--- /dev/null
+#!/usr/bin/env perl
+
+# ====================================================================
+# Written by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL
+# project. The module is, however, dual licensed under OpenSSL and
+# CRYPTOGAMS licenses depending on where you obtain it. For further
+# details see http://www.openssl.org/~appro/cryptogams/.
+# ====================================================================
+
+# October 2005
+#
+# This is a "teaser" code, as it can be improved in several ways...
+# First of all non-SSE2 path should be implemented (yes, for now it
+# performs Montgomery multiplication/convolution only on SSE2-capable
+# CPUs such as P4, others fall down to original code). Then inner loop
+# can be unrolled and modulo-scheduled to improve ILP and possibly
+# moved to 128-bit XMM register bank (though it would require input
+# rearrangement and/or increase bus bandwidth utilization). Dedicated
+# squaring procedure should give further performance improvement...
+# Yet, for being draft, the code improves rsa512 *sign* benchmark by
+# 110%(!), rsa1024 one - by 70% and rsa4096 - by 20%:-)
+
+# December 2006
+#
+# Modulo-scheduling SSE2 loops results in further 15-20% improvement.
+# Integer-only code [being equipped with dedicated squaring procedure]
+# gives ~40% on rsa512 sign benchmark...
+
+$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
+push(@INC,"${dir}","${dir}../../perlasm");
+require "x86asm.pl";
+
+&asm_init($ARGV[0],$0);
+
+$sse2=0;
+for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); }
+
+&external_label("OPENSSL_ia32cap_P") if ($sse2);
+
+&function_begin("bn_mul_mont");
+
+$i="edx";
+$j="ecx";
+$ap="esi"; $tp="esi"; # overlapping variables!!!
+$rp="edi"; $bp="edi"; # overlapping variables!!!
+$np="ebp";
+$num="ebx";
+
+$_num=&DWP(4*0,"esp"); # stack top layout
+$_rp=&DWP(4*1,"esp");
+$_ap=&DWP(4*2,"esp");
+$_bp=&DWP(4*3,"esp");
+$_np=&DWP(4*4,"esp");
+$_n0=&DWP(4*5,"esp"); $_n0q=&QWP(4*5,"esp");
+$_sp=&DWP(4*6,"esp");
+$_bpend=&DWP(4*7,"esp");
+$frame=32; # size of above frame rounded up to 16n
+
+ &xor ("eax","eax");
+ &mov ("edi",&wparam(5)); # int num
+ &cmp ("edi",4);
+ &jl (&label("just_leave"));
+
+ &lea ("esi",&wparam(0)); # put aside pointer to argument block
+ &lea ("edx",&wparam(1)); # load ap
+ &mov ("ebp","esp"); # saved stack pointer!
+ &add ("edi",2); # extra two words on top of tp
+ &neg ("edi");
+ &lea ("esp",&DWP(-$frame,"esp","edi",4)); # alloca($frame+4*(num+2))
+ &neg ("edi");
+
+ # minimize cache contention by arraning 2K window between stack
+ # pointer and ap argument [np is also position sensitive vector,
+ # but it's assumed to be near ap, as it's allocated at ~same
+ # time].
+ &mov ("eax","esp");
+ &sub ("eax","edx");
+ &and ("eax",2047);
+ &sub ("esp","eax"); # this aligns sp and ap modulo 2048
+
+ &xor ("edx","esp");
+ &and ("edx",2048);
+ &xor ("edx",2048);
+ &sub ("esp","edx"); # this splits them apart modulo 4096
+
+ &and ("esp",-64); # align to cache line
+
+ ################################# load argument block...
