Hi, Can anyone tell me the pros and cons of gcc vs the arm-cc compiler for ARM Cortex M3 development? I understand that the ARM compiler always used to be said to give smaller code size with the downside that it cost a bit more but can anyone tell me whether that is still true in 2012 ? How do they compare on execution speed ? My application is power sensitive and increased execution speed might pay for a clock speed reduction which could save power so that would be an issue. Issues like debugger and IDE support are bigger with me than code size and things like standards compliance are also important, also whether there are other snags / advantages of one against the other would be of interest. Many thanks, Mike
ARM Cortex M3 compilers - gcc vs arm-cc ?
Started by ●June 27, 2012
Reply by ●June 27, 20122012-06-27
> Can anyone tell me the pros and cons of gcc vs the arm-cc compiler for > ARM Cortex M3 development? I understand that the ARM compiler always > used to be said to give smaller code size with the downside that it > cost a bit more but can anyone tell me whether that is still true in > 2012 ?Don't know about arm-cc, but it is definitely true for gcc vs IAR. IAR has a free download (limited to 32 kbytes codesize), so you could just try both. Leo Havm�ller.
Reply by ●June 27, 20122012-06-27
On Wed, 27 Jun 2012 12:53:36 +0200, Leo Havmøller wrote:>> Can anyone tell me the pros and cons of gcc vs the arm-cc compiler for >> ARM Cortex M3 development? I understand that the ARM compiler always >> used to be said to give smaller code size with the downside that it >> cost a bit more but can anyone tell me whether that is still true in >> 2012 ? > > Don't know about arm-cc, but it is definitely true for gcc vs IAR. IAR > has a free download (limited to 32 kbytes codesize), so you could just > try both.So, which do you feel is better? -- My liberal friends think I'm a conservative kook. My conservative friends think I'm a liberal kook. Why am I not happy that they have found common ground? Tim Wescott, Communications, Control, Circuits & Software http://www.wescottdesign.com
Reply by ●June 28, 20122012-06-28
> Don't know about arm-cc, but it is definitely true for gcc vs IAR. IAR > has a free download (limited to 32 kbytes codesize), so you could just > try both. > So, which do you feel is better?IAR produces 10-20% smaller code than gcc (Sourcey CodeBench Lite). We use both. Leo Havmøller.
Reply by ●June 28, 20122012-06-28
On Thu, 28 Jun 2012 05:33:59 +0200, Leo Havmøller wrote:>> Don't know about arm-cc, but it is definitely true for gcc vs IAR. IAR >> has a free download (limited to 32 kbytes codesize), so you could just >> try both. >> So, which do you feel is better? > > IAR produces 10-20% smaller code than gcc (Sourcey CodeBench Lite). We > use both.I wonder how much is the compiler and how much is the library. Newlib has some amazing fluff-bombs that you can set off quite unexpectedly (just one example: pow, in the math library, is huge). -- My liberal friends think I'm a conservative kook. My conservative friends think I'm a liberal kook. Why am I not happy that they have found common ground? Tim Wescott, Communications, Control, Circuits & Software http://www.wescottdesign.com
Reply by ●June 28, 20122012-06-28
If you appreciate a good IDE, the ARM stinks! Also I'm a little bit surprised about their QA department. Last version V-4.53 came up with some peculiar error-messages regarding temporary files. The file failing was changing from compile to compile (without any source changes). When asking Keil about it, they had to admit that it was a known bug in projects which consists of sub-projects. This is several weeks ago, and no new version has appeared. I don't think I would buy a Keil again..... -- Regards Ole Asbjorn Fadum
Reply by ●June 28, 20122012-06-28
> I wonder how much is the compiler and how much is the library.It's the compiler and linker. Newlib would make the code size explode. Leo Havmøller.
Reply by ●June 29, 20122012-06-29
On Thu, 28 Jun 2012 09:11:56 +0200, Leo Havmøller wrote:>> I wonder how much is the compiler and how much is the library. > > It's the compiler and linker. Newlib would make the code size explode.Is that with -O2, or whatever the "optimize for size" switch is? -- Tim Wescott Control system and signal processing consulting www.wescottdesign.com
Reply by ●June 29, 20122012-06-29
On 29.6.12 6:12 , Tim Wescott wrote:> On Thu, 28 Jun 2012 09:11:56 +0200, Leo Havmøller wrote: > >>> I wonder how much is the compiler and how much is the library. >> >> It's the compiler and linker. Newlib would make the code size explode. > > Is that with -O2, or whatever the "optimize for size" switch is? >Compiling the library with -Os makes small wonders here. -- Tauno Voipio
Reply by ●June 29, 20122012-06-29
> Is that with -O2, or whatever the "optimize for size" switch is?gcc optimize for size is -Os. For dead code elimination you would also use -ffunction-sections and -fdata-sections, and link with -gc-sections. I use this to compile (defines and includes removed): C:\Program Files\CodeSourcery\Sourcery G++ Lite\bin\arm-none-eabi-gcc.exe -x c -fpack-struct=1 -c -gdwarf-3 -mcpu=cortex-m3 -mthumb -mfix-cortex-m3-ldrd -Os -fshort-enums -ffunction-sections -fdata-sections -fconserve-stack -fverbose-asm -fno-common -fno-merge-constants -fno-defer-pop -Wall -Wformat -Wimplicit -Wreturn-type -Wunused -Wuninitialized -Wunknown-pragmas -Wno-switch -Wno-strict-aliasing -Wtype-limits And this to link: C:\Program Files\CodeSourcery\Sourcery G++ Lite\bin\arm-none-eabi-gcc.exe -mcpu=cortex-m3 -mthumb -Wl,-static -Wl,--cref -Wl,--gc-sections -Wl,-Map=CoreTest.map Obj\\*.o -T CoreTest.def -L"C:\Program Files\CodeSourcery\Sourcery G++ Lite\arm-none-eabi\lib\thumb2" -o CoreTest.elf Leo Havmøller.
