From patchwork Tue Nov  9 15:38:32 2010
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Subject: ira: Respect HARD_REGNO_CALL_PART_CLOBBERED
Date: Tue, 09 Nov 2010 05:38:32 -0000
From: Vladimir Makarov <vmakarov@redhat.com>
X-Patchwork-Id: 70553
Message-Id: <4CD96AF8.3010500@redhat.com>
To: Andreas Krebbel <krebbel@linux.vnet.ibm.com>
Cc: gcc-patches@gcc.gnu.org

On 11/08/2010 11:08 AM, Andreas Krebbel wrote:
> Hi Vladimir,
>
> here are updated versions of the patches.
>
> I've verified that the 4.5 as well as the mainline version still fixes
> the testcase for me.
>
> Ok for 4.5 and mainline?
>
> Bye,
>
> -Andreas-
>
>
> 2010-11-08  Andreas Krebbel<Andreas.Krebbel@de.ibm.com>
>
> 	PR rtl-optimization/46237
> 	* ira-conflicts.c (ira_build_conflicts): Record conflicts for call
> 	saved hard regs if they might get partially clobbered.
>
>
> For GCC mainline:
>
> Index: gcc/ira-conflicts.c
> ===================================================================
> *** gcc/ira-conflicts.c.orig
> --- gcc/ira-conflicts.c
> *************** ira_build_conflicts (void)
> *** 882,887 ****
> --- 882,888 ----
>    	  ira_object_t obj = ALLOCNO_OBJECT (a, i);
>    	  reg_attrs *attrs = REG_ATTRS (regno_reg_rtx [ALLOCNO_REGNO (a)]);
>    	  tree decl;
> + 	  int regno;
>
>    	  if ((! flag_caller_saves&&  ALLOCNO_CALLS_CROSSED_NUM (a) != 0)
>    	      /* For debugging purposes don't put user defined variables in
> *************** ira_build_conflicts (void)
> *** 896,901 ****
> --- 897,912 ----
>    				call_used_reg_set);
>    	      IOR_HARD_REG_SET (OBJECT_CONFLICT_HARD_REGS (obj),
>    				call_used_reg_set);
> +
> + 	      /* Allocnos bigger than the saved part of call saved
> + 		 regs must conflict with them.  */
> + 	      for (regno = 0; regno<  FIRST_PSEUDO_REGISTER; regno++)
> + 		if (!TEST_HARD_REG_BIT (call_used_reg_set, regno)
> + 		&&   HARD_REGNO_CALL_PART_CLOBBERED (regno, obj->allocno->mode))
> + 		  {
> + 		    SET_HARD_REG_BIT (OBJECT_CONFLICT_HARD_REGS (obj), regno);
> + 		    SET_HARD_REG_BIT (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj), regno);
> + 		  }
>    	    }
>    	  else if (ALLOCNO_CALLS_CROSSED_NUM (a) != 0)
>    	    {
>
It is close but the code should work independently from -fcaller-saves.  
So it should look like the patch in the attachment.

And gcc4.5 patch change should be analogous.

With this change, the patch is ok for trunk and gcc4.5.

Thanks for working on the PR.


Index: ira-conflicts.c
===================================================================
--- ira-conflicts.c	(revision 165518)
+++ ira-conflicts.c	(working copy)
@@ -877,6 +884,8 @@ ira_build_conflicts (void)
   FOR_EACH_ALLOCNO (a, ai)
     {
       int i, n = ALLOCNO_NUM_OBJECTS (a);
+      int regno;
+
       for (i = 0; i < n; i++)
 	{
 	  ira_object_t obj = ALLOCNO_OBJECT (a, i);
@@ -907,6 +916,21 @@ ira_build_conflicts (void)
 				no_caller_save_reg_set);
 	      IOR_HARD_REG_SET (OBJECT_CONFLICT_HARD_REGS (obj),
 				temp_hard_reg_set);
+
+	    }
+	  if (ALLOCNO_CALLS_CROSSED_NUM (a) != 0)
+	    {
+	      /* Allocnos bigger than the saved part of call saved
+		 regs must conflict with them.  */
+	      for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
+		if (!TEST_HARD_REG_BIT (call_used_reg_set, regno)
+		    && HARD_REGNO_CALL_PART_CLOBBERED (regno,
+						       obj->allocno->mode))
+		  {
+		    SET_HARD_REG_BIT (OBJECT_CONFLICT_HARD_REGS (obj), regno);
+		    SET_HARD_REG_BIT (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj),
+				      regno);
+		  }
 	    }
 	}
     }