+ &mov ("eax",&DWP(0*4,"esi"));# BN_ULONG *rp
+ &mov ("ebx",&DWP(1*4,"esi"));# const BN_ULONG *ap
+ &mov ("ecx",&DWP(2*4,"esi"));# const BN_ULONG *bp
+ &mov ("edx",&DWP(3*4,"esi"));# const BN_ULONG *np
+ &mov ("esi",&DWP(4*4,"esi"));# const BN_ULONG *n0
+ #&mov ("edi",&DWP(5*4,"esi"));# int num
+
+ &mov ("esi",&DWP(0,"esi")); # pull n0[0]
+ &mov ($_rp,"eax"); # ... save a copy of argument block
+ &mov ($_ap,"ebx");
+ &mov ($_bp,"ecx");
+ &mov ($_np,"edx");
+ &mov ($_n0,"esi");
+ &lea ($num,&DWP(-3,"edi")); # num=num-1 to assist modulo-scheduling
+ #&mov ($_num,$num); # redundant as $num is not reused
+ &mov ($_sp,"ebp"); # saved stack pointer!
+\f
+if($sse2) {
+$acc0="mm0"; # mmx register bank layout
+$acc1="mm1";
+$car0="mm2";
+$car1="mm3";
+$mul0="mm4";
+$mul1="mm5";
+$temp="mm6";
+$mask="mm7";
+
+ &picmeup("eax","OPENSSL_ia32cap_P");
+ &bt (&DWP(0,"eax"),26);
+ &jnc (&label("non_sse2"));
+
+ &mov ("eax",-1);
+ &movd ($mask,"eax"); # mask 32 lower bits
+
+ &mov ($ap,$_ap); # load input pointers
+ &mov ($bp,$_bp);
+ &mov ($np,$_np);
+
+ &xor ($i,$i); # i=0
+ &xor ($j,$j); # j=0
+
+ &movd ($mul0,&DWP(0,$bp)); # bp[0]
+ &movd ($mul1,&DWP(0,$ap)); # ap[0]
+ &movd ($car1,&DWP(0,$np)); # np[0]
+
+ &pmuludq($mul1,$mul0); # ap[0]*bp[0]
+ &movq ($car0,$mul1);
+ &movq ($acc0,$mul1); # I wish movd worked for
+ &pand ($acc0,$mask); # inter-register transfers
+
+ &pmuludq($mul1,$_n0q); # *=n0
+
+ &pmuludq($car1,$mul1); # "t[0]"*np[0]*n0
+ &paddq ($car1,$acc0);
+
+ &movd ($acc1,&DWP(4,$np)); # np[1]
+ &movd ($acc0,&DWP(4,$ap)); # ap[1]
+
+ &psrlq ($car0,32);
+ &psrlq ($car1,32);
+
+ &inc ($j); # j++
+&set_label("1st",16);
+ &pmuludq($acc0,$mul0); # ap[j]*bp[0]
+ &pmuludq($acc1,$mul1); # np[j]*m1
+ &paddq ($car0,$acc0); # +=c0
+ &paddq ($car1,$acc1); # +=c1
+
+ &movq ($acc0,$car0);
+ &pand ($acc0,$mask);
+ &movd ($acc1,&DWP(4,$np,$j,4)); # np[j+1]
+ &paddq ($car1,$acc0); # +=ap[j]*bp[0];
+ &movd ($acc0,&DWP(4,$ap,$j,4)); # ap[j+1]
+ &psrlq ($car0,32);
+ &movd (&DWP($frame-4,"esp",$j,4),$car1); # tp[j-1]=
+ &psrlq ($car1,32);
+
+ &lea ($j,&DWP(1,$j));
+ &cmp ($j,$num);
+ &jl (&label("1st"));
+
+ &pmuludq($acc0,$mul0); # ap[num-1]*bp[0]
+ &pmuludq($acc1,$mul1); # np[num-1]*m1
+ &paddq ($car0,$acc0); # +=c0
+ &paddq ($car1,$acc1); # +=c1
+
+ &movq ($acc0,$car0);
+ &pand ($acc0,$mask);
+ &paddq ($car1,$acc0); # +=ap[num-1]*bp[0];
+ &movd (&DWP($frame-4,"esp",$j,4),$car1); # tp[num-2]=
+
+ &psrlq ($car0,32);
+ &psrlq ($car1,32);
+
