From: Sebastian Huber <sebastian.huber@embedded-brains.de>
To: newlib@sourceware.org
Subject: [PATCH 04/11] RB_REMOVE invokes RB_REMOVE_COLOR either when
Date: Mon, 19 Oct 2020 18:05:17 +0200 [thread overview]
Message-ID: <20201019160522.15408-5-sebastian.huber@embedded-brains.de> (raw)
In-Reply-To: <20201019160522.15408-1-sebastian.huber@embedded-brains.de>
From: dougm <dougm@FreeBSD.org>
child is red or child is null. In the first case, RB_REMOVE_COLOR just changes
the child to black and returns. With this change, RB_REMOVE handles that case,
and drops the child argument to RB_REMOVE_COLOR, since that value is always
null.
RB_REMOVE_COLOR is changed to remove a couple of unneeded tests, and
to eliminate some deep indentation.
RB_ISRED is defined to combine a null check with a test for redness,
to replace that combination in several places.
Reviewed by: markj
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D25032
---
newlib/libc/include/sys/tree.h | 137 ++++++++++++++++-----------------
1 file changed, 65 insertions(+), 72 deletions(-)
diff --git a/newlib/libc/include/sys/tree.h b/newlib/libc/include/sys/tree.h
index b1e5e23a7..d5adfdd4e 100644
--- a/newlib/libc/include/sys/tree.h
+++ b/newlib/libc/include/sys/tree.h
@@ -321,6 +321,7 @@ struct { \
#define RB_RIGHT(elm, field) (elm)->field.rbe_right
#define RB_PARENT(elm, field) (elm)->field.rbe_parent
#define RB_COLOR(elm, field) (elm)->field.rbe_color
+#define RB_ISRED(elm, field) ((elm) != NULL && RB_COLOR(elm, field) == RB_RED)
#define RB_ROOT(head) (head)->rbh_root
#define RB_EMPTY(head) (RB_ROOT(head) == NULL)
@@ -396,7 +397,7 @@ struct { \
#define RB_PROTOTYPE_INSERT_COLOR(name, type, attr) \
attr void name##_RB_INSERT_COLOR(struct name *, struct type *)
#define RB_PROTOTYPE_REMOVE_COLOR(name, type, attr) \
- attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *)
+ attr void name##_RB_REMOVE_COLOR(struct name *, struct type *)
#define RB_PROTOTYPE_REMOVE(name, type, attr) \
attr struct type *name##_RB_REMOVE(struct name *, struct type *)
#define RB_PROTOTYPE_INSERT(name, type, attr) \
@@ -439,12 +440,11 @@ attr void \
name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \
{ \
struct type *parent, *gparent, *tmp; \
- while ((parent = RB_PARENT(elm, field)) != NULL && \
- RB_COLOR(parent, field) == RB_RED) { \
+ while (RB_ISRED((parent = RB_PARENT(elm, field)), field)) { \
gparent = RB_PARENT(parent, field); \
if (parent == RB_LEFT(gparent, field)) { \
tmp = RB_RIGHT(gparent, field); \
- if (tmp && RB_COLOR(tmp, field) == RB_RED) { \
+ if (RB_ISRED(tmp, field)) { \
RB_COLOR(tmp, field) = RB_BLACK; \
RB_SET_BLACKRED(parent, gparent, field);\
elm = gparent; \
@@ -460,7 +460,7 @@ name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \
RB_ROTATE_RIGHT(head, gparent, tmp, field); \
} else { \
tmp = RB_LEFT(gparent, field); \
- if (tmp && RB_COLOR(tmp, field) == RB_RED) { \
+ if (RB_ISRED(tmp, field)) { \
RB_COLOR(tmp, field) = RB_BLACK; \
RB_SET_BLACKRED(parent, gparent, field);\
elm = gparent; \
@@ -481,11 +481,11 @@ name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \
#define RB_GENERATE_REMOVE_COLOR(name, type, field, attr) \
attr void \
-name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
+name##_RB_REMOVE_COLOR(struct name *head, struct type *parent) \
{ \
- struct type *tmp; \
- while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) && \
- elm != RB_ROOT(head)) { \
+ struct type *elm, *tmp; \
+ elm = NULL; \
+ do { \
if (RB_LEFT(parent, field) == elm) { \
