diff mbox series

[6/7] : Remaining support for clobber high

Message ID 03CBD65C-26DF-4538-AEDF-27C8169282DC@arm.com
State New
Headers show
Series [1/7] : SVE: Add CLOBBER_HIGH expression | expand

Commit Message

Alan Hayward Nov. 16, 2017, 12:35 p.m. UTC
This patch simply adds the remainder of clobber high checks.
Happy to split this into smaller patches if required (there didn't
seem anything obvious to split into).


Alan.

2017-11-16  Alan Hayward  <alan.hayward@arm.com>

	* alias.c (record_set): Check for clobber high.
	* cfgexpand.c (expand_gimple_stmt): Likewise.
	* combine-stack-adj.c (single_set_for_csa): Likewise.
	* combine.c (find_single_use_1): Likewise.
	(set_nonzero_bits_and_sign_copies): Likewise.
	(get_combine_src_dest): Likewise.
	(is_parallel_of_n_reg_sets): Likewise.
	(try_combine): Likewise.
	(record_dead_and_set_regs_1): Likewise.
	(reg_dead_at_p_1): Likewise.
	(reg_dead_at_p): Likewise.
	* dce.c (deletable_insn_p): Likewise.
	(mark_nonreg_stores_1): Likewise.
	(mark_nonreg_stores_2): Likewise.
	* df-scan.c (df_find_hard_reg_defs): Likewise.
	(df_uses_record): Likewise.
	(df_get_call_refs): Likewise.
	* dwarf2out.c (mem_loc_descriptor): 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): Likewise.
	(rtx_moveable_p): Likewise.
	(interesting_dest_for_shprep): Likewise.
	* jump.c (mark_jump_label_1): Likewise.
	* postreload-gcse.c (record_opr_changes): Likewise.
	* postreload.c (reload_cse_simplify): Likewise.
	(struct reg_use): Add source expr.
	(reload_combine): Check for clobber high.
	(reload_combine_note_use): Likewise.
	(reload_cse_move2add): Likewise.
	(move2add_note_store): Likewise.
	* print-rtl.c (print_pattern): Likewise.
	* recog.c (decode_asm_operands): Likewise.
	(store_data_bypass_p): Likewise.
	(if_test_bypass_p): Likewise.
	* regcprop.c (kill_clobbered_value): Likewise.
	(kill_set_value): Likewise.
	* reginfo.c (reg_scan_mark_refs): Likewise.
	* reload1.c (maybe_fix_stack_asms): Likewise.
	(eliminate_regs_1): Likewise.
	(elimination_effects): Likewise.
	(mark_not_eliminable): Likewise.
	(scan_paradoxical_subregs): Likewise.
	(forget_old_reloads_1): Likewise.
	* reorg.c (find_end_label): Likewise.
	(try_merge_delay_insns): Likewise.
	(redundant_insn): Likewise.
	(own_thread_p): Likewise.
	(fill_simple_delay_slots): Likewise.
	(fill_slots_from_thread): Likewise.
	(dbr_schedule): Likewise.
	* resource.c (update_live_status): Likewise.
	(mark_referenced_resources): Likewise.
	(mark_set_resources): Likewise.
	* rtl.c (copy_rtx): Likewise.
	* rtlanal.c (reg_referenced_p): Likewise.
	(single_set_2): Likewise.
	(noop_move_p): Likewise.
	(note_stores): Likewise.
	* sched-deps.c (sched_analyze_reg): Likewise.
	(sched_analyze_insn): Likewise.
diff mbox series

Patch

diff --git a/gcc/alias.c b/gcc/alias.c
index c69ef410edac2ab0ab93e8ec9fe4c89a7078c001..6a6734bd7d5732c255c009be47e68aa073a9ebb1 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -1554,6 +1554,17 @@  record_set (rtx dest, const_rtx set, void *data ATTRIBUTE_UNUSED)
 	  new_reg_base_value[regno] = 0;
 	  return;
 	}
+      /* A CLOBBER_HIGH only wipes out the old value if the mode of the old
+	 value is greater than that of the clobber.  */
+      else if (GET_CODE (set) == CLOBBER_HIGH)
+	{
+	  if (new_reg_base_value[regno] != 0
+	      && reg_is_clobbered_by_clobber_high (
+		   regno, GET_MODE (new_reg_base_value[regno]), XEXP (set, 0)))
+	    new_reg_base_value[regno] = 0;
+	  return;
+	}
+
       src = SET_SRC (set);
     }
   else
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index 06a8af8a1663c9e518a8169650a0c9969990df1f..ea6fc265f757543cff635a805fd4045a10add23e 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -3803,6 +3803,7 @@  expand_gimple_stmt (gimple *stmt)
 	      /* If we want exceptions for non-call insns, any
 		 may_trap_p instruction may throw.  */
 	      && GET_CODE (PATTERN (insn)) != CLOBBER
+	      && GET_CODE (PATTERN (insn)) != CLOBBER_HIGH
 	      && GET_CODE (PATTERN (insn)) != USE
 	      && insn_could_throw_p (insn))
 	    make_reg_eh_region_note (insn, 0, lp_nr);
diff --git a/gcc/combine-stack-adj.c b/gcc/combine-stack-adj.c
index 09f0be814f98922b6926a929401894809a890f61..595e83c73760a97e0f8ebd99e12b1853d1d52b92 100644
--- a/gcc/combine-stack-adj.c
+++ b/gcc/combine-stack-adj.c
@@ -133,6 +133,7 @@  single_set_for_csa (rtx_insn *insn)
 	  && SET_SRC (this_rtx) == SET_DEST (this_rtx))
 	;
       else if (GET_CODE (this_rtx) != CLOBBER
+	       && GET_CODE (this_rtx) != CLOBBER_HIGH
 	       && GET_CODE (this_rtx) != USE)
 	return NULL_RTX;
     }
diff --git a/gcc/combine.c b/gcc/combine.c
index 99cc343192ec4e2f8bdca0667858fbdf11baaffb..8b17349c240bea7a752cfd58f392f5a9dbfd53d6 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -573,6 +573,7 @@  find_single_use_1 (rtx dest, rtx *loc)
     case SYMBOL_REF:
     CASE_CONST_ANY:
     case CLOBBER:
+    case CLOBBER_HIGH:
       return 0;

