--- rand48.h.orig 2003-05-20 15:21:02.000000000 -0700
+++ rand48.h 2005-11-03 14:06:17.000000000 -0800
@@ -19,8 +19,6 @@
#include <math.h>
#include <stdlib.h>
-void _dorand48(unsigned short[3]);
-
#define RAND48_SEED_0 (0x330e)
#define RAND48_SEED_1 (0xabcd)
#define RAND48_SEED_2 (0x1234)
@@ -29,4 +27,55 @@
#define RAND48_MULT_2 (0x0005)
#define RAND48_ADD (0x000b)
+typedef unsigned long long uint48;
+
+extern uint48 _rand48_seed;
+extern uint48 _rand48_mult;
+extern uint48 _rand48_add;
+
+#define TOUINT48(x,y,z) \
+ ((uint48)(x) + (((uint48)(y)) << 16) + (((uint48)(z)) << 32))
+
+#define RAND48_SEED TOUINT48(RAND48_SEED_0, RAND48_SEED_1, RAND48_SEED_2)
+#define RAND48_MULT TOUINT48(RAND48_MULT_0, RAND48_MULT_1, RAND48_MULT_2)
+
+#define LOADRAND48(l,x) \
+ (l) = TOUINT48((x)[0], (x)[1], (x)[2])
+
+#define STORERAND48(l,x) \
+ (x)[0] = (unsigned short)(l); \
+ (x)[1] = (unsigned short)((l) >> 16); \
+ (x)[2] = (unsigned short)((l) >> 32)
+
+#define _DORAND48(l) \
+ (l) = (l) * _rand48_mult + _rand48_add
+
+#define DORAND48(l,x) \
+ LOADRAND48(l, x); \
+ _DORAND48(l); \
+ STORERAND48(l, x)
+
+#include "fpmath.h"
+
+/*
+ * Optimization for speed: avoid int-to-double conversion. Assume doubles
+ * are IEEE-754 and insert the bits directly. To normalize, the (1 << 52)
+ * is the hidden bit, which the first set bit is shifted to.
+ */
+#define ERAND48_BEGIN \
+ union { \
+ union IEEEd2bits ieee; \
+ unsigned long long l; \
+ } u; \
+ int s
+
+#define ERAND48_END(x) \
+ u.l = ((x) & 0xffffffffffffULL); \
+ if (u.l == 0) \
+ return 0.0; \
+ u.l <<= 5; \
+ for(s = 0; !(u.l & (1LL << 52)); s++, u.l <<= 1) {} \
+ u.ieee.bits.exp = 1022 - s; \
+ return u.ieee.d
+
#endif /* _RAND48_H_ */