Committed: cefcc09723c

Thanks!

> On 6 May 2026, at 6:26 PM, Alex Coplan <[email protected]> wrote:
> 
> External email: Use caution opening links or attachments
> 
> 
> On 06/05/2026 10:13, Soumya AR wrote:
>> The narrow_gp_writes pass uses RTL-SSA and updates DF state via
>> df_insn_rescan / df_insn_delete.  Both routines look up the insn's bb via
>> BLOCK_FOR_INSN to mark it dirty after a change, but pass_free_cfg has already
>> cleared those per-insn pointers by the time narrow_gp_writes runs. When
>> BLOCK_FOR_INSN returns NULL, the dirty-marking step is silently skipped,
>> leaving the DF stale.
>> 
>> Move the pass to run before pass_free_cfg.
>> 
>> Bootstrapped and regtested on aarch64-linux-gnu.
>> SPEC CPU 2017 shows no codegen differences (compared to previous placement).
>> OK for trunk?
>> 
>> Signed-off-by: Soumya AR <[email protected]>
>> 
>>      PR target/124895
>> 
>> gcc/ChangeLog:
>> 
>>      * config/aarch64/aarch64-passes.def (INSERT_PASS_BEFORE): Move pass
> 
> I think the text in parens here should be pass_narrow_gp_writes.
> 
> LGTM with that change, but please give others 24 hours to comment.
> 
> Thanks,
> Alex
> 
>>      before pass_free_cfg.
>> 
>> gcc/testsuite/ChangeLog:
>> 
>>      * gcc.target/aarch64/narrow-gp-writes-8.c: New test.
>> ---
>> gcc/config/aarch64/aarch64-passes.def                 |  2 +-
>> gcc/testsuite/gcc.target/aarch64/narrow-gp-writes-8.c | 10 ++++++++++
>> 2 files changed, 11 insertions(+), 1 deletion(-)
>> create mode 100644 gcc/testsuite/gcc.target/aarch64/narrow-gp-writes-8.c
>> 
>> diff --git a/gcc/config/aarch64/aarch64-passes.def 
>> b/gcc/config/aarch64/aarch64-passes.def
>> index f4307aab551..2df7459af92 100644
>> --- a/gcc/config/aarch64/aarch64-passes.def
>> +++ b/gcc/config/aarch64/aarch64-passes.def
>> @@ -26,4 +26,4 @@ INSERT_PASS_BEFORE 
>> (pass_late_thread_prologue_and_epilogue, 1, pass_late_track_s
>> INSERT_PASS_BEFORE (pass_shorten_branches, 1, pass_insert_bti);
>> INSERT_PASS_BEFORE (pass_early_remat, 1, pass_ldp_fusion);
>> INSERT_PASS_BEFORE (pass_peephole2, 1, pass_ldp_fusion);
>> -INSERT_PASS_BEFORE (pass_cleanup_barriers, 1, pass_narrow_gp_writes);
>> +INSERT_PASS_BEFORE (pass_free_cfg, 1, pass_narrow_gp_writes);
>> diff --git a/gcc/testsuite/gcc.target/aarch64/narrow-gp-writes-8.c 
>> b/gcc/testsuite/gcc.target/aarch64/narrow-gp-writes-8.c
>> new file mode 100644
>> index 00000000000..94ef761e801
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/aarch64/narrow-gp-writes-8.c
>> @@ -0,0 +1,10 @@
>> +/* PR target/124895 */
>> +/* { dg-do compile } */
>> +/* { dg-options "-Os -fpath-coverage -fno-tree-ccp -fprofile-generate 
>> -mnarrow-gp-writes" } */
>> +
>> +void
>> +foo (unsigned u)
>> +{
>> +  while (u)
>> +    ;
>> +}
>> --
>> 2.43.0


Reply via email to