X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Futil%2Fbitscan.h;h=611e812059696c10c2d82bb171c57343cff1dd71;hb=1966d9ff412359c4189601231ca9182071bef285;hp=4999b744d1d24141ad8e552340bef4c827f882fe;hpb=c3b66566760dd44eaeed9e4df13687dc3ee69bd9;p=mesa.git

diff --git a/src/util/bitscan.h b/src/util/bitscan.h
index 4999b744d1d..611e8120596 100644
--- a/src/util/bitscan.h
+++ b/src/util/bitscan.h
@@ -29,7 +29,9 @@
 #ifndef BITSCAN_H
 #define BITSCAN_H
 
+#include <assert.h>
 #include <stdint.h>
+#include <string.h>
 
 #if defined(_MSC_VER)
 #include <intrin.h>
@@ -50,7 +52,7 @@ extern "C" {
 #define ffs __builtin_ffs
 #elif defined(_MSC_VER) && (_M_IX86 || _M_ARM || _M_AMD64 || _M_IA64)
 static inline
-int ffs(unsigned i)
+int ffs(int i)
 {
    unsigned long index;
    if (_BitScanForward(&index, i))
@@ -60,14 +62,14 @@ int ffs(unsigned i)
 }
 #else
 extern
-int ffs(unsigned i);
+int ffs(int i);
 #endif
 
 #ifdef HAVE___BUILTIN_FFSLL
 #define ffsll __builtin_ffsll
 #elif defined(_MSC_VER) && (_M_AMD64 || _M_ARM || _M_IA64)
 static inline int
-ffsll(uint64_t i)
+ffsll(long long int i)
 {
    unsigned long index;
    if (_BitScanForward64(&index, i))
@@ -77,7 +79,7 @@ ffsll(uint64_t i)
 }
 #else
 extern int
-ffsll(uint64_t val);
+ffsll(long long int val);
 #endif
 
 
@@ -134,7 +136,7 @@ u_bit_scan_consecutive_range(unsigned *mask, int *start, int *count)
 static inline void
 u_bit_scan_consecutive_range64(uint64_t *mask, int *start, int *count)
 {
-   if (*mask == ~0llu) {
+   if (*mask == ~0ull) {
       *start = 0;
       *count = 64;
       *mask = 0;
@@ -146,6 +148,94 @@ u_bit_scan_consecutive_range64(uint64_t *mask, int *start, int *count)
 }
 
 
+/**
+ * Find last bit set in a word.  The least significant bit is 1.
+ * Return 0 if no bits are set.
+ * Essentially ffs() in the reverse direction.
+ */
+static inline unsigned
+util_last_bit(unsigned u)
+{
+#if defined(HAVE___BUILTIN_CLZ)
+   return u == 0 ? 0 : 32 - __builtin_clz(u);
+#elif defined(_MSC_VER) && (_M_IX86 || _M_ARM || _M_AMD64 || _M_IA64)
+   unsigned long index;
+   if (_BitScanReverse(&index, u))
+      return index + 1;
+   else
+      return 0;
+#else
+   unsigned r = 0;
+   while (u) {
+      r++;
+      u >>= 1;
+   }
+   return r;
+#endif
+}
+
+/**
+ * Find last bit set in a word.  The least significant bit is 1.
+ * Return 0 if no bits are set.
+ * Essentially ffsll() in the reverse direction.
+ */
+static inline unsigned
+util_last_bit64(uint64_t u)
+{
+#if defined(HAVE___BUILTIN_CLZLL)
+   return u == 0 ? 0 : 64 - __builtin_clzll(u);
+#elif defined(_MSC_VER) && (_M_AMD64 || _M_ARM || _M_IA64)
+   unsigned long index;
+   if (_BitScanReverse64(&index, u))
+      return index + 1;
+   else
+      return 0;
+#else
+   unsigned r = 0;
+   while (u) {
+      r++;
+      u >>= 1;
+   }
+   return r;
+#endif
+}
+
+/**
+ * Find last bit in a word that does not match the sign bit. The least
+ * significant bit is 1.
+ * Return 0 if no bits are set.
+ */
+static inline unsigned
+util_last_bit_signed(int i)
+{
+   if (i >= 0)
+      return util_last_bit(i);
+   else
+      return util_last_bit(~(unsigned)i);
+}
+
+/* Returns a bitfield in which the first count bits starting at start are
+ * set.
+ */
+static inline unsigned
+u_bit_consecutive(unsigned start, unsigned count)
+{
+   assert(start + count <= 32);
+   if (count == 32)
+      return ~0;
+   return ((1u << count) - 1) << start;
+}
+
+static inline uint64_t
+u_bit_consecutive64(unsigned start, unsigned count)
+{
+   assert(start + count <= 64);
+   if (count == 64)
+      return ~(uint64_t)0;
+   return (((uint64_t)1 << count) - 1) << start;
+}
+
+
 #ifdef __cplusplus
 }
 #endif