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| author | Andy Wingo <wingo@pobox.com> | 2022-01-10 11:56:13 +0100 |
|---|---|---|
| committer | Andy Wingo <wingo@pobox.com> | 2022-01-13 09:37:17 +0100 |
| commit | 9e5aa173c79b2f14c8a1ffe758a91a63f52cc3b7 (patch) | |
| tree | bb582432b28e5545074d757f5ec095cff56fa916 /libguile/integers.c | |
| parent | 6fe43301aa66f898f3b27d604c45c93da5286e12 (diff) | |
| download | guile-9e5aa173c79b2f14c8a1ffe758a91a63f52cc3b7.tar.gz | |
Optimize logand against a positive inum
* libguile/integers.c (scm_integer_logand_zi): Optimize.
Diffstat (limited to 'libguile/integers.c')
| -rw-r--r-- | libguile/integers.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/libguile/integers.c b/libguile/integers.c index a173d01f2..a1231a10d 100644 --- a/libguile/integers.c +++ b/libguile/integers.c @@ -2119,6 +2119,18 @@ scm_integer_logand_zi (struct scm_bignum *x, scm_t_inum y) if (y == 0) return SCM_INUM0; + if (y > 0) + { + mp_limb_t rd = bignum_limbs (x)[0]; + mp_limb_t yd = y; + if (bignum_is_negative (x)) + rd = ~rd + 1; + scm_remember_upto_here_1 (x); + rd &= yd; + // Result must be a positive inum. + return SCM_I_MAKINUM (rd); + } + mpz_t result, zx, zy; mpz_init (result); alias_bignum_to_mpz (x, zx); |