On 2/23/21 3:14 AM, YunQiang Su wrote:
> For MIPSr6, we may wish to use compact-branches only.
> Currently, we have to use `always' option, while it is mark as conflict
> with pre-R6.
> cc1: error: unsupported combination: ‘mips32r2’ -mcompact-branches=always
> Just ignore -mcompact-branches=always for pre-R6.
>
> This patch also defines
> __mips_compact_branches_never
> __mips_compact_branches_always
> __mips_compact_branches_optimal
> predefined macros
>
> gcc/ChangeLog:
> * config/mips/mips.c (mips_option_override):
> * config/mips/mips.h (TARGET_RTP_PIC): not trigger error for
> compact-branches=always for pre-R6.
> (TARGET_CB_NEVER): Likewise.
> (TARGET_CB_ALWAYS): Likewise.
> (struct mips_cpu_info): define macros for compact branch policy.
> * doc/invoke.texi: Document "always" with pre-R6.
>
> gcc/testsuite/ChangeLog:
> * gcc.target/mips/compact-branches-1.c: add isa_rev>=6.
> * gcc.target/mips/mips.exp: don't add -mipsXXr6 option for
> -mcompact-branches=always. It is usable for pre-R6 now.
> * gcc.target/mips/compact-branches-8.c: New test.
> * gcc.target/mips/compact-branches-9.c: New test.
So I think Maciej's comment was that you simply shouldn't be using
-mcompact-branches=always at mips32r2 (or anything pre-r6) together.
I think what you're trying to do here is set up a scenario where you're
defaulting to mips32r6 and compact-branches, but not error if something
specifies -mcpu=mips32r2 or something similar, right?
jeff
