regression with binutils 2.28 for ppc
Waldemar Brodkorb
wbx@openadk.org
Wed Feb 23 17:34:24 GMT 2022
Hi Alan,
Alan Modra wrote,
> All things considered, I think all I can do in gas is to partially
> revert commit b25f942e18d6 which made .machine more strict. At least
> that way -many (passed by release gcc) or other user sticky -Wa
> options like -maltivec will not be lost. Bad luck if a user wants
> -mcpu=power9 -Wa,-power10 for example.
>
> * config/tc-ppc.c (ppc_machine): Treat an early .machine specially,
> keeping sticky options to work around gcc bugs.
>
> diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
> index 054f9c72161..89bc7d3f9b9 100644
> --- a/gas/config/tc-ppc.c
> +++ b/gas/config/tc-ppc.c
> @@ -5965,7 +5965,30 @@ ppc_machine (int ignore ATTRIBUTE_UNUSED)
> options do not count as a new machine, instead they add
> to currently selected opcodes. */
> ppc_cpu_t machine_sticky = 0;
> - new_cpu = ppc_parse_cpu (ppc_cpu, &machine_sticky, cpu_string);
> + /* Unfortunately, some versions of gcc emit a .machine
> + directive very near the start of the compiler's assembly
> + output file. This is bad because it overrides user -Wa
> + cpu selection. Worse, there are versions of gcc that
> + emit the *wrong* cpu, not even respecting the -mcpu given
> + to gcc. See gcc pr101393. And to compound the problem,
> + as of 20220222 gcc doesn't pass the correct cpu option to
> + gas on the command line. See gcc pr59828. Hack around
> + this by keeping sticky options for an early .machine. */
> + asection *sec;
> + for (sec = stdoutput->sections; sec != NULL; sec = sec->next)
> + {
> + segment_info_type *info = seg_info (sec);
> + /* Are the frags for this section perturbed from their
> + initial state? Even .align will count here. */
> + if (info != NULL
> + && (info->frchainP->frch_root != info->frchainP->frch_last
> + || info->frchainP->frch_root->fr_type != rs_fill
> + || info->frchainP->frch_root->fr_fix != 0))
> + break;
> + }
> + new_cpu = ppc_parse_cpu (ppc_cpu,
> + sec == NULL ? &sticky : &machine_sticky,
> + cpu_string);
> if (new_cpu != 0)
> ppc_cpu = new_cpu;
> else
That fixes the kernel compile for me, too. thanks Alan!
best regards
Waldemar
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