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-rw-r--r--stdlib/drand48-iter.c47
1 files changed, 13 insertions, 34 deletions
diff --git a/stdlib/drand48-iter.c b/stdlib/drand48-iter.c
index 707be8e566..3e8ea0e9c6 100644
--- a/stdlib/drand48-iter.c
+++ b/stdlib/drand48-iter.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+/* Copyright (C) 1995, 1996, 2001 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
@@ -20,6 +20,7 @@
#include <errno.h>
#include <stdlib.h>
#include <limits.h>
+#include <stdint.h>
#include <sys/types.h>
/* Global state for non-reentrant functions. */
@@ -31,50 +32,28 @@ __drand48_iterate (xsubi, buffer)
unsigned short int xsubi[3];
struct drand48_data *buffer;
{
- u_int64_t X, a, result;
+ uint64_t X;
+ uint64_t result;
/* Initialize buffer, if not yet done. */
- if (!buffer->init)
+ if (__builtin_expect (!buffer->__init, 0))
{
-#if (USHRT_MAX == 0xffffU)
- buffer->a[2] = 0x5;
- buffer->a[1] = 0xdeec;
- buffer->a[0] = 0xe66d;
-#else
- buffer->a[2] = 0x5deecUL;
- buffer->a[1] = 0xe66d0000UL;
- buffer->a[0] = 0;
-#endif
- buffer->c = 0xb;
- buffer->init = 1;
+ buffer->__a = 0x5deece66dull;
+ buffer->__c = 0xb;
+ buffer->__init = 1;
}
/* Do the real work. We choose a data type which contains at least
48 bits. Because we compute the modulus it does not care how
many bits really are computed. */
- if (sizeof (unsigned short int) == 2)
- {
- X = (u_int64_t)xsubi[2] << 32 | (u_int64_t)xsubi[1] << 16 | xsubi[0];
- a = ((u_int64_t)buffer->a[2] << 32 | (u_int64_t)buffer->a[1] << 16
- | buffer->a[0]);
-
- result = X * a + buffer->c;
-
- xsubi[0] = result & 0xffff;
- xsubi[1] = (result >> 16) & 0xffff;
- xsubi[2] = (result >> 32) & 0xffff;
- }
- else
- {
- X = (u_int64_t)xsubi[2] << 16 | xsubi[1] >> 16;
- a = (u_int64_t)buffer->a[2] << 16 | buffer->a[1] >> 16;
+ X = (uint64_t) xsubi[2] << 32 | (uint32_t) xsubi[1] << 16 | xsubi[0];
- result = X * a + buffer->c;
+ result = X * buffer->__a + buffer->__c;
- xsubi[0] = result >> 16 & 0xffffffffl;
- xsubi[1] = result << 16 & 0xffff0000l;
- }
+ xsubi[0] = result & 0xffff;
+ xsubi[1] = (result >> 16) & 0xffff;
+ xsubi[2] = (result >> 32) & 0xffff;
return 0;
}