1#!/usr/local/bin/perl 2# alpha assember 3 4sub bn_sub_words 5 { 6 local($name)=@_; 7 local($cc,$a,$b,$r); 8 9 &init_pool(4); 10 ($cc)=GR("r0"); 11 12 $rp=&wparam(0); 13 $ap=&wparam(1); 14 $bp=&wparam(2); 15 $count=&wparam(3); 16 17 &function_begin($name,""); 18 19 &comment(""); 20 &sub($count,4,$count); 21 &mov("zero",$cc); 22 &blt($count,&label("finish")); 23 24 ($a0,$b0)=&NR(2); 25 &ld($a0,&QWPw(0,$ap)); 26 &ld($b0,&QWPw(0,$bp)); 27 28########################################################## 29 &set_label("loop"); 30 31 ($a1,$tmp,$b1,$a2,$b2,$a3,$b3,$o0)=&NR(8); 32 &ld($a1,&QWPw(1,$ap)); 33 &cmpult($a0,$b0,$tmp); # will we borrow? 34 &ld($b1,&QWPw(1,$bp)); 35 &sub($a0,$b0,$a0); # do the subtract 36 &ld($a2,&QWPw(2,$ap)); 37 &cmpult($a0,$cc,$b0); # will we borrow? 38 &ld($b2,&QWPw(2,$bp)); 39 &sub($a0,$cc,$o0); # will we borrow? 40 &ld($a3,&QWPw(3,$ap)); 41 &add($b0,$tmp,$cc); ($t1,$o1)=&NR(2); &FR($tmp); 42 43 &cmpult($a1,$b1,$t1); # will we borrow? 44 &sub($a1,$b1,$a1); # do the subtract 45 &ld($b3,&QWPw(3,$bp)); 46 &cmpult($a1,$cc,$b1); # will we borrow? 47 &sub($a1,$cc,$o1); # will we borrow? 48 &add($b1,$t1,$cc); ($tmp,$o2)=&NR(2); &FR($t1,$a1,$b1); 49 50 &cmpult($a2,$b2,$tmp); # will we borrow? 51 &sub($a2,$b2,$a2); # do the subtract 52 &st($o0,&QWPw(0,$rp)); &FR($o0); # save 53 &cmpult($a2,$cc,$b2); # will we borrow? 54 &sub($a2,$cc,$o2); # will we borrow? 55 &add($b2,$tmp,$cc); ($t3,$o3)=&NR(2); &FR($tmp,$a2,$b2); 56 57 &cmpult($a3,$b3,$t3); # will we borrow? 58 &sub($a3,$b3,$a3); # do the subtract 59 &st($o1,&QWPw(1,$rp)); &FR($o1); 60 &cmpult($a3,$cc,$b3); # will we borrow? 61 &sub($a3,$cc,$o3); # will we borrow? 62 &add($b3,$t3,$cc); &FR($t3,$a3,$b3); 63 64 &st($o2,&QWPw(2,$rp)); &FR($o2); 65 &sub($count,4,$count); # count-=4 66 &st($o3,&QWPw(3,$rp)); &FR($o3); 67 &add($ap,4*$QWS,$ap); # count+=4 68 &add($bp,4*$QWS,$bp); # count+=4 69 &add($rp,4*$QWS,$rp); # count+=4 70 71 &blt($count,&label("finish")); 72 &ld($a0,&QWPw(0,$ap)); 73 &ld($b0,&QWPw(0,$bp)); 74 &br(&label("loop")); 75################################################## 76 # Do the last 0..3 words 77 78 &set_label("last_loop"); 79 80 &ld($a0,&QWPw(0,$ap)); # get a 81 &ld($b0,&QWPw(0,$bp)); # get b 82 &cmpult($a0,$b0,$tmp); # will we borrow? 83 &sub($a0,$b0,$a0); # do the subtract 84 &cmpult($a0,$cc,$b0); # will we borrow? 85 &sub($a0,$cc,$a0); # will we borrow? 86 &st($a0,&QWPw(0,$rp)); # save 87 &add($b0,$tmp,$cc); # add the borrows 88 89 &add($ap,$QWS,$ap); 90 &add($bp,$QWS,$bp); 91 &add($rp,$QWS,$rp); 92 &sub($count,1,$count); 93 &bgt($count,&label("last_loop")); 94 &function_end_A($name); 95 96###################################################### 97 &set_label("finish"); 98 &add($count,4,$count); 99 &bgt($count,&label("last_loop")); 100 101 &FR($a0,$b0); 102 &set_label("end"); 103 &function_end($name); 104 105 &fin_pool; 106 } 107 1081; 109