Index: loop.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/loop.c,v
retrieving revision 1.470
diff -u -d -b -w -u -p -r1.470 loop.c
--- loop.c	7 Sep 2003 05:21:35 -0000	1.470
+++ loop.c	8 Sep 2003 05:25:34 -0000
@@ -4029,7 +4029,7 @@ emit_prefetch_instructions (struct loop 
 
       /* Prefetch might be worthwhile only when the loads/stores are dense.  */
       if (PREFETCH_ONLY_DENSE_MEM)
-	if (density * 256 > PREFETCH_DENSE_MEM * 100
+	if (PREFETCH_BLOCK != 0 && density * 256 > PREFETCH_DENSE_MEM * 100
 	    && (info[i].total_bytes / PREFETCH_BLOCK
 		>= PREFETCH_BLOCKS_BEFORE_LOOP_MIN))
 	  {
@@ -4050,7 +4050,7 @@ emit_prefetch_instructions (struct loop 
 	info[i].prefetch_in_loop = 1, info[i].prefetch_before_loop = 1;
 
       /* Find how many prefetch instructions we'll use within the loop.  */
-      if (info[i].prefetch_in_loop != 0)
+      if (info[i].prefetch_in_loop != 0 && PREFETCH_BLOCK != 0)
 	{
 	  info[i].prefetch_in_loop = ((info[i].stride + PREFETCH_BLOCK - 1)
 				  / PREFETCH_BLOCK);
@@ -4085,7 +4085,7 @@ emit_prefetch_instructions (struct loop 
 	info[i].prefetch_in_loop = 0;
 
       /* Find how many prefetch instructions we'll use before the loop.  */
-      if (info[i].prefetch_before_loop != 0)
+      if (info[i].prefetch_before_loop != 0 && PREFETCH_BLOCK != 0)
 	{
 	  int n = info[i].total_bytes / PREFETCH_BLOCK;
 	  if (n > ahead)