reload.c (reg_overlap_mentioned_for_reload_p): When looking at a PLUS in X...

* reload.c (reg_overlap_mentioned_for_reload_p):
	When looking at a PLUS in X, avoid spuriously returning nonzero
	when IN is a REG or another simple PLUS, or a MEM containing one.

	* loop.c (loop_invariant_p): Amend comment about where new registers
	might come from.

From-SVN: r74638

gcc/ChangeLog

@@ -1,3 +1,12 @@
+2003-12-15  J"orn Rennecke <joern.rennecke@superh.com>
+
+	* reload.c (reg_overlap_mentioned_for_reload_p):
+	When looking at a PLUS in X, avoid spuriously returning nonzero
+	when IN is a REG or another simple PLUS, or a MEM containing one.
+
+	* loop.c (loop_invariant_p): Amend comment about where new registers
+	might come from.
+
 2003-12-15  Andreas Jaeger  <aj@suse.de>
 
 	* config/rs6000/rs6000.c (rs6000_output_function_epilogue): Remove

gcc/loop.c

@@ -3298,8 +3298,14 @@ loop_invariant_p (const struct loop *loop, rtx x)
 	return 0;
 
       /* Out-of-range regs can occur when we are called from unrolling.
-	 These have always been created by the unroller and are set in
+	 These registers created by the unroller are set in the loop,
-	 the loop, hence are never invariant.  */
+	 hence are never invariant.
+	 Other out-of-range regs can be generated by load_mems; those that
+	 are written to in the loop are not invariant, while those that are
+	 not written to are invariant.  It would be easy for load_mems
+	 to set n_times_set correctly for these registers, however, there
+	 is no easy way to distinguish them from registers created by the
+	 unroller.  */
 
       if (REGNO (x) >= (unsigned) regs->num)
 	return 0;

gcc/reload.c

@@ -6290,8 +6290,22 @@ reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
 	   || GET_CODE (x) == CC0)
     return reg_mentioned_p (x, in);
   else if (GET_CODE (x) == PLUS)
-    return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
+    {
-	    || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
+      /* We actually want to know if X is mentioned somewhere inside IN.
+	 We must not say that (plus (sp) (const_int 124)) is in
+	 (plus (sp) (const_int 64)), since that can lead to incorrect reload
+	 allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
+	 into a RELOAD_OTHER on behalf of another RELOAD_OTHER.  */
+      while (GET_CODE (in) == MEM)
+	in = XEXP (in, 0);
+      if (GET_CODE (in) == REG)
+	return 0;
+      else if (GET_CODE (in) == PLUS)
+	return (reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
+		|| reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
+      else return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
+		   || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
+    }
   else
     abort ();