Merge branch 'glsl2'

[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 e2766d15cd17292c68c8daad2b3b7e4569d0564e..1fa3ec8300ab7d688397b0ee748d52652c0d55fe 100644 (file)
--- a/src/gallium/include/pipe/p_compiler.h
+++ b/src/gallium/include/pipe/p_compiler.h
@@ -60,6 +60,11 @@
 #include <stdbool.h>
 
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
 #if !defined(__HAIKU__) && !defined(__USE_MISC)
 typedef unsigned int       uint;
 typedef unsigned short     ushort;
@@ -74,7 +79,6 @@ typedef unsigned char boolean;
 #define FALSE false
 #endif
 
-
 /* Function inlining */
 #ifndef INLINE
 #  ifdef __cplusplus
@@ -98,11 +102,23 @@ typedef unsigned char boolean;
 #  endif
 #endif
 
+/* Forced function inlining */
+#ifndef ALWAYS_INLINE
+#  ifdef __GNUC__
+#    define ALWAYS_INLINE inline __attribute__((always_inline))
+#  elif defined(_MSC_VER)
+#    define ALWAYS_INLINE __forceinline
+#  else
+#    define ALWAYS_INLINE INLINE
+#  endif
+#endif
 
 /* Function visibility */
 #ifndef PUBLIC
 #  if defined(__GNUC__) || (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x590))
 #    define PUBLIC __attribute__((visibility("default")))
+#  elif defined(_MSC_VER)
+#    define PUBLIC __declspec(dllexport)
 #  else
 #    define PUBLIC
 #  endif
@@ -184,5 +200,68 @@ typedef unsigned char boolean;
 #endif
 
 
+#if defined(__GNUC__)
+
+#define PIPE_READ_WRITE_BARRIER() __asm__("":::"memory")
+
+#elif defined(_MSC_VER)
+
+void _ReadWriteBarrier(void);
+#pragma intrinsic(_ReadWriteBarrier)
+#define PIPE_READ_WRITE_BARRIER() _ReadWriteBarrier()
+
+#else
+
+#warning "Unsupported compiler"
+#define PIPE_READ_WRITE_BARRIER() /* */
+
+#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
+
+
+#if defined(__cplusplus)
+}
+#endif
+
 
 #endif /* P_COMPILER_H */