diff mbox

[FFmpeg-devel,1/9] configure: [loongson] revert no-expensive-optimizations

Message ID 1531399462-14221-1-git-send-email-yinshiyou-hf@loongson.cn
State Superseded
Headers show

Commit Message

殷时友 July 12, 2018, 12:44 p.m. UTC
The bug in  gcc-4.9.x has been fixed in gcc master branch.
Loongson released gcc-4.9.3-3.fc21.loongson with this patch.
More bug info see:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67736
https://gcc.gnu.org/ml/gcc-patches/2012-05/msg00401.html

Change-Id: I780125d4cdee71d40457aaee22126ba0547a2c8f
Signed-off-by: Shiyou Yin <yinshiyou-hf@loongson.cn>
---
 configure | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

殷时友 Aug. 21, 2018, 8:06 a.m. UTC | #1
>-----Original Message-----
>From: ffmpeg-devel-bounces@ffmpeg.org [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of
>Shiyou Yin
>Sent: Thursday, July 12, 2018 8:44 PM
>To: ffmpeg-devel@ffmpeg.org
>Subject: [FFmpeg-devel] [PATCH 1/9] configure: [loongson] revert no-expensive-optimizations
>
>The bug in  gcc-4.9.x has been fixed in gcc master branch.
>Loongson released gcc-4.9.3-3.fc21.loongson with this patch.
>More bug info see:
>https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67736
>https://gcc.gnu.org/ml/gcc-patches/2012-05/msg00401.html
>
>Change-Id: I780125d4cdee71d40457aaee22126ba0547a2c8f
>Signed-off-by: Shiyou Yin <yinshiyou-hf@loongson.cn>
>---
> configure | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
>diff --git a/configure b/configure
>index b1a4dcf..17a7ea9 100755
>--- a/configure
>+++ b/configure
>@@ -4789,13 +4789,13 @@ elif enabled mips; then
>                 disable mipsdspr2
>                 case $cpu in
>                     loongson3*)
>-                        cpuflags="-march=loongson3a -mhard-float -fno-expensive-optimizations"
>+                        cpuflags="-march=loongson3a -mhard-float"
>                     ;;
>                     loongson2e)
>-                        cpuflags="-march=loongson2e -mhard-float -fno-expensive-optimizations"
>+                        cpuflags="-march=loongson2e -mhard-float"
>                     ;;
>                     loongson2f)
>-                        cpuflags="-march=loongson2f -mhard-float -fno-expensive-optimizations"
>+                        cpuflags="-march=loongson2f -mhard-float"
>                     ;;
>                 esac
>             ;;
>--
>2.1.0
>

Hi Michael, could you please help to apply this patch. It has been tested on loongson platform.
Michael Niedermayer Aug. 21, 2018, 10:03 p.m. UTC | #2
On Tue, Aug 21, 2018 at 04:06:05PM +0800, Shiyou Yin wrote:
> >-----Original Message-----
> >From: ffmpeg-devel-bounces@ffmpeg.org [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of
> >Shiyou Yin
> >Sent: Thursday, July 12, 2018 8:44 PM
> >To: ffmpeg-devel@ffmpeg.org
> >Subject: [FFmpeg-devel] [PATCH 1/9] configure: [loongson] revert no-expensive-optimizations
> >
> >The bug in  gcc-4.9.x has been fixed in gcc master branch.
> >Loongson released gcc-4.9.3-3.fc21.loongson with this patch.
> >More bug info see:
> >https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67736
> >https://gcc.gnu.org/ml/gcc-patches/2012-05/msg00401.html
> >
> >Change-Id: I780125d4cdee71d40457aaee22126ba0547a2c8f
> >Signed-off-by: Shiyou Yin <yinshiyou-hf@loongson.cn>
> >---
> > configure | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> >diff --git a/configure b/configure
> >index b1a4dcf..17a7ea9 100755
> >--- a/configure
> >+++ b/configure
> >@@ -4789,13 +4789,13 @@ elif enabled mips; then
> >                 disable mipsdspr2
> >                 case $cpu in
> >                     loongson3*)
> >-                        cpuflags="-march=loongson3a -mhard-float -fno-expensive-optimizations"
> >+                        cpuflags="-march=loongson3a -mhard-float"
> >                     ;;
> >                     loongson2e)
> >-                        cpuflags="-march=loongson2e -mhard-float -fno-expensive-optimizations"
> >+                        cpuflags="-march=loongson2e -mhard-float"
> >                     ;;
> >                     loongson2f)
> >-                        cpuflags="-march=loongson2f -mhard-float -fno-expensive-optimizations"
> >+                        cpuflags="-march=loongson2f -mhard-float"
> >                     ;;
> >                 esac
> >             ;;
> >--
> >2.1.0
> >
> 
> Hi Michael, could you please help to apply this patch. It has been tested on loongson platform.