     case SET:
@@ -1755,6 +1756,9 @@  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
@@ -1853,6 +1857,7 @@  get_combine_src_dest (combine_insn *insnc, rtx *pdest, rtx *psrc)

 	      /* We can ignore CLOBBERs.  */
 	    case CLOBBER:
+	    case CLOBBER_HIGH:
 	      break;

 	    case SET:
@@ -2715,10 +2720,17 @@  is_parallel_of_n_reg_sets (rtx pat, int n)
 	|| !REG_P (SET_DEST (XVECEXP (pat, 0, i))))
       return false;
   for ( ; i < len; i++)
-    if (GET_CODE (XVECEXP (pat, 0, i)) != CLOBBER
-	|| XEXP (XVECEXP (pat, 0, i), 0) == const0_rtx)
-      return false;
-
+    switch (GET_CODE (XVECEXP (pat, 0, i)))
+      {
+      case CLOBBER:
+	if (XEXP (XVECEXP (pat, 0, i), 0) == const0_rtx)
+	  return false;
+	break;
+      case CLOBBER_HIGH:
+	break;
+      default:
+	return false;
+      }
   return true;
 }

@@ -3099,7 +3111,8 @@  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
+	       || GET_CODE (XVECEXP (p2, 0, i)) == CLOBBER_HIGH)
 	      && reg_overlap_mentioned_p (SET_DEST (PATTERN (i3)),
 					  SET_DEST (XVECEXP (p2, 0, i))))
 	    ok = false;
@@ -13553,6 +13566,15 @@  record_dead_and_set_regs_1 (rtx dest, const_rtx setter, void *data)
 	record_value_for_reg (dest, record_dead_insn,
 			      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);
     }
@@ -14030,6 +14052,7 @@  use_crosses_set_p (const_rtx x, rtx_insn *from, rtx_insn *to)

 static unsigned int reg_dead_regno, reg_dead_endregno;
 static int reg_dead_flag;
+rtx reg_dead_reg;

 /* Function called via note_stores from reg_dead_at_p.

@@ -14044,6 +14067,10 @@  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, x))
+    return;
+
   regno = REGNO (dest);
   endregno = END_REGNO (dest);
   if (reg_dead_endregno > regno && reg_dead_regno < endregno)
@@ -14067,6 +14094,7 @@  reg_dead_at_p (rtx reg, rtx_insn *insn)
   /* Set variables for reg_dead_at_p_1.  */
   reg_dead_regno = REGNO (reg);
   reg_dead_endregno = END_REGNO (reg);
+  reg_dead_reg = reg;

   reg_dead_flag = 0;

diff --git a/gcc/dce.c b/gcc/dce.c
index 9f3021f13fe5171e0eaa26918eaee6bb690a3eb0..b0518a7d23d677e7192c173375473e03e68812cd 100644
--- a/gcc/dce.c
+++ b/gcc/dce.c
@@ -139,6 +139,7 @@  deletable_insn_p (rtx_insn *insn, bool fast, bitmap arg_stores)
       return false;

     case CLOBBER:
+    case CLOBBER_HIGH:
       if (fast)
 	{
 	  /* A CLOBBER of a dead pseudo register serves no purpose.
@@ -207,7 +208,10 @@  static void
 mark_nonreg_stores_1 (rtx dest, const_rtx pattern, void *data)
 {
   if (GET_CODE (pattern) != CLOBBER && !REG_P (dest))
-    mark_insn ((rtx_insn *) data, true);
+    {
+      gcc_checking_assert (GET_CODE (pattern) != CLOBBER_HIGH);
+      mark_insn ((rtx_insn *) data, true);
+    }
 }


