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authorNoah Goldstein <goldstein.w.n@gmail.com>2023-04-04 17:13:51 -0500
committerAndrew Morton <akpm@linux-foundation.org>2023-04-18 16:39:33 -0700
commitb0687c1119b4e8c88a651b6e876b7eae28d076e3 (patch)
tree82529e06903d712793f28d544a531f54f5711d6c /lib
parent1be2edb25c72c3fe1bf955694c5521b035fcb276 (diff)
lib/rbtree: use '+' instead of '|' for setting color.
This has a slight benefit for x86 and has no effect on other targets. The benefit to x86 is it change the codegen for setting a node to block from `mov %r0, %r1; or $RB_BLACK, %r1` to `lea RB_BLACK(%r0), %r1` which saves an instructions. In all other cases it just replace ALU with ALU (or -> and) which perform the same on all machines I am aware of. Total instructions in rbtree.o: Before - 802 After - 782 so it saves about 20 `mov` instructions. Link: https://lkml.kernel.org/r/20230404221350.3806566-1-goldstein.w.n@gmail.com Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Cc: Michel Lespinasse <michel@lespinasse.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/rbtree.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/rbtree.c b/lib/rbtree.c
index c4ac5c2421f2..5114eda6309c 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -58,7 +58,7 @@
static inline void rb_set_black(struct rb_node *rb)
{
- rb->__rb_parent_color |= RB_BLACK;
+ rb->__rb_parent_color += RB_BLACK;
}
static inline struct rb_node *rb_red_parent(struct rb_node *red)