[meta-qt5] why does Qt5 build with ARM_INSTRUCTION_SET = "arm"

[meta-qt5] why does Qt5 build with ARM_INSTRUCTION_SET = "arm"

[Nicolas Dechesne]

hi,

does anybody know why in Qt5/qtbase.inc, we have:

ARM_INSTRUCTION_SET = "arm"

Could it be an a low hanging fruit from the past? e.g. before
https://bugreports.qt-project.org/browse/QTBUG-16402 or
https://qt.gitorious.org/qt/qtbase/commit/a3bd9d4c0f3d9e80dbe35bd88649b245dca5f410?

as a matter of fact, for our project Qt5 (and QtWebkit) are building
(and working fine) when built with Thumb2, outside of OE. Also using
ARM instruction set instead of Thumb2 enforces Webkit to use the ARM
version of the javascript JIT, while the Thumb2 JIT engine seems to
work a lot better in our testing...

cheers

nico

Re: [meta-qt5] why does Qt5 build with ARM_INSTRUCTION_SET = "arm"

[Denys Dmytriyenko]

On Mon, Feb 17, 2014 at 02:27:51PM -0700, Nicolas Dechesne wrote:
> hi,
> 
> does anybody know why in Qt5/qtbase.inc, we have:
> 
> ARM_INSTRUCTION_SET = "arm"
> 
> Could it be an a low hanging fruit from the past? e.g. before
> https://bugreports.qt-project.org/browse/QTBUG-16402 or
> https://qt.gitorious.org/qt/qtbase/commit/a3bd9d4c0f3d9e80dbe35bd88649b245dca5f410?

Hmm, I would assume that's here from 4.8 days, although I haven't tried 
dropping that line for latest Qt5... Would make sense to do some more testing.


> as a matter of fact, for our project Qt5 (and QtWebkit) are building
> (and working fine) when built with Thumb2, outside of OE. Also using
> ARM instruction set instead of Thumb2 enforces Webkit to use the ARM
> version of the javascript JIT, while the Thumb2 JIT engine seems to
> work a lot better in our testing...

Seems like worth the effort to re-test the need for that setting. Unless 
someone else has tried it already and found out the issue is still there

-- 
Denys

Re: [meta-qt5] why does Qt5 build with ARM_INSTRUCTION_SET = "arm"

[Khem Raj]

-Khem
On Feb 17, 2014 1:28 PM, "Nicolas Dechesne" <nicolas.dechesne@linaro.org>
wrote:
>
> hi,
>
> does anybody know why in Qt5/qtbase.inc, we have:
>
> ARM_INSTRUCTION_SET = "arm"

there were issues with thumb1 and i guess legacy continued may be its not
needed any longer test it out and send a patch
make sure that when its using thumb1 then current logic still kicks in
>
> Could it be an a low hanging fruit from the past? e.g. before
> https://bugreports.qt-project.org/browse/QTBUG-16402 or
>
https://qt.gitorious.org/qt/qtbase/commit/a3bd9d4c0f3d9e80dbe35bd88649b245dca5f410
?
>
> as a matter of fact, for our project Qt5 (and QtWebkit) are building
> (and working fine) when built with Thumb2, outside of OE. Also using
> ARM instruction set instead of Thumb2 enforces Webkit to use the ARM
> version of the javascript JIT, while the Thumb2 JIT engine seems to
> work a lot better in our testing...
>
> cheers
>
> nico
> _______________________________________________
> Openembedded-devel mailing list
> Openembedded-devel@lists.openembedded.org
> http://lists.openembedded.org/mailman/listinfo/openembedded-devel

Re: [meta-qt5] why does Qt5 build with ARM_INSTRUCTION_SET = "arm"

[Martin Jansa]

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On Mon, Feb 17, 2014 at 04:46:23PM -0500, Denys Dmytriyenko wrote:
> On Mon, Feb 17, 2014 at 02:27:51PM -0700, Nicolas Dechesne wrote:
> > hi,
> > 
> > does anybody know why in Qt5/qtbase.inc, we have:
> > 
> > ARM_INSTRUCTION_SET = "arm"
> > 
> > Could it be an a low hanging fruit from the past? e.g. before
> > https://bugreports.qt-project.org/browse/QTBUG-16402 or
> > https://qt.gitorious.org/qt/qtbase/commit/a3bd9d4c0f3d9e80dbe35bd88649b245dca5f410?
> 
> Hmm, I would assume that's here from 4.8 days, although I haven't tried 
> dropping that line for latest Qt5... Would make sense to do some more testing.
> 
> 
> > as a matter of fact, for our project Qt5 (and QtWebkit) are building
> > (and working fine) when built with Thumb2, outside of OE. Also using
> > ARM instruction set instead of Thumb2 enforces Webkit to use the ARM
> > version of the javascript JIT, while the Thumb2 JIT engine seems to
> > work a lot better in our testing...
> 
> Seems like worth the effort to re-test the need for that setting. Unless 
> someone else has tried it already and found out the issue is still there

IIRC it was failing to build for armv4t (at least with 5.0.0) if someone
tests that armv4t builds with 5.2.*, I'll accept the patch.

