Uvision optimisation level

[chrissnow]

Description

The default optimisation level is O0 which wastes a lot of resources.

I think O1 is a more appropriate level as dead code\variables are removed without causing debugging issues.

From
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0472k/chr1359124221739.html

Although the debug view produced by -O0 corresponds most closely to the source code, users might prefer the debug view produced by -O1 because this improves the quality of the code without changing the fundamental structure.

Happy to sort a PR if this seems reasonable.

Issue request type

[ ] Question
[X] Enhancement
[ ] Bug

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/MBOCUSTRIA-1480

[0xc0170]

This might land soon: #11126

Should resolve this one.

[chrissnow]

@0xc0170 that wont help, the debug level is hard coded when exported.

[0xc0170]

I see, in the template. I dont recall now but our profile sets it to Og (once PR is in) then template value should be ignored , shouldn't it? That would fix it.

To summarize: template contains default value that our profile overwrites (O0 for develop, O3 for release profiles).

[chrissnow]

I don't think the profiles affect this, It would be better if it did set it though.

I have had a look and can't see anything that tries to override the field.
I also suspect that if -Ox was passed as an LD flag it would cause issues since Keil will also pass it the IDE value(unless default stops it)

[0xc0170]

The field not, that one is in the template. We have -O from profiles set via cmd option - I recall it's in misc field in the uvision - check that - you should see it in the cmd when building. From what I recall misc overwrites what is in the template (some options are available via misc and uvision checkboxes, but not all).

[chrissnow]

My Misc controls has
-fdata-sections -Wno-deprecated-register -g -c --target=arm-arm-none-eabi -fshort-enums -fshort-wchar -Wno-armcc-pragma-push-pop -Wno-reserved-user-defined-literal -mcpu=cortex-m3 -Wno-armcc-pragma-anon-unions -fno-exceptions -mthumb -fno-rtti -include ./mbed_config.h

My experience is that that drop down does affect the optimisation level, and the compiler control string seems to update to match when it is set.

-xc -std=gnu11 --target=arm-arm-none-eabi -mcpu=cortex-m3 -c
-fno-rtti -funsigned-char -fshort-enums -fshort-wchar
-gdwarf-3 -O0 -ffunction-sections -I . -I

[0xc0170]

Thanks for testing. The PR should be OK then 👍