[PATCH] 2.4.22pre10: {,un}likely_p() macros for pointers

From: Chip Salzenberg (chip@pobox.com)
Date: Mon Aug 04 2003 - 12:06:53 EST

GCC is warning about a pointer-to-int conversion when the likely() and
unlikely() macros are used with pointer values. So, for architectures
where pointers are larger than 'int', I suggest this patch.

PS: This patch was made against 2.4.22pre10 plus many patches from the
'aa' kernel series, so it should be considered an example of the patch
that might be required in other kernel versions.

Index: linux/include/linux/compiler.h
--- linux/include/linux/compiler.h.old 2001-09-18 17:12:45.000000000 -0400
+++ linux/include/linux/compiler.h 2003-08-04 12:24:15.000000000 -0400
@@ -11,6 +11,8 @@
 #endif
 
-#define likely(x) __builtin_expect((x),1)
-#define unlikely(x) __builtin_expect((x),0)
+#define likely(x) __builtin_expect((x), 1)
+#define likely_p(x) __builtin_expect((x) != 0, 1)
+#define unlikely(x) __builtin_expect((x) ,0)
+#define unlikely_p(x) __builtin_expect((x) != 0 ,0)
 
 #endif /* __LINUX_COMPILER_H */

Index: linux/kernel/sched.c
--- linux/kernel/sched.c.old 2003-08-04 12:09:47.000000000 -0400
+++ linux/kernel/sched.c 2003-08-04 12:25:44.000000000 -0400
@@ -477,5 +477,5 @@
         if (unlikely(!prev->mm)) {
                 prev->active_mm = NULL;
- if (unlikely(rq->prev_mm)) {
+ if (unlikely_p(rq->prev_mm)) {
                         printk(KERN_ERR "rq->prev_mm was %p set to %p - %s\n", rq->prev_mm, oldmm, current->comm);
                         dump_stack();

Index: linux/mm/filemap.c
--- linux/mm/filemap.c.old 2003-08-04 12:09:41.000000000 -0400
+++ linux/mm/filemap.c 2003-08-04 12:27:07.000000000 -0400
@@ -3749,5 +3749,5 @@
                 pr_debug("attempting to read %lu\n", page->index);
                 io->did_read = 1;
- if (likely(page->mapping)) {
+ if (likely_p(page->mapping)) {
                         locked = 0;
                         io->err = page->mapping->a_ops->readpage(io->file, page);
@@ -3813,5 +3813,5 @@
                  */
                 if (!TryLockPage(page)) {
- if (likely(page->mapping)) {
+ if (likely_p(page->mapping)) {
                                 int ret = readpage(io->file, page);
                                 if (ret) 

-- 
Chip Salzenberg               - a.k.a. -               <chip@pobox.com>
"I wanted to play hopscotch with the impenetrable mystery of existence,
    but he stepped in a wormhole and had to go in early."  // MST3K
-
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