'ceillog2' now is exported (other modules may need it)

1 files changed, 20 insertions, 2 deletions

diff --git a/lobject.c b/lobject.c
index b77600be..3b4f945c 100644
--- a/lobject.c
+++ b/lobject.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.c,v 2.26 2007/11/09 18:54:25 roberto Exp roberto $
+** $Id: lobject.c,v 2.27 2007/12/19 17:24:38 roberto Exp roberto $
 ** Some generic functions over Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -33,7 +33,7 @@ const TValue luaO_nilobject_ = {{NULL}, LUA_TNIL};
 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
 ** eeeee != 0 and (xxx) otherwise.
 */
-int luaO_int2fb (unsigned int x) {
+int luaO_int2fb (lu_int32 x) {
   int e = 0;  /* exponent */
   if (x < 8) return x;
   while (x >= 0x10) {
@@ -52,6 +52,24 @@ int luaO_fb2int (int x) {
 }
 
 
+int luaO_ceillog2 (unsigned int x) {
+  static const lu_byte log_2[256] = {
+    0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
+  };
+  int l = 0;
+  x--;
+  while (x >= 256) { l += 8; x >>= 8; }
+  return l + log_2[x];
+}
+
+
 int luaO_rawequalObj (const TValue *t1, const TValue *t2) {
   if (ttype(t1) != ttype(t2)) return 0;
   else switch (ttype(t1)) {