[1/9] Make more use of END_REGNO

[Richard Sandiford <richard.sandiford@arm.com>]

This patch just handles some obvious cases where END_REGNO could be used.


gcc/
	* cfgcleanup.c (mentions_nonequal_regs): Use END_REGNO.
	* dse.c (note_add_store): Likewise.
	* ira-lives.c (mark_hard_reg_dead): Likewise.
	* loop-invariant.c (mark_reg_store): Likewise.
	(mark_reg_death): Likewise.
	* postreload.c (reload_combine): Likewise.
	(reload_combine_note_store): Likewise.
	(reload_combine_note_use): Likewise.
	* recog.c (peep2_reg_dead_p): Likewise.

Index: gcc/cfgcleanup.c
===================================================================
--- gcc/cfgcleanup.c	2015-05-18 08:19:38.719489341 +0100
+++ gcc/cfgcleanup.c	2015-05-18 08:19:52.000000000 +0100
@@ -267,26 +267,20 @@ mark_effect (rtx exp, regset nonequal)
 mentions_nonequal_regs (const_rtx x, regset nonequal)
 {
   subrtx_iterator::array_type array;
   FOR_EACH_SUBRTX (iter, array, x, NONCONST)
     {
       const_rtx x = *iter;
       if (REG_P (x))
 	{
-	  unsigned int regno = REGNO (x);
-	  if (REGNO_REG_SET_P (nonequal, regno))
-	    return true;
-	  if (regno < FIRST_PSEUDO_REGISTER)
-	    {
-	      int n = hard_regno_nregs[regno][GET_MODE (x)];
-	      while (--n > 0)
-		if (REGNO_REG_SET_P (nonequal, regno + n))
-		  return true;
-	    }
+	  unsigned int end_regno = END_REGNO (x);
+	  for (unsigned int regno = REGNO (x); regno < end_regno; ++regno)
+	    if (REGNO_REG_SET_P (nonequal, regno))
+	      return true;
 	}
     }
   return false;
 }
 
 /* Attempt to prove that the basic block B will have no side effects and
    always continues in the same edge if reached via E.  Return the edge
    if exist, NULL otherwise.  */
Index: gcc/dse.c
===================================================================
--- gcc/dse.c	2015-05-18 08:19:38.719489341 +0100
+++ gcc/dse.c	2015-05-18 08:19:52.000000000 +0100
@@ -850,17 +850,16 @@ typedef struct
 /* Callback for emit_inc_dec_insn_before via note_stores.
    Check if a register is clobbered which is live afterwards.  */
 
 static void
 note_add_store (rtx loc, const_rtx expr ATTRIBUTE_UNUSED, void *data)
 {
   rtx_insn *insn;
   note_add_store_info *info = (note_add_store_info *) data;
-  int r, n;
 
   if (!REG_P (loc))
     return;
 
   /* If this register is referenced by the current or an earlier insn,
      that's OK.  E.g. this applies to the register that is being incremented
      with this addition.  */
   for (insn = info->first;
@@ -869,25 +868,24 @@ note_add_store (rtx loc, const_rtx expr
     if (reg_referenced_p (loc, PATTERN (insn)))
       return;
 
   /* If we come here, we have a clobber of a register that's only OK
      if that register is not live.  If we don't have liveness information
      available, fail now.  */
   if (!info->fixed_regs_live)
     {
-      info->failure =  true;
+      info->failure = true;
       return;
     }
   /* Now check if this is a live fixed register.  */
-  r = REGNO (loc);
-  n = hard_regno_nregs[r][GET_MODE (loc)];
-  while (--n >=  0)
-    if (REGNO_REG_SET_P (info->fixed_regs_live, r+n))
-      info->failure =  true;
+  unsigned int end_regno = END_REGNO (loc);
+  for (unsigned int regno = REGNO (loc); regno < end_regno; ++regno)
+    if (REGNO_REG_SET_P (info->fixed_regs_live, regno))
+      info->failure = true;
 }
 