tmp = RB_RIGHT(parent, field); \
if (RB_COLOR(tmp, field) == RB_RED) { \
@@ -493,32 +493,29 @@ name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm)
RB_ROTATE_LEFT(head, parent, tmp, field);\
tmp = RB_RIGHT(parent, field); \
} \
- if ((RB_LEFT(tmp, field) == NULL || \
- RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
- (RB_RIGHT(tmp, field) == NULL || \
- RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
+ if (!RB_ISRED(RB_LEFT(tmp, field), field) && \
+ !RB_ISRED(RB_RIGHT(tmp, field), field)) { \
RB_COLOR(tmp, field) = RB_RED; \
elm = parent; \
parent = RB_PARENT(elm, field); \
- } else { \
- if (RB_RIGHT(tmp, field) == NULL || \
- RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
- struct type *oleft; \
- if ((oleft = RB_LEFT(tmp, field)) \
- != NULL) \
- RB_COLOR(oleft, field) = RB_BLACK;\
- RB_COLOR(tmp, field) = RB_RED; \
- RB_ROTATE_RIGHT(head, tmp, oleft, field);\
- tmp = RB_RIGHT(parent, field); \
- } \
- RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
- RB_COLOR(parent, field) = RB_BLACK; \
- if (RB_RIGHT(tmp, field)) \
- RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
- RB_ROTATE_LEFT(head, parent, tmp, field);\
- elm = RB_ROOT(head); \
- break; \
+ continue; \
} \
+ if (!RB_ISRED(RB_RIGHT(tmp, field), field)) { \
+ struct type *oleft; \
+ if ((oleft = RB_LEFT(tmp, field)) \
+ != NULL) \
+ RB_COLOR(oleft, field) = RB_BLACK; \
+ RB_COLOR(tmp, field) = RB_RED; \
+ RB_ROTATE_RIGHT(head, tmp, oleft, field); \
+ tmp = RB_RIGHT(parent, field); \
+ } \
+ RB_COLOR(tmp, field) = RB_COLOR(parent, field); \
+ RB_COLOR(parent, field) = RB_BLACK; \
+ if (RB_RIGHT(tmp, field)) \
+ RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK; \
+ RB_ROTATE_LEFT(head, parent, tmp, field); \
+ elm = RB_ROOT(head); \
+ break; \
} else { \
tmp = RB_LEFT(parent, field); \
if (RB_COLOR(tmp, field) == RB_RED) { \
@@ -526,59 +523,54 @@ name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm)
RB_ROTATE_RIGHT(head, parent, tmp, field);\
tmp = RB_LEFT(parent, field); \
} \
- if ((RB_LEFT(tmp, field) == NULL || \
- RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
- (RB_RIGHT(tmp, field) == NULL || \
- RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
+ if (!RB_ISRED(RB_LEFT(tmp, field), field) && \
+ !RB_ISRED(RB_RIGHT(tmp, field), field)) { \
RB_COLOR(tmp, field) = RB_RED; \
elm = parent; \
parent = RB_PARENT(elm, field); \
- } else { \
- if (RB_LEFT(tmp, field) == NULL || \
- RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
- struct type *oright; \
- if ((oright = RB_RIGHT(tmp, field)) \
- != NULL) \
- RB_COLOR(oright, field) = RB_BLACK;\
- RB_COLOR(tmp, field) = RB_RED; \
- RB_ROTATE_LEFT(head, tmp, oright, field);\
- tmp = RB_LEFT(parent, field); \
- } \
- RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
- RB_COLOR(parent, field) = RB_BLACK; \
- if (RB_LEFT(tmp, field)) \
- RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
- RB_ROTATE_RIGHT(head, parent, tmp, field);\
- elm = RB_ROOT(head); \
- break; \
+ continue; \
+ } \
+ if (!RB_ISRED(RB_LEFT(tmp, field), field)) { \
+ struct type *oright; \
+ if ((oright = RB_RIGHT(tmp, field)) \
+ != NULL) \
+ RB_COLOR(oright, field) = RB_BLACK; \
+ RB_COLOR(tmp, field) = RB_RED; \
+ RB_ROTATE_LEFT(head, tmp, oright, field); \
+ tmp = RB_LEFT(parent, field); \
} \
+ RB_COLOR(tmp, field) = RB_COLOR(parent, field); \
+ RB_COLOR(parent, field) = RB_BLACK; \
+ if (RB_LEFT(tmp, field)) \
+ RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK; \