+ &paddq ($car1,$car0);
+ &movq (&QWP($frame,"esp",$num,4),$car1); # tp[num].tp[num-1]
+\f
+ &inc ($i); # i++
+&set_label("outer");
+ &xor ($j,$j); # j=0
+
+ &movd ($mul0,&DWP(0,$bp,$i,4)); # bp[i]
+ &movd ($mul1,&DWP(0,$ap)); # ap[0]
+ &movd ($temp,&DWP($frame,"esp")); # tp[0]
+ &movd ($car1,&DWP(0,$np)); # np[0]
+ &pmuludq($mul1,$mul0); # ap[0]*bp[i]
+
+ &paddq ($mul1,$temp); # +=tp[0]
+ &movq ($acc0,$mul1);
+ &movq ($car0,$mul1);
+ &pand ($acc0,$mask);
+
+ &pmuludq($mul1,$_n0q); # *=n0
+
+ &pmuludq($car1,$mul1);
+ &paddq ($car1,$acc0);
+
+ &movd ($temp,&DWP($frame+4,"esp")); # tp[1]
+ &movd ($acc1,&DWP(4,$np)); # np[1]
+ &movd ($acc0,&DWP(4,$ap)); # ap[1]
+
+ &psrlq ($car0,32);
+ &psrlq ($car1,32);
+ &paddq ($car0,$temp); # +=tp[1]
+
+ &inc ($j); # j++
+ &dec ($num);
+&set_label("inner");
+ &pmuludq($acc0,$mul0); # ap[j]*bp[i]
+ &pmuludq($acc1,$mul1); # np[j]*m1
+ &paddq ($car0,$acc0); # +=c0
+ &paddq ($car1,$acc1); # +=c1
+
+ &movq ($acc0,$car0);
+ &movd ($temp,&DWP($frame+4,"esp",$j,4));# tp[j+1]
+ &pand ($acc0,$mask);
+ &movd ($acc1,&DWP(4,$np,$j,4)); # np[j+1]
+ &paddq ($car1,$acc0); # +=ap[j]*bp[i]+tp[j]
+ &movd ($acc0,&DWP(4,$ap,$j,4)); # ap[j+1]
+ &psrlq ($car0,32);
+ &movd (&DWP($frame-4,"esp",$j,4),$car1);# tp[j-1]=
+ &psrlq ($car1,32);
+ &paddq ($car0,$temp); # +=tp[j+1]
+
+ &dec ($num);
+ &lea ($j,&DWP(1,$j)); # j++
+ &jnz (&label("inner"));
+
+ &mov ($num,$j);
+ &pmuludq($acc0,$mul0); # ap[num-1]*bp[i]
+ &pmuludq($acc1,$mul1); # np[num-1]*m1
+ &paddq ($car0,$acc0); # +=c0
+ &paddq ($car1,$acc1); # +=c1
+
+ &movq ($acc0,$car0);
+ &pand ($acc0,$mask);
+ &paddq ($car1,$acc0); # +=ap[num-1]*bp[i]+tp[num-1]
+ &movd (&DWP($frame-4,"esp",$j,4),$car1); # tp[num-2]=
+ &psrlq ($car0,32);
+ &psrlq ($car1,32);
+
+ &movd ($temp,&DWP($frame+4,"esp",$num,4)); # += tp[num]
+ &paddq ($car1,$car0);
+ &paddq ($car1,$temp);
+ &movq (&QWP($frame,"esp",$num,4),$car1); # tp[num].tp[num-1]
+
+ &lea ($i,&DWP(1,$i)); # i++
+ &cmp ($i,$num);
+ &jle (&label("outer"));
+
+ &emms (); # done with mmx bank
+ &jmp (&label("common_tail"));
+
+&set_label("non_sse2",16);
+}
+\f
+if (0) {
+ &mov ("esp",$_sp);
+ &xor ("eax","eax"); # signal "not fast enough [yet]"
+ &jmp (&label("just_leave"));
+ # While the below code provides competitive performance for
+ # all key lengthes on modern Intel cores, it's still more
+ # than 10% slower for 4096-bit key elsewhere:-( "Competitive"
+ # means compared to the original integer-only assembler.