Cheers,
-- 
Martin 'JaMa' Jansa     jabber: Martin.Jansa@gmail.com

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Re: [meta-qt5] why does Qt5 build with ARM_INSTRUCTION_SET = "arm"

[Andre McCurdy]

On Mon, Feb 17, 2014 at 3:03 PM, Martin Jansa <martin.jansa@gmail.com> wrote:
> On Mon, Feb 17, 2014 at 04:46:23PM -0500, Denys Dmytriyenko wrote:
>> On Mon, Feb 17, 2014 at 02:27:51PM -0700, Nicolas Dechesne wrote:
>> > hi,
>> >
>> > does anybody know why in Qt5/qtbase.inc, we have:
>> >
>> > ARM_INSTRUCTION_SET = "arm"
>> >
>> > Could it be an a low hanging fruit from the past? e.g. before
>> > https://bugreports.qt-project.org/browse/QTBUG-16402 or
>> > https://qt.gitorious.org/qt/qtbase/commit/a3bd9d4c0f3d9e80dbe35bd88649b245dca5f410?
>>
>> Hmm, I would assume that's here from 4.8 days, although I haven't tried
>> dropping that line for latest Qt5... Would make sense to do some more testing.
>>
>> > as a matter of fact, for our project Qt5 (and QtWebkit) are building
>> > (and working fine) when built with Thumb2, outside of OE. Also using
>> > ARM instruction set instead of Thumb2 enforces Webkit to use the ARM
>> > version of the javascript JIT, while the Thumb2 JIT engine seems to
>> > work a lot better in our testing...
>>
>> Seems like worth the effort to re-test the need for that setting. Unless
>> someone else has tried it already and found out the issue is still there
>
> IIRC it was failing to build for armv4t (at least with 5.0.0) if someone
> tests that armv4t builds with 5.2.*, I'll accept the patch.

With ARM_INSTRUCTION_SET forced to thumb I'm able to build qtbase
5.1.1 and 5.2.1 tuned for both armv4t and cortexa9thf-neon.

Andre
--

Re: [meta-qt5] why does Qt5 build with ARM_INSTRUCTION_SET = "arm"

[Martin Jansa]

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On Mon, Feb 17, 2014 at 09:33:10PM -0800, Andre McCurdy wrote:
> On Mon, Feb 17, 2014 at 3:03 PM, Martin Jansa <martin.jansa@gmail.com> wrote:
> > On Mon, Feb 17, 2014 at 04:46:23PM -0500, Denys Dmytriyenko wrote:
> >> On Mon, Feb 17, 2014 at 02:27:51PM -0700, Nicolas Dechesne wrote:
> >> > hi,
> >> >
> >> > does anybody know why in Qt5/qtbase.inc, we have:
> >> >
> >> > ARM_INSTRUCTION_SET = "arm"
> >> >
> >> > Could it be an a low hanging fruit from the past? e.g. before
> >> > https://bugreports.qt-project.org/browse/QTBUG-16402 or
> >> > https://qt.gitorious.org/qt/qtbase/commit/a3bd9d4c0f3d9e80dbe35bd88649b245dca5f410?
> >>
> >> Hmm, I would assume that's here from 4.8 days, although I haven't tried
> >> dropping that line for latest Qt5... Would make sense to do some more testing.
> >>
> >> > as a matter of fact, for our project Qt5 (and QtWebkit) are building
> >> > (and working fine) when built with Thumb2, outside of OE. Also using
> >> > ARM instruction set instead of Thumb2 enforces Webkit to use the ARM
> >> > version of the javascript JIT, while the Thumb2 JIT engine seems to
> >> > work a lot better in our testing...
> >>
> >> Seems like worth the effort to re-test the need for that setting. Unless
> >> someone else has tried it already and found out the issue is still there
> >
> > IIRC it was failing to build for armv4t (at least with 5.0.0) if someone
> > tests that armv4t builds with 5.2.*, I'll accept the patch.
> 
> With ARM_INSTRUCTION_SET forced to thumb I'm able to build qtbase
> 5.1.1 and 5.2.1 tuned for both armv4t and cortexa9thf-neon.

Cool, can you please send the patch removing ARM_INSTRUCTION_SET?

Thanks

-- 
Martin 'JaMa' Jansa     jabber: Martin.Jansa@gmail.com

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[meta-qt5][PATCH] qtbase.inc: don't force ARM_INSTRUCTION_SET to arm

[Andre McCurdy]

Forcing ARM_INSTRUCTION_SET to arm when building qtbase no longer
seems to be required.

Confirmed by forcing ARM_INSTRUCTION_SET to thumb and building
qtbase 5.1.1 and 5.2.1 tuned for both armv4t and cortexa9thf-neon.

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
---
 recipes-qt/qt5/qtbase.inc | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/recipes-qt/qt5/qtbase.inc b/recipes-qt/qt5/qtbase.inc
index f056393..ff62297 100644
--- a/recipes-qt/qt5/qtbase.inc
+++ b/recipes-qt/qt5/qtbase.inc
@@ -126,9 +126,6 @@ QT_CONFIG_FLAGS += " \
     ${EXTRA_OECONF} \
 "
 
-# Qt uses atomic instructions not supported in thumb mode
-ARM_INSTRUCTION_SET = "arm"
-
 do_generate_qt_config_file_append() {
     cat >> ${QT_CONF_PATH} <<EOF
 
-- 
1.8.1.2