Remove clobber_high

The AArch64 SVE tlsdesc patterns were the main motivating reason
for clobber_high.  It's no longer needed now that the patterns use
calls instead.

At the time, one of the possible future uses for clobber_high was for
asm statements.  However, the current code wouldn't handle that case
without modification, so I think we might as well remove it for now.
We can always reapply it in future if it turns out to be useful again.

2019-10-01  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* rtl.def (CLOBBER_HIGH): Delete.
	* doc/rtl.texi (clobber_high): Remove documentation.
	* rtl.h (SET_DEST): Remove CLOBBER_HIGH from the list of codes.
	(reg_is_clobbered_by_clobber_high): Delete.
	(gen_hard_reg_clobber_high): Likewise.
	* alias.c (record_set): Remove CLOBBER_HIGH handling.
	* cfgexpand.c (expand_gimple_stmt): Likewise.
	* combine-stack-adj.c (single_set_for_csa): Likewise.
	* combine.c (find_single_use_1, set_nonzero_bits_and_sign_copies)
	(can_combine_p, is_parallel_of_n_reg_sets, try_combine)
	(record_dead_and_set_regs_1, reg_dead_at_p_1): Likewise.
	* cse.c (invalidate_reg): Remove clobber_high parameter.
	(invalidate): Update call accordingly.
	(canonicalize_insn): Remove CLOBBER_HIGH handling.
	(invalidate_from_clobbers, invalidate_from_sets_and_clobbers)
	(count_reg_usage, insn_live_p): Likewise.
	* cselib.h (cselib_invalidate_rtx): Remove sett argument.
	* cselib.c (cselib_invalidate_regno, cselib_invalidate_rtx): Likewise.
	(cselib_invalidate_rtx_note_stores): Update call accordingly.
	(cselib_expand_value_rtx_1): Remove CLOBBER_HIGH handling.
	(cselib_invalidate_regno, cselib_process_insn): Likewise.
	* dce.c (deletable_insn_p, mark_nonreg_stores_1): Likewise.
	(mark_nonreg_stores_2): Likewise.
	* df-scan.c (df_find_hard_reg_defs, df_uses_record): Likewise.
	(df_get_call_refs): Likewise.
	* dwarf2out.c (mem_loc_descriptor): Likewise.
	* emit-rtl.c (verify_rtx_sharing): Likewise.
	(copy_insn_1, copy_rtx_if_shared_1): Likewise.
	(hard_reg_clobbers_high, gen_hard_reg_clobber_high): Delete.
	* genconfig.c (walk_insn_part): Remove CLOBBER_HIGH handling.
	* genemit.c (gen_exp, gen_insn): Likewise.
	* genrecog.c (validate_pattern, remove_clobbers): Likewise.
	* haifa-sched.c (haifa_classify_rtx): Likewise.
	* ira-build.c (create_insn_allocnos): Likewise.
	* ira-costs.c (scan_one_insn): Likewise.
	* ira.c (equiv_init_movable_p, memref_referenced_p): Likewise.
	(rtx_moveable_p, interesting_dest_for_shprep): Likewise.
	* jump.c (mark_jump_label_1): Likewise.
	* lra-int.h (lra_insn_reg::clobber_high): Delete.
	* lra-eliminations.c (lra_eliminate_regs_1): Remove CLOBBER_HIGH
	handling.
	(mark_not_eliminable): Likewise.
	* lra-lives.c (process_bb_lives): Likewise.
	* lra.c (new_insn_reg): Remove clobber_high parameter.
	(collect_non_operand_hard_regs): Likewise.  Update call to new
	insn_reg.  Remove CLOBBER_HIGH handling.
	(lra_set_insn_recog_data): Remove CLOBBER_HIGH handling.  Update call
	to collect_non_operand_hard_regs.
	(add_regs_to_insn_regno_info): Remove CLOBBER_HIGH handling.
	Update call to new_insn_reg.
	(lra_update_insn_regno_info): Remove CLOBBER_HIGH handling.
	* postreload.c (reload_cse_simplify, reload_combine_note_use)
	(move2add_note_store): Likewise.
	* print-rtl.c (print_pattern): Likewise.
	* recog.c (store_data_bypass_p_1, store_data_bypass_p): Likewise.
	(if_test_bypass_p): Likewise.
	* regcprop.c (kill_clobbered_value, kill_set_value): Likewise.
	* reginfo.c (reg_scan_mark_refs): Likewise.
	* reload1.c (maybe_fix_stack_asms, eliminate_regs_1): Likewise.
	(elimination_effects, mark_not_eliminable, scan_paradoxical_subregs)
	(forget_old_reloads_1): Likewise.
	* reorg.c (find_end_label, try_merge_delay_insns, redundant_insn)
	(own_thread_p, fill_simple_delay_slots, fill_slots_from_thread)
	(dbr_schedule): Likewise.
	* resource.c (update_live_status, mark_referenced_resources)
	(mark_set_resources): Likewise.
	* rtl.c (copy_rtx): Likewise.
	* rtlanal.c (reg_referenced_p, set_of_1, single_set_2, noop_move_p)
	(note_pattern_stores): Likewise.
	(reg_is_clobbered_by_clobber_high): Delete.
	* sched-deps.c (sched_analyze_reg, sched_analyze_insn): Remove
	CLOBBER_HIGH handling.

