Tamar Christina <tamar.christ...@arm.com> writes:
> Hi All,
>
> When both -mcpu and -march are specified, the value of -march wins out.
>
> This is done correctly for the calls to cc1 and for the assembler directives
> we
> put out in assembly files.
>
> However in the call to as we don't do this and instead use the arch from the
> cpu. This leads to a situation that GCC cannot reliably be used to compile
> assembly files which don't have a .arch directive.
>
> This is quite common with .S files which use macros to selectively enable
> codepath based on what the preprocessor sees.
>
> The fix is to change MCPU_TO_MARCH_SPEC to not override the march if an march
> is already specified.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
>
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> PR target/110901
> * config/aarch64/aarch64.h (MCPU_TO_MARCH_SPEC): Don't override if
> march is set.
>
> gcc/testsuite/ChangeLog:
>
> PR target/110901
> * gcc.target/aarch64/options_set_29.c: New test.
LGTM. OK if there are no other comments in 24 hours.
Thanks,
Richard
> ---
>
> diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
> index
> 1ab49e229b080d29187690abdb0c0767c12a157a..218868a5246a19c293c03e7be48107c1b0770e27
> 100644
> --- a/gcc/config/aarch64/aarch64.h
> +++ b/gcc/config/aarch64/aarch64.h
> @@ -1510,7 +1510,7 @@ extern const char *host_detect_local_cpu (int argc,
> const char **argv);
> CONFIG_TUNE_SPEC
>
> #define MCPU_TO_MARCH_SPEC \
> - " %{mcpu=*:-march=%:rewrite_mcpu(%{mcpu=*:%*})}"
> + "%{!march=*:%{mcpu=*:-march=%:rewrite_mcpu(%{mcpu=*:%*})}}"
>
> extern const char *aarch64_rewrite_mcpu (int argc, const char **argv);
> extern const char *is_host_cpu_not_armv8_base (int argc, const char **argv);
> diff --git a/gcc/testsuite/gcc.target/aarch64/options_set_29.c
> b/gcc/testsuite/gcc.target/aarch64/options_set_29.c
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..0a68550951ce61422c4cfea50762b2420a92091e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/options_set_29.c
> @@ -0,0 +1,11 @@
> +/* { dg-do assemble } */
> +/* { dg-additional-options "-march=armv8.2-a+sve -mcpu=cortex-a72 -O1 -w
> -###" } */
> +
> +int main ()
> +{
> + return 0;
> +}
> +
> +/* { dg-message "-march=armv8-a\+crc" "no arch from cpu" { xfail *-*-* } 0 }
> */
> +/* { dg-message "-march=armv8\\.2-a\\+sve" "using only sve" { target *-*-* }
> 0 } */
> +/* { dg-excess-errors "" } */
