Patch to fix recent local-alloc IA-64 breakage

[John Wehle]

This appears to fix the recent problem.  A make bootstrap and make
check is in progress on an Alpha to sanity check the change.  I
unfortunately don't have access to an IA-64 (I looked at the testcase
with gcc set up as a cross compiler).

ChangeLog:

Mon Oct 23 01:34:44 EDT 2000  John Wehle  (john@feith.com)

	* local-alloc.c (equiv_init_call_clobbered_p): New function.
	(struct equivalence): Add call_clobbered field.
	(update_equiv_regs): Set it.
	(equiv_init_movable_p): An equivalence which uses a call clobbered
	register can't be moved past any calls.
	

Enjoy!

-- John Wehle
------------------8<------------------------8<------------------------
*** gcc/local-alloc.c.ORIGINAL	Fri Oct 20 00:47:25 2000
--- gcc/local-alloc.c	Mon Oct 23 02:38:58 2000
*************** struct equivalence
*** 251,256 ****
--- 251,262 ----
  
    rtx src;
  
+   /* Used to recognize equivalences which can't be moved
+      across a call.  For example the PIC register on the
+      IA-64 is call clobbered even though it's invariant.  */
+ 
+   char call_clobbered;
+ 
    /* Loop depth is used to recognize equivalences which appear
       to be present within the same loop (or in an inner loop).  */
  
*************** static int recorded_label_ref;
*** 272,277 ****
--- 278,284 ----
  static void alloc_qty		PARAMS ((int, enum machine_mode, int, int));
  static void validate_equiv_mem_from_store PARAMS ((rtx, rtx, void *));
  static int validate_equiv_mem	PARAMS ((rtx, rtx, rtx));
+ static int equiv_init_call_clobbered_p PARAMS ((rtx));
  static int equiv_init_varies_p  PARAMS ((rtx));
  static int equiv_init_movable_p PARAMS ((rtx, int));
  static int contains_replace_regs PARAMS ((rtx));
*************** validate_equiv_mem (start, reg, memref)
*** 514,519 ****
--- 521,573 ----
    return 0;
  }
  
+ /* Returns non-zero if a register X mentions is call clobbered
+    or has an equivalent initialization which is call clobbered.  */
+ 
+ static int
+ equiv_init_call_clobbered_p (x)
+      rtx x;
+ {
+   register RTX_CODE code = GET_CODE (x);
+   register int i;
+   register const char *fmt;
+ 
+   switch (code)
+     {
+     case CONST:
+     case CONST_INT:
+     case CONST_DOUBLE:
+     case SYMBOL_REF:
+     case LABEL_REF:
+       return 0;
+ 
+     case REG:
+       return reg_equiv[REGNO (x)].call_clobbered
+ 	     || (REGNO (x) < FIRST_PSEUDO_REGISTER
+ 		&& call_used_regs[REGNO (x)]);
+ 
+     default:
+       break;
+     }
+ 
+   fmt = GET_RTX_FORMAT (code);
+   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+     if (fmt[i] == 'e')
+       {
+ 	if (equiv_init_call_clobbered_p (XEXP (x, i)))
+ 	  return 1;
+       }
+     else if (fmt[i] == 'E')
+       {
+ 	int j;
+ 	for (j = 0; j < XVECLEN (x, i); j++)
+ 	  if (equiv_init_call_clobbered_p (XVECEXP (x, i, j)))
+ 	    return 1;
+       }
+ 
+   return 0;
+ }
+ 
  /* Returns zero if X is known to be invariant.  */
  
  static int
*************** equiv_init_movable_p (x, regno)
*** 601,606 ****
--- 655,668 ----
        return 0;
  
      case REG:
+       /* The equivalence can't be moved across a call if it depends
+ 	 on other equivalences which contain call clobbered registers
+ 	 or if it contains call clobbered registers.  */
+       if ((reg_equiv[REGNO (x)].call_clobbered
+ 	   || (REGNO (x) < FIRST_PSEUDO_REGISTER && call_used_regs[REGNO (x)]))
+ 	  && REG_N_CALLS_CROSSED (regno))
+ 	return 0;
+ 
        return (reg_equiv[REGNO (x)].loop_depth >= reg_equiv[regno].loop_depth
  	      && reg_equiv[REGNO (x)].replace)
  	     || (REG_BASIC_BLOCK (REGNO (x)) < 0 && ! rtx_varies_p (x));
*************** update_equiv_regs ()
*** 998,1003 ****
--- 1060,1067 ----
  
  	  reg_equiv[regno].replacement = XEXP (note, 0);
  	  reg_equiv[regno].src = src;
+ 	  reg_equiv[regno].call_clobbered
+ 	    = equiv_init_call_clobbered_p (src);
  	  reg_equiv[regno].loop_depth = loop_depth;
  
  	  /* Don't mess with things live during setjmp.  */
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|    John Wehle    |     Fax: 1-215-540-5495  |                         |
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