+ # 512-bit RSA sign is better by ~40%, but that's about all
+ # one can say about all CPUs...
+} else {
+$inp="esi"; # integer path uses these registers differently
+$word="edi";
+$carry="ebp";
+
+ &mov ($inp,$_ap);
+ &lea ($carry,&DWP(1,$num));
+ &mov ($word,$_bp);
+ &xor ($j,$j); # j=0
+ &mov ("edx",$inp);
+ &and ($carry,1); # see if num is even
+ &sub ("edx",$word); # see if ap==bp
+ &lea ("eax",&DWP(4,$word,$num,4)); # &bp[num]
+ &or ($carry,"edx");
+ &mov ($word,&DWP(0,$word)); # bp[0]
+ &jz (&label("bn_sqr_mont"));
+ &mov ($_bpend,"eax");
+ &mov ("eax",&DWP(0,$inp));
+ &xor ("edx","edx");
+
+&set_label("mull",16);
+ &mov ($carry,"edx");
+ &mul ($word); # ap[j]*bp[0]
+ &add ($carry,"eax");
+ &lea ($j,&DWP(1,$j));
+ &adc ("edx",0);
+ &mov ("eax",&DWP(0,$inp,$j,4)); # ap[j+1]
+ &cmp ($j,$num);
+ &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j]=
+ &jl (&label("mull"));
+
+ &mov ($carry,"edx");
+ &mul ($word); # ap[num-1]*bp[0]
+ &mov ($word,$_n0);
+ &add ("eax",$carry);
+ &mov ($inp,$_np);
+ &adc ("edx",0);
+ &imul ($word,&DWP($frame,"esp")); # n0*tp[0]
+
+ &mov (&DWP($frame,"esp",$num,4),"eax"); # tp[num-1]=
+ &xor ($j,$j);
+ &mov (&DWP($frame+4,"esp",$num,4),"edx"); # tp[num]=
+ &mov (&DWP($frame+8,"esp",$num,4),$j); # tp[num+1]=
+
+ &mov ("eax",&DWP(0,$inp)); # np[0]
+ &mul ($word); # np[0]*m
+ &add ("eax",&DWP($frame,"esp")); # +=tp[0]
+ &mov ("eax",&DWP(4,$inp)); # np[1]
+ &adc ("edx",0);
+ &inc ($j);
+
+ &jmp (&label("2ndmadd"));
+\f\f
+&set_label("1stmadd",16);
+ &mov ($carry,"edx");
+ &mul ($word); # ap[j]*bp[i]
+ &add ($carry,&DWP($frame,"esp",$j,4)); # +=tp[j]
+ &lea ($j,&DWP(1,$j));
+ &adc ("edx",0);
+ &add ($carry,"eax");
+ &mov ("eax",&DWP(0,$inp,$j,4)); # ap[j+1]
+ &adc ("edx",0);
+ &cmp ($j,$num);
+ &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j]=
+ &jl (&label("1stmadd"));
+
+ &mov ($carry,"edx");
+ &mul ($word); # ap[num-1]*bp[i]
+ &add ("eax",&DWP($frame,"esp",$num,4)); # +=tp[num-1]
+ &mov ($word,$_n0);
+ &adc ("edx",0);
+ &mov ($inp,$_np);
+ &add ($carry,"eax");
+ &adc ("edx",0);
+ &imul ($word,&DWP($frame,"esp")); # n0*tp[0]
+
+ &xor ($j,$j);
+ &add ("edx",&DWP($frame+4,"esp",$num,4)); # carry+=tp[num]
+ &mov (&DWP($frame,"esp",$num,4),$carry); # tp[num-1]=
