[backport gcc-4.6.0 r169321 to fix PR46856 ICE regression from r162270,
 may need elbow grease to apply to older revisions <mikpe@it.uu.se>]

gcc/

2011-01-26  Mikael Pettersson <mikpe@it.uu.se>

	PR rtl-optimization/46856
	* postreload.c (reload_combine_recognize_const_pattern): Do not
	separate cc0 setter and user on cc0 targets.

gcc/testsuite/

2011-01-26  Mikael Pettersson <mikpe@it.uu.se>

	PR rtl-optimization/46856
	* gcc.c-torture/compile/pr46856.c: New test.

Index: gcc-4.6/gcc/postreload.c
===================================================================
--- gcc-4.6/gcc/postreload.c	(revision 169320)
+++ gcc-4.6/gcc/postreload.c	(revision 169321)
@@ -1009,6 +1009,12 @@ reload_combine_recognize_const_pattern (
 	      && reg_state[clobbered_regno].real_store_ruid >= use_ruid)
 	    break;
 
+#ifdef HAVE_cc0
+	  /* Do not separate cc0 setter and cc0 user on HAVE_cc0 targets.  */
+	  if (must_move_add && sets_cc0_p (PATTERN (use_insn)))
+	    break;
+#endif
+
 	  gcc_assert (reg_state[regno].store_ruid <= use_ruid);
 	  /* Avoid moving a use of ADDREG past a point where it is stored.  */
 	  if (reg_state[REGNO (addreg)].store_ruid > use_ruid)
Index: gcc-4.6/gcc/testsuite/gcc.c-torture/compile/pr46856.c
===================================================================
--- gcc-4.6/gcc/testsuite/gcc.c-torture/compile/pr46856.c	(revision 0)
+++ gcc-4.6/gcc/testsuite/gcc.c-torture/compile/pr46856.c	(revision 169321)
@@ -0,0 +1,26 @@
+struct data {
+    int prio;
+    signed char status;
+};
+
+struct base {
+    unsigned _num;
+    struct data vec[10];
+};
+
+static struct data *ix(struct base *base, unsigned i)
+{
+    return &base->vec[i];
+}
+
+struct heap {
+    struct base base;
+};
+
+struct heap *heap;
+
+void increase_insn_priority (int *fld, int amount)
+{
+    if (ix(heap ? &heap->base : 0, *fld)->status > 0)
+	ix(heap ? &heap->base : 0, *fld)->prio += amount;
+}