git: 6f7a96cfe537 - stable/13 - rb_tree: optimize tree rotation
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Date: Mon, 01 Aug 2022 05:45:40 UTC
The branch stable/13 has been updated by dougm: URL: https://cgit.FreeBSD.org/src/commit/?id=6f7a96cfe53716cc65e6f2ac8eea4d8aeafd1e56 commit 6f7a96cfe53716cc65e6f2ac8eea4d8aeafd1e56 Author: Doug Moore <dougm@FreeBSD.org> AuthorDate: 2022-06-25 07:40:16 +0000 Commit: Doug Moore <dougm@FreeBSD.org> CommitDate: 2022-08-01 05:43:08 +0000 rb_tree: optimize tree rotation The RB_ROTATE macros begin with fetching a field via a pointer. In most cases, that value is one that has already been pulled into a register, and the compiler cannot infer that. So, to eliminate those needless fetches, have the caller of the RB_ROTATE macros present the data in the third macro parameter, rather than having the macro fetch it. Differential Revision: https://reviews.freebsd.org/D35520 (cherry picked from commit 61c74fb66f1bef776923cbd5b2a62fb06b003f0c) --- sys/sys/tree.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/sys/sys/tree.h b/sys/sys/tree.h index 2206469db492..f6252ff7ac25 100644 --- a/sys/sys/tree.h +++ b/sys/sys/tree.h @@ -380,7 +380,6 @@ struct { \ } while (/*CONSTCOND*/ 0) #define RB_ROTATE_LEFT(head, elm, tmp, field) do { \ - (tmp) = RB_RIGHT(elm, field); \ if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field)) != NULL) { \ RB_SET_PARENT(RB_RIGHT(elm, field), elm, field); \ } \ @@ -392,7 +391,6 @@ struct { \ } while (/*CONSTCOND*/ 0) #define RB_ROTATE_RIGHT(head, elm, tmp, field) do { \ - (tmp) = RB_LEFT(elm, field); \ if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field)) != NULL) { \ RB_SET_PARENT(RB_LEFT(elm, field), elm, field); \ } \ @@ -484,6 +482,7 @@ name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \ } \ RB_FLIP_RIGHT(parent, field); \ if (RB_RED_RIGHT(parent, field)) { \ + child = elm; \ elm = parent; \ continue; \ } \ @@ -505,6 +504,7 @@ name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \ } \ RB_FLIP_LEFT(parent, field); \ if (RB_RED_LEFT(parent, field)) { \ + child = elm; \ elm = parent; \ continue; \ } \ @@ -561,6 +561,7 @@ name##_RB_REMOVE_COLOR(struct name *head, \ RB_FLIP_LEFT(parent, field); \ else if (!RB_RED_RIGHT(sib, field)) { \ RB_FLIP_LEFT(parent, field); \ + elm = RB_LEFT(sib, field); \ RB_ROTATE_RIGHT(head, sib, elm, field); \ if (RB_RED_RIGHT(elm, field)) \ RB_FLIP_LEFT(sib, field); \ @@ -591,6 +592,7 @@ name##_RB_REMOVE_COLOR(struct name *head, \ RB_FLIP_RIGHT(parent, field); \ else if (!RB_RED_LEFT(sib, field)) { \ RB_FLIP_RIGHT(parent, field); \ + elm = RB_RIGHT(sib, field); \ RB_ROTATE_LEFT(head, sib, elm, field); \ if (RB_RED_LEFT(elm, field)) \ RB_FLIP_RIGHT(sib, field); \