Pure, const and malloc attributes to libavutil.

Patch by Zuxy Meng: zuxy meng gmail com
Original thread:
[FFmpeg-devel] [PATCH] Pure, const and malloc attributes to libavutil
Date: 03/18/2008 6:09 AM

Originally committed as revision 12489 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 24 insertions, 8 deletions

diff --git a/libavutil/common.h b/libavutil/common.h
index fd1d00c7b3..d2489e3f32 100644
--- a/libavutil/common.h
+++ b/libavutil/common.h
@@ -57,6 +57,22 @@
 #endif
 #endif
 
+#ifndef av_pure
+#if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
+#    define av_pure __attribute__((pure))
+#else
+#    define av_pure
+#endif
+#endif
+
+#ifndef av_const
+#if defined(__GNUC__) && (__GNUC__ > 2 || __GNUC__ == 2 && __GNUC_MINOR__ > 5)
+#    define av_const __attribute__((const))
+#else
+#    define av_const
+#endif
+#endif
+
 #ifdef HAVE_AV_CONFIG_H
 #    include "internal.h"
 #endif /* HAVE_AV_CONFIG_H */
@@ -94,7 +110,7 @@
 /* misc math functions */
 extern const uint8_t ff_log2_tab[256];
 
-static inline int av_log2(unsigned int v)
+static inline av_const int av_log2(unsigned int v)
 {
     int n = 0;
     if (v & 0xffff0000) {
@@ -110,7 +126,7 @@ static inline int av_log2(unsigned int v)
     return n;
 }
 
-static inline int av_log2_16bit(unsigned int v)
+static inline av_const int av_log2_16bit(unsigned int v)
 {
     int n = 0;
     if (v & 0xff00) {
@@ -123,7 +139,7 @@ static inline int av_log2_16bit(unsigned int v)
 }
 
 /* median of 3 */
-static inline int mid_pred(int a, int b, int c)
+static inline av_const int mid_pred(int a, int b, int c)
 {
 #ifdef HAVE_CMOV
     int i=b;
@@ -170,7 +186,7 @@ static inline int mid_pred(int a, int b, int c)
  * @param amax maximum value of the clip range
  * @return clipped value
  */
-static inline int av_clip(int a, int amin, int amax)
+static inline av_const int av_clip(int a, int amin, int amax)
 {
     if      (a < amin) return amin;
     else if (a > amax) return amax;
@@ -182,7 +198,7 @@ static inline int av_clip(int a, int amin, int amax)
  * @param a value to clip
  * @return clipped value
  */
-static inline uint8_t av_clip_uint8(int a)
+static inline av_const uint8_t av_clip_uint8(int a)
 {
     if (a&(~255)) return (-a)>>31;
     else          return a;
@@ -193,19 +209,19 @@ static inline uint8_t av_clip_uint8(int a)
  * @param a value to clip
  * @return clipped value
  */
-static inline int16_t av_clip_int16(int a)
+static inline av_const int16_t av_clip_int16(int a)
 {
     if ((a+32768) & ~65535) return (a>>31) ^ 32767;
     else                    return a;
 }
 
 /* math */
-int64_t ff_gcd(int64_t a, int64_t b);
+int64_t av_const ff_gcd(int64_t a, int64_t b);
 
 /**
  * converts fourcc string to int
  */
-static inline int ff_get_fourcc(const char *s){
+static inline av_pure int ff_get_fourcc(const char *s){
 #ifdef HAVE_AV_CONFIG_H
     assert( strlen(s)==4 );
 #endif