Fix reload ICE with define-split

[Roman Zippel]

Hi,

On Fri, 23 Feb 2007, Nathan Sidwell wrote:

> After discussing this with Richard Sandiford, we agreed that the place to fix
> this was in the middle end, and not in m68k specific code.  To that end, this
> patch adds an update_reg_inc_notes_between function and calls it after
> splitting an instruction.

I have a similiar patch, which I think is a bit better. try_split() 
already tries to recreate notes, so the patch below adds the hook for 
REG_INC notes there.

bye, Roman


	* emit-rtl.c (find_auto_inc): New.
	(try_split): recreate REG_INC notes.

Index: gcc-4.1/gcc/emit-rtl.c
===================================================================
--- gcc-4.1.orig/gcc/emit-rtl.c
+++ gcc-4.1/gcc/emit-rtl.c
@@ -3103,6 +3103,34 @@ prev_cc0_setter (rtx insn)
 }
 #endif
 
+#ifdef AUTO_INC_DEC
+static int
+find_auto_inc (rtx *xp, void *data)
+{
+  rtx x = *xp;
+  rtx reg = data;
+
+  if (GET_RTX_CLASS (GET_CODE (x)) != RTX_AUTOINC)
+    return 0;
+
+  switch (GET_CODE (x)) {
+  case PRE_DEC:
+  case PRE_INC:
+  case POST_DEC:
+  case POST_INC:
+  case PRE_MODIFY:
+  case POST_MODIFY:
+    if (rtx_equal_p (reg, XEXP (x, 0)))
+      return 1;
+    break;
+
+  default:
+    gcc_unreachable ();
+  }
+  return -1;
+}
+#endif
+
 /* Increment the label uses for all labels present in rtx.  */
 
 static void
@@ -3268,6 +3296,18 @@ try_split (rtx pat, rtx trial, int last)
 	    }
 	  break;
 
+#ifdef AUTO_INC_DEC
+	case REG_INC:
+	  for (insn = insn_last; insn; insn = PREV_INSN (insn))
+	    {
+	      rtx reg = XEXP (note, 0);
+	      if (for_each_rtx (&PATTERN (insn), find_auto_inc, reg) > 0)
+		REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_INC, reg,
+						      REG_NOTES (insn));
+	    }
+	  break;
+#endif
+
 	default:
 	  break;
 	}