--- deliantra/server/include/util.h	2009/10/15 21:09:32	1.91
+++ deliantra/server/include/util.h	2010/04/22 13:01:58	1.100
@@ -1,7 +1,7 @@
 /*
  * This file is part of Deliantra, the Roguelike Realtime MMORPG.
  * 
- * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
+ * Copyright (©) 2005,2006,2007,2008,2009,2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
  * 
  * Deliantra is free software: you can redistribute it and/or modify it under
  * the terms of the Affero GNU General Public License as published by the
@@ -23,32 +23,12 @@
 #ifndef UTIL_H__
 #define UTIL_H__
 
+#include <compiler.h>
+
 #define DEBUG_POISON 0x00 // poison memory before freeing it if != 0
 #define DEBUG_SALLOC  0   // add a debug wrapper around all sallocs
 #define PREFER_MALLOC 0   // use malloc and not the slice allocator
 
-#if __GNUC__ >= 3
-# define is_constant(c)             __builtin_constant_p (c)
-# define expect(expr,value)         __builtin_expect ((expr),(value))
-# define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
-# define noinline                   __attribute__((__noinline__))
-#else
-# define is_constant(c)             0
-# define expect(expr,value)         (expr)
-# define prefetch(addr,rw,locality)
-# define noinline
-#endif
-
-#if __GNUC__ < 4 || (__GNUC__ == 4 || __GNUC_MINOR__ < 4)
-# define decltype(x) typeof(x)
-#endif
-
-// put into ifs if you are very sure that the expression
-// is mostly true or mosty false. note that these return
-// booleans, not the expression.
-#define expect_false(expr) expect ((expr) ? 1 : 0, 0)
-#define expect_true(expr)  expect ((expr) ? 1 : 0, 1)
-
 #include <pthread.h>
 
 #include <cstddef>
@@ -121,6 +101,9 @@
 template<typename T>
 static inline T sign0 (T v) { return v ? sign (v) : 0; }
 
+template<typename T, typename U>
+static inline T copysign (T a, U b) { return a > 0 ? b : -b; }
+
 // div* only work correctly for div > 0
 // div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
 template<typename T> static inline T div    (T val, T div)
@@ -208,7 +191,7 @@
   return b - d;
 }
 
-// this is much faster than crossfires original algorithm
+// this is much faster than crossfire's original algorithm
 // on modern cpus
 inline int
 isqrt (int n)
@@ -216,6 +199,20 @@
   return (int)sqrtf ((float)n);
 }
 
+// this is kind of like the ^^ operator, if it would exist, without sequence point.
+// more handy than it looks like, due to the implicit !! done on its arguments
+inline bool
+logical_xor (bool a, bool b)
+{
+  return a != b;
+}
+
+inline bool
+logical_implies (bool a, bool b)
+{
+  return a <= b;
+}
+
 // this is only twice as fast as naive sqrtf (dx*dy+dy*dy)
 #if 0
 // and has a max. error of 6 in the range -100..+100.
@@ -248,6 +245,20 @@
   return ((d - 1) & 7) + 1;
 }
 
+// avoid ctz name because netbsd or freebsd spams it's namespace with it
+#if GCC_VERSION(3,4)
+static inline int least_significant_bit (uint32_t x)
+{
+  return __builtin_ctz (x);
+}
+#else
+int least_significant_bit (uint32_t x);
+#endif
+
+#define for_all_bits_sparse_32(mask, idxvar)      \
+  for (uint32_t idxvar, mask_ = mask;   \
+       mask_ && ((idxvar = least_significant_bit (mask_)), mask_ &= ~(1 << idxvar), 1);)
+
 extern ssize_t slice_alloc; // statistics
 
 void *salloc_ (int n)            throw (std::bad_alloc);
@@ -461,7 +472,7 @@
          :                      this->next () & (num - 1);             // constant, power-of-two
   }
 
-  // return a number within (min .. max)
+  // return a number within the closed interval [min .. max]
   int operator () (int r_min, int r_max)
   {
     return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
@@ -469,6 +480,7 @@
               : get_range (r_min, r_max);
   }
 
+  // return a number within the closed interval [0..1]
   double operator ()()
   {
     return this->next () / (double)0xFFFFFFFFU;
@@ -554,41 +566,45 @@
 typedef refptr<client>    client_ptr;
 typedef refptr<player>    player_ptr;
 
+#define STRHSH_NULL 2166136261
+
+static inline uint32_t
+strhsh (const char *s)
+{
+  // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
+  // it is about twice as fast as the one-at-a-time one,
+  // with good distribution.
+  // FNV-1a is faster on many cpus because the multiplication
+  // runs concurrently with the looping logic.
+  uint32_t hash = STRHSH_NULL;
+  
+  while (*s)
+    hash = (hash ^ *s++) * 16777619U;
+
+  return hash;
+}
+
+static inline uint32_t
+memhsh (const char *s, size_t len)
+{
+  uint32_t hash = STRHSH_NULL;
+  
+  while (len--)
+    hash = (hash ^ *s++) * 16777619U;
+
+  return hash;
+}
+
 struct str_hash
 {
   std::size_t operator ()(const char *s) const
   {
-#if 0
-    uint32_t hash = 0;
-
-    /* use the one-at-a-time hash function, which supposedly is
-     * better than the djb2-like one used by perl5.005, but
-     * certainly is better then the bug used here before.
-     * see http://burtleburtle.net/bob/hash/doobs.html
-     */
-    while (*s)
-      {
-        hash += *s++;
-        hash += hash << 10;
-        hash ^= hash >>  6;
-      }
-
-    hash += hash <<  3;
-    hash ^= hash >> 11;
-    hash += hash << 15;
-#else
-    // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
-    // it is about twice as fast as the one-at-a-time one,
-    // with good distribution.
-    // FNV-1a is faster on many cpus because the multiplication
-    // runs concurrent with the looping logic.
-    uint32_t hash = 2166136261;
-    
-    while (*s)
-      hash = (hash ^ *s++) * 16777619;
-#endif
+    return strhsh (s);
+  }
 
-    return hash;
+  std::size_t operator ()(const shstr &s) const
+  {
+    return strhsh (s);
   }
 };
 
@@ -710,7 +726,7 @@
 
 // like v?sprintf, but returns a "static" buffer
 char *vformat (const char *format, va_list ap);
-char *format (const char *format, ...);
+char *format (const char *format, ...) attribute ((format (printf, 1, 2)));
 
 // safety-check player input which will become object->msg
 bool msg_is_safe (const char *msg);