From 053a1e9b7dc46053bb99b57a1e036fcaa433a895 Mon Sep 17 00:00:00 2001 From: dougm Date: Mon, 27 Jan 2020 15:09:13 +0000 Subject: [PATCH] Correct the use of RB_AUGMENT in the RB_TREE macros so that is invoked at the root of every subtree that changes in an insert or delete, and only once, and ordered from the bottom of the tree to the top. For intel_gas.c, the only user of RB_AUGMENT I can find, change the augmenting routine so that it does not climb from entry to tree root on every call, and remove a 'tree correcting' function that can be supplanted by proper tree augmentation. Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D23189 --- newlib/libc/include/sys/tree.h | 88 +++++++++++++++------------------- 1 file changed, 38 insertions(+), 50 deletions(-) diff --git a/newlib/libc/include/sys/tree.h b/newlib/libc/include/sys/tree.h index 0eacf951d..5c31ff2ea 100644 --- a/newlib/libc/include/sys/tree.h +++ b/newlib/libc/include/sys/tree.h @@ -335,8 +335,12 @@ struct { \ RB_COLOR(red, field) = RB_RED; \ } while (/*CONSTCOND*/ 0) +/* + * Something to be invoked in a loop at the root of every modified subtree, + * from the bottom up to the root, to update augmented node data. + */ #ifndef RB_AUGMENT -#define RB_AUGMENT(x) do {} while (0) +#define RB_AUGMENT(x) break #endif #define RB_ROTATE_LEFT(head, elm, tmp, field) do { \ @@ -344,7 +348,6 @@ struct { \ if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field)) != NULL) { \ RB_PARENT(RB_LEFT(tmp, field), field) = (elm); \ } \ - RB_AUGMENT(elm); \ if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) { \ if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \ RB_LEFT(RB_PARENT(elm, field), field) = (tmp); \ @@ -354,9 +357,7 @@ struct { \ (head)->rbh_root = (tmp); \ RB_LEFT(tmp, field) = (elm); \ RB_PARENT(elm, field) = (tmp); \ - RB_AUGMENT(tmp); \ - if ((RB_PARENT(tmp, field))) \ - RB_AUGMENT(RB_PARENT(tmp, field)); \ + RB_AUGMENT(elm); \ } while (/*CONSTCOND*/ 0) #define RB_ROTATE_RIGHT(head, elm, tmp, field) do { \ @@ -364,7 +365,6 @@ struct { \ if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field)) != NULL) { \ RB_PARENT(RB_RIGHT(tmp, field), field) = (elm); \ } \ - RB_AUGMENT(elm); \ if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) { \ if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \ RB_LEFT(RB_PARENT(elm, field), field) = (tmp); \ @@ -374,9 +374,7 @@ struct { \ (head)->rbh_root = (tmp); \ RB_RIGHT(tmp, field) = (elm); \ RB_PARENT(elm, field) = (tmp); \ - RB_AUGMENT(tmp); \ - if ((RB_PARENT(tmp, field))) \ - RB_AUGMENT(RB_PARENT(tmp, field)); \ + RB_AUGMENT(elm); \ } while (/*CONSTCOND*/ 0) /* Generates prototypes and inline functions */ @@ -571,62 +569,49 @@ name##_RB_REMOVE(struct name *head, struct type *elm) \ else if (RB_RIGHT(elm, field) == NULL) \ child = RB_LEFT(elm, field); \ else { \ - struct type *left; \ - elm = RB_RIGHT(elm, field); \ - while ((left = RB_LEFT(elm, field)) != NULL) \ - elm = left; \ - child = RB_RIGHT(elm, field); \ - parent = RB_PARENT(elm, field); \ - color = RB_COLOR(elm, field); \ - if (child) \ - RB_PARENT(child, field) = parent; \ - if (parent) { \ - if (RB_LEFT(parent, field) == elm) \ - RB_LEFT(parent, field) = child; \ + elm = RB_RIGHT(old, field); \ + if ((child = RB_LEFT(elm, field)) == NULL) { \ + child = RB_RIGHT(elm, field); \ + RB_RIGHT(old, field) = child; \ + RB_PARENT(elm, field) = elm; \ + } else { \ + do \ + elm = child; \ + while ((child = RB_LEFT(elm, field)) != NULL); \ + child = RB_RIGHT(elm, field); \ + RB_PARENT(RB_RIGHT(old, field), field) = elm; \ + } \ + RB_PARENT(RB_LEFT(old, field), field) = elm; \ + parent = RB_PARENT(old, field); \ + if (parent != NULL) { \ + if (RB_LEFT(parent, field) == old) \ + RB_LEFT(parent, field) = elm; \ else \ - RB_RIGHT(parent, field) = child; \ - RB_AUGMENT(parent); \ - } else \ - RB_ROOT(head) = child; \ - if (RB_PARENT(elm, field) == old) \ - parent = elm; \ - (elm)->field = (old)->field; \ - if (RB_PARENT(old, field)) { \ - if (RB_LEFT(RB_PARENT(old, field), field) == old)\ - RB_LEFT(RB_PARENT(old, field), field) = elm;\ - else \ - RB_RIGHT(RB_PARENT(old, field), field) = elm;\ - RB_AUGMENT(RB_PARENT(old, field)); \ + RB_RIGHT(parent, field) = elm; \ } else \ RB_ROOT(head) = elm; \ - RB_PARENT(RB_LEFT(old, field), field) = elm; \ - if (RB_RIGHT(old, field)) \ - RB_PARENT(RB_RIGHT(old, field), field) = elm; \ - if (parent) { \ - left = parent; \ - do { \ - RB_AUGMENT(left); \ - } while ((left = RB_PARENT(left, field)) != NULL); \ - } \ - goto color; \ } \ parent = RB_PARENT(elm, field); \ color = RB_COLOR(elm, field); \ - if (child) \ + if (child != NULL) \ RB_PARENT(child, field) = parent; \ - if (parent) { \ + if (parent != NULL) { \ if (RB_LEFT(parent, field) == elm) \ RB_LEFT(parent, field) = child; \ else \ RB_RIGHT(parent, field) = child; \ - RB_AUGMENT(parent); \ } else \ RB_ROOT(head) = child; \ -color: \ + if (elm != old) \ + (elm)->field = (old)->field; \ if (color == RB_BLACK) \ name##_RB_REMOVE_COLOR(head, parent, child); \ + while (parent != NULL) { \ + RB_AUGMENT(parent); \ + parent = RB_PARENT(parent, field); \ + } \ return (old); \ -} \ +} #define RB_GENERATE_INSERT(name, type, field, cmp, attr) \ /* Inserts a node into the RB tree */ \ @@ -653,10 +638,13 @@ name##_RB_INSERT(struct name *head, struct type *elm) \ RB_LEFT(parent, field) = elm; \ else \ RB_RIGHT(parent, field) = elm; \ - RB_AUGMENT(parent); \ } else \ RB_ROOT(head) = elm; \ name##_RB_INSERT_COLOR(head, elm); \ + while (elm != NULL) { \ + RB_AUGMENT(elm); \ + elm = RB_PARENT(elm, field); \ + } \ return (NULL); \ }