@@ -218,7 +222,10 @@  static void
 mark_nonreg_stores_2 (rtx dest, const_rtx pattern, void *data)
 {
   if (GET_CODE (pattern) != CLOBBER && !REG_P (dest))
-    mark_insn ((rtx_insn *) data, false);
+    {
+      gcc_checking_assert (GET_CODE (pattern) != CLOBBER_HIGH);
+      mark_insn ((rtx_insn *) data, false);
+    }
 }


diff --git a/gcc/df-scan.c b/gcc/df-scan.c
index 8ab3d716ea2975ed687e1e3cf61ab3233e378f63..3962d5ab49cf321a4d8e866ec84f3867c0f34248 100644
--- a/gcc/df-scan.c
+++ b/gcc/df-scan.c
@@ -2777,6 +2777,7 @@  df_find_hard_reg_defs (rtx x, HARD_REG_SET *defs)
       break;

     case CLOBBER:
+    case CLOBBER_HIGH:
       df_find_hard_reg_defs_1 (XEXP (x, 0), defs);
       break;

@@ -2836,6 +2837,10 @@  df_uses_record (struct df_collection_rec *collection_rec,
       /* If we're clobbering a REG then we have a def so ignore.  */
       return;

+    case CLOBBER_HIGH:
+      gcc_assert (REG_P (XEXP (x, 0)));
+      return;
+
     case MEM:
       df_uses_record (collection_rec,
 		      &XEXP (x, 0), DF_REF_REG_MEM_LOAD,
@@ -3132,6 +3137,7 @@  df_get_call_refs (struct df_collection_rec *collection_rec,
   for (note = CALL_INSN_FUNCTION_USAGE (insn_info->insn); note;
        note = XEXP (note, 1))
     {
+      gcc_assert (GET_CODE (XEXP (note, 0)) != CLOBBER_HIGH);
       if (GET_CODE (XEXP (note, 0)) == USE)
         df_uses_record (collection_rec, &XEXP (XEXP (note, 0), 0),
 			DF_REF_REG_USE, bb, insn_info, flags);
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index c0f93d763f5163cff5db2241df383c48777803ac..78811a6861e6100ebaaeb7ed4b143da55657d6e1 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -15663,6 +15663,7 @@  mem_loc_descriptor (rtx rtl, machine_mode mode,
     case CONST_FIXED:
     case CLRSB:
     case CLOBBER:
+    case CLOBBER_HIGH:
       /* If delegitimize_address couldn't do anything with the UNSPEC, we
 	 can't express it in the debug info.  This can happen e.g. with some
 	 TLS UNSPECs.  */
diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index f5c06a95bb6742475bf7d1f2c5ea16456fa21efe..81c9ae378333079e99372153b64e5ffb1a088fc5 100644
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -529,6 +529,9 @@  haifa_classify_rtx (const_rtx x)
 	  /* Test if it is a 'store'.  */
 	  tmp_class = may_trap_exp (XEXP (x, 0), 1);
 	  break;
+	case CLOBBER_HIGH:
+	  gcc_assert (REG_P (XEXP (x, 0)));
+	  break;
 	case SET:
 	  /* Test if it is a store.  */
 	  tmp_class = may_trap_exp (SET_DEST (x), 1);
diff --git a/gcc/ira-build.c b/gcc/ira-build.c
index 67c0305a1685d432904e93d2057b38daf7fac315..8a1f2bac04600bc18cc0e3d6b45fb75c0be2ad97 100644
--- a/gcc/ira-build.c
+++ b/gcc/ira-build.c
@@ -1876,6 +1876,11 @@  create_insn_allocnos (rtx x, rtx outer, bool output_p)
       create_insn_allocnos (XEXP (x, 0), NULL, true);
       return;
     }
+  else if (code == CLOBBER_HIGH)
+    {
+      gcc_assert (REG_P (XEXP (x, 0)) && HARD_REGISTER_P (XEXP (x, 0)));
+      return;
+    }
   else if (code == MEM)
     {
       create_insn_allocnos (XEXP (x, 0), NULL, false);
diff --git a/gcc/ira-costs.c b/gcc/ira-costs.c
index e24dbc2e01be3048dbec379c0823c90271d7e768..9f03036e18b1abc03dc043c8deee023fa7a82fd4 100644
--- a/gcc/ira-costs.c
+++ b/gcc/ira-costs.c
@@ -1444,6 +1444,13 @@  scan_one_insn (rtx_insn *insn)
       return insn;
     }

+  if (pat_code == CLOBBER_HIGH)
+    {
+      gcc_assert (REG_P (XEXP (PATTERN (insn), 0))
+		  && HARD_REGISTER_P (XEXP (PATTERN (insn), 0)));
+      return insn;
+    }
+
   counted_mem = false;
   set = single_set (insn);
   extract_insn (insn);
diff --git a/gcc/ira.c b/gcc/ira.c
index 93d02093757c2db1e0133db2a2f388cea81e497a..bb6421853a7a7a049a79f0c6e82ef82f667f8321 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -3086,6 +3086,7 @@  equiv_init_movable_p (rtx x, int regno)

     case CC0:
     case CLOBBER:
+    case CLOBBER_HIGH:
       return 0;

     case PRE_INC:
@@ -4411,6 +4412,7 @@  rtx_moveable_p (rtx *loc, enum op_type type)
 	      && rtx_moveable_p (&XEXP (x, 2), OP_IN));

     case CLOBBER:
+    case CLOBBER_HIGH:
       return rtx_moveable_p (&SET_DEST (x), OP_OUT);

