gallium: add PIPE_OS_ANDROID support

Android uses Linux kernel and its own C runtime.  It resembles
PIPE_OS_LINUX a lot with some minor exceptions.

Reviewed-by: Brian Paul <brianp@vmware.com>

src/gallium/auxiliary/os/os_thread.h

@@ -314,7 +314,7 @@ typedef int64_t pipe_condvar;
  * pipe_barrier
  */
 
-#if defined(PIPE_OS_LINUX) || defined(PIPE_OS_BSD) || defined(PIPE_OS_SOLARIS) || defined(PIPE_OS_HAIKU)
+#if (defined(PIPE_OS_LINUX) || defined(PIPE_OS_BSD) || defined(PIPE_OS_SOLARIS) || defined(PIPE_OS_HAIKU)) && !defined(PIPE_OS_ANDROID)
 
 typedef pthread_barrier_t pipe_barrier;
 

src/gallium/auxiliary/util/u_math.h

@@ -199,6 +199,16 @@ roundf(float x)
 #endif /* _MSC_VER */
 
 
+#ifdef PIPE_OS_ANDROID
+
+static INLINE
+double log2(double d)
+{
+   return log(d) * (1.0 / M_LN2);
+}
+
+#endif
+
 
 
 
@@ -409,7 +419,7 @@ unsigned ffs( unsigned u )
 
    return i;
 }
-#elif defined(__MINGW32__)
+#elif defined(__MINGW32__) || defined(PIPE_OS_ANDROID)
 #define ffs __builtin_ffs
 #endif
 

src/gallium/include/pipe/p_compiler.h

@@ -67,7 +67,9 @@ extern "C" {
 
 
 #if !defined(__HAIKU__) && !defined(__USE_MISC)
+#if !defined(PIPE_OS_ANDROID)
 typedef unsigned int       uint;
+#endif
 typedef unsigned short     ushort;
 #endif
 typedef unsigned char      ubyte;

src/gallium/include/pipe/p_config.h

@@ -154,6 +154,14 @@
 #define PIPE_OS_UNIX
 #endif
 
+/*
+ * Android defines __linux__ so PIPE_OS_LINUX and PIPE_OS_UNIX will also be
+ * defined.
+ */
+#if defined(ANDROID)
+#define PIPE_OS_ANDROID
+#endif
+
 #if defined(__FreeBSD__)
 #define PIPE_OS_FREEBSD
 #define PIPE_OS_BSD