patch to fix PR66782

[Vladimir Makarov <vmakarov at redhat dot com>]

The following patch fixes

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66782

The patch was bootstrapped and tested on x86/x86-64.

Committed as rev. 225618.

2015-07-09  Vladimir Makarov  <vmakarov@redhat.com>

        PR rtl-optimization/66782
        * lra-int.h (struct lra_insn_recog_data): Add comment about
        clobbered hard regs for arg_hard_regs.
        * lra.c (lra_set_insn_recog_data): Add clobbered hard regs.
        * lra-lives.c (process_bb_lives): Process clobbered hard regs.
        Add condition for processing used hard regs.
        * lra-constraints.c (update_ebb_live_info, inherit_in_ebb):
        Process clobbered hard regs.

Index: lra-constraints.c
===================================================================
--- lra-constraints.c	(revision 225561)
+++ lra-constraints.c	(working copy)
@@ -5149,6 +5149,11 @@ update_ebb_live_info (rtx_insn *head, rt
       for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next)
 	if (reg->type == OP_OUT && ! reg->subreg_p)
 	  bitmap_clear_bit (&live_regs, reg->regno);
+      if (curr_id->arg_hard_regs != NULL)
+	/* Make clobbered argument hard registers die.  */
+	for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++)
+	  if (regno >= FIRST_PSEUDO_REGISTER)
+	    bitmap_clear_bit (&live_regs, regno - FIRST_PSEUDO_REGISTER);
       /* Mark each used value as live.  */
       for (reg = curr_id->regs; reg != NULL; reg = reg->next)
 	if (reg->type != OP_OUT
@@ -5159,9 +5164,10 @@ update_ebb_live_info (rtx_insn *head, rt
 	    && bitmap_bit_p (&check_only_regs, reg->regno))
 	  bitmap_set_bit (&live_regs, reg->regno);
       if (curr_id->arg_hard_regs != NULL)
-	/* Make argument hard registers live.  */
+	/* Make used argument hard registers live.  */
 	for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++)
-	  if (bitmap_bit_p (&check_only_regs, regno))
+	  if (regno < FIRST_PSEUDO_REGISTER
+	      && bitmap_bit_p (&check_only_regs, regno))
 	    bitmap_set_bit (&live_regs, regno);
       /* It is quite important to remove dead move insns because it
 	 means removing dead store.  We don't need to process them for
@@ -5471,6 +5477,12 @@ inherit_in_ebb (rtx_insn *head, rtx_insn
 			}
 		    }
 		}
+	  /* Process clobbered call regs.  */
+	  if (curr_id->arg_hard_regs != NULL)
+	    for (i = 0; (dst_regno = curr_id->arg_hard_regs[i]) >= 0; i++)
+	      if (dst_regno >= FIRST_PSEUDO_REGISTER)
+		usage_insns[dst_regno - FIRST_PSEUDO_REGISTER].check
+		  = -(int) INSN_UID (curr_insn);
 	  if (! JUMP_P (curr_insn))
 	    for (i = 0; i < to_inherit_num; i++)
 	      if (inherit_reload_reg (true, to_inherit[i].regno,
@@ -5578,7 +5590,7 @@ inherit_in_ebb (rtx_insn *head, rtx_insn
 		      add_next_usage_insn (src_regno, use_insn, reloads_num);
 		    }
 		}
-	  /* Process call args.  */
+	  /* Process used call regs.  */
 	  if (curr_id->arg_hard_regs != NULL)
 	    for (i = 0; (src_regno = curr_id->arg_hard_regs[i]) >= 0; i++)
 	      if (src_regno < FIRST_PSEUDO_REGISTER)
Index: lra-int.h
===================================================================
--- lra-int.h	(revision 225561)
+++ lra-int.h	(working copy)
@@ -267,9 +267,11 @@ struct lra_insn_recog_data
      duplication numbers: */
   rtx **operand_loc; /* The operand locations, NULL if no operands.  */
   rtx **dup_loc; /* The dup locations, NULL if no dups.	 */
-  /* Number of hard registers implicitly used in given call insn.  The
-     value can be NULL or points to array of the hard register numbers
-     ending with a negative value.  */
+  /* Number of hard registers implicitly used/clobbered in given call
+     insn.  The value can be NULL or points to array of the hard
+     register numbers ending with a negative value.  To differ
+     clobbered and used hard regs, clobbered hard regs are incremented
+     by FIRST_PSEUDO_REGISTER.  */
   int *arg_hard_regs;
   /* Cached value of get_preferred_alternatives.  */
   alternative_mask preferred_alternatives;
Index: lra-lives.c
===================================================================
--- lra-lives.c	(revision 225561)
+++ lra-lives.c	(working copy)
@@ -814,6 +814,12 @@ process_bb_lives (basic_block bb, int &c
 	if (reg->type != OP_IN)
 	  make_hard_regno_born (reg->regno, false);
 
