re PR rtl-optimization/56144 (ICE in get_reload_reg, at lra-constraints.c:421)

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.

From-SVN: r195582

4 files changed, 67 insertions, 19 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 44535ed..0eb5f7c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+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  Richard Biener  <rguenther@suse.de>
 
 	* sparseset.h (sparseset_bit_p): Use gcc_checking_assert.
diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index 03728b7..cc28854 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -414,24 +414,26 @@ get_reload_reg (enum op_type type, enum machine_mode mode, rtx original,
 	= 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;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1c6a0df..17c91ee 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,10 +1,15 @@
+2013-01-30  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR rtl-optimization/56144
+	* gcc.dg/pr56144.c: New.
+
 2013-01-30  David Edelsohn  <dje.gcc@gmail.com>
 
 	* g++.dg/cpp0x/constexpr-53094-2.C: Ignore non-standard ABI
 	message.
 	* g++.dg/cpp0x/constexpr-53094-3.C: Same.
 	* g++.dg/cpp0x/constexpr-55573.C: Same
-	
+
 2013-01-30  Georg-Johann Lay  <avr@gjlay.de>
 
 	PR tree-optimization/56064
diff --git a/gcc/testsuite/gcc.dg/pr56144.c b/gcc/testsuite/gcc.dg/pr56144.c
new file mode 100644
index 0000000..4b98225
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr56144.c
@@ -0,0 +1,35 @@
+/* PR rtl-optimization/56144 */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+int a;
+union U0 { volatile unsigned f2, f4; };
+volatile int b;
+static union U0 c;
+volatile unsigned d, f;
+volatile int e, g, h, i, j, k, l, m, n, o, p;
+int
+main ()
+{
+  a = b;
+  a += c.f2;
+  a += c.f4;
+  unsigned q = h;
+  a += q;
+  q = g;
+  a += q;
+  a += f;
+  q = e;
+  a += q;
+  a += d;
+  a += 2L;
+  a += j;
+  a += i;
+  a += k;
+  a += p;
+  a += o;
+  a += n;
+  a += m;
+  a += l;
+  return 0;
+}