From: Kim Nguyễn <kn@lri.fr>
Date: Wed, 18 Apr 2012 15:45:21 +0000 (+0200)
Subject: Micro optimization for find_close
X-Git-Url: http://git.nguyen.vg/gitweb/?p=SXSI%2Flibbp.git;a=commitdiff_plain;h=c6a99c1234da55afed4675d2db035176f229abd4

Micro optimization for find_close
---

diff --git a/Makefile b/Makefile
index 59e83a1..94027c1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 POPCOUNT=$(shell grep -q popcnt /proc/cpuinfo && echo 1)
 
 ifeq ($(POPCOUNT), 1)
-	POPCOUNT_FLAG=-DHAS_NATIVE_POPCOUNT -mpopcnt -mtune=corei7 -march=corei7
+	POPCOUNT_FLAG=-DHAS_NATIVE_POPCOUNT -mpopcnt
 else
 	#POPCOUNT_FLAG=-DHAS_POPCOUNT_TABLE
 	POPCOUNT_FLAG=
diff --git a/bp.h b/bp.h
index 6177b83..e0eb4c9 100644
--- a/bp.h
+++ b/bp.h
@@ -86,6 +86,14 @@ static inline int bp_root_node(bp *b)
   return 0;
 }
 
+///////////////////////////////////////////
+//  inspect(bp *b, int s)
+//    returns OP (==1) or CP (==0) at s-th bit (0 <= s < n)
+///////////////////////////////////////////
+static inline int bp_inspect(bp *b, int s)
+{
+  return bp_getbit(b->B, s);
+}
 
 ///////////////////////////////////////////
 //  find_close(bp *b,int s)
@@ -93,7 +101,11 @@ static inline int bp_root_node(bp *b)
 ///////////////////////////////////////////
 static inline int bp_find_close(bp *b,int s)
 {
-  return bp_fwd_excess(b, s, -1);
+  int s1 = s + 1;
+  if (bp_inspect(b, s1) == CP)
+    return s1;
+  else
+    return bp_fwd_excess(b, s, -1);
 }
 
 ///////////////////////////////////////////
@@ -187,15 +199,6 @@ static inline int bp_preorder_select(bp *b,int s)
 
 int bp_postorder_rank(bp *b,int s);
 
-///////////////////////////////////////////
-//  inspect(bp *b, int s)
-//    returns OP (==1) or CP (==0) at s-th bit (0 <= s < n)
-///////////////////////////////////////////
-static inline int bp_inspect(bp *b, int s)
-{
-  return bp_getbit(b->B, s);
-}
-
 static inline int bp_isleaf(bp *b, int s)
 {
   return (bp_inspect(b, s+1) == CP);
@@ -218,7 +221,8 @@ static inline int bp_subtree_size(bp *b, int s)
 
 static inline int bp_first_child(bp *b, int s)
 {
-  return (bp_inspect(b, s+1) == CP) ? -1 : s+1;
+  int s1 = s + 1;
+  return bp_inspect(b, s1) ? s1 : -1;
 }
 
 
@@ -231,7 +235,7 @@ static inline int bp_next_sibling(bp *b, int s)
 {
   int t;
   t = bp_find_close(b, s) + 1;
-  return (bp_inspect(b, t) == CP) ? -1 : t;
+  return bp_inspect(b, t) ? t : -1;
 
 }