From-SVN: r276393

1 files changed, 1 insertions, 22 deletions

diff --git a/gcc/combine.c b/gcc/combine.c
index d200c5a..d295a81 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -572,7 +572,6 @@ find_single_use_1 (rtx dest, rtx *loc)
     case SYMBOL_REF:
     CASE_CONST_ANY:
     case CLOBBER:
-    case CLOBBER_HIGH:
       return 0;
 
     case SET:
@@ -1763,9 +1762,6 @@ set_nonzero_bits_and_sign_copies (rtx x, const_rtx set, void *data)
 	  return;
 	}
 
-      /* Should not happen as we only using pseduo registers.  */
-      gcc_assert (GET_CODE (set) != CLOBBER_HIGH);
-
       /* If this register is being initialized using itself, and the
 	 register is uninitialized in this basic block, and there are
 	 no LOG_LINKS which set the register, then part of the
@@ -1924,7 +1920,6 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED,
 
 	      /* We can ignore CLOBBERs.  */
 	    case CLOBBER:
-	    case CLOBBER_HIGH:
 	      break;
 
 	    case SET:
@@ -2595,8 +2590,6 @@ is_parallel_of_n_reg_sets (rtx pat, int n)
 	if (XEXP (XVECEXP (pat, 0, i), 0) == const0_rtx)
 	  return false;
 	break;
-      case CLOBBER_HIGH:
-	break;
       default:
 	return false;
       }
@@ -2897,8 +2890,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
       for (i = 0; ok && i < XVECLEN (p2, 0); i++)
 	{
 	  if ((GET_CODE (XVECEXP (p2, 0, i)) == SET
-	       || GET_CODE (XVECEXP (p2, 0, i)) == CLOBBER
-	       || GET_CODE (XVECEXP (p2, 0, i)) == CLOBBER_HIGH)
+	       || GET_CODE (XVECEXP (p2, 0, i)) == CLOBBER)
 	      && reg_overlap_mentioned_p (SET_DEST (PATTERN (i3)),
 					  SET_DEST (XVECEXP (p2, 0, i))))
 	    ok = false;
@@ -13409,15 +13401,6 @@ record_dead_and_set_regs_1 (rtx dest, const_rtx setter, void *data)
 			      ? SET_SRC (setter)
 			      : gen_lowpart (GET_MODE (dest),
 					     SET_SRC (setter)));
-      else if (GET_CODE (setter) == CLOBBER_HIGH)
-	{
-	  reg_stat_type *rsp = &reg_stat[REGNO (dest)];
-	  if (rsp->last_set_value
-	      && reg_is_clobbered_by_clobber_high
-		   (REGNO (dest), GET_MODE (rsp->last_set_value),
-		    XEXP (setter, 0)))
-	    record_value_for_reg (dest, NULL, NULL_RTX);
-	}
       else
 	record_value_for_reg (dest, record_dead_insn, NULL_RTX);
     }
@@ -13863,10 +13846,6 @@ reg_dead_at_p_1 (rtx dest, const_rtx x, void *data ATTRIBUTE_UNUSED)
   if (!REG_P (dest))
     return;
 
-  if (GET_CODE (x) == CLOBBER_HIGH
-      && !reg_is_clobbered_by_clobber_high (reg_dead_reg, XEXP (x, 0)))
-    return;
-
   regno = REGNO (dest);
   endregno = END_REGNO (dest);
   if (reg_dead_endregno > regno && reg_dead_regno < endregno)