     case UNSPEC_VOLATILE:
@@ -4863,7 +4865,9 @@  interesting_dest_for_shprep (rtx_insn *insn, basic_block call_dom)
   for (int i = 0; i < XVECLEN (pat, 0); i++)
     {
       rtx sub = XVECEXP (pat, 0, i);
-      if (GET_CODE (sub) == USE || GET_CODE (sub) == CLOBBER)
+      if (GET_CODE (sub) == USE
+	  || GET_CODE (sub) == CLOBBER
+	  || GET_CODE (sub) == CLOBBER_HIGH)
 	continue;
       if (GET_CODE (sub) != SET
 	  || side_effects_p (sub))
diff --git a/gcc/jump.c b/gcc/jump.c
index b5392011b533e83ae7094e0f5870b281e35c2bea..03fc1c20840832c65d65711151c47dbde7c2acef 100644
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -1105,6 +1105,7 @@  mark_jump_label_1 (rtx x, rtx_insn *insn, bool in_mem, bool is_target)
     case CC0:
     case REG:
     case CLOBBER:
+    case CLOBBER_HIGH:
     case CALL:
       return;

diff --git a/gcc/postreload-gcse.c b/gcc/postreload-gcse.c
index 15fdb7e0cfe7767e559cd9ef6d5f66d3501ffd90..f4f6af75ea56d79a7579a971a3019c586fc9bfc1 100644
--- a/gcc/postreload-gcse.c
+++ b/gcc/postreload-gcse.c
@@ -791,15 +791,18 @@  record_opr_changes (rtx_insn *insn)
 	record_last_reg_set_info_regno (insn, regno);

       for (link = CALL_INSN_FUNCTION_USAGE (insn); link; link = XEXP (link, 1))
-	if (GET_CODE (XEXP (link, 0)) == CLOBBER)
-	  {
-	    x = XEXP (XEXP (link, 0), 0);
-	    if (REG_P (x))
-	      {
-		gcc_assert (HARD_REGISTER_P (x));
-		record_last_reg_set_info (insn, x);
-	      }
-	  }
+	{
+	  gcc_assert (GET_CODE (XEXP (link, 0)) != CLOBBER_HIGH);
+	  if (GET_CODE (XEXP (link, 0)) == CLOBBER)
+	    {
+	      x = XEXP (XEXP (link, 0), 0);
+	      if (REG_P (x))
+		{
+		  gcc_assert (HARD_REGISTER_P (x));
+		  record_last_reg_set_info (insn, x);
+		}
+	    }
+	}

       if (! RTL_CONST_OR_PURE_CALL_P (insn))
 	record_last_mem_set_info (insn);
diff --git a/gcc/postreload.c b/gcc/postreload.c
index a70d11a6c878871fea86a1afe0caec4507c0d394..6bdb4a4f3217b1d263f1cedf0234500f20b1516e 100644
--- a/gcc/postreload.c
+++ b/gcc/postreload.c
@@ -133,6 +133,8 @@  reload_cse_simplify (rtx_insn *insn, rtx testreg)
 	  for (i = XVECLEN (body, 0) - 1; i >= 0; --i)
 	    {
 	      rtx part = XVECEXP (body, 0, i);
+	      /* asms can only have full clobbers, not clobber_highs.  */
+	      gcc_assert (GET_CODE (part) != CLOBBER_HIGH);
 	      if (GET_CODE (part) == CLOBBER && REG_P (XEXP (part, 0)))
 		cselib_invalidate_rtx (XEXP (part, 0));
 	    }
@@ -156,6 +158,7 @@  reload_cse_simplify (rtx_insn *insn, rtx testreg)
 		}
 	    }
 	  else if (GET_CODE (part) != CLOBBER
+		   && GET_CODE (part) != CLOBBER_HIGH
 		   && GET_CODE (part) != USE)
 	    break;
 	}
@@ -667,7 +670,8 @@  struct reg_use
    STORE_RUID is always meaningful if we only want to use a value in a
    register in a different place: it denotes the next insn in the insn
    stream (i.e. the last encountered) that sets or clobbers the register.
-   REAL_STORE_RUID is similar, but clobbers are ignored when updating it.  */
+   REAL_STORE_RUID is similar, but clobbers are ignored when updating it.
+   EXPR is the expression used when storing the register.  */
 static struct
   {
     struct reg_use reg_use[RELOAD_COMBINE_MAX_USES];
@@ -677,6 +681,7 @@  static struct
     int real_store_ruid;
     int use_ruid;
     bool all_offsets_match;
+    rtx expr;
   } reg_state[FIRST_PSEUDO_REGISTER];

 /* Reverse linear uid.  This is increased in reload_combine while scanning
@@ -1339,6 +1344,10 @@  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))
 	        {
@@ -1514,6 +1523,10 @@  reload_combine_note_use (rtx *xp, rtx_insn *insn, int ruid, rtx containing_mem)
 	}
       break;

