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-rw-r--r--Build/source/libs/potrace/potrace-1.12/src/bitops.h83
1 files changed, 83 insertions, 0 deletions
diff --git a/Build/source/libs/potrace/potrace-1.12/src/bitops.h b/Build/source/libs/potrace/potrace-1.12/src/bitops.h
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index 00000000000..cff734a4615
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+++ b/Build/source/libs/potrace/potrace-1.12/src/bitops.h
@@ -0,0 +1,83 @@
+/* Copyright (C) 2001-2015 Peter Selinger.
+ This file is part of Potrace. It is free software and it is covered
+ by the GNU General Public License. See the file COPYING for details. */
+
+
+/* bits.h: this file defines some macros for bit manipulations. We
+ provide a generic implementation, as well as machine- and
+ compiler-specific fast implementations */
+
+/* lobit: return the position of the rightmost "1" bit of an int, or
+ 32 if none. hibit: return 1 + the position of the leftmost "1" bit
+ of an int, or 0 if none. Note: these functions work on 32-bit
+ integers. */
+
+#ifndef BITOPS_H
+#define BITOPS_H
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* ---------------------------------------------------------------------- */
+/* machine specific macros */
+
+#if defined(HAVE_I386)
+
+static inline unsigned int lobit(unsigned int x) {
+ unsigned int res;
+ asm ("bsf %1,%0\n\t"
+ "jnz 0f\n\t"
+ "movl $32,%0\n"
+ "0:"
+ : "=r" (res)
+ : "r" (x)
+ : "cc");
+ return res;
+}
+
+static inline unsigned int hibit(unsigned int x) {
+ unsigned int res;
+
+ asm ("bsr %1,%0\n\t"
+ "jnz 0f\n\t"
+ "movl $-1,%0\n"
+ "0:"
+ : "=r" (res)
+ : "r" (x)
+ : "cc");
+ return res+1;
+}
+
+/* ---------------------------------------------------------------------- */
+#else /* generic macros */
+
+static inline unsigned int lobit(unsigned int x) {
+ unsigned int res = 32;
+ while (x & 0xffffff) {
+ x <<= 8;
+ res -= 8;
+ }
+ while (x) {
+ x <<= 1;
+ res -= 1;
+ }
+ return res;
+}
+
+static inline unsigned int hibit(unsigned int x) {
+ unsigned int res = 0;
+ while (x > 0xff) {
+ x >>= 8;
+ res += 8;
+ }
+ while (x) {
+ x >>= 1;
+ res += 1;
+ }
+ return res;
+}
+
+#endif
+
+#endif /* BITOPS_H */