+ &adc ($j,0);
+ &mov ("eax",&DWP(0,$inp)); # np[0]
+ &mov (&DWP($frame+4,"esp",$num,4),"edx"); # tp[num]=
+ &mov (&DWP($frame+8,"esp",$num,4),$j); # tp[num+1]=
+
+ &mul ($word); # np[0]*m
+ &add ("eax",&DWP($frame,"esp")); # +=tp[0]
+ &mov ("eax",&DWP(4,$inp)); # np[1]
+ &adc ("edx",0);
+ &mov ($j,1);
+\f
+&set_label("2ndmadd",16);
+ &mov ($carry,"edx");
+ &mul ($word); # np[j]*m
+ &add ($carry,&DWP($frame,"esp",$j,4)); # +=tp[j]
+ &lea ($j,&DWP(1,$j));
+ &adc ("edx",0);
+ &add ($carry,"eax");
+ &mov ("eax",&DWP(0,$inp,$j,4)); # np[j+1]
+ &adc ("edx",0);
+ &cmp ($j,$num);
+ &mov (&DWP($frame-8,"esp",$j,4),$carry); # tp[j-1]=
+ &jl (&label("2ndmadd"));
+
+ &mov ($carry,"edx");
+ &mul ($word); # np[j]*m
+ &add ($carry,&DWP($frame,"esp",$num,4)); # +=tp[num-1]
+ &adc ("edx",0);
+ &add ($carry,"eax");
+ &adc ("edx",0);
+ &mov (&DWP($frame-4,"esp",$num,4),$carry); # tp[num-2]=
+
+ &xor ("eax","eax");
+ &mov ($j,$_bp); # &bp[i]
+ &add ("edx",&DWP($frame+4,"esp",$num,4)); # carry+=tp[num]
+ &adc ("eax",&DWP($frame+8,"esp",$num,4)); # +=tp[num+1]
+ &lea ($j,&DWP(4,$j));
+ &mov (&DWP($frame,"esp",$num,4),"edx"); # tp[num-1]=
+ &cmp ($j,$_bpend);
+ &mov (&DWP($frame+4,"esp",$num,4),"eax"); # tp[num]=
+ &je (&label("common_tail"));
+
+ &mov ($word,&DWP(0,$j)); # bp[i+1]
+ &mov ($inp,$_ap);
+ &mov ($_bp,$j); # &bp[++i]
+ &xor ($j,$j);
+ &xor ("edx","edx");
+ &mov ("eax",&DWP(0,$inp));
+ &jmp (&label("1stmadd"));
+\f
+&set_label("bn_sqr_mont",16);
+$sbit=$num;
+ &mov ($_num,$num);
+ &mov ($_bp,$j); # i=0
+
+ &mov ("eax",$word); # ap[0]
+ &mul ($word); # ap[0]*ap[0]
+ &mov (&DWP($frame,"esp"),"eax"); # tp[0]=
+ &mov ($sbit,"edx");
+ &shr ("edx",1);
+ &and ($sbit,1);
+ &inc ($j);
+&set_label("sqr",16);
+ &mov ("eax",&DWP(0,$inp,$j,4)); # ap[j]
+ &mov ($carry,"edx");
+ &mul ($word); # ap[j]*ap[0]
+ &add ("eax",$carry);
+ &lea ($j,&DWP(1,$j));
+ &adc ("edx",0);
+ &lea ($carry,&DWP(0,$sbit,"eax",2));
+ &shr ("eax",31);
+ &cmp ($j,$_num);
+ &mov ($sbit,"eax");
+ &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j]=
+ &jl (&label("sqr"));
+
+ &mov ("eax",&DWP(0,$inp,$j,4)); # ap[num-1]
+ &mov ($carry,"edx");
+ &mul ($word); # ap[num-1]*ap[0]
+ &add ("eax",$carry);
+ &mov ($word,$_n0);
+ &adc ("edx",0);