+    case CLOBBER_HIGH:
+      gcc_assert (REG_P (SET_DEST (x)));
+      return;
+
     case PLUS:
       /* We are interested in (plus (reg) (const_int)) .  */
       if (!REG_P (XEXP (x, 0))
@@ -2133,6 +2146,9 @@  reload_cse_move2add (rtx_insn *first)
 	    {
 	      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))
 	        {
@@ -2295,6 +2311,13 @@  move2add_note_store (rtx dst, const_rtx set, void *data)

       move2add_record_mode (dst);
     }
+  else if (GET_CODE (set) == CLOBBER_HIGH)
+    {
+      /* Only invalidate if actually clobbered.  */
+      if (reg_mode[regno] == BLKmode
+	  || reg_is_clobbered_by_clobber_high (regno, reg_mode[regno], dst))
+	 goto invalidate;
+    }
   else
     {
     invalidate:
diff --git a/gcc/print-rtl.c b/gcc/print-rtl.c
index 2ecdbb4299e2c64e8eea76a4534fe264fce613c4..5920165ceb416e7eec370e6863ffe887161f4b92 100644
--- a/gcc/print-rtl.c
+++ b/gcc/print-rtl.c
@@ -1715,6 +1715,7 @@  print_pattern (pretty_printer *pp, const_rtx x, int verbose)
       print_exp (pp, x, verbose);
       break;
     case CLOBBER:
+    case CLOBBER_HIGH:
     case USE:
       pp_printf (pp, "%s ", GET_RTX_NAME (GET_CODE (x)));
       print_value (pp, XEXP (x, 0), verbose);
diff --git a/gcc/recog.c b/gcc/recog.c
index 05e69134236c2266b966744a54b7ca7e9ed26fa1..769f462d0407673781a2634218c5c62579fb4ac1 100644
--- a/gcc/recog.c
+++ b/gcc/recog.c
@@ -1600,6 +1600,7 @@  decode_asm_operands (rtx body, rtx *operands, rtx **operand_locs,
 	      {
 		if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
 		  break;		/* Past last SET */
+		gcc_assert (GET_CODE (XVECEXP (body, 0, i)) == SET);
 		if (operands)
 		  operands[i] = SET_DEST (XVECEXP (body, 0, i));
 		if (operand_locs)
@@ -3690,7 +3691,8 @@  store_data_bypass_p (rtx_insn *out_insn, rtx_insn *in_insn)
           {
             out_exp = XVECEXP (out_pat, 0, i);

-            if (GET_CODE (out_exp) == CLOBBER)
+	    if (GET_CODE (out_exp) == CLOBBER
+		|| GET_CODE (out_exp) == CLOBBER_HIGH)
               continue;

             gcc_assert (GET_CODE (out_exp) == SET);
@@ -3709,7 +3711,8 @@  store_data_bypass_p (rtx_insn *out_insn, rtx_insn *in_insn)
 	{
 	  in_exp = XVECEXP (in_pat, 0, i);

-	  if (GET_CODE (in_exp) == CLOBBER)
+	  if (GET_CODE (in_exp) == CLOBBER
+	      || GET_CODE (in_exp) == CLOBBER_HIGH)
 	    continue;

 	  gcc_assert (GET_CODE (in_exp) == SET);
@@ -3732,7 +3735,8 @@  store_data_bypass_p (rtx_insn *out_insn, rtx_insn *in_insn)
                 {
                   out_exp = XVECEXP (out_pat, 0, j);

-                  if (GET_CODE (out_exp) == CLOBBER)
+		  if (GET_CODE (out_exp) == CLOBBER
+		      || GET_CODE (out_exp) == CLOBBER_HIGH)
                     continue;

                   gcc_assert (GET_CODE (out_exp) == SET);
@@ -3787,7 +3791,7 @@  if_test_bypass_p (rtx_insn *out_insn, rtx_insn *in_insn)
 	{
 	  rtx exp = XVECEXP (out_pat, 0, i);

-	  if (GET_CODE (exp) == CLOBBER)
+	  if (GET_CODE (exp) == CLOBBER  || GET_CODE (exp) == CLOBBER_HIGH)
 	    continue;

 	  gcc_assert (GET_CODE (exp) == SET);
diff --git a/gcc/regcprop.c b/gcc/regcprop.c
index 4ca10f58a58aa4c7605b001ec851c79a25fd6a8c..85b474544b22c915af9ea55230443186563dd624 100644
--- a/gcc/regcprop.c
+++ b/gcc/regcprop.c
@@ -237,7 +237,11 @@  static void
 kill_clobbered_value (rtx x, const_rtx set, void *data)
 {
   struct value_data *const vd = (struct value_data *) data;
-  if (GET_CODE (set) == CLOBBER)
+  gcc_assert (GET_CODE (set) != CLOBBER_HIGH || REG_P (x));
+
+  if (GET_CODE (set) == CLOBBER
+      || (GET_CODE (set) == CLOBBER_HIGH
+	  && reg_is_clobbered_by_clobber_high (x, XEXP (set, 0))))
     kill_value (x, vd);
 }

