X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fadt%2Fbitfiddle.h;h=29ff4387e733c7d74db14aa3ceb38a846fd3febc;hb=48b0fa8564962b17e136a0f925eff458ca16abef;hp=885e0fea1736be566b7e776ef9ac8ef4ca5b48fc;hpb=863d31d7a5c8210432fef88b30fc3e8353131538;p=libfirm

diff --git a/ir/adt/bitfiddle.h b/ir/adt/bitfiddle.h
index 885e0fea1..29ff4387e 100644
--- a/ir/adt/bitfiddle.h
+++ b/ir/adt/bitfiddle.h
@@ -1,3 +1,22 @@
+/*
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
 /**
  * @file
  * @date    28.9.2004
@@ -5,12 +24,13 @@
  * @author  Sebastian Hack, Matthias Braun
  * @version $Id$
  */
-#ifndef _FIRM_BITFIDDLE_H_
-#define _FIRM_BITFIDDLE_H_
+#ifndef FIRM_ADT_BITFIDDLE_H
+#define FIRM_ADT_BITFIDDLE_H
+
+#include "compiler.h"
 
 #include <limits.h>
 #include <assert.h>
-#include "util.h"
 
 /* some functions here assume ints are 32 bit wide */
 #define HACKDEL_WORDSIZE 32
@@ -25,7 +45,7 @@ COMPILETIME_ASSERT(UINT_MAX == 4294967295U, uintmax)
  *
  * @note See hacker's delight, page 27.
  */
-static inline __attribute__((const))
+static inline
 int add_saturated(int x, int y)
 {
 	int sum      = x + y;
@@ -54,7 +74,7 @@ int add_saturated(int x, int y)
  * @param x A 32-bit word.
  * @return The number of bits set in x.
  */
-static inline __attribute__((const))
+static inline
 unsigned popcnt(unsigned x) {
 	x -= ((x >> 1) & 0x55555555);
 	x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
@@ -69,7 +89,7 @@ unsigned popcnt(unsigned x) {
  * @param x The word.
  * @return The number of leading (from the most significant bit) zeros.
  */
-static inline __attribute__((const))
+static inline
 unsigned nlz(unsigned x) {
 #ifdef USE_X86_ASSEMBLY
 	unsigned res;
@@ -81,12 +101,15 @@ unsigned nlz(unsigned x) {
 			: "r" (x));
 	return 31 - res;
 #else
-   	x |= x >> 1;
-	x |= x >> 2;
-	x |= x >> 4;
-	x |= x >> 8;
-	x |= x >> 16;
-	return popcnt(~x);
+   unsigned y;
+   int n = 32;
+
+   y = x >>16;  if (y != 0) { n -= 16;  x = y; }
+   y = x >> 8;  if (y != 0) { n -=  8;  x = y; }
+   y = x >> 4;  if (y != 0) { n -=  4;  x = y; }
+   y = x >> 2;  if (y != 0) { n -=  2;  x = y; }
+   y = x >> 1;  if (y != 0) return n - 2;
+   return n - x;
 #endif
 }
 
@@ -95,7 +118,7 @@ unsigned nlz(unsigned x) {
  * @param x The word.
  * @return The number of trailing zeros.
  */
-static inline __attribute__((const))
+static inline
 unsigned ntz(unsigned x) {
 #ifdef USE_X86_ASSEMBLY
 	unsigned res;
@@ -139,7 +162,7 @@ unsigned ntz(unsigned x) {
  * Returns the biggest power of 2 that is equal or smaller than @p x
  * (see hackers delight power-of-2 boundaries, page 48)
  */
-static inline __attribute__((const))
+static inline
 unsigned floor_po2(unsigned x)
 {
 #ifdef USE_X86_ASSEMBLY // in this case nlz is fast
@@ -162,7 +185,7 @@ unsigned floor_po2(unsigned x)
  * @remark x has to be <= 0x8000000 of course
  * @note see hackers delight power-of-2 boundaries, page 48
  */
-static inline __attribute__((const))
+static inline
 unsigned ceil_po2(unsigned x)
 {
 	if(x == 0)
@@ -186,7 +209,7 @@ unsigned ceil_po2(unsigned x)
 /**
  * Tests whether @p x is a power of 2
  */
-static inline __attribute__((const))
+static inline
 int is_po2(unsigned x)
 {
 	return (x & (x-1)) == 0;