Patchwork patch to fix PR56144

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Submitter Vladimir Makarov
Date Jan. 30, 2013, 5:24 p.m.
Message ID <51095737.6070109@redhat.com>
Download mbox | patch
Permalink /patch/216977/
State New
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Comments

Vladimir Makarov - Jan. 30, 2013, 5:24 p.m.
The following patch fixes

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56144

The patch was successfully bootstrapped and tested on x86/x86-64.

Committed as rev. 195582.

2013-01-30  Vladimir Makarov  <vmakarov@redhat.com>

         PR rtl-optimization/56144
         * lra-constraints.c (get_reload_reg): Don't reuse reload pseudo
         for values with side effects.

2013-01-30  Vladimir Makarov  <vmakarov@redhat.com>

         PR rtl-optimization/56144
         * gcc.dg/pr56144.c: New.
Steven Bosscher - Jan. 31, 2013, 11:36 p.m.
On Wed, Jan 30, 2013 at 6:24 PM, Vladimir Makarov wrote:
> The following patch fixes
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56144
>
> The patch was successfully bootstrapped and tested on x86/x86-64.

Hello Vlad,

Can you please put this patch on the lra-branch too, so that the
auto-testers can pick it up?

Ciao!
Steven
Vladimir Makarov - Feb. 1, 2013, 9:55 p.m.
On 13-01-31 6:36 PM, Steven Bosscher wrote:
> On Wed, Jan 30, 2013 at 6:24 PM, Vladimir Makarov wrote:
>> The following patch fixes
>>
>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56144
>>
>> The patch was successfully bootstrapped and tested on x86/x86-64.
> Hello Vlad,
>
> Can you please put this patch on the lra-branch too, so that the
> auto-testers can pick it up?
>
I've merged the branch with trunk instead.

Patch

Index: lra-constraints.c
===================================================================
--- lra-constraints.c	(revision 195581)
+++ lra-constraints.c	(working copy)
@@ -414,24 +414,26 @@  get_reload_reg (enum op_type type, enum
 	= lra_create_new_reg_with_unique_value (mode, original, rclass, title);
       return true;
     }
-  for (i = 0; i < curr_insn_input_reloads_num; i++)
-    if (rtx_equal_p (curr_insn_input_reloads[i].input, original)
-	&& in_class_p (curr_insn_input_reloads[i].reg, rclass, &new_class))
-      {
-	lra_assert (! side_effects_p (original));
-	*result_reg = curr_insn_input_reloads[i].reg;
-	regno = REGNO (*result_reg);
-	if (lra_dump_file != NULL)
-	  {
-	    fprintf (lra_dump_file, "	 Reuse r%d for reload ", regno);
-	    dump_value_slim (lra_dump_file, original, 1);
-	  }
-	if (new_class != lra_get_allocno_class (regno))
-	  change_class (regno, new_class, ", change", false);
-	if (lra_dump_file != NULL)
-	  fprintf (lra_dump_file, "\n");
-	return false;
-      }
+  /* Prevent reuse value of expression with side effects,
+     e.g. volatile memory.  */
+  if (! side_effects_p (original))
+    for (i = 0; i < curr_insn_input_reloads_num; i++)
+      if (rtx_equal_p (curr_insn_input_reloads[i].input, original)
+	  && in_class_p (curr_insn_input_reloads[i].reg, rclass, &new_class))
+	{
+	  *result_reg = curr_insn_input_reloads[i].reg;
+	  regno = REGNO (*result_reg);
+	  if (lra_dump_file != NULL)
+	    {
+	      fprintf (lra_dump_file, "	 Reuse r%d for reload ", regno);
+	      dump_value_slim (lra_dump_file, original, 1);
+	    }
+	  if (new_class != lra_get_allocno_class (regno))
+	    change_class (regno, new_class, ", change", false);
+	  if (lra_dump_file != NULL)
+	    fprintf (lra_dump_file, "\n");
+	  return false;
+	}
   *result_reg = lra_create_new_reg (mode, original, rclass, title);
   lra_assert (curr_insn_input_reloads_num < LRA_MAX_INSN_RELOADS);
   curr_insn_input_reloads[curr_insn_input_reloads_num].input = original;