@@ -257,7 +261,9 @@  kill_set_value (rtx x, const_rtx set, void *data)
   struct kill_set_value_data *ksvd = (struct kill_set_value_data *) data;
   if (rtx_equal_p (x, ksvd->ignore_set_reg))
     return;
-  if (GET_CODE (set) != CLOBBER)
+
+  gcc_assert (GET_CODE (set) != CLOBBER_HIGH || REG_P (x));
+  if (GET_CODE (set) != CLOBBER && GET_CODE (set) != CLOBBER_HIGH)
     {
       kill_value (x, ksvd->vd);
       if (REG_P (x))
diff --git a/gcc/reginfo.c b/gcc/reginfo.c
index 847305ebe61fd3cd0cf02c01a02c537ad8b22c4a..bd9dd05e53404490b795b86b473e3b252bde1b50 100644
--- a/gcc/reginfo.c
+++ b/gcc/reginfo.c
@@ -1100,6 +1100,10 @@  reg_scan_mark_refs (rtx x, rtx_insn *insn)
 	reg_scan_mark_refs (XEXP (XEXP (x, 0), 0), insn);
       break;

+    case CLOBBER_HIGH:
+      gcc_assert (!(MEM_P (XEXP (x, 0))));
+      break;
+
     case SET:
       /* Count a set of the destination if it is a register.  */
       for (dest = SET_DEST (x);
diff --git a/gcc/reload1.c b/gcc/reload1.c
index 902d940245dfcb73c10de8670adb22375fbfe098..68b16ca8bd747511589a74529c1ac922acf04215 100644
--- a/gcc/reload1.c
+++ b/gcc/reload1.c
@@ -1339,6 +1339,8 @@  maybe_fix_stack_asms (void)
 	  rtx t = XVECEXP (pat, 0, i);
 	  if (GET_CODE (t) == CLOBBER && STACK_REG_P (XEXP (t, 0)))
 	    SET_HARD_REG_BIT (clobbered, REGNO (XEXP (t, 0)));
+	  /* CLOBBER_HIGH is only supported for LRA.  */
+	  gcc_assert (GET_CODE (t) != CLOBBER_HIGH);
 	}

       /* Get the operand values and constraints out of the insn.  */
@@ -2879,6 +2881,7 @@  eliminate_regs_1 (rtx x, machine_mode mem_mode, rtx insn,
       return x;

     case CLOBBER:
+    case CLOBBER_HIGH:
     case ASM_OPERANDS:
       gcc_assert (insn && DEBUG_INSN_P (insn));
       break;
@@ -3089,6 +3092,10 @@  elimination_effects (rtx x, machine_mode mem_mode)
       elimination_effects (XEXP (x, 0), mem_mode);
       return;

+    case CLOBBER_HIGH:
+      /* CLOBBER_HIGH is only supported for LRA.  */
+      return;
+
     case SET:
       /* Check for setting a register that we know about.  */
       if (REG_P (SET_DEST (x)))
@@ -3810,6 +3817,9 @@  mark_not_eliminable (rtx dest, const_rtx x, void *data ATTRIBUTE_UNUSED)
   if (dest == hard_frame_pointer_rtx)
     return;

+  /* CLOBBER_HIGH is only supported for LRA.  */
+  gcc_assert (GET_CODE (x) != CLOBBER_HIGH);
+
   for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
     if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx
 	&& (GET_CODE (x) != SET
@@ -4445,6 +4455,7 @@  scan_paradoxical_subregs (rtx x)
     case PC:
     case USE:
     case CLOBBER:
+    case CLOBBER_HIGH:
       return;

     case SUBREG:
@@ -4899,7 +4910,7 @@  reload_as_needed (int live_known)
    to be forgotten later.  */

 static void
-forget_old_reloads_1 (rtx x, const_rtx ignored ATTRIBUTE_UNUSED,
+forget_old_reloads_1 (rtx x, const_rtx setter,
 		      void *data)
 {
   unsigned int regno;
@@ -4919,6 +4930,9 @@  forget_old_reloads_1 (rtx x, const_rtx ignored ATTRIBUTE_UNUSED,
   if (!REG_P (x))
     return;

+  /* CLOBBER_HIGH is only supported for LRA.  */
+  gcc_assert (GET_CODE (setter) != CLOBBER_HIGH);
+
   regno = REGNO (x);

   if (regno >= FIRST_PSEUDO_REGISTER)
diff --git a/gcc/reorg.c b/gcc/reorg.c
index 5914af655b6bbbddc98f23f53c0d1e6e496dc2eb..4f97e78b2a3c03db89a1bd2fa10bf8e83c374ae7 100644
--- a/gcc/reorg.c
+++ b/gcc/reorg.c
@@ -396,7 +396,8 @@  find_end_label (rtx kind)
   while (NOTE_P (insn)
 	 || (NONJUMP_INSN_P (insn)
 	     && (GET_CODE (PATTERN (insn)) == USE
-		 || GET_CODE (PATTERN (insn)) == CLOBBER)))
+		 || GET_CODE (PATTERN (insn)) == CLOBBER
+		 || GET_CODE (PATTERN (insn)) == CLOBBER_HIGH)))
     insn = PREV_INSN (insn);

   /* When a target threads its epilogue we might already have a
@@ -1290,7 +1291,8 @@  try_merge_delay_insns (rtx_insn *insn, rtx_insn *thread)

