mesa/gallium: Move u_bit_scan{,64} from gallium to util.

The functions are also useful for mesa.
Introduce src/util/bitscan.{h,c}. Move ffs function
implementations from src/mesa/main/imports.{h,c}.
Move bit scan related functions from
src/gallium/auxiliary/util/u_math.h. Merge platform
handling with what is available from within mesa.

v2: Try to fix MSVC compile.

Reviewed-by: Brian Paul <[email protected]>
Tested-by: Brian Paul <[email protected]>
Signed-off-by: Mathias Fröhlich <[email protected]>

2 files changed, 1 insertions, 74 deletions

diff --git a/src/mesa/main/imports.c b/src/mesa/main/imports.c
index fe54109322d..808b8f67302 100644
--- a/src/mesa/main/imports.c
+++ b/src/mesa/main/imports.c
@@ -219,64 +219,6 @@ _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
 /*@{*/
 
 
-#ifndef HAVE___BUILTIN_FFS
-/**
- * Find the first bit set in a word.
- */
-int
-ffs(int i)
-{
-   register int bit = 0;
-   if (i != 0) {
-      if ((i & 0xffff) == 0) {
-         bit += 16;
-         i >>= 16;
-      }
-      if ((i & 0xff) == 0) {
-         bit += 8;
-         i >>= 8;
-      }
-      if ((i & 0xf) == 0) {
-         bit += 4;
-         i >>= 4;
-      }
-      while ((i & 1) == 0) {
-         bit++;
-         i >>= 1;
-      }
-      bit++;
-   }
-   return bit;
-}
-#endif
-
-#ifndef HAVE___BUILTIN_FFSLL
-/**
- * Find position of first bit set in given value.
- * XXX Warning: this function can only be used on 64-bit systems!
- * \return  position of least-significant bit set, starting at 1, return zero
- *          if no bits set.
- */
-int
-ffsll(long long int val)
-{
-   int bit;
-
-   STATIC_ASSERT(sizeof(val) == 8);
-
-   bit = ffs((int) val);
-   if (bit != 0)
-      return bit;
-
-   bit = ffs((int) (val >> 32));
-   if (bit != 0)
-      return 32 + bit;
-
-   return 0;
-}
-#endif
-
-
 #ifndef HAVE___BUILTIN_POPCOUNT
 /**
  * Return number of bits set in given GLuint.
diff --git a/src/mesa/main/imports.h b/src/mesa/main/imports.h
index d96d666e15f..4ff5941487f 100644
--- a/src/mesa/main/imports.h
+++ b/src/mesa/main/imports.h
@@ -42,6 +42,7 @@
 #include "compiler.h"
 #include "glheader.h"
 #include "errors.h"
+#include "util/bitscan.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -324,22 +325,6 @@ extern void
 _mesa_exec_free( void *addr );
 
 
-#ifndef FFS_DEFINED
-#define FFS_DEFINED 1
-#ifdef HAVE___BUILTIN_FFS
-#define ffs __builtin_ffs
-#else
-extern int ffs(int i);
-#endif
-
-#ifdef HAVE___BUILTIN_FFSLL
-#define ffsll __builtin_ffsll
-#else
-extern int ffsll(long long int i);
-#endif
-#endif /* FFS_DEFINED */
-
-
 #ifdef HAVE___BUILTIN_POPCOUNT
 #define _mesa_bitcount(i) __builtin_popcount(i)
 #else