-27 22:34 ` Gerald Pfeifer
2017-02-28 2:52 ` Sandra Loosemore
2017-02-28 10:10 ` Gerald Pfeifer
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