       /* TRIAL must be a CALL_INSN or INSN.  Skip USE and CLOBBER.  */
       if (NONJUMP_INSN_P (trial)
-	  && (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER))
+	  && (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER
+	      || GET_CODE (pat) == CLOBBER_HIGH))
 	continue;

       if (GET_CODE (next_to_match) == GET_CODE (trial)
@@ -1484,7 +1486,8 @@  redundant_insn (rtx insn, rtx_insn *target, const vec<rtx_insn *> &delay_list)
       --insns_to_search;

       pat = PATTERN (trial);
-      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER)
+      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER
+	  || GET_CODE (pat) == CLOBBER_HIGH)
 	continue;

       if (rtx_sequence *seq = dyn_cast <rtx_sequence *> (pat))
@@ -1579,7 +1582,8 @@  redundant_insn (rtx insn, rtx_insn *target, const vec<rtx_insn *> &delay_list)
       --insns_to_search;

       pat = PATTERN (trial);
-      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER)
+      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER
+	  || GET_CODE (pat) == CLOBBER_HIGH)
 	continue;

       if (rtx_sequence *seq = dyn_cast <rtx_sequence *> (pat))
@@ -1688,7 +1692,8 @@  own_thread_p (rtx thread, rtx label, int allow_fallthrough)
 	|| LABEL_P (insn)
 	|| (NONJUMP_INSN_P (insn)
 	    && GET_CODE (PATTERN (insn)) != USE
-	    && GET_CODE (PATTERN (insn)) != CLOBBER))
+	    && GET_CODE (PATTERN (insn)) != CLOBBER
+	    && GET_CODE (PATTERN (insn)) != CLOBBER_HIGH))
       return 0;

   return 1;
@@ -2013,7 +2018,8 @@  fill_simple_delay_slots (int non_jumps_p)
 	      pat = PATTERN (trial);

 	      /* Stand-alone USE and CLOBBER are just for flow.  */
-	      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER)
+	      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER
+		  || GET_CODE (pat) == CLOBBER_HIGH)
 		continue;

 	      /* Check for resource conflict first, to avoid unnecessary
@@ -2135,7 +2141,8 @@  fill_simple_delay_slots (int non_jumps_p)
 	      pat = PATTERN (trial);

 	      /* Stand-alone USE and CLOBBER are just for flow.  */
-	      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER)
+	      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER
+		  || GET_CODE (pat) == CLOBBER_HIGH)
 		continue;

 	      /* If this already has filled delay slots, get the insn needing
@@ -2400,7 +2407,8 @@  fill_slots_from_thread (rtx_jump_insn *insn, rtx condition,
 	}

       pat = PATTERN (trial);
-      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER)
+      if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER
+	  || GET_CODE (pat) == CLOBBER_HIGH)
 	continue;

       /* If TRIAL conflicts with the insns ahead of it, we lose.  Also,
@@ -3790,7 +3798,8 @@  dbr_schedule (rtx_insn *first)
 	  if (! insn->deleted ()
 	      && NONJUMP_INSN_P (insn)
 	      && GET_CODE (PATTERN (insn)) != USE
-	      && GET_CODE (PATTERN (insn)) != CLOBBER)
+	      && GET_CODE (PATTERN (insn)) != CLOBBER
+	      && GET_CODE (PATTERN (insn)) != CLOBBER_HIGH)
 	    {
 	      if (GET_CODE (PATTERN (insn)) == SEQUENCE)
 		{
diff --git a/gcc/resource.c b/gcc/resource.c
index 95911c5c718f8ae79a401c782624ec8a01a9e8ab..463e370b2d8610787ba21b4be3925aa1ae86e71e 100644
--- a/gcc/resource.c
+++ b/gcc/resource.c
@@ -108,6 +108,11 @@  update_live_status (rtx dest, const_rtx x, void *data ATTRIBUTE_UNUSED)
   if (GET_CODE (x) == CLOBBER)
     for (i = first_regno; i < last_regno; i++)
       CLEAR_HARD_REG_BIT (current_live_regs, i);
+  else if (GET_CODE (x) == CLOBBER_HIGH)
+    /* No current target supports both branch delay slots and CLOBBER_HIGH.
+       We'd need more elaborate liveness tracking to handle that
+       combination.  */
+    gcc_unreachable ();
   else
     for (i = first_regno; i < last_regno; i++)
       {
@@ -292,6 +297,7 @@  mark_referenced_resources (rtx x, struct resources *res,
       return;

     case CLOBBER:
+    case CLOBBER_HIGH:
       return;

     case CALL_INSN:
@@ -665,9 +671,15 @@  mark_set_resources (rtx x, struct resources *res, int in_dest,

 	  for (link = CALL_INSN_FUNCTION_USAGE (call_insn);
 	       link; link = XEXP (link, 1))
-	    if (GET_CODE (XEXP (link, 0)) == CLOBBER)
-	      mark_set_resources (SET_DEST (XEXP (link, 0)), res, 1,
-				  MARK_SRC_DEST);
+	    {
+	      /* 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 (XEXP (link, 0)) != CLOBBER_HIGH);
+	      if (GET_CODE (XEXP (link, 0)) == CLOBBER)
+		mark_set_resources (SET_DEST (XEXP (link, 0)), res, 1,
+				    MARK_SRC_DEST);
+	    }

