Adding compiler options to armcc using abld

[bjoto]

When using "abld.pl" to build an ARMV5 UREL project, I *allways* get the "-O2" switch to armcc!

I would like to be able to override this, for example using OPTION keyword in the MMP-file.

What happens now is:

> abld build armv5 urel -i arm -v

armcc -O2 ... and here goes the other options, such as --arm and -O3. This will result in that -O2 is used, allthough that the -O3 input parameter is specified.

Very annoying - It would be nice to be able to alter the options without patching the CL_ARM.PM file in \epoc32\tools.

[real_lingchen]

I have the same trouble of unable to change the optimization levels.

Please somebody give some advices...

[laa-laa]

You can add new options with the OPTION ARMCC keyword pair in your .mmp file.

To change some implicit default options, edit epoc32\tools\compilation_config\armv5_abiv2.mk. In this case, the REL_OPTIMISATION definition.

On the other hand, the -O2 is only supplied for release builds. Use a debug build instead if you can. It doesn't get -O2 and you can still supply additional options with the OPTION ARMCC mechanism.

Lauri

[skumar_rao]

i suggest you include below lines in your application MMP File for Symbian 9.x

#ifdef __ARMCC_2__
OPTION                                      ARMCC --no_debug_macros -O2 -Otime
#else //__GCCE__
OPTION                                      GCCE -O2 -fno-unit-at-a-time

[real_lingchen]

Thanks laa-laa and skumar_rao for your suggestions!

I'm exploring different compiler options in order to maximize the speed of my application. Before use RVCT2.2, I used the free GCCE compiler come along with Carbide IDE. But the speed of the binary generated by GCCE is not satisfactory.

The approach works for me is suggested in ARM5 build customization:
http://www.symbian.com/developer/tec...%2earm5%2dcust

In summary, generate different BSF files with different optimization options. For example, for Otime option, I used:

thumb_options -thumb -Otime
arm_options -arm -Otime
kernel_options -arm -Otime

And in bld.inf file, I used

PRJ_MMPFILES
my_proj.mmp BUILD_AS_ARM

to force the code to be built using ARM instruction set rather than THUMB.

My only hope is to maximize the speed of the code rather than to minimize its size. To my surprise, after tried all optimization options:
-O0,-O1,-O2,-O3,-Otime,-Ospace. The speed of the generated binary can not even match that of GCCE. But the code size is much smaller comparing to that of GCCE. For example, the RVCT binaries:
O0: 50Kb
O1: 47Kb
O2: 46Kb
O3: 46Kb
Otime: 54Kb
Ospace: 46Kb

The GCCE binary: 65Kb

Can you please help to analysis this situation? Because I am expecting RVCT can render faster binary than GCCE, and this is not what I see.

[skumar_rao]

Have you tried compiler options given by me. those were the most optimized compiler options for me.

[real_lingchen]

Hi, skumar_rao,

As you suggested, I've put:

#ifdef __ARMCC_2__
OPTION ARMCC --no_debug_macros -O2 -Otime
#else //__GCCE__
OPTION GCCE -O2 -fno-unit-at-a-time
#endif

in the mmp file, then "clean project" and "rebuild project" for "Phone Release (ARMV5) [S60_3rd_FP2_Beta]. But somehow it has no effects, I don't see any changes when armcc is called:

armcc -O2 --diag_suppress 66,161,611,654,997,1152,1300,1464,1488,6318,6331 --diag_error 1267 --thumb --fpu softvfp --exceptions --exceptions_unwind -D__MARM_THUMB__ -D__MARM_INTERWORK__ --cpu 5T --enum_is_int -Ono_known_library --fpmode ieee_no_fenv --export_all_vtbl --no_vfe --apcs /inter --dllimport_runtime -c -DNDEBUG -D_UNICODE -D__SYMBIAN32__ -D__S60_32__ -D__S60_3X__ -D__SERIES60_3X__ -D__ARMCC__ -D__EPOC32__ -D__MARM__ -D__EABI__ -D__ARMCC_2__ -D__ARMCC_2_2__ -D__MARM_ARMV5__ -D__DLL__ -D__SUPPORT_CPP_EXCEPTIONS__ -D__PRODUCT_INCLUDE__=\"\Symbian\9.3\S60_3rd_FP2_Beta\epoc32\include\variant\Symbian_OS_v9.3.hrh\" --cpp --preinclude \Symbian\9.3\S60_3rd_FP2_Beta\epoc32\include\RVCT2_2\RVCT2_2.h -J \Symbian\Projects\SBDecoderS60_dev\sc_2D_slow\src -J \Symbian\Projects\SBDecoderS60_dev\sc_2D_slow\inc -J \Symbian\9.3\S60_3rd_FP2_Beta\epoc32\include -J \Symbian\9.3\S60_3rd_FP2_Beta\epoc32\include\variant -o \Symbian\9.3\S60_3rd_FP2_Beta\EPOC32\BUILD\Symbian\Projects\my_proj\my_proj1\group\MY_PROJ1\ARMV5\urel\my_src.o \Symbian\Projects\my_proj\my_proj1\src\my_src.cpp

I don't know if I did anything wrong or not. So I have to generate the BSF file with the setting:
thumb_options -thumb -Otime
arm_options -arm -Otime
kernel_options -arm -Otime

Then the armcc is called as below:

armcc -O2 --diag_suppress 66,161,611,654,997,1152,1300,1464,1488,6318,6331 --diag_error 1267 -thumb -Otime -D__MARM_THUMB__ -D__MARM_INTERWORK__ --cpu 5T --enum_is_int -Ono_known_library --fpmode ieee_no_fenv --export_all_vtbl --no_vfe --apcs /inter --dllimport_runtime -c -DNDEBUG -D_UNICODE -D__SYMBIAN32__ -D__S60_32__ -D__S60_3X__ -D__SERIES60_3X__ -D__ARMCC__ -D__EPOC32__ -D__MARM__ -D__EABI__ -D__ARMCC_2__ -D__ARMCC_2_2__ -D__ARMV5OTIME__ -D__MARM_ARMV5__ -D__DLL__ -D__SUPPORT_CPP_EXCEPTIONS__ -D__PRODUCT_INCLUDE__=\"\Symbian\9.3\S60_3rd_FP2_Beta\epoc32\include\variant\Symbian_OS_v9.3.hrh\" --cpp --preinclude \Symbian\9.3\S60_3rd_FP2_Beta\epoc32\include\RVCT2_2\RVCT2_2.h -J \Symbian\Projects\SBDecoderS60_dev\sc_2D_slow\src -J \Symbian\Projects\SBDecoderS60_dev\sc_2D_slow\inc -J \Symbian\9.3\S60_3rd_FP2_Beta\epoc32\include -J \Symbian\9.3\S60_3rd_FP2_Beta\epoc32\include\variant -o \Symbian\9.3\S60_3rd_FP2_Beta\EPOC32\\BUILD\Symbian\Projects\my_proj\my_proj1\group\MY_PROJ1\ARMV5\urel\my_src.o \Symbian\Projects\my_proj\my_proj1\src\my_src.cpp

Now I can see -Otime is present in this case. But I don't know why the -O2 options is always there. And it seems to me the -thumb option is also always there. And my understanding is THUMB code is generally slower than ARM code. That's why I modified the bld.inf file to force ARM instruction set been used.

Have you ever compared the code size and speed of code geneated by RVCT and GCCE? My expectation is somehow contradict to what I saw, don't know where I made any mistakes.

[skumar_rao]

Hi,
I have not gone that deep in to changing any scripts. but i have seen that by using these options i got reduced in size.

But nice to know that we can change the build environment to this extent.