re PR rtl-optimization/56903 (gcc is 4.8.0 fails to compile netdev.c from the…

re PR rtl-optimization/56903 (gcc is 4.8.0 fails to compile netdev.c from the linux kernel [internal compiler error: Maximum number of LRA constraint passes is achieved])

2013-04-12  Vladimir Makarov  <vmakarov@redhat.com>

	PR target/56903
	* config/i386/i386.c (ix86_hard_regno_mode_ok): Add
	lra_in_progress for return.

2013-04-12  Vladimir Makarov  <vmakarov@redhat.com>

	PR target/56903
	* gcc.target/i386/pr56903.c: New test.

From-SVN: r197927

gcc/ChangeLog

+2013-04-12  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/56903
+	* config/i386/i386.c (ix86_hard_regno_mode_ok): Add
+	lra_in_progress for return.
+
 2013-04-12  Greta Yorsh  <Greta.Yorsh@arm.com>
 
 	* config/arm/arm.md (mov_scc,mov_negscc,mov_notscc): Convert

gcc/config/i386/i386.c

@@ -33976,6 +33976,11 @@ ix86_hard_regno_mode_ok (int regno, enum machine_mode mode)
 	return true;
       if (!TARGET_PARTIAL_REG_STALL)
 	return true;
+      /* LRA checks if the hard register is OK for the given mode.
+        QImode values can live in non-QI regs, so we allow all
+        registers here.  */
+      if (lra_in_progress)
+       return true;
       return !can_create_pseudo_p ();
     }
   /* We handle both integer and floats in the general purpose registers.  */

gcc/testsuite/ChangeLog

+2013-04-12  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/56903
+	* gcc.target/i386/pr56903.c: New test.
+
 2013-04-12  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/56261

gcc/testsuite/gcc.target/i386/pr56903.c

+/* PR rtl-optimization/56903 */
+/* { dg-do compile } */
+/* { dg-options "-Os" } */
+/* { dg-additional-options "-march=pentium3" { target ia32 } } */
+
+int a, *b, c;
+struct S { int s : 1; } *fn1 (void);
+extern int fn3 (void), fn4 (int *);
+
+void
+fn2 (void)
+{
+  int e = fn3 ();
+  char f = c + fn1 ()->s * 4;
+  if (*b && f == e)
+    a = *b;
+  fn4 (b);
+}