On Thu, Sep 29, 2022 at 01:45:16PM +0800, Kewen.Lin wrote:
> I found this flag is mainly related to tune setting and spotted that we have
> some code
> for tune setting when no explicit cpu is given.
>
> ...
>
> else
> {
> size_t i;
> enum processor_type tune_proc
> = (TARGET_POWERPC64 ? PROCESSOR_DEFAULT64 : PROCESSOR_DEFAULT);
>
> tune_index = -1;
> for (i = 0; i < ARRAY_SIZE (processor_target_table); i++)
> if (processor_target_table[i].processor == tune_proc)
> {
> tune_index = i;
> break;
> }
> }
Ah cool, that needs fixing yes.
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -3702,7 +3702,7 @@ rs6000_option_override_internal (bool global_init_p)
> else
> {
> /* PowerPC 64-bit LE requires at least ISA 2.07. */
> - const char *default_cpu = (!TARGET_POWERPC64
> + const char *default_cpu = (!TARGET_POWERPC64 && TARGET_32BIT
> ? "powerpc"
> : (BYTES_BIG_ENDIAN
> ? "powerpc64"
... but not like that. If this snippet should happen later just move it
later. Or introduce a new variable to make the control flow less
confused. Or something else. But don't make the code more complex,
introducing more special cases like this.
> +#ifdef OS_MISSING_POWERPC64
> + else if (OS_MISSING_POWERPC64)
> + /* It's unexpected to have OPTION_MASK_POWERPC64 on for OSes which
> + miss powerpc64 support, so disable it. */
> + rs6000_isa_flags &= ~OPTION_MASK_POWERPC64;
> +#endif
All silent stuff is always bad.
If things are done well, we will end up with *less* code than what we
had before, not more!
Segher
