Make note_stores take an rtx_insn

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.

2019-09-09  Richard Sandiford  <richard.sandiford@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.

From-SVN: r275527

1 files changed, 4 insertions, 34 deletions

diff --git a/gcc/postreload.c b/gcc/postreload.c
index 728aa9b0ed5..497a4b0e9f9 100644
--- a/gcc/postreload.c
+++ b/gcc/postreload.c
@@ -1325,7 +1325,7 @@ reload_combine (void)
 	  || reload_combine_recognize_pattern (insn))
 	continue;
 
-      note_stores (PATTERN (insn), reload_combine_note_store, NULL);
+      note_stores (insn, reload_combine_note_store, NULL);
 
       if (CALL_P (insn))
 	{
@@ -1346,22 +1346,12 @@ reload_combine (void)
 	    {
 	      rtx setuse = XEXP (link, 0);
 	      rtx usage_rtx = XEXP (setuse, 0);
-	      /* We could support CLOBBER_HIGH and treat it in the same way as
-		 HARD_REGNO_CALL_PART_CLOBBERED, but no port needs that yet.  */
-	      gcc_assert (GET_CODE (setuse) != CLOBBER_HIGH);
 
-	      if ((GET_CODE (setuse) == USE || GET_CODE (setuse) == CLOBBER)
-		  && REG_P (usage_rtx))
+	      if (GET_CODE (setuse) == USE && REG_P (usage_rtx))
 	        {
 		  unsigned int end_regno = END_REGNO (usage_rtx);
 		  for (unsigned int i = REGNO (usage_rtx); i < end_regno; ++i)
-		    if (GET_CODE (XEXP (link, 0)) == CLOBBER)
-		      {
-		        reg_state[i].use_index = RELOAD_COMBINE_MAX_USES;
-		        reg_state[i].store_ruid = reload_combine_ruid;
-		      }
-		    else
-		      reg_state[i].use_index = -1;
+		    reg_state[i].use_index = -1;
 	         }
 	     }
 	}
@@ -2104,7 +2094,7 @@ reload_cse_move2add (rtx_insn *first)
 		}
 	    }
 	}
-      note_stores (PATTERN (insn), move2add_note_store, insn);
+      note_stores (insn, move2add_note_store, insn);
 
       /* If INSN is a conditional branch, we try to extract an
 	 implicit set out of it.  */
@@ -2134,32 +2124,12 @@ reload_cse_move2add (rtx_insn *first)
 	 unknown values.  */
       if (CALL_P (insn))
 	{
-	  rtx link;
-
 	  for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; i--)
 	    {
 	      if (call_used_regs[i])
 		/* Reset the information about this register.  */
 		reg_mode[i] = VOIDmode;
 	    }
-
-	  for (link = CALL_INSN_FUNCTION_USAGE (insn); link;
-	       link = XEXP (link, 1))
-	    {
-	      rtx setuse = XEXP (link, 0);
-	      rtx usage_rtx = XEXP (setuse, 0);
-	      /* CALL_INSN_FUNCTION_USAGEs can only have full clobbers, not
-		 clobber_highs.  */
-	      gcc_assert (GET_CODE (setuse) != CLOBBER_HIGH);
-	      if (GET_CODE (setuse) == CLOBBER
-		  && REG_P (usage_rtx))
-	        {
-		  unsigned int end_regno = END_REGNO (usage_rtx);
-		  for (unsigned int r = REGNO (usage_rtx); r < end_regno; ++r)
-		    /* Reset the information about this register.  */
-		    reg_mode[r] = VOIDmode;
-		}
-	    }
 	}
     }
   return changed;