+ RB_ROTATE_RIGHT(head, parent, tmp, field); \
+ elm = RB_ROOT(head); \
+ break; \
} \
- } \
- if (elm) \
- RB_COLOR(elm, field) = RB_BLACK; \
+ } while (!RB_ISRED(elm, field) && parent != NULL); \
+ RB_COLOR(elm, field) = RB_BLACK; \
}
#define RB_GENERATE_REMOVE(name, type, field, attr) \
attr struct type * \
name##_RB_REMOVE(struct name *head, struct type *elm) \
{ \
- struct type *child, *parent, *parent_old, *old = elm; \
+ struct type *child, *old, *parent, *parent_old, *right; \
int color; \
+ \
+ old = elm; \
parent_old = parent = RB_PARENT(elm, field); \
+ right = RB_RIGHT(elm, field); \
color = RB_COLOR(elm, field); \
- if (RB_LEFT(elm, field) == NULL) { \
- elm = child = RB_RIGHT(elm, field); \
- if (elm != NULL) \
- RB_PARENT(elm, field) = parent; \
- } else if (RB_RIGHT(elm, field) == NULL) { \
+ if (RB_LEFT(elm, field) == NULL) \
+ elm = child = right; \
+ else if (right == NULL) \
elm = child = RB_LEFT(elm, field); \
- RB_PARENT(elm, field) = parent; \
- } else { \
- elm = RB_RIGHT(old, field); \
- if ((child = RB_LEFT(elm, field)) == NULL) { \
- child = RB_RIGHT(elm, field); \
+ else { \
+ if ((child = RB_LEFT(right, field)) == NULL) { \
+ child = RB_RIGHT(right, field); \
RB_RIGHT(old, field) = child; \
- parent = elm; \
+ parent = elm = right; \
} else { \
do \
elm = child; \
@@ -586,8 +578,6 @@ name##_RB_REMOVE(struct name *head, struct type *elm) \
child = RB_RIGHT(elm, field); \
parent = RB_PARENT(elm, field); \
RB_LEFT(parent, field) = child; \
- if (child != NULL) \
- RB_PARENT(child, field) = parent; \
RB_PARENT(RB_RIGHT(old, field), field) = elm; \
} \
RB_PARENT(RB_LEFT(old, field), field) = elm; \
@@ -600,8 +590,11 @@ name##_RB_REMOVE(struct name *head, struct type *elm) \
RB_LEFT(parent_old, field) = elm; \
else \
RB_RIGHT(parent_old, field) = elm; \
- if (color == RB_BLACK) \
- name##_RB_REMOVE_COLOR(head, parent, child); \
+ if (child != NULL) { \
+ RB_PARENT(child, field) = parent; \
+ RB_COLOR(child, field) = RB_BLACK; \
+ } else if (color != RB_RED && parent != NULL) \
+ name##_RB_REMOVE_COLOR(head, parent); \
while (parent != NULL) { \
RB_AUGMENT(parent); \
parent = RB_PARENT(parent, field); \
--
2.26.2
next prev parent reply other threads:[~2020-10-19 16:05 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-19 16:05 [PATCH 00/11] Synchronize <sys/tree.h> with FreeBSD Sebastian Huber
2020-10-19 16:05 ` [PATCH 01/11] Add RB_REINSERT(3), a low overhead alternative to Sebastian Huber
2020-10-19 16:05 ` [PATCH 02/11] Correct the use of RB_AUGMENT in the RB_TREE Sebastian Huber
2020-10-19 16:05 ` [PATCH 03/11] For the case when RB_REMOVE requires a nontrivial Sebastian Huber
2020-10-19 16:05 ` Sebastian Huber [this message]
2020-10-19 16:05 ` [PATCH 05/11] Remove from RB_REMOVE_COLOR some null checks Sebastian Huber
2020-10-19 16:05 ` [PATCH 06/11] To reduce the size of an rb_node, drop the color Sebastian Huber
2020-10-19 16:05 ` [PATCH 07/11] Restore an RB_COLOR macro, for the benefit of Sebastian Huber
2020-10-19 16:05 ` [PATCH 08/11] Fixup r361997 by balancing parens. Duh Sebastian Huber
2020-10-19 16:05 ` [PATCH 09/11] Linuxkpi uses the rb-tree structures Sebastian Huber
2020-10-26 9:52 ` [PATCH 00/11] Synchronize <sys/tree.h> with FreeBSD Corinna Vinschen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201019160522.15408-5-sebastian.huber@embedded-brains.de \
--to=sebastian.huber@embedded-brains.de \
--cc=newlib@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).