Author: dougm Date: Sat May 30 01:48:12 2020 New Revision: 361640 URL: https://svnweb.freebsd.org/changeset/base/361640
Log: RB_REMOVE invokes RB_REMOVE_COLOR either when 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 Modified: head/sys/sys/tree.h Modified: head/sys/sys/tree.h ============================================================================== --- head/sys/sys/tree.h Sat May 30 01:17:26 2020 (r361639) +++ head/sys/sys/tree.h Sat May 30 01:48:12 2020 (r361640) @@ -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 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 #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 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 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); \ _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
