[Bug middle-end/30751] [4.3 Regression] internal compiler error: in extract_insn, at recog.c:2108

["ian at airs dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #4 from ian at airs dot com  2007-02-12 18:45 -------
Tom Tromey helped me recreate this with a cross-compiler.

I'm currently testing this patch:

Index: lower-subreg.c
===================================================================
--- lower-subreg.c      (revision 121769)
+++ lower-subreg.c      (working copy)
@@ -711,6 +711,23 @@ resolve_simple_move (rtx set, rtx insn)
       return insn;
     }

+  /* It's possible for the code to use a subreg of a decomposed
+     register while forming an address.  We need to handle that before
+     passing the address to emit_move_insn.  We pass NULL_RTX as the
+     insn parameter to resolve_subreg_use because we can not validate
+     the insn yet.  */
+  if (MEM_P (src) || MEM_P (dest))
+    {
+      int acg;
+
+      if (MEM_P (src))
+       for_each_rtx (&XEXP (src, 0), resolve_subreg_use, NULL_RTX);
+      if (MEM_P (dest))
+       for_each_rtx (&XEXP (dest, 0), resolve_subreg_use, NULL_RTX);
+      acg = apply_change_group ();
+      gcc_assert (acg);
+    }
+
   /* If SRC is a register which we can't decompose, or has side
      effects, we need to move via a temporary register.  */


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30751