crypto/openssl-0.9.7d/crypto/bn/asm/x86/sub.pl

   1 #!/usr/local/bin/perl
   2 # x86 assember
   3
   4 sub bn_sub_words
   5         {
   6         local($name)=@_;
   7
   8         &function_begin($name,"");
   9
  10         &comment("");
  11         $a="esi";
  12         $b="edi";
  13         $c="eax";
  14         $r="ebx";
  15         $tmp1="ecx";
  16         $tmp2="edx";
  17         $num="ebp";
  18
  19         &mov($r,&wparam(0));    # get r
  20          &mov($a,&wparam(1));   # get a
  21         &mov($b,&wparam(2));    # get b
  22          &mov($num,&wparam(3)); # get num
  23         &xor($c,$c);            # clear carry
  24          &and($num,0xfffffff8); # num / 8
  25
  26         &jz(&label("aw_finish"));
  27
  28         &set_label("aw_loop",0);
  29         for ($i=0; $i<8; $i++)
  30                 {
  31                 &comment("Round $i");
  32
  33                 &mov($tmp1,&DWP($i*4,$a,"",0));         # *a
  34                  &mov($tmp2,&DWP($i*4,$b,"",0));        # *b
  35                 &sub($tmp1,$c);
  36                  &mov($c,0);
  37                 &adc($c,$c);
  38                  &sub($tmp1,$tmp2);
  39                 &adc($c,0);
  40                  &mov(&DWP($i*4,$r,"",0),$tmp1);        # *r
  41                 }
  42
  43         &comment("");
  44         &add($a,32);
  45          &add($b,32);
  46         &add($r,32);
  47          &sub($num,8);
  48         &jnz(&label("aw_loop"));
  49
  50         &set_label("aw_finish",0);
  51         &mov($num,&wparam(3));  # get num
  52         &and($num,7);
  53          &jz(&label("aw_end"));
  54
  55         for ($i=0; $i<7; $i++)
  56                 {
  57                 &comment("Tail Round $i");
  58                 &mov($tmp1,&DWP($i*4,$a,"",0)); # *a
  59                  &mov($tmp2,&DWP($i*4,$b,"",0));# *b
  60                 &sub($tmp1,$c);
  61                  &mov($c,0);
  62                 &adc($c,$c);
  63                  &sub($tmp1,$tmp2);
  64                 &adc($c,0);
  65                  &dec($num) if ($i != 6);
  66                 &mov(&DWP($i*4,$r,"",0),$tmp1); # *a
  67                  &jz(&label("aw_end")) if ($i != 6);
  68                 }
  69         &set_label("aw_end",0);
  70
  71 #       &mov("eax",$c);         # $c is "eax"
  72
  73         &function_end($name);
  74         }
  75
  76 1;