On 9/9/19 5:33 AM, Richard Sandiford wrote: > I have a series of patches that (as a side effect) makes all rtl > passes use the information collected by -fipa-ra. This showed up a > latent bug in the liveness tracking in regrename.c, which doesn't take > CALL_INSN_FUNCTION_USAGE into account when processing clobbers. > > This actually seems to be quite a common problem with passes that use > note_stores; only a handful remember to walk CALL_INSN_FUNCTION_USAGE > too. I think it was just luck that I saw it with regrename first.> > This patch tries to make things more robust by passing an insn rather > than a pattern to note_stores. The old function is still available > as note_pattern_stores for the few places that need it. > > When updating callers, I've erred on the side of using note_stores > rather than note_pattern_stores, because IMO note_stores should be > the default choice and we should only use note_pattern_stores if > there's a specific reason. Specifically: > > * For cselib.c, "body" may be a COND_EXEC_CODE instead of the main > insn pattern. > > * For ira.c, I wasn't sure whether extending no_equiv to > CALL_INSN_FUNCTION_USAGE really made sense, since we don't do that > for normal call-clobbered registers. Same for mark_not_eliminable > in reload1.c > > * Some other places only have a pattern available, and since those > places wouldn't benefit from walking CALL_INSN_FUNCTION_USAGE, > it seemed better to alter the code as little as possible. > > * In the config/ changes, quite a few callers have already weeded > out CALL insns. It still seemed better to use note_stores rather > than prematurely optimise. (note_stores should tail call to > note_pattern_stores once it sees that the insn isn't a call.) > > The patch also documents what SETs mean in CALL_INSN_FUNCTION_USAGE. > > Tested on aarch64-linux-gnu and x86_64-linux-gnu. Also tested by > building one target for each CPU directory and testing for no new > warnings. Comparing the asm output for gcc.c-torture, gcc.dg and > g++.dg for those targets at -O2 showed some changes for AArch64 > and AArch32 targets (all neutral or very minor improvements). > There were no changes for other ports. > > (This was before BPF, but fortunately BPF doesn't use note_stores. :-)) > > OK to install? > > Richard > > > 2019-09-09 Richard Sandiford <richard.sandif...@arm.com> > > gcc/ > * rtl.h (CALL_INSN_FUNCTION_USAGE): Document what SETs mean. > (note_pattern_stores): Declare. > (note_stores): Take an rtx_insn *. > * rtlanal.c (set_of): Use note_pattern_stores instead of note_stores. > (find_all_hard_reg_sets): Pass the insn rather than its pattern to > note_stores. Remove explicit handling of CALL_INSN_FUNCTION_USAGE. > (note_stores): Take an rtx_insn * as argument and process > CALL_INSN_FUNCTION_USAGE. Rename old function to... > (note_pattern_stores): ...this. > (find_first_parameter_load): Pass the insn rather than > its pattern to note_stores. > * alias.c (memory_modified_in_insn_p, init_alias_analysis): Likewise. > * caller-save.c (setup_save_areas, save_call_clobbered_regs) > (insert_one_insn): Likewise. > * combine.c (combine_instructions): Likewise. > (likely_spilled_retval_p): Likewise. > (try_combine): Use note_pattern_stores instead of note_stores. > (record_dead_and_set_regs): Pass the insn rather than its pattern > to note_stores. > (reg_dead_at_p): Likewise. > * config/bfin/bfin.c (workaround_speculation): Likewise. > * config/c6x/c6x.c (maybe_clobber_cond): Likewise. Take an rtx_insn * > rather than an rtx. > * config/frv/frv.c (frv_registers_update): Use note_pattern_stores > instead of note_stores. > (frv_optimize_membar_local): Pass the insn rather than its pattern > to note_stores. > * config/gcn/gcn.c (gcn_md_reorg): Likewise. > * config/i386/i386.c (ix86_avx_u128_mode_after): Likewise. > * config/mips/mips.c (vr4130_true_reg_dependence_p): Likewise. > (r10k_needs_protection_p, mips_sim_issue_insn): Likewise. > (mips_reorg_process_insns): Likewise. > * config/s390/s390.c (s390_regs_ever_clobbered): Likewise. > * config/sh/sh.c (flow_dependent_p): Likewise. Take rtx_insn *s > rather than rtxes. > * cse.c (delete_trivially_dead_insns): Pass the insn rather than > its pattern to note_stores. > * cselib.c (cselib_record_sets): Use note_pattern_stores instead > of note_stores. > * dce.c (mark_nonreg_stores): Remove the "body" parameter and pass > the insn to note_stores. > (prescan_insns_for_dce): Update call accordingly. > * ddg.c (mem_write_insn_p): Pass the insn rather than its pattern > to note_stores. > * df-problems.c (can_move_insns_across): Likewise. > * dse.c (emit_inc_dec_insn_before, replace_read): Likewise. > * function.c (assign_parm_setup_reg): Likewise. > * gcse-common.c (record_last_mem_set_info_common): Likewise. > * gcse.c (load_killed_in_block_p, compute_hash_table_work): Likewise. > (single_set_gcse): Likewise. > * ira.c (validate_equiv_mem): Likewise. > (update_equiv_regs): Use note_pattern_stores rather than note_stores > for no_equiv. > * loop-doloop.c (doloop_optimize): Pass the insn rather than its > pattern to note_stores. > * loop-invariant.c (calculate_loop_reg_pressure): Likewise. > * loop-iv.c (simplify_using_initial_values): Likewise. > * mode-switching.c (optimize_mode_switching): Likewise. > * optabs.c (emit_libcall_block_1): Likewise. > (expand_atomic_compare_and_swap): Likewise. > * postreload-gcse.c (load_killed_in_block_p): Likewise. > (record_opr_changes): Likewise. Remove explicit handling of > CALL_INSN_FUNCTION_USAGE. > * postreload.c (reload_combine, reload_cse_move2add): Likewise. > * regcprop.c (kill_clobbered_values): Likewise. > (copyprop_hardreg_forward_1): Pass the insn rather than its pattern > to note_stores. > * regrename.c (build_def_use): Likewise. > * reload1.c (reload): Use note_pattern_stores instead of note_stores > for mark_not_eliminable. > (reload_as_needed): Pass the insn rather than its pattern > to note_stores. > (emit_output_reload_insns): Likewise. > * resource.c (mark_target_live_regs): Likewise. > * sched-deps.c (init_insn_reg_pressure_info): Likewise. > * sched-rgn.c (sets_likely_spilled): Use note_pattern_stores > instead of note_stores. > * shrink-wrap.c (try_shrink_wrapping): Pass the insn rather than > its pattern to note_stores. > * stack-ptr-mod.c (pass_stack_ptr_mod::execute): Likewise. > * var-tracking.c (adjust_insn, add_with_sets): Likewise. Kind of surprising how pervasive this problem was. As you said, just happened to hit it in regrename first...
If you can get it in Mon/Tues, then my tester will fully spin it prior to Cauldron... OK for the trunk. Jeff