+ &mov ($inp,$_np);
+ &lea ($carry,&DWP(0,$sbit,"eax",2));
+ &imul ($word,&DWP($frame,"esp")); # n0*tp[0]
+ &shr ("eax",31);
+ &mov (&DWP($frame,"esp",$j,4),$carry); # tp[num-1]=
+
+ &lea ($carry,&DWP(0,"eax","edx",2));
+ &mov ("eax",&DWP(0,$inp)); # np[0]
+ &shr ("edx",31);
+ &mov (&DWP($frame+4,"esp",$j,4),$carry); # tp[num]=
+ &mov (&DWP($frame+8,"esp",$j,4),"edx"); # tp[num+1]=
+
+ &mul ($word); # np[0]*m
+ &add ("eax",&DWP($frame,"esp")); # +=tp[0]
+ &mov ($num,$j);
+ &adc ("edx",0);
+ &mov ("eax",&DWP(4,$inp)); # np[1]
+ &mov ($j,1);
+\f\f
+&set_label("3rdmadd",16);
+ &mov ($carry,"edx");
+ &mul ($word); # np[j]*m
+ &add ($carry,&DWP($frame,"esp",$j,4)); # +=tp[j]
+ &adc ("edx",0);
+ &add ($carry,"eax");
+ &mov ("eax",&DWP(4,$inp,$j,4)); # np[j+1]
+ &adc ("edx",0);
+ &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j-1]=
+
+ &mov ($carry,"edx");
+ &mul ($word); # np[j+1]*m
+ &add ($carry,&DWP($frame+4,"esp",$j,4)); # +=tp[j+1]
+ &lea ($j,&DWP(2,$j));
+ &adc ("edx",0);
+ &add ($carry,"eax");
+ &mov ("eax",&DWP(0,$inp,$j,4)); # np[j+2]
+ &adc ("edx",0);
+ &cmp ($j,$num);
+ &mov (&DWP($frame-8,"esp",$j,4),$carry); # tp[j]=
+ &jl (&label("3rdmadd"));
+
+ &mov ($carry,"edx");
+ &mul ($word); # np[j]*m
+ &add ($carry,&DWP($frame,"esp",$num,4)); # +=tp[num-1]
+ &adc ("edx",0);
+ &add ($carry,"eax");
+ &adc ("edx",0);
+ &mov (&DWP($frame-4,"esp",$num,4),$carry); # tp[num-2]=
+
+ &mov ($j,$_bp); # i
+ &xor ("eax","eax");
+ &mov ($inp,$_ap);
+ &add ("edx",&DWP($frame+4,"esp",$num,4)); # carry+=tp[num]
+ &adc ("eax",&DWP($frame+8,"esp",$num,4)); # +=tp[num+1]
+ &mov (&DWP($frame,"esp",$num,4),"edx"); # tp[num-1]=
+ &cmp ($j,$num);
+ &mov (&DWP($frame+4,"esp",$num,4),"eax"); # tp[num]=
+ &je (&label("common_tail"));
+\f
+ &mov ($word,&DWP(4,$inp,$j,4)); # ap[i]
+ &lea ($j,&DWP(1,$j));
+ &mov ("eax",$word);
+ &mov ($_bp,$j); # ++i
+ &mul ($word); # ap[i]*ap[i]
+ &add ("eax",&DWP($frame,"esp",$j,4)); # +=tp[i]
+ &adc ("edx",0);
+ &mov (&DWP($frame,"esp",$j,4),"eax"); # tp[i]=
+ &xor ($carry,$carry);
+ &cmp ($j,$num);
+ &lea ($j,&DWP(1,$j));
+ &je (&label("sqrlast"));
+
+ &mov ($sbit,"edx"); # zaps $num
+ &shr ("edx",1);
+ &and ($sbit,1);
+&set_label("sqradd",16);
+ &mov ("eax",&DWP(0,$inp,$j,4)); # ap[j]
