[Guile-commits] 04/69: Implement abs with new integer lib

[Andy Wingo]

wingo pushed a commit to branch wip-inline-digits
in repository guile.

commit 452052f3be3c6c71d5ca879ce80f0ab36e507c53
Author: Andy Wingo <wingo@pobox.com>
AuthorDate: Fri Dec 3 14:23:51 2021 +0100

    Implement abs with new integer lib
    
    * libguile/integers.c (scm_integer_abs_i, scm_integer_abs_z): New
    internal functions.
    * libguile/integers.h: Declare internal functions.
    * libguile/numbers.c (scm_abs): Use the new functions.
---
 libguile/integers.c | 22 ++++++++++++++++++++++
 libguile/integers.h |  3 +++
 libguile/numbers.c  | 18 ++----------------
 3 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/libguile/integers.c b/libguile/integers.c
index e449ff635..34a1d4af8 100644
--- a/libguile/integers.c
+++ b/libguile/integers.c
@@ -244,3 +244,25 @@ scm_is_integer_odd_z (SCM z)
 {
   return bignum_limbs (scm_bignum (z))[0] & 1;
 }
+
+SCM
+scm_integer_abs_i (scm_t_inum i)
+{
+  if (i >= 0)
+    return SCM_I_MAKINUM (i);
+
+  unsigned long abs = long_magnitude (i);
+  if (SCM_LIKELY (SCM_POSFIXABLE (abs)))
+    return SCM_I_MAKINUM (abs);
+
+  return ulong_to_bignum (abs);
+}
+
+SCM
+scm_integer_abs_z (SCM z)
+{
+  if (!bignum_is_negative (scm_bignum (z)))
+    return z;
+
+  return SCM_PACK (negate_bignum (clone_bignum (scm_bignum (z))));
+}
diff --git a/libguile/integers.h b/libguile/integers.h
index 2bd937669..753ff1f74 100644
--- a/libguile/integers.h
+++ b/libguile/integers.h
@@ -26,6 +26,9 @@
 SCM_INTERNAL int scm_is_integer_odd_i (scm_t_inum i);
 SCM_INTERNAL int scm_is_integer_odd_z (SCM z);
 
+SCM_INTERNAL SCM scm_integer_abs_i (scm_t_inum i);
+SCM_INTERNAL SCM scm_integer_abs_z (SCM z);
+
 
 
 #endif  /* SCM_INTEGERS_H */
diff --git a/libguile/numbers.c b/libguile/numbers.c
index a91d5963d..ea0cf67bb 100644
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -919,15 +919,7 @@ SCM_PRIMITIVE_GENERIC (scm_abs, "abs", 1, 0, 0,
 #define FUNC_NAME s_scm_abs
 {
   if (SCM_I_INUMP (x))
-    {
-      scm_t_inum xx = SCM_I_INUM (x);
-      if (xx >= 0)
-       return x;
-      else if (SCM_POSFIXABLE (-xx))
-       return SCM_I_MAKINUM (-xx);
-      else
-       return scm_i_inum2big (-xx);
-    }
+    return scm_integer_abs_i (SCM_I_INUM (x));
   else if (SCM_LIKELY (SCM_REALP (x)))
     {
       double xx = SCM_REAL_VALUE (x);
@@ -941,13 +933,7 @@ SCM_PRIMITIVE_GENERIC (scm_abs, "abs", 1, 0, 0,
         return x;
     }
   else if (SCM_BIGP (x))
-    {
-      const int sgn = mpz_sgn (SCM_I_BIG_MPZ (x));
-      if (sgn < 0)
-       return scm_i_clonebig (x, 0);
-      else
-       return x;
-    }
+    return scm_integer_abs_z (x);
   else if (SCM_FRACTIONP (x))
     {
       if (scm_is_false (scm_negative_p (SCM_FRACTION_NUMERATOR (x))))