| Message ID | 1489654.ccaA29ro9n@polaris |
|---|---|
| State | New |
| Headers | show |
On Sun, Sep 23, 2012 at 10:46 AM, Eric Botcazou <ebotcazou@adacore.com> wrote: > Hi, > > we have run into optimization regressions in Ada caused by the interaction > between the new GIMPLE clobbers and SRA: on the one hand GIMPLE clobbers > create artificial EH handlers for aggregate variables, on the other hand SRA > refuses to scalarize objects that appear in a statement that can throw > internally. The result is that GIMPLE clobbers block the scalarization of > variables that used to be possible up to the 4.6 series. > > Therefore the attached patch moves the ehcleanup pass to before early SRA in > the pipeline. It has a small but measurable positive effect on some of our > benchmarks (with a 4.7-based compiler). Tested on x86-64/Linux. Hmm. I think cleanup EH is scheduled late to help early inlining. Do you have a testcase where I can quickly look at the issue you describe? Thanks, Richard. > > 2012-09-23 Eric Botcazou <ebotcazou@adacore.com> > > * passes.c (init_optimization_passes): Run first EH cleanup pass early. > > > -- > Eric Botcazou
Index: passes.c =================================================================== --- passes.c (revision 191365) +++ passes.c (working copy) @@ -1303,6 +1303,10 @@ init_optimization_passes (void) /* pass_build_ealias is a dummy pass that ensures that we execute TODO_rebuild_alias at this point. */ NEXT_PASS (pass_build_ealias); + /* SRA refuses to scalarize objects that appear in a statement + that can throw internally so we need to cleanup the EH tree + early to remove handlers that contain only clobbers. */ + NEXT_PASS (pass_cleanup_eh); NEXT_PASS (pass_sra_early); NEXT_PASS (pass_fre); NEXT_PASS (pass_copy_prop); @@ -1311,7 +1315,6 @@ init_optimization_passes (void) NEXT_PASS (pass_early_ipa_sra); NEXT_PASS (pass_tail_recursion); NEXT_PASS (pass_convert_switch); - NEXT_PASS (pass_cleanup_eh); NEXT_PASS (pass_profile); NEXT_PASS (pass_local_pure_const); /* Split functions creates parts that are not run through