[PATCH 1/2] augmented rbtree: use max3() in the *_compute_max() function
From: Uladzislau Rezki (Sony)
Date: Sun Aug 11 2019 - 14:46:35 EST
Recently there was introduced RB_DECLARE_CALLBACKS_MAX template.
One of the callback, to be more specific *_compute_max(), calculates
a maximum scalar value of node against its left/right sub-tree.
To simplify the code and improve readability we can switch and
make use of max3() macro that makes the code more transparent.
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
---
include/linux/rbtree_augmented.h | 40 +++++++++++++++++-----------------
tools/include/linux/rbtree_augmented.h | 40 +++++++++++++++++-----------------
2 files changed, 40 insertions(+), 40 deletions(-)
diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h
index fdd421b8d9ae..fb29d6627646 100644
--- a/include/linux/rbtree_augmented.h
+++ b/include/linux/rbtree_augmented.h
@@ -119,26 +119,26 @@ RBSTATIC const struct rb_augment_callbacks RBNAME = { \
#define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \
RBTYPE, RBAUGMENTED, RBCOMPUTE) \
-static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \
-{ \
- RBSTRUCT *child; \
- RBTYPE max = RBCOMPUTE(node); \
- if (node->RBFIELD.rb_left) { \
- child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD); \
- if (child->RBAUGMENTED > max) \
- max = child->RBAUGMENTED; \
- } \
- if (node->RBFIELD.rb_right) { \
- child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD); \
- if (child->RBAUGMENTED > max) \
- max = child->RBAUGMENTED; \
- } \
- if (exit && node->RBAUGMENTED == max) \
- return true; \
- node->RBAUGMENTED = max; \
- return false; \
-} \
-RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \
+static inline RBTYPE RBNAME ## _get_max(struct rb_node *node) \
+{ \
+ RBSTRUCT *tmp; \
+ \
+ tmp = rb_entry_safe(node, RBSTRUCT, RBFIELD); \
+ return tmp ? tmp->RBAUGMENTED : 0; \
+} \
+ \
+static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \
+{ \
+ RBTYPE max = max3(RBCOMPUTE(node), \
+ RBNAME ## _get_max(node->RBFIELD.rb_left), \
+ RBNAME ## _get_max(node->RBFIELD.rb_right)); \
+ \
+ if (exit && node->RBAUGMENTED == max) \
+ return true; \
+ node->RBAUGMENTED = max; \
+ return false; \
+} \
+RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \
RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max)
diff --git a/tools/include/linux/rbtree_augmented.h b/tools/include/linux/rbtree_augmented.h
index 381aa948610d..3b8284479e98 100644
--- a/tools/include/linux/rbtree_augmented.h
+++ b/tools/include/linux/rbtree_augmented.h
@@ -121,26 +121,26 @@ RBSTATIC const struct rb_augment_callbacks RBNAME = { \
#define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \
RBTYPE, RBAUGMENTED, RBCOMPUTE) \
-static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \
-{ \
- RBSTRUCT *child; \
- RBTYPE max = RBCOMPUTE(node); \
- if (node->RBFIELD.rb_left) { \
- child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD); \
- if (child->RBAUGMENTED > max) \
- max = child->RBAUGMENTED; \
- } \
- if (node->RBFIELD.rb_right) { \
- child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD); \
- if (child->RBAUGMENTED > max) \
- max = child->RBAUGMENTED; \
- } \
- if (exit && node->RBAUGMENTED == max) \
- return true; \
- node->RBAUGMENTED = max; \
- return false; \
-} \
-RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \
+static inline RBTYPE RBNAME ## _get_max(struct rb_node *node) \
+{ \
+ RBSTRUCT *tmp; \
+ \
+ tmp = rb_entry_safe(node, RBSTRUCT, RBFIELD); \
+ return tmp ? tmp->RBAUGMENTED : 0; \
+} \
+ \
+static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \
+{ \
+ RBTYPE max = max3(RBCOMPUTE(node), \
+ RBNAME ## _get_max(node->RBFIELD.rb_left), \
+ RBNAME ## _get_max(node->RBFIELD.rb_right)); \
+ \
+ if (exit && node->RBAUGMENTED == max) \
+ return true; \
+ node->RBAUGMENTED = max; \
+ return false; \
+} \
+RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \
RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max)
--
2.11.0