shouldnt this test the compiler the user uses ? its version or something ?

[...]
殷时友 Aug. 22, 2018, 10:11 a.m. UTC | #3
>-----Original Message-----
>From: ffmpeg-devel-bounces@ffmpeg.org [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of
>Michael Niedermayer
>Sent: Wednesday, August 22, 2018 6:04 AM
>To: FFmpeg development discussions and patches
>Subject: Re: [FFmpeg-devel] [PATCH 1/9] configure: [loongson] revert no-expensive-optimizations
>
>On Tue, Aug 21, 2018 at 04:06:05PM +0800, Shiyou Yin wrote:
>> >-----Original Message-----
>> >From: ffmpeg-devel-bounces@ffmpeg.org
>> >[mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of Shiyou Yin
>> >Sent: Thursday, July 12, 2018 8:44 PM
>> >To: ffmpeg-devel@ffmpeg.org
>> >Subject: [FFmpeg-devel] [PATCH 1/9] configure: [loongson] revert
>> >no-expensive-optimizations
>> >
>> >The bug in  gcc-4.9.x has been fixed in gcc master branch.
>> >Loongson released gcc-4.9.3-3.fc21.loongson with this patch.
>> >More bug info see:
>> >https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67736
>> >https://gcc.gnu.org/ml/gcc-patches/2012-05/msg00401.html
>> >
>> >Change-Id: I780125d4cdee71d40457aaee22126ba0547a2c8f
>> >Signed-off-by: Shiyou Yin <yinshiyou-hf@loongson.cn>
>> >---
>> > configure | 6 +++---
>> > 1 file changed, 3 insertions(+), 3 deletions(-)
>> >
>> >diff --git a/configure b/configure
>> >index b1a4dcf..17a7ea9 100755
>> >--- a/configure
>> >+++ b/configure
>> >@@ -4789,13 +4789,13 @@ elif enabled mips; then
>> >                 disable mipsdspr2
>> >                 case $cpu in
>> >                     loongson3*)
>> >-                        cpuflags="-march=loongson3a -mhard-float
>-fno-expensive-optimizations"
>> >+                        cpuflags="-march=loongson3a -mhard-float"
>> >                     ;;
>> >                     loongson2e)
>> >-                        cpuflags="-march=loongson2e -mhard-float
>-fno-expensive-optimizations"
>> >+                        cpuflags="-march=loongson2e -mhard-float"
>> >                     ;;
>> >                     loongson2f)
>> >-                        cpuflags="-march=loongson2f -mhard-float
>-fno-expensive-optimizations"
>> >+                        cpuflags="-march=loongson2f -mhard-float"
>> >                     ;;
>> >                 esac
>> >             ;;
>> >--
>> >2.1.0
>> >
>>
>> Hi Michael, could you please help to apply this patch. It has been tested on loongson platform.
>
>shouldnt this test the compiler the user uses ? its version or something ?
>
Thank you very much for your review. Be strictly, it's needed to check the compiler version which
user uses. 
Consider that this bug has been fixed about three years and the compiler has been upgraded a lot of
times in loongson yum repository.
At present, there are still only a few developers will build ffmpeg on loongson platform. The risk
of his change is controllable. 
So, between the simplicity and absolute reliability of the code I chosed the simplicity this time.
Should I still add version check here?
Michael Niedermayer Aug. 22, 2018, 7:27 p.m. UTC | #4
On Wed, Aug 22, 2018 at 06:11:15PM +0800, Shiyou Yin wrote:
> >-----Original Message-----
> >From: ffmpeg-devel-bounces@ffmpeg.org [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of
> >Michael Niedermayer
> >Sent: Wednesday, August 22, 2018 6:04 AM
> >To: FFmpeg development discussions and patches
> >Subject: Re: [FFmpeg-devel] [PATCH 1/9] configure: [loongson] revert no-expensive-optimizations
> >
> >On Tue, Aug 21, 2018 at 04:06:05PM +0800, Shiyou Yin wrote:
> >> >-----Original Message-----
> >> >From: ffmpeg-devel-bounces@ffmpeg.org
> >> >[mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of Shiyou Yin
