[Gmp-commit] /var/hg/gmp: mpn/generic/sec_powm.c (sec_binvert_limb): Simpler ...

[mercurial at gmplib.org]

details:   /var/hg/gmp/rev/1d1aff591461
changeset: 18548:1d1aff591461
user:      Marco Bodrato <bodrato at mail.dm.unipi.it>
date:      Thu Jul 02 07:58:25 2026 +0200
description:
mpn/generic/sec_powm.c (sec_binvert_limb): Simpler 5-bits inverse,
					suggested by David Sparks

diffstat:

 mpn/generic/sec_powm.c |  2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diffs (12 lines):

diff -r b5f6b754d5bc -r 1d1aff591461 mpn/generic/sec_powm.c
--- a/mpn/generic/sec_powm.c	Mon Jun 29 15:21:15 2026 +0200
+++ b/mpn/generic/sec_powm.c	Thu Jul 02 07:58:25 2026 +0200
@@ -211,7 +211,7 @@
   mp_limb_t inv, t;
   ASSERT ((n & 1) == 1);
   /* 3 + 2 -> 5 */
-  inv = n + (((n + 1) << 1) & 0x18);
+  inv = 3 * n ^ 2;
 
   t = n * inv;
 #if GMP_NUMB_BITS <= 10