boringssl/crypto/bn/asm/x86/sub.pl
Adam Langley 95c29f3cd1 Inital import.
Initial fork from f2d678e6e89b6508147086610e985d4e8416e867 (1.0.2 beta).

(This change contains substantial changes from the original and
effectively starts a new history.)
2014-06-20 13:17:32 -07:00

77 lines
1.3 KiB
Raku

#!/usr/local/bin/perl
# x86 assember
sub bn_sub_words
{
local($name)=@_;
&function_begin($name,"");
&comment("");
$a="esi";
$b="edi";
$c="eax";
$r="ebx";
$tmp1="ecx";
$tmp2="edx";
$num="ebp";
&mov($r,&wparam(0)); # get r
&mov($a,&wparam(1)); # get a
&mov($b,&wparam(2)); # get b
&mov($num,&wparam(3)); # get num
&xor($c,$c); # clear carry
&and($num,0xfffffff8); # num / 8
&jz(&label("aw_finish"));
&set_label("aw_loop",0);
for ($i=0; $i<8; $i++)
{
&comment("Round $i");
&mov($tmp1,&DWP($i*4,$a,"",0)); # *a
&mov($tmp2,&DWP($i*4,$b,"",0)); # *b
&sub($tmp1,$c);
&mov($c,0);
&adc($c,$c);
&sub($tmp1,$tmp2);
&adc($c,0);
&mov(&DWP($i*4,$r,"",0),$tmp1); # *r
}
&comment("");
&add($a,32);
&add($b,32);
&add($r,32);
&sub($num,8);
&jnz(&label("aw_loop"));
&set_label("aw_finish",0);
&mov($num,&wparam(3)); # get num
&and($num,7);
&jz(&label("aw_end"));
for ($i=0; $i<7; $i++)
{
&comment("Tail Round $i");
&mov($tmp1,&DWP($i*4,$a,"",0)); # *a
&mov($tmp2,&DWP($i*4,$b,"",0));# *b
&sub($tmp1,$c);
&mov($c,0);
&adc($c,$c);
&sub($tmp1,$tmp2);
&adc($c,0);
&dec($num) if ($i != 6);
&mov(&DWP($i*4,$r,"",0),$tmp1); # *a
&jz(&label("aw_end")) if ($i != 6);
}
&set_label("aw_end",0);
# &mov("eax",$c); # $c is "eax"
&function_end($name);
}
1;