patch to fix PR 48435

patch to fix PR 48435

[Vladimir Makarov]

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The following patch should solve problem 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48435.  It might solve other 
latest IRA problems too including performance related ones.  The patch 
is for targets which require some values to be placed in hard registers 
starting with an even (odd) hard registers.

I already addressed an analogous problem recently and the patch I sent 
that time although solved some problems it created even more new 
problems.  I should acknowledge this.

The problem was in that profitable hard regs were used for colorability 
criterion and finding hard registers where allocno values can be resided 
but *also* as starting allocno hard registers.  It resulted in spilling 
allocnos which should be placed in multi-registers starting on a 
specific border because profitable hard registers were only starting 
registers and when we calculated number of available hard registers 
multi-register allocnos can not fit only in their starting hard registers.

The following patch was successfully bootstrapped on x86/x86-64 and on 
i686 with H.J.'s autotester options.

OK to commit?

2011-04-07  Vladimir Makarov <vmakarov@redhat.com>

     PR 4435
     * ira-color.c (setup_profitable_hard_regs): Add comments.
     Don't take prohibited hard regs into account.
     (setup_conflict_profitable_regs): Rename to
     get_conflict_profitable_regs.
     (check_hard_reg_p): Check prohibited hard regs.




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Index: ira-color.c
===================================================================
--- ira-color.c	(revision 172107)
+++ ira-color.c	(working copy)
@@ -1057,6 +1057,8 @@ setup_profitable_hard_regs (void)
   enum reg_class aclass;
   enum machine_mode mode;
 
+  /* Initial set up from allocno classes and explicitly conflicting
+     hard regs.  */
   EXECUTE_IF_SET_IN_BITMAP (coloring_allocno_bitmap, 0, i, bi)
     {
       a = ira_allocnos[i];
@@ -1076,9 +1078,6 @@ setup_profitable_hard_regs (void)
 	    {
 	      COPY_HARD_REG_SET (obj_data->profitable_hard_regs,
 				 reg_class_contents[aclass]);
-	      AND_COMPL_HARD_REG_SET
-		(obj_data->profitable_hard_regs,
-		 ira_prohibited_class_mode_regs[aclass][mode]);
 	      AND_COMPL_HARD_REG_SET (obj_data->profitable_hard_regs,
 				      ira_no_alloc_regs);
 	      AND_COMPL_HARD_REG_SET (obj_data->profitable_hard_regs,
@@ -1086,6 +1085,7 @@ setup_profitable_hard_regs (void)
 	    }
 	}
     }
+  /* Exclude hard regs already assigned for conflicting objects.  */
   EXECUTE_IF_SET_IN_BITMAP (consideration_allocno_bitmap, 0, i, bi)
     {
       a = ira_allocnos[i];
@@ -1124,6 +1124,7 @@ setup_profitable_hard_regs (void)
 	    }
 	}
     }
+  /* Exclude too costly hard regs.  */
   EXECUTE_IF_SET_IN_BITMAP (coloring_allocno_bitmap, 0, i, bi)
     {
       int min_cost = INT_MAX;
@@ -1451,9 +1452,9 @@ update_conflict_hard_regno_costs (int *c
    profitable regs exclude hard regs which can not hold value of mode
    of allocno A.  */
 static inline void
-setup_conflict_profitable_regs (ira_allocno_t a, bool retry_p,
-				HARD_REG_SET *conflict_regs,
-				HARD_REG_SET *profitable_regs)
+get_conflict_profitable_regs (ira_allocno_t a, bool retry_p,
+			      HARD_REG_SET *conflict_regs,
+			      HARD_REG_SET *profitable_regs)
 {
   int i, nwords;
   ira_object_t obj;
@@ -1485,8 +1486,15 @@ check_hard_reg_p (ira_allocno_t a, int h
 		  HARD_REG_SET *conflict_regs, HARD_REG_SET *profitable_regs)
 {
   int j, nwords, nregs;
+  enum reg_class aclass;
+  enum machine_mode mode;
 
-  nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (a)];
+  aclass = ALLOCNO_CLASS (a);
+  mode = ALLOCNO_MODE (a);
+  if (TEST_HARD_REG_BIT (ira_prohibited_class_mode_regs[aclass][mode],
+			 hard_regno))
+    return false;
+  nregs = hard_regno_nregs[hard_regno][mode];
   nwords = ALLOCNO_NUM_OBJECTS (a);
   for (j = 0; j < nregs; j++)
     {
@@ -1554,8 +1562,8 @@ assign_hard_reg (ira_allocno_t a, bool r
 #endif
 
   ira_assert (! ALLOCNO_ASSIGNED_P (a));
-  setup_conflict_profitable_regs (a, retry_p,
-				  conflicting_regs, profitable_hard_regs);
+  get_conflict_profitable_regs (a, retry_p,
+				conflicting_regs, profitable_hard_regs);
   aclass = ALLOCNO_CLASS (a);
   class_size = ira_class_hard_regs_num[aclass];
   best_hard_regno = -1;
@@ -2233,7 +2241,8 @@ setup_allocno_available_regs_num (ira_al
 	      ira_object_t obj = ALLOCNO_OBJECT (a, k);
 	      object_color_data_t obj_data = OBJECT_COLOR_DATA (obj);
 
