From patchwork Thu Feb  7 17:06:29 2013
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Subject: patch to fix PR56225
Date: Thu, 07 Feb 2013 07:06:29 -0000
From: Vladimir Makarov <vmakarov@redhat.com>
X-Patchwork-Id: 218958
Message-Id: <5113DF15.8040009@redhat.com>
To: gcc-patches <gcc-patches@gcc.gnu.org>

The following patch fixes

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56225

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

Committed as rev. 195856.

2013-02-07  Vladimir Makarov  <vmakarov@redhat.com>

         PR rtl-optimization/56225
         * lra-constraints.c (process_alt_operands): Check that reload hard
         reg can hold value for strict_low_part.

2013-02-07  Vladimir Makarov  <vmakarov@redhat.com>

         PR rtl-optimization/56225
         * gcc.target/i386/pr56225.c: New test.


Index: lra-constraints.c
===================================================================
--- lra-constraints.c	(revision 195807)
+++ lra-constraints.c	(working copy)
@@ -1895,7 +1895,22 @@ process_alt_operands (int only_alternati
 			? in_hard_reg_set_p (this_alternative_set,
 					     mode, hard_regno[nop])
 			: in_class_p (op, this_alternative, NULL))))
-		losers++;
+		{
+		  /* Strict_low_part requires reload the register not
+		     the sub-register.  In this case we should check
+		     that a final reload hard reg can hold the
+		     value.  */
+		  if (curr_static_id->operand[nop].strict_low
+		      && REG_P (op)
+		      && hard_regno[nop] < 0
+		      && GET_CODE (*curr_id->operand_loc[nop]) == SUBREG
+		      && ira_class_hard_regs_num[this_alternative] > 0
+		      && ! HARD_REGNO_MODE_OK (ira_class_hard_regs
+					       [this_alternative][0],
+					       GET_MODE (op)))
+		    goto fail;
+		  losers++;
+		}
 	      if (operand_reg[nop] != NULL_RTX
 		  /* Output operands and matched input operands are
 		     not inherited.  The following conditions do not
Index: testsuite/gcc.target/i386/pr56225.c
===================================================================
--- testsuite/gcc.target/i386/pr56225.c	(revision 0)
+++ testsuite/gcc.target/i386/pr56225.c	(working copy)
@@ -0,0 +1,12 @@
+/* PR target/56225 */
+/* { dg-do compile { target { ia32 } } } */
+/* { dg-options "-O2 -march=pentium3 -mtune=generic" } */
+
+void bar (int);
+
+void
+foo (int x, int y)
+{
+  __attribute__ ((vector_size (8 * sizeof (short)))) short s0 = { x };
+  bar ((short) (long) &s0 + y);
+}