X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=include%2Fwimlib%2Fbitops.h;h=e5c4872e40b4035cd987ad70bcc8e0026be73fbf;hb=HEAD;hp=1fc30f6c69a1b9a03e0987e215ffe5abe5900340;hpb=4a20aae0dd8469a352517a0b107416ffa99ccc55;p=wimlib

diff --git a/include/wimlib/bitops.h b/include/wimlib/bitops.h
index 1fc30f6c..e5c4872e 100644
--- a/include/wimlib/bitops.h
+++ b/include/wimlib/bitops.h
@@ -1,21 +1,28 @@
 /*
  * bitops.h - inline functions for bit manipulation
  *
- * The following copying information applies to this specific source code file:
+ * Copyright 2022 Eric Biggers
  *
- * Written in 2014-2016 by Eric Biggers <ebiggers3@gmail.com>
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
  *
- * To the extent possible under law, the author(s) have dedicated all copyright
- * and related and neighboring rights to this software to the public domain
- * worldwide via the Creative Commons Zero 1.0 Universal Public Domain
- * Dedication (the "CC0").
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
  *
- * This software is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE. See the CC0 for more details.
- *
- * You should have received a copy of the CC0 along with this software; if not
- * see <http://creativecommons.org/publicdomain/zero/1.0/>.
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
  */
 
 #ifndef _WIMLIB_BITOPS_H
@@ -33,27 +40,13 @@
 static forceinline unsigned
 bsr32(u32 v)
 {
-#ifdef compiler_bsr32
-	return compiler_bsr32(v);
-#else
-	unsigned bit = 0;
-	while ((v >>= 1) != 0)
-		bit++;
-	return bit;
-#endif
+	return 31 - __builtin_clz(v);
 }
 
 static forceinline unsigned
 bsr64(u64 v)
 {
-#ifdef compiler_bsr64
-	return compiler_bsr64(v);
-#else
-	unsigned bit = 0;
-	while ((v >>= 1) != 0)
-		bit++;
-	return bit;
-#endif
+	return 63 - __builtin_clzll(v);
 }
 
 static forceinline unsigned
@@ -75,27 +68,13 @@ bsrw(machine_word_t v)
 static forceinline unsigned
 bsf32(u32 v)
 {
-#ifdef compiler_bsf32
-	return compiler_bsf32(v);
-#else
-	unsigned bit;
-	for (bit = 0; !(v & 1); bit++, v >>= 1)
-		;
-	return bit;
-#endif
+	return __builtin_ctz(v);
 }
 
 static forceinline unsigned
 bsf64(u64 v)
 {
-#ifdef compiler_bsf64
-	return compiler_bsf64(v);
-#else
-	unsigned bit;
-	for (bit = 0; !(v & 1); bit++, v >>= 1)
-		;
-	return bit;
-#endif
+	return __builtin_ctzll(v);
 }
 
 static forceinline unsigned