From c4b1cd5cc5d321d7c918ae42de085081984ef088 Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Mon, 7 Mar 2022 22:11:09 +0000 Subject: [PATCH] code-comments --- openpower/sv/gf2.py | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/openpower/sv/gf2.py b/openpower/sv/gf2.py index a07ebf6e1..6798cd1f6 100644 --- a/openpower/sv/gf2.py +++ b/openpower/sv/gf2.py @@ -83,21 +83,22 @@ def gf_invert(a) : j = 0 for i in range(1, 2*degree+1): - if r & mask1: - if s & mask1: + # could use count-trailing-1s here to skip ahead + if r & mask1: # test MSB of r + if s & mask1: # test MSB of s s ^= r v ^= u - s <<= 1 # shift left 1 + s <<= 1 # shift left 1 if j == 0: - r, s = s, r # swap r,s + r, s = s, r # swap r,s u, v = v<<1, u # shift v and swap j = 1 else: - u >>= 1 # right shift left + u >>= 1 # right shift left j -= 1 else: - r <<= 1 # shift left 1 - u <<= 1 # shift left 1 + r <<= 1 # shift left 1 + u <<= 1 # shift left 1 j += 1 return u -- 2.30.2