target/9929: [3.3/3.4 regression] Can't find spill register

[Jan Hubicka]

The following reply was made to PR target/9929; it has been noted by GNATS.

From: Jan Hubicka <jh@suse.cz>
To: Janis Johnson <janis187@us.ibm.com>
Cc: Steven Bosscher <s.bosscher@student.tudelft.nl>, gabor@mac.com,
	gcc-gnats@gcc.gnu.org, gcc-bugs@gcc.gnu.org, nobody@gcc.gnu.org,
	gcc-prs@gcc.gnu.org, jh@suse.cz
Subject: Re: target/9929: [3.3/3.4 regression] Can't find spill register
Date: Tue, 25 Mar 2003 00:06:42 +0100

 > On Mon, Mar 24, 2003 at 09:00:40PM +0100, Steven Bosscher wrote:
 > > 
 > > Janis, can you hunt this one?
 > 
 > The regression showed up with this patch:
 > 
 > Sat Mar 30 14:08:55 CET 2002  Jan Hubicka  <jh@suse.cz>
 > 
 > 	* local-alloc.c (local_alloc): Avoid call of update_equiv_regs
 > 	when not optimizing.
 > 
 > 	* toplev.c (rest_of_compilation): Cann mark_constant_function
 > 	only when optimizing.
 > 
 > 	* flow.c (calculate_global_regs_live): Ensure that all AUX fields
 > 	are NULL.
 > 
 > 	* cfgcleanup.c (bb_flags): Add BB_NONTHREADABLE_BLOCK.
 > 	(thread_jump): Set BB_NONTHREADABLE_BLOCK, check it.
 > 	(try_optimize_cfg): clear all AUX fields.
 > 
 > 	* i386.c (aligned_operand): Be prepared for SUBREGed registers.
 > 	(ix86_decompose_address): Use REG_P instead of GET_CODE (...) == REG.
 > 	(ix86_address_cost): Be prepared for SUBREGed registers.
 > 	(legitimate_address_p): Accept SUBREGed registers.
 > 
 > The hunt used Wolfgang's reduced test case with "-O -fPIC" on
 > i686-pc-linux-gnu.
 
 Tue Mar 25 00:05:27 CET 2003  Jan Hubicka  <jh@suse.cz>
 	* i386.c (legitimate_address_p):  Refuse DImore registers in 32bit compilation.
 Index: i386.c
 ===================================================================
 RCS file: /cvs/gcc/gcc/gcc/config/i386/i386.c,v
 retrieving revision 1.552
 diff -c -3 -p -r1.552 i386.c
 *** i386.c	22 Mar 2003 20:02:22 -0000	1.552
 --- i386.c	24 Mar 2003 23:05:11 -0000
 *************** legitimate_address_p (mode, addr, strict
 *** 5936,5941 ****
 --- 5936,5949 ----
   	  goto report_error;
   	}
   
 +       /* We can run out of registers when we do allow subregs
 +          of DImode regsiters.  */
 +       if (GET_MODE (reg) == DImode && !TARGET_64BIT)
 + 	{
 + 	  reason = "base reg is DImore";
 + 	  goto report_error;
 + 	}
 + 
         if ((strict && ! REG_OK_FOR_BASE_STRICT_P (reg))
   	  || (! strict && ! REG_OK_FOR_BASE_NONSTRICT_P (reg)))
   	{
 *************** legitimate_address_p (mode, addr, strict
 *** 5971,5976 ****
 --- 5979,5993 ----
   	  reason = "index is not in Pmode";
   	  goto report_error;
   	}
 + 
 +       /* We can run out of registers when we do allow subregs
 +          of DImode regsiters.  */
 +       if (GET_MODE (reg) == DImode && !TARGET_64BIT)
 + 	{
 + 	  reason = "index reg is DImore";
 + 	  goto report_error;
 + 	}
 + 
   
         if ((strict && ! REG_OK_FOR_INDEX_STRICT_P (reg))
   	  || (! strict && ! REG_OK_FOR_INDEX_NONSTRICT_P (reg)))