+ &mov ($carry,"edx");
+ &mul ($word); # ap[j]*ap[i]
+ &add ("eax",$carry);
+ &lea ($carry,&DWP(0,"eax","eax"));
+ &adc ("edx",0);
+ &shr ("eax",31);
+ &add ($carry,&DWP($frame,"esp",$j,4)); # +=tp[j]
+ &lea ($j,&DWP(1,$j));
+ &adc ("eax",0);
+ &add ($carry,$sbit);
+ &adc ("eax",0);
+ &cmp ($j,$_num);
+ &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j]=
+ &mov ($sbit,"eax");
+ &jle (&label("sqradd"));
+
+ &mov ($carry,"edx");
+ &add ("edx","edx");
+ &shr ($carry,31);
+ &add ("edx",$sbit);
+ &adc ($carry,0);
+&set_label("sqrlast");
+ &mov ($word,$_n0);
+ &mov ($inp,$_np);
+ &imul ($word,&DWP($frame,"esp")); # n0*tp[0]
+
+ &add ("edx",&DWP($frame,"esp",$j,4)); # +=tp[num]
+ &mov ("eax",&DWP(0,$inp)); # np[0]
+ &adc ($carry,0);
+ &mov (&DWP($frame,"esp",$j,4),"edx"); # tp[num]=
+ &mov (&DWP($frame+4,"esp",$j,4),$carry); # tp[num+1]=
+
+ &mul ($word); # np[0]*m
+ &add ("eax",&DWP($frame,"esp")); # +=tp[0]
+ &lea ($num,&DWP(-1,$j));
+ &adc ("edx",0);
+ &mov ($j,1);
+ &mov ("eax",&DWP(4,$inp)); # np[1]
+
+ &jmp (&label("3rdmadd"));
+}
+\f
+&set_label("common_tail",16);
+ &mov ($np,$_np); # load modulus pointer
+ &mov ($rp,$_rp); # load result pointer
+ &lea ($tp,&DWP($frame,"esp")); # [$ap and $bp are zapped]
+
+ &mov ("eax",&DWP(0,$tp)); # tp[0]
+ &mov ($j,$num); # j=num-1
+ &xor ($i,$i); # i=0 and clear CF!
+
+&set_label("sub",16);
+ &sbb ("eax",&DWP(0,$np,$i,4));
+ &mov (&DWP(0,$rp,$i,4),"eax"); # rp[i]=tp[i]-np[i]
+ &dec ($j); # doesn't affect CF!
+ &mov ("eax",&DWP(4,$tp,$i,4)); # tp[i+1]
+ &lea ($i,&DWP(1,$i)); # i++
+ &jge (&label("sub"));
+
+ &sbb ("eax",0); # handle upmost overflow bit
+ &and ($tp,"eax");
+ ¬ ("eax");
+ &mov ($np,$rp);
+ &and ($np,"eax");
+ &or ($tp,$np); # tp=carry?tp:rp
+
+&set_label("copy",16); # copy or in-place refresh
+ &mov ("eax",&DWP(0,$tp,$num,4));
+ &mov (&DWP(0,$rp,$num,4),"eax"); # rp[i]=tp[i]
+ &mov (&DWP($frame,"esp",$num,4),$j); # zap temporary vector
+ &dec ($num);
+ &jge (&label("copy"));
+
+ &mov ("esp",$_sp); # pull saved stack pointer
+ &mov ("eax",1);
+&set_label("just_leave");
+&function_end("bn_mul_mont");
+
+&asciz("Montgomery Multiplication for x86, CRYPTOGAMS by <appro\@openssl.org>");
+
+&asm_finish();
projects / cassiopeia.git / blobdiff