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Cortex M-0 compilation with GCC > 5

Posted: Tue Mar 31, 2020 9:52 am
by elagil
Hello,

compiling for Cortex M-0 I get the following warning:

Code: Select all

  
132 | # "*** Use GCC version 5 or below ***"
      |  warning^~~~~~~ "This compiler has a know problem with Cortex-M0, see bugs: 88167, 88656."


However, checking the bug tracker, these bugs seem to be fixed in the current release.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88167
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88656

I use the latest arm gcc, which is dated after the closure of the bugs:
gcc version 9.2.1 20191025 (release) [ARM/arm-9-branch revision 277599] (GNU Tools for Arm Embedded Processors 9-2019-q4-major)

Would it make sense to remove the warning for the new revisions?

Best regards

Re: Cortex M-0 compilation with GCC > 5

Posted: Tue Mar 31, 2020 10:20 am
by Giovanni
Hi,

The latest released compiler, the one you have, still has the bug.

Giovanni

Re: Cortex M-0 compilation with GCC > 5

Posted: Tue Mar 31, 2020 10:24 am
by elagil
Ok, that is unfortunate. Thanks for the information!

Re: Cortex M-0 compilation with GCC > 5

Posted: Fri Jun 05, 2020 6:49 am
by Giovanni
Hi,

I just tried 9.3.1 2020q2 and looking at generated code it seems to be fine, LR register is preserved in the function prologue, later today I will run some tests and change the preprocessor check in the repository.

The new compiler also supports Cortex-A now, which is very nice.

Giovanni