> >> >Sent: Thursday, July 12, 2018 8:44 PM
> >> >To: ffmpeg-devel@ffmpeg.org
> >> >Subject: [FFmpeg-devel] [PATCH 1/9] configure: [loongson] revert
> >> >no-expensive-optimizations
> >> >
> >> >The bug in  gcc-4.9.x has been fixed in gcc master branch.
> >> >Loongson released gcc-4.9.3-3.fc21.loongson with this patch.
> >> >More bug info see:
> >> >https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67736
> >> >https://gcc.gnu.org/ml/gcc-patches/2012-05/msg00401.html
> >> >
> >> >Change-Id: I780125d4cdee71d40457aaee22126ba0547a2c8f
> >> >Signed-off-by: Shiyou Yin <yinshiyou-hf@loongson.cn>
> >> >---
> >> > configure | 6 +++---
> >> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >> >
> >> >diff --git a/configure b/configure
> >> >index b1a4dcf..17a7ea9 100755
> >> >--- a/configure
> >> >+++ b/configure
> >> >@@ -4789,13 +4789,13 @@ elif enabled mips; then
> >> >                 disable mipsdspr2
> >> >                 case $cpu in
> >> >                     loongson3*)
> >> >-                        cpuflags="-march=loongson3a -mhard-float
> >-fno-expensive-optimizations"
> >> >+                        cpuflags="-march=loongson3a -mhard-float"
> >> >                     ;;
> >> >                     loongson2e)
> >> >-                        cpuflags="-march=loongson2e -mhard-float
> >-fno-expensive-optimizations"
> >> >+                        cpuflags="-march=loongson2e -mhard-float"
> >> >                     ;;
> >> >                     loongson2f)
> >> >-                        cpuflags="-march=loongson2f -mhard-float
> >-fno-expensive-optimizations"
> >> >+                        cpuflags="-march=loongson2f -mhard-float"
> >> >                     ;;
> >> >                 esac
> >> >             ;;
> >> >--
> >> >2.1.0
> >> >
> >>
> >> Hi Michael, could you please help to apply this patch. It has been tested on loongson platform.
> >
> >shouldnt this test the compiler the user uses ? its version or something ?
> >
> Thank you very much for your review. Be strictly, it's needed to check the compiler version which
> user uses. 
> Consider that this bug has been fixed about three years and the compiler has been upgraded a lot of
> times in loongson yum repository.
> At present, there are still only a few developers will build ffmpeg on loongson platform. The risk
> of his change is controllable. 
> So, between the simplicity and absolute reliability of the code I chosed the simplicity this time.
> Should I still add version check here?

I think there should maybe be a check for the minimum gcc version supported then to ensure
that no too old version is used. If you do not want to add teh flag for 
specific versions
The effect of the bug was IIRC not trivial to connect to the gcc version so
it could leave a developer quite lost and confused what is causing it


[...]
diff mbox

Patch

diff --git a/configure b/configure
index b1a4dcf..17a7ea9 100755
--- a/configure
+++ b/configure
@@ -4789,13 +4789,13 @@  elif enabled mips; then
                 disable mipsdspr2
                 case $cpu in
                     loongson3*)
-                        cpuflags="-march=loongson3a -mhard-float -fno-expensive-optimizations"
+                        cpuflags="-march=loongson3a -mhard-float"
                     ;;
                     loongson2e)
-                        cpuflags="-march=loongson2e -mhard-float -fno-expensive-optimizations"
+                        cpuflags="-march=loongson2e -mhard-float"
                     ;;
                     loongson2f)
-                        cpuflags="-march=loongson2f -mhard-float -fno-expensive-optimizations"
+                        cpuflags="-march=loongson2f -mhard-float"
                     ;;
                 esac
             ;;