Patch to fix gcc.c-torture/compile/20010102-1.c on IA64 HP-UX

[Steve Ellcey <sje@cup.hp.com>]

The test case gcc.c-torture/compile/20010102-1.c is failing on IA64
HP-UX in 32 bit mode when compiled with -O3 -funroll-loops.  My analysis
shows that this is because regrename is not copying the REG_POINTER
attribute of a register when renaming it.  This causes a problem with
the use of the IA64 addp4 instruction which, when used with two
registers, requires that one of the registers be a pointer and the other
be an offset (and that we know which one is which).  Without this
patch neither register is marked as a pointer.

This patch copies the REG_POINTER setting of a register whenever we
are copying the attributes.  Tested on IA64 HP-UX and Linux with
no regressions.

I am cc'ing Paolo and Peter Bergner because this problem started with
the patch to PR 28690.

OK for checkin?

Steve Ellcey
sje@cup.hp.com


2008-08-16  Steve Ellcey  <sje@cup.hp.com>

	* regrename.c (do_replace): Copy REG_POINTER value to new reg.
	(find_oldest_value_reg): Ditto.
	(copyprop_hardreg_forward_1): Ditto.


Index: regrename.c
===================================================================
--- regrename.c	(revision 140386)
+++ regrename.c	(working copy)
@@ -357,11 +357,13 @@ do_replace (struct du_chain *chain, int 
     {
       unsigned int regno = ORIGINAL_REGNO (*chain->loc);
       struct reg_attrs * attr = REG_ATTRS (*chain->loc);
+      int reg_ptr = REG_POINTER (*chain->loc);
 
       *chain->loc = gen_raw_REG (GET_MODE (*chain->loc), reg);
       if (regno >= FIRST_PSEUDO_REGISTER)
 	ORIGINAL_REGNO (*chain->loc) = regno;
       REG_ATTRS (*chain->loc) = attr;
+      REG_POINTER (*chain->loc) = reg_ptr;
       df_insn_rescan (chain->insn);
       chain = chain->next_use;
     }
@@ -1375,6 +1377,7 @@ find_oldest_value_reg (enum reg_class cl
 	{
 	  ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (reg);
 	  REG_ATTRS (new_rtx) = REG_ATTRS (reg);
+	  REG_POINTER (new_rtx) = REG_POINTER (reg);
 	  return new_rtx;
 	}
     }
@@ -1673,6 +1676,7 @@ copyprop_hardreg_forward_1 (basic_block 
 		    {
 		      ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (src);
 		      REG_ATTRS (new_rtx) = REG_ATTRS (src);
+		      REG_POINTER (new_rtx) = REG_POINTER (src);
 		      if (dump_file)
 			fprintf (dump_file,
 				 "insn %u: replaced reg %u with %u\n",