+      if (curr_id->arg_hard_regs != NULL)
+	for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++)
+	  if (regno >= FIRST_PSEUDO_REGISTER)
+	    /* It is a clobber.  */
+	    make_hard_regno_born (regno - FIRST_PSEUDO_REGISTER, false);
+
       sparseset_copy (unused_set, start_living);
 
       sparseset_clear (start_dying);
@@ -829,6 +835,12 @@ process_bb_lives (basic_block bb, int &c
 	if (reg->type == OP_OUT && ! reg->early_clobber && ! reg->subreg_p)
 	  make_hard_regno_dead (reg->regno);
 
+      if (curr_id->arg_hard_regs != NULL)
+	for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++)
+	  if (regno >= FIRST_PSEUDO_REGISTER)
+	    /* It is a clobber.  */
+	    make_hard_regno_dead (regno - FIRST_PSEUDO_REGISTER);
+
       if (call_p)
 	{
 	  if (flag_ipa_ra)
@@ -877,7 +889,8 @@ process_bb_lives (basic_block bb, int &c
 	/* Make argument hard registers live.  Don't create conflict
 	   of used REAL_PIC_OFFSET_TABLE_REGNUM and the pic pseudo.  */
 	for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++)
-	  make_hard_regno_born (regno, true);
+	  if (regno < FIRST_PSEUDO_REGISTER)
+	    make_hard_regno_born (regno, true);
 
       sparseset_and_compl (dead_set, start_living, start_dying);
 
Index: lra.c
===================================================================
--- lra.c	(revision 225561)
+++ lra.c	(working copy)
@@ -1055,6 +1055,7 @@ lra_set_insn_recog_data (rtx_insn *insn)
   data->arg_hard_regs = NULL;
   if (CALL_P (insn))
     {
+      bool use_p;
       rtx link;
       int n_hard_regs, regno, arg_hard_regs[FIRST_PSEUDO_REGISTER];
 
@@ -1065,14 +1066,16 @@ lra_set_insn_recog_data (rtx_insn *insn)
       for (link = CALL_INSN_FUNCTION_USAGE (insn);
 	   link != NULL_RTX;
 	   link = XEXP (link, 1))
-	if (GET_CODE (XEXP (link, 0)) == USE
+	if (((use_p = GET_CODE (XEXP (link, 0)) == USE)
+	     || GET_CODE (XEXP (link, 0)) == CLOBBER)
 	    && REG_P (XEXP (XEXP (link, 0), 0)))
 	  {
 	    regno = REGNO (XEXP (XEXP (link, 0), 0));
 	    lra_assert (regno < FIRST_PSEUDO_REGISTER);
 	    /* It is an argument register.  */
 	    for (i = REG_NREGS (XEXP (XEXP (link, 0), 0)) - 1; i >= 0; i--)
-	      arg_hard_regs[n_hard_regs++] = regno + i;
+	      arg_hard_regs[n_hard_regs++]
+		= regno + i + (use_p ? 0 : FIRST_PSEUDO_REGISTER);
 	  }
       if (n_hard_regs != 0)
 	{