 	  /* Check for a REG_SETJMP.  If it exists, then we must
 	     assume that this call can clobber any register.  */
@@ -710,6 +722,12 @@  mark_set_resources (rtx x, struct resources *res, int in_dest,
       mark_set_resources (XEXP (x, 0), res, 1, MARK_SRC_DEST);
       return;

+    case CLOBBER_HIGH:
+      /* No current target supports both branch delay slots and CLOBBER_HIGH.
+	 We'd need more elaborate liveness tracking to handle that
+	 combination.  */
+      gcc_unreachable ();
+
     case SEQUENCE:
       {
         rtx_sequence *seq = as_a <rtx_sequence *> (x);
diff --git a/gcc/rtl.c b/gcc/rtl.c
index 6db84f99627bb8617c6e227892ca44076f4e729b..12a01e8ed1f9005e5c0dfeb0f86c762069520284 100644
--- a/gcc/rtl.c
+++ b/gcc/rtl.c
@@ -307,6 +307,10 @@  copy_rtx (rtx orig)
 	return orig;
       break;

+    case CLOBBER_HIGH:
+	gcc_assert (REG_P (XEXP (orig, 0)));
+	return orig;
+
     case CONST:
       if (shared_const_p (orig))
 	return orig;
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index 923e3314d25c05f9055907c61b4a24186701cc23..d907d636ed5f22d9cdc7237d66fdb05da9922f60 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -1196,6 +1196,10 @@  reg_referenced_p (const_rtx x, const_rtx body)
 	  return 1;
       return 0;

+    case CLOBBER_HIGH:
+      gcc_assert (REG_P (XEXP (body, 0)));
+      return 0;
+
     case COND_EXEC:
       if (reg_overlap_mentioned_p (x, COND_EXEC_TEST (body)))
 	return 1;
@@ -1507,6 +1511,7 @@  single_set_2 (const rtx_insn *insn, const_rtx pat)
 	    {
 	    case USE:
 	    case CLOBBER:
+	    case CLOBBER_HIGH:
 	      break;

 	    case SET:
@@ -1660,7 +1665,8 @@  noop_move_p (const rtx_insn *insn)
 	  rtx tem = XVECEXP (pat, 0, i);

 	  if (GET_CODE (tem) == USE
-	      || GET_CODE (tem) == CLOBBER)
+	      || GET_CODE (tem) == CLOBBER
+	      || GET_CODE (tem) == CLOBBER_HIGH)
 	    continue;

 	  if (GET_CODE (tem) != SET || ! set_noop_p (tem))
@@ -1892,7 +1898,9 @@  note_stores (const_rtx x, void (*fun) (rtx, const_rtx, void *), void *data)
   if (GET_CODE (x) == COND_EXEC)
     x = COND_EXEC_CODE (x);

-  if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
+  if (GET_CODE (x) == SET
+      || GET_CODE (x) == CLOBBER
+      || GET_CODE (x) == CLOBBER_HIGH)
     {
       rtx dest = SET_DEST (x);

diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index a64e4e17bbc8115982d253d041032243e9506802..8eb0ed350557d3c0af87bbba674cefd4478d97aa 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -2319,6 +2319,13 @@  sched_analyze_reg (struct deps_desc *deps, int regno, machine_mode mode,
 	  while (--i >= 0)
 	    note_reg_use (regno + i);
 	}
+      else if (ref == CLOBBER_HIGH)
+	{
+	  gcc_assert (i == 1);
+	  /* We don't know the current state of the register, so have to treat
+	     the clobber high as a full clobber.  */
+	  note_reg_clobber (regno);
+	}
       else
 	{
 	  while (--i >= 0)
@@ -2342,6 +2349,8 @@  sched_analyze_reg (struct deps_desc *deps, int regno, machine_mode mode,
       else if (ref == USE)
 	note_reg_use (regno);
       else
+	/* For CLOBBER_HIGH, we don't know the current state of the register,
+	   so have to treat it as a full clobber.  */
 	note_reg_clobber (regno);

       /* Pseudos that are REG_EQUIV to something may be replaced
@@ -2953,7 +2962,7 @@  sched_analyze_insn (struct deps_desc *deps, rtx x, rtx_insn *insn)
 	      sub = COND_EXEC_CODE (sub);
 	      code = GET_CODE (sub);
 	    }
-	  if (code == SET || code == CLOBBER)
+	  else if (code == SET || code == CLOBBER || code == CLOBBER_HIGH)
 	    sched_analyze_1 (deps, sub, insn);
 	  else
 	    sched_analyze_2 (deps, sub, insn);
@@ -2969,6 +2978,10 @@  sched_analyze_insn (struct deps_desc *deps, rtx x, rtx_insn *insn)
 	{
 	  if (GET_CODE (XEXP (link, 0)) == CLOBBER)
 	    sched_analyze_1 (deps, XEXP (link, 0), insn);
+	  else if (GET_CODE (XEXP (link, 0)) == CLOBBER_HIGH)
+	    /* 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_unreachable ();
 	  else if (GET_CODE (XEXP (link, 0)) != SET)
 	    sched_analyze_2 (deps, XEXP (link, 0), insn);
 	}