 /* Callback for for_each_inc_dec that emits an INSN that sets DEST to
    SRC + SRCOFF before insn ARG.  */
 
 static int
 emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED,
 			  rtx op ATTRIBUTE_UNUSED,
Index: gcc/ira-lives.c
===================================================================
--- gcc/ira-lives.c	2015-05-18 08:19:38.719489341 +0100
+++ gcc/ira-lives.c	2015-05-18 08:19:52.000000000 +0100
@@ -473,17 +473,17 @@ mark_pseudo_regno_subword_dead (int regn
    register.  */
 static void
 mark_hard_reg_dead (rtx reg)
 {
   int regno = REGNO (reg);
 
   if (! TEST_HARD_REG_BIT (ira_no_alloc_regs, regno))
     {
-      int last = regno + hard_regno_nregs[regno][GET_MODE (reg)];
+      int last = END_REGNO (reg);
       enum reg_class aclass, pclass;
 
       while (regno < last)
 	{
 	  if (TEST_HARD_REG_BIT (hard_regs_live, regno))
 	    {
 	      aclass = ira_hard_regno_allocno_class[regno];
 	      pclass = ira_pressure_class_translate[aclass];
Index: gcc/loop-invariant.c
===================================================================
--- gcc/loop-invariant.c	2015-05-18 08:19:38.719489341 +0100
+++ gcc/loop-invariant.c	2015-05-18 08:19:38.719489341 +0100
@@ -1802,68 +1802,44 @@ mark_regno_death (int regno)
   change_pressure (regno, false);
 }
 
 /* Mark setting register REG.  */
 static void
 mark_reg_store (rtx reg, const_rtx setter ATTRIBUTE_UNUSED,
 		void *data ATTRIBUTE_UNUSED)
 {
-  int regno;
-
   if (GET_CODE (reg) == SUBREG)
     reg = SUBREG_REG (reg);
 
   if (! REG_P (reg))
     return;
 
   regs_set[n_regs_set++] = reg;
 
-  regno = REGNO (reg);
-
-  if (regno >= FIRST_PSEUDO_REGISTER)
+  unsigned int end_regno = END_REGNO (reg);
+  for (unsigned int regno = REGNO (reg); regno < end_regno; ++regno)
     mark_regno_live (regno);
-  else
-    {
-      int last = regno + hard_regno_nregs[regno][GET_MODE (reg)];
-
-      while (regno < last)
-	{
-	  mark_regno_live (regno);
-	  regno++;
-	}
-    }
 }
 
 /* Mark clobbering register REG.  */
 static void
 mark_reg_clobber (rtx reg, const_rtx setter, void *data)
 {
   if (GET_CODE (setter) == CLOBBER)
     mark_reg_store (reg, setter, data);
 }
 
 /* Mark register REG death.  */
 static void
 mark_reg_death (rtx reg)
 {
-  int regno = REGNO (reg);
-
-  if (regno >= FIRST_PSEUDO_REGISTER)
+  unsigned int end_regno = END_REGNO (reg);
+  for (unsigned int regno = REGNO (reg); regno < end_regno; ++regno)
     mark_regno_death (regno);
-  else
-    {
-      int last = regno + hard_regno_nregs[regno][GET_MODE (reg)];
-
-      while (regno < last)
-	{
-	  mark_regno_death (regno);
-	  regno++;
-	}
-    }
 }
 
 /* Mark occurrence of registers in X for the current loop.  */
 static void
 mark_ref_regs (rtx x)
 {
   RTX_CODE code;
   int i;
Index: gcc/postreload.c
===================================================================
--- gcc/postreload.c	2015-05-18 08:19:38.719489341 +0100
+++ gcc/postreload.c	2015-05-18 08:19:52.000000000 +0100
@@ -1372,22 +1372,18 @@ reload_combine (void)
 	  for (link = CALL_INSN_FUNCTION_USAGE (insn); link;
 	       link = XEXP (link, 1))
 	    {
 	      rtx setuse = XEXP (link, 0);
 	      rtx usage_rtx = XEXP (setuse, 0);
 	      if ((GET_CODE (setuse) == USE || GET_CODE (setuse) == CLOBBER)
 		  && REG_P (usage_rtx))
 	        {
-		  unsigned int i;
-		  unsigned int start_reg = REGNO (usage_rtx);
-		  unsigned int num_regs
-		    = hard_regno_nregs[start_reg][GET_MODE (usage_rtx)];
-		  unsigned int end_reg = start_reg + num_regs - 1;
-		  for (i = start_reg; i <= end_reg; i++)
+		  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;
 	         }
@@ -1459,19 +1455,18 @@ reload_combine_note_store (rtx dst, cons
 
