Re: [PATCH 1/2] genopinit: Distribute generated code across multiple files

On 8/4/2026 10:57 AM, Kyrylo Tkachov wrote:
>
>> On 4 Aug 2026, at 18:26, Jeffrey Law <[email protected]> wrote:
>>
>>
>>
>> On 7/23/2026 7:20 AM, [email protected] wrote:
>>> From: Kyrylo Tkachov <[email protected]>
>>>
>>> insn-opinit.cc contains large generated initialization functions with
>>> thousands of target-feature expressions.  The single file is among the
>>> slowest objects in every AArch64 bootstrap stage.
>>>
>>> Teach genopinit to accept repeatable -O output options, following genemit and
>>> genrecog.  Reuse the existing --with-insnemit-partitions count, while
>>> preserving the default init-opinit.c output and -cFILE interface when -O is not
>>> used.  Collect and validate all output names before opening them, rejecting
>>> duplicates, resolvable aliases, header collisions, and incompatible -c and -O
>>> options.
>>>
>>> Keep shared lookup code and all helper declarations in the first output, then
>>> place helper definitions in the shortest output.  One-file output retains the
>>> historical static helper names.  Split output uses generator-private external
>>> names for cross-file references.
>>>
>>> With the default ten AArch64 partitions, the largest part compiles about 90%
>>> faster than the original single object.
>>>
>>> Bootstrapped and tested on aarch64-none-linux-gnu and x86_64-linux.
>>> Ok for trunk?
>>> Thanks,
>>> Kyrill
>>>
>>> gcc/ChangeLog:
>>>
>>> * Makefile.in (INSNOPINIT_SPLITS_SEQ, INSNOPINIT_SEQ_SRC)
>>> (INSNOPINIT_SEQ_TMP, INSNOPINIT_SEQ_O): New variables.
>>> (OBJS): Replace insn-opinit.o with $(INSNOPINIT_SEQ_O).
>>> (MOSTLYCLEANFILES): Add $(INSNOPINIT_SEQ_SRC), retaining the legacy
>>> unnumbered source for cleanup.
>>> (s-opinit): Generate and move numbered insn-opinit-N.cc files.  Stop if
>>> moving an output fails.
>>> * configure.ac (--with-insnemit-partitions): Mention genopinit outputs.
>>> * configure: Regenerate.
>>> * genopinit.cc (source_file_option, output_file_names, output_files):
>>> New variables.
>>> (handle_arg): Record and validate repeatable -O output names.
>>> (main): Validate all output modes before opening files.  Preserve static
>>> helper linkage for one output and distribute private split helpers.
>>>
>>> Signed-off-by: Kyrylo Tkachov <[email protected]>
>> It'll be interesting to see if this improves the RISC-V build times too.  Robin fixed the worst of the offenders a while back, but we've got daily build data and if there's a meaningful improvement we should be able to see it.
>>
>> The only concern is the INSNOPINIT_SPLITS_SEQ is slightly different than the other _SEQ variables.    The others use:
>>
>> MATCH_SPLITS_SEQ = $(wordlist 1,$(NUM_MATCH_SPLITS),$(one_to_9999))
>> INSNEMIT_SPLITS_SEQ = $(wordlist 1,$(NUM_INSNEMIT_SPLITS),$(one_to_9999))
>> INSNRECOG_SPLITS_SEQ = $(wordlist 1,$(NUM_INSNEMIT_SPLITS),$(one_to_9999))
>>
>> Is there a reason you didn't use that form?
> No particular reason, they both work the same in practice, I can change to use that form.
> Ok with that change if testing passes?
Yea, let's keep them consistent.  OK assuming testing passes.

jeff