[Guile-commits] 26/85: Implement scm_lognot with new integer library

[Andy Wingo]

wingo pushed a commit to branch main
in repository guile.

commit b41714d277b8d6629e358344b81d55b7ca4ef377
Author: Andy Wingo <wingo@pobox.com>
AuthorDate: Sun Dec 19 14:43:05 2021 +0100

    Implement scm_lognot with new integer library
    
    * libguile/integers.c (scm_integer_lognot_i, scm_integer_lognot_z):
    * libguile/integers.h: Declare the new internal functions.
    * libguile/numbers.c (scm_lognot): Use new internal functions.
---
 libguile/integers.c | 17 +++++++++++++++++
 libguile/integers.h |  3 +++
 libguile/numbers.c  | 20 +++++---------------
 3 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/libguile/integers.c b/libguile/integers.c
index fc71c7acc..2ae2c30d5 100644
--- a/libguile/integers.c
+++ b/libguile/integers.c
@@ -2028,3 +2028,20 @@ scm_integer_logbit_uz (unsigned long index, SCM n)
   scm_remember_upto_here_1 (n);
   return val;
 }
+
+SCM
+scm_integer_lognot_i (scm_t_inum n)
+{
+  return SCM_I_MAKINUM (~n);
+}
+
+SCM
+scm_integer_lognot_z (SCM n)
+{
+  mpz_t result, zn;
+  mpz_init (result);
+  alias_bignum_to_mpz (scm_bignum (n), zn);
+  mpz_com (result, zn);
+  scm_remember_upto_here_1 (n);
+  return take_mpz (result);
+}
diff --git a/libguile/integers.h b/libguile/integers.h
index feba5963f..105b86b63 100644
--- a/libguile/integers.h
+++ b/libguile/integers.h
@@ -151,6 +151,9 @@ SCM_INTERNAL int scm_integer_logtest_zz (SCM x, SCM y);
 SCM_INTERNAL int scm_integer_logbit_ui (unsigned long bit, scm_t_inum n);
 SCM_INTERNAL int scm_integer_logbit_uz (unsigned long bit, SCM n);
 
+SCM_INTERNAL SCM scm_integer_lognot_i (scm_t_inum n);
+SCM_INTERNAL SCM scm_integer_lognot_z (SCM n);
+
 
 
 #endif  /* SCM_INTEGERS_H */
diff --git a/libguile/numbers.c b/libguile/numbers.c
index 548618e74..3e8431757 100644
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -3177,22 +3177,12 @@ SCM_DEFINE (scm_lognot, "lognot", 1, 0, 0,
            "@end lisp")
 #define FUNC_NAME s_scm_lognot
 {
-  if (SCM_I_INUMP (n)) {
-    /* No overflow here, just need to toggle all the bits making up the inum.
-       Enhancement: No need to strip the tag and add it back, could just xor
-       a block of 1 bits, if that worked with the various debug versions of
-       the SCM typedef.  */
-    return SCM_I_MAKINUM (~ SCM_I_INUM (n));
-
-  } else if (SCM_BIGP (n)) {
-    SCM result = scm_i_mkbig ();
-    mpz_com (SCM_I_BIG_MPZ (result), SCM_I_BIG_MPZ (n));
-    scm_remember_upto_here_1 (n);
-    return result;
-
-  } else {
+  if (SCM_I_INUMP (n))
+    return scm_integer_lognot_i (SCM_I_INUM (n));
+  else if (SCM_BIGP (n))
+    return scm_integer_lognot_z (n);
+  else
     SCM_WRONG_TYPE_ARG (SCM_ARG1, n);
-  }
 }
 #undef FUNC_NAME