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-rw-r--r--libguile/integers.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/libguile/integers.c b/libguile/integers.c
index ff5499af9..fc71c7acc 100644
--- a/libguile/integers.c
+++ b/libguile/integers.c
@@ -2008,3 +2008,23 @@ scm_integer_logtest_zz (SCM x, SCM y)
{
return scm_is_eq (scm_integer_logand_zz (x, y), SCM_INUM0);
}
+
+int
+scm_integer_logbit_ui (unsigned long index, scm_t_inum n)
+{
+ if (index < SCM_LONG_BIT)
+ /* Assume two's complement representation. */
+ return (n >> index) & 1;
+ else
+ return n < 0;
+}
+
+int
+scm_integer_logbit_uz (unsigned long index, SCM n)
+{
+ mpz_t zn;
+ alias_bignum_to_mpz (scm_bignum (n), zn);
+ int val = mpz_tstbit (zn, index);
+ scm_remember_upto_here_1 (n);
+ return val;
+}