   if (MEM_P (dst))
     {
       dst = XEXP (dst, 0);
       if (GET_CODE (dst) == PRE_INC || GET_CODE (dst) == POST_INC
 	  || GET_CODE (dst) == PRE_DEC || GET_CODE (dst) == POST_DEC
 	  || GET_CODE (dst) == PRE_MODIFY || GET_CODE (dst) == POST_MODIFY)
 	{
-	  regno = REGNO (XEXP (dst, 0));
-	  mode = GET_MODE (XEXP (dst, 0));
-	  for (i = hard_regno_nregs[regno][mode] - 1 + regno; i >= regno; i--)
+	  unsigned int end_regno = END_REGNO (XEXP (dst, 0));
+	  for (unsigned int i = REGNO (XEXP (dst, 0)); i < end_regno; ++i)
 	    {
 	      /* We could probably do better, but for now mark the register
 		 as used in an unknown fashion and set/clobbered at this
 		 insn.  */
 	      reg_state[i].use_index = -1;
 	      reg_state[i].store_ruid = reload_combine_ruid;
 	      reg_state[i].real_store_ruid = reload_combine_ruid;
 	    }
@@ -1531,23 +1526,21 @@ reload_combine_note_use (rtx *xp, rtx_in
 	  return;
 	}
       break;
 
     case USE:
       /* If this is the USE of a return value, we can't change it.  */
       if (REG_P (XEXP (x, 0)) && REG_FUNCTION_VALUE_P (XEXP (x, 0)))
 	{
-	/* Mark the return register as used in an unknown fashion.  */
+	  /* Mark the return register as used in an unknown fashion.  */
 	  rtx reg = XEXP (x, 0);
-	  int regno = REGNO (reg);
-	  int nregs = hard_regno_nregs[regno][GET_MODE (reg)];
-
-	  while (--nregs >= 0)
-	    reg_state[regno + nregs].use_index = -1;
+	  unsigned int end_regno = END_REGNO (reg);
+	  for (unsigned int regno = REGNO (reg); regno < end_regno; ++regno)
+	    reg_state[regno].use_index = -1;
 	  return;
 	}
       break;
 
     case CLOBBER:
       if (REG_P (SET_DEST (x)))
 	{
 	  /* No spurious CLOBBERs of pseudo registers may remain.  */
Index: gcc/recog.c
===================================================================
--- gcc/recog.c	2015-05-18 08:19:38.719489341 +0100
+++ gcc/recog.c	2015-05-18 08:19:38.719489341 +0100
@@ -3123,28 +3123,25 @@ peep2_regno_dead_p (int ofs, int regno)
   return ! REGNO_REG_SET_P (peep2_insn_data[ofs].live_before, regno);
 }
 
 /* Similarly for a REG.  */
 
 int
 peep2_reg_dead_p (int ofs, rtx reg)
 {
-  int regno, n;
-
   gcc_assert (ofs < MAX_INSNS_PER_PEEP2 + 1);
 
   ofs = peep2_buf_position (peep2_current + ofs);
 
   gcc_assert (peep2_insn_data[ofs].insn != NULL_RTX);
 
-  regno = REGNO (reg);
-  n = hard_regno_nregs[regno][GET_MODE (reg)];
-  while (--n >= 0)
-    if (REGNO_REG_SET_P (peep2_insn_data[ofs].live_before, regno + n))
+  unsigned int end_regno = END_REGNO (reg);
+  for (unsigned int regno = REGNO (reg); regno < end_regno; ++regno)
+    if (REGNO_REG_SET_P (peep2_insn_data[ofs].live_before, regno))
       return 0;
   return 1;
 }
 
 /* Regno offset to be used in the register search.  */
 static int search_ofs;
 
 /* Try to find a hard register of mode MODE, matching the register class in