re PR rtl-optimization/41619 (ICE in insert_save (caller-save.c) for SPEC CPU2000's 252.eon)

	PR rtl-optimization/41619
	* caller-save.c (setup_save_areas): Break out code to determine
	which hard regs are live across calls by examining the reload chains
	so that it is always used.
	Eliminate code which checked REG_N_CALLS_CROSSED.

	PR rtl-optimization/41619
	* gcc.dg/pr41619.c: New.

From-SVN: r169095

gcc/ChangeLog

+2011-01-21  Jeff Law  <law@redhat.com>
+
+	PR rtl-optimization/41619
+	* caller-save.c (setup_save_areas): Break out code to determine
+	which hard regs are live across calls by examining the reload chains
+	so that it is always used.
+	Eliminate code which checked REG_N_CALLS_CROSSED.
+
 2011-01-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/47355

gcc/caller-save.c

 /* Save and restore call-clobbered registers which are live across a call.
    Copyright (C) 1989, 1992, 1994, 1995, 1997, 1998, 1999, 2000,
-   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -416,43 +416,19 @@ saved_hard_reg_compare_func (const void *v1p, const void *v2p)
 void
 setup_save_areas (void)
 {
-  int i, j, k;
-  unsigned int r;
+  int i, j, k, freq;
   HARD_REG_SET hard_regs_used;
-
-  /* Allocate space in the save area for the largest multi-register
-     pseudos first, then work backwards to single register
-     pseudos.  */
-
-  /* Find and record all call-used hard-registers in this function.  */
-  CLEAR_HARD_REG_SET (hard_regs_used);
-  for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
-    if (reg_renumber[i] >= 0 && REG_N_CALLS_CROSSED (i) > 0)
-      {
-	unsigned int regno = reg_renumber[i];
-	unsigned int endregno
-	  = end_hard_regno (GET_MODE (regno_reg_rtx[i]), regno);
-	for (r = regno; r < endregno; r++)
-	  if (call_used_regs[r])
-	    SET_HARD_REG_BIT (hard_regs_used, r);
-      }
-
-  if (optimize && flag_ira_share_save_slots)
-    {
-      rtx insn, slot;
+  struct saved_hard_reg *saved_reg;
+  rtx insn;
   struct insn_chain *chain, *next;
-      char *saved_reg_conflicts;
   unsigned int regno;
-      int next_k, freq;
-      struct saved_hard_reg *saved_reg, *saved_reg2, *saved_reg3;
-      int call_saved_regs_num;
-      struct saved_hard_reg *call_saved_regs[FIRST_PSEUDO_REGISTER];
   HARD_REG_SET hard_regs_to_save, used_regs, this_insn_sets;
   reg_set_iterator rsi;
-      int best_slot_num;
-      int prev_save_slots_num;
-      rtx prev_save_slots[FIRST_PSEUDO_REGISTER];
 
+  CLEAR_HARD_REG_SET (hard_regs_used);
+
+  /* Find every CALL_INSN and record which hard regs are live across the
+     call into HARD_REG_MAP and HARD_REGS_USED.  */
   initiate_saved_hard_regs ();
   /* Create hard reg saved regs.  */
   for (chain = reload_insn_chain; chain != 0; chain = next)
@@ -488,6 +464,7 @@ setup_save_areas (void)
 	      hard_reg_map[regno]->call_freq += freq;
 	    else
 	      saved_reg = new_saved_hard_reg (regno, freq);
+	    SET_HARD_REG_BIT (hard_regs_used, regno);
 	  }
       /* Look through all live pseudos, mark their hard registers.  */
       EXECUTE_IF_SET_IN_REG_SET
@@ -508,9 +485,24 @@ setup_save_areas (void)
 		else
 		  saved_reg = new_saved_hard_reg (r, freq);
 		 SET_HARD_REG_BIT (hard_regs_to_save, r);
+		 SET_HARD_REG_BIT (hard_regs_used, r);
 	      }
 	}
     }
+
+  /* If requested, figure out which hard regs can share save slots.  */
+  if (optimize && flag_ira_share_save_slots)
+    {
+      rtx slot;
+      char *saved_reg_conflicts;
+      int next_k;
+      struct saved_hard_reg *saved_reg2, *saved_reg3;
+      int call_saved_regs_num;
+      struct saved_hard_reg *call_saved_regs[FIRST_PSEUDO_REGISTER];
+      int best_slot_num;
+      int prev_save_slots_num;
+      rtx prev_save_slots[FIRST_PSEUDO_REGISTER];
+
       /* Find saved hard register conflicts.  */
       saved_reg_conflicts = (char *) xmalloc (saved_regs_num * saved_regs_num);
       memset (saved_reg_conflicts, 0, saved_regs_num * saved_regs_num);
@@ -668,8 +660,10 @@ setup_save_areas (void)
     }
   else
     {
-      /* Now run through all the call-used hard-registers and allocate
-	 space for them in the caller-save area.  Try to allocate space
+      /* We are not sharing slots. 
+
+	 Run through all the call-used hard-registers and allocate
+	 space for each in the caller-save area.  Try to allocate space
 	 in a manner which allows multi-register saves/restores to be done.  */
 
       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)

gcc/testsuite/ChangeLog

+2011-01-21  Jeff Law <law@redhat.com>
+
+	PR rtl-optimization/41619
+	* gcc.dg/pr41619.c: New.
+
 2011-01-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/47355

gcc/testsuite/gcc.dg/pr41619.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-ira-share-save-slots" } */
+
+struct A {};
+
+int foo();
+
+struct A bar(double x)
+{
+  double y;
+  if (foo())
+    y = 1 / x;
+  return bar(y);
+}