Merge branch '7.8'

[mesa.git] / src / gallium / include / pipe / p_compiler.h

diff --git a/src/gallium/include/pipe/p_compiler.h b/src/gallium/include/pipe/p_compiler.h
index 272d0308cc1cde1ed7b57fedca6dd5f85dc64926..9b31555f1b1a89a62567e04fef8c6eebb0dad93a 100644 (file)
--- a/src/gallium/include/pipe/p_compiler.h
+++ b/src/gallium/include/pipe/p_compiler.h
@@ -31,13 +31,10 @@
 
 #include "p_config.h"
 
-#ifndef XFree86Server
 #include <stdlib.h>
 #include <string.h>
-#else
-#include "xf86_ansic.h"
-#include "xf86_libc.h"
-#endif
+#include <stddef.h>
+#include <stdarg.h>
 
 
 #if defined(_WIN32) && !defined(__WIN32__)
@@ -63,7 +60,7 @@
 #include <stdbool.h>
 
 
-#ifndef __HAIKU__
+#if !defined(__HAIKU__) && !defined(__USE_MISC)
 typedef unsigned int       uint;
 typedef unsigned short     ushort;
 #endif
@@ -77,7 +74,6 @@ typedef unsigned char boolean;
 #define FALSE false
 #endif
 
-
 /* Function inlining */
 #ifndef INLINE
 #  ifdef __cplusplus
@@ -104,8 +100,7 @@ typedef unsigned char boolean;
 
 /* Function visibility */
 #ifndef PUBLIC
-#  if (defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__) >= 303) \
-       || (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x590))
+#  if defined(__GNUC__) || (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x590))
 #    define PUBLIC __attribute__((visibility("default")))
 #  else
 #    define PUBLIC
@@ -117,7 +112,7 @@ typedef unsigned char boolean;
  * If we're not using gcc, define __FUNCTION__ as a cpp symbol here.
  */
 #ifndef __FUNCTION__
-# if (!defined(__GNUC__) || (__GNUC__ < 2))
+# if !defined(__GNUC__)
 #  if (__STDC_VERSION__ >= 199901L) /* C99 */ || \
     (defined(__SUNPRO_C) && defined(__C99FEATURES__))
 #   define __FUNCTION__ __func__
@@ -125,6 +120,9 @@ typedef unsigned char boolean;
 #   define __FUNCTION__ "<unknown>"
 #  endif
 # endif
+# if defined(_MSC_VER) && _MSC_VER < 1300
+#  define __FUNCTION__ "<unknown>"
+# endif
 #endif
 
 
@@ -140,6 +138,14 @@ typedef unsigned char boolean;
 
 
 
+#if defined(__GNUC__)
+#define PIPE_DEPRECATED  __attribute__((__deprecated__))
+#else
+#define PIPE_DEPRECATED
+#endif
+
+
+
 /* Macros for data alignment. */
 #if defined(__GNUC__) || (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x590))
 
@@ -176,6 +182,44 @@ typedef unsigned char boolean;
 
 #endif
 
-
+/* You should use these macros to mark if blocks where the if condition
+ * is either likely to be true, or unlikely to be true.
+ *
+ * This will inform human readers of this fact, and will also inform
+ * the compiler, who will in turn inform the CPU.
+ *
+ * CPUs often start executing code inside the if or the else blocks
+ * without knowing whether the condition is true or not, and will have
+ * to throw the work away if they find out later they executed the
+ * wrong part of the if.
+ *
+ * If these macros are used, the CPU is more likely to correctly predict
+ * the right path, and will avoid speculatively executing the wrong branch,
+ * thus not throwing away work, resulting in better performance.
+ *
+ * In light of this, it is also a good idea to mark as "likely" a path
+ * which is not necessarily always more likely, but that will benefit much
+ * more from performance improvements since it is already much faster than
+ * the other path, or viceversa with "unlikely".
+ *
+ * Example usage:
+ * if(unlikely(do_we_need_a_software_fallback()))
+ *    do_software_fallback();
+ * else
+ *    render_with_gpu();
+ *
+ * The macros follow the Linux kernel convention, and more examples can
+ * be found there.
+ *
+ * Note that profile guided optimization can offer better results, but
+ * needs an appropriate coverage suite and does not inform human readers.
+ */
+#ifdef __GNUC__
+#define likely(x) __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+#else
+#define likely(x) !!(x)
+#define unlikely(x) !!(x)
+#endif
 
 #endif /* P_COMPILER_H */