-	      /* Checking only profitable hard regs.  */
+	      /* Checking only profitable hard regs which exclude
+		 object's conflict hard regs.  */
 	      if (TEST_HARD_REG_BIT (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj),
 				     hard_regno + j)
 		  || ! TEST_HARD_REG_BIT (obj_data->profitable_hard_regs,
@@ -2403,8 +2412,8 @@ improve_allocation (void)
       else
 	base_cost = allocno_costs[ira_class_hard_reg_index[aclass][hregno]];
       try_p = false;
-      setup_conflict_profitable_regs (a, false,
-				      conflicting_regs, profitable_hard_regs);
+      get_conflict_profitable_regs (a, false,
+				    conflicting_regs, profitable_hard_regs);
       class_size = ira_class_hard_regs_num[aclass];
       /* Set up cost improvement for usage of each profitable hard
 	 register for allocno A.  */

Re: patch to fix PR 48435

[Jeff Law]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 04/07/11 13:41, Vladimir Makarov wrote:
> The following patch should solve problem
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48435.  It might solve other
> latest IRA problems too including performance related ones.  The patch
> is for targets which require some values to be placed in hard registers
> starting with an even (odd) hard registers.
> 
> I already addressed an analogous problem recently and the patch I sent
> that time although solved some problems it created even more new
> problems.  I should acknowledge this.
> 
> The problem was in that profitable hard regs were used for colorability
> criterion and finding hard registers where allocno values can be resided
> but *also* as starting allocno hard registers.  It resulted in spilling
> allocnos which should be placed in multi-registers starting on a
> specific border because profitable hard registers were only starting
> registers and when we calculated number of available hard registers
> multi-register allocnos can not fit only in their starting hard registers.
> 
> The following patch was successfully bootstrapped on x86/x86-64 and on
> i686 with H.J.'s autotester options.
> 
> OK to commit?
> 
> 2011-04-07  Vladimir Makarov <vmakarov@redhat.com>
> 
>     PR 4435
>     * ira-color.c (setup_profitable_hard_regs): Add comments.
>     Don't take prohibited hard regs into account.
>     (setup_conflict_profitable_regs): Rename to
>     get_conflict_profitable_regs.
>     (check_hard_reg_p): Check prohibited hard regs.
OK.
jeff
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Re: patch to fix PR 48435

[Graham Stott]

Vladimir,

The wrong PR 4435 was in referrenced the commit 

--- On Fri, 8/4/11, Jeff Law <law@redhat.com> wrote:

> From: Jeff Law <law@redhat.com>
> Subject: Re: patch to fix PR 48435
> To: "Vladimir Makarov" <vmakarov@redhat.com>
> Cc: "gcc-patches" <gcc-patches@gcc.gnu.org>
> Date: Friday, 8 April, 2011, 16:18
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On 04/07/11 13:41, Vladimir Makarov wrote:
> > The following patch should solve problem
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48435. 
> It might solve other
> > latest IRA problems too including performance related
> ones.  The patch
> > is for targets which require some values to be placed
> in hard registers
> > starting with an even (odd) hard registers.
> > 
> > I already addressed an analogous problem recently and
> the patch I sent
> > that time although solved some problems it created
> even more new
> > problems.  I should acknowledge this.
> > 
> > The problem was in that profitable hard regs were used
> for colorability
> > criterion and finding hard registers where allocno
> values can be resided
> > but *also* as starting allocno hard registers. 
> It resulted in spilling
> > allocnos which should be placed in multi-registers
> starting on a
> > specific border because profitable hard registers were
> only starting
> > registers and when we calculated number of available
> hard registers
> > multi-register allocnos can not fit only in their
> starting hard registers.
> > 
> > The following patch was successfully bootstrapped on
> x86/x86-64 and on
> > i686 with H.J.'s autotester options.
> > 
> > OK to commit?
> > 
> > 2011-04-07  Vladimir Makarov <vmakarov@redhat.com>
> > 
> >     PR 4435
> >     * ira-color.c
> (setup_profitable_hard_regs): Add comments.
> >     Don't take prohibited hard
> regs into account.
> > 
>    (setup_conflict_profitable_regs): Rename
> to
> >     get_conflict_profitable_regs.
> >     (check_hard_reg_p): Check
> prohibited hard regs.
> OK.
> jeff
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> Version: GnuPG v1.4.11 (GNU/Linux)
> Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/
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Re: patch to fix PR 48435

[Vladimir Makarov]

On 04/08/2011 01:28 PM, Graham Stott wrote:
> Vladimir,
>
> The wrong PR 4435 was in referrenced the commit
>
Thanks, Graham.  I've just fixed it.  I should change my keyboard.  This 
is not the first time when some symbols are missed.