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| author | Mikael Djurfeldt <djurfeldt@nada.kth.se> | 1999-01-21 02:13:23 +0000 |
|---|---|---|
| committer | Mikael Djurfeldt <djurfeldt@nada.kth.se> | 1999-01-21 02:13:23 +0000 |
| commit | 2a0279c9b89251c4bd13b7da45a7bdde46d99b03 (patch) | |
| tree | ad0b114fc2f08e23c059af9dbfca40b5eddd0211 | |
| parent | 6bcb5a82c3953484e365168378e8f1285697fcd7 (diff) | |
| download | guile-2a0279c9b89251c4bd13b7da45a7bdde46d99b03.tar.gz | |
* random.c: Bugfix: Retrieve and store most significant 32 bits in
different order if the machine is bigendian.
(scm_init_random): Added safety check for bignum digit size.
| -rw-r--r-- | libguile/random.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/libguile/random.c b/libguile/random.c index c9665d6bc..d65def935 100644 --- a/libguile/random.c +++ b/libguile/random.c @@ -247,7 +247,11 @@ scm_i_random_bignum (SCM m, scm_rstate *state) #endif { /* fix most significant 32 bits */ +#if SIZEOF_INT == 4 && defined (WORDS_BIGENDIAN) + w = SCM_BDIGITS (m)[nd - 1] << 16 | SCM_BDIGITS (m)[nd - 2]; +#else w = ((LONG32 *) SCM_BDIGITS (m))[nd / 2 - 1]; +#endif mask = (w < 0x10000 ? (w < 0x100 ? scm_masktab[w] @@ -274,7 +278,12 @@ scm_i_random_bignum (SCM m, scm_rstate *state) { /* fix most significant 32 bits */ i /= 2; +#if SIZEOF_INT == 4 && defined (WORDS_BIGENDIAN) + w = scm_the_rng.random_bits (state) & mask; + bits[--i] = (w & 0xffff) << 16 | w >> 16; +#else bits[--i] = scm_the_rng.random_bits (state) & mask; +#endif } /* now fill up the rest of the bignum */ while (i) @@ -553,5 +562,17 @@ scm_init_random () #include "random.x" + /* Check that the assumptions about bits per bignum digit are correct. */ +#if SIZEOF_INT == 4 + m = 16; +#else + m = 32; +#endif + if (m != SCM_BITSPERDIG) + { + fprintf (stderr, "Internal inconsistency: Confused about bignum digit size in random.c\n"); + exit (1); + } + scm_add_feature ("random"); } |