From e608273a8094a95a5703c26a428a007497e74392 Mon Sep 17 00:00:00 2001 From: Andy Polyakov Date: Thu, 21 Aug 2014 00:13:55 +0200 Subject: [PATCH] sha1-mb-x86_64.pl: add commentary. Reviewed-by: Emilia Kasper --- crypto/sha/asm/sha1-mb-x86_64.pl | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/crypto/sha/asm/sha1-mb-x86_64.pl b/crypto/sha/asm/sha1-mb-x86_64.pl index e9bc8e5c47..a8ee075eaa 100644 --- a/crypto/sha/asm/sha1-mb-x86_64.pl +++ b/crypto/sha/asm/sha1-mb-x86_64.pl @@ -107,6 +107,19 @@ my ($i,$a,$b,$c,$d,$e)=@_; my $j=$i+1; my $k=$i+2; +# Loads are performed 2+3/4 iterations in advance. 3/4 means that out +# of 4 words you would expect to be loaded per given iteration one is +# spilled to next iteration. In other words indices in four input +# streams are distributed as following: +# +# $i==0: 0,0,0,0,1,1,1,1,2,2,2, +# $i==1: 2,3,3,3, +# $i==2: 3,4,4,4, +# ... +# $i==13: 14,15,15,15, +# $i==14: 15 +# +# Then at $i==15 Xupdate is applied one iteration in advance... $code.=<<___ if ($i==0); movd (@ptr[0]),@Xi[0] lea `16*4`(@ptr[0]),@ptr[0] -- 2.25.1