Commit 48d2335d authored by Andy Polyakov's avatar Andy Polyakov
Browse files

Non-SSE2 path to bn_mul_mont. But it's disabled, because it currently 

doesn't give performance improvement.
parent 96ea4ae9

crypto/bn/asm/x86-mont.pl

+187 −41
Original line number Diff line number Diff line
@@ -2,8 +2,9 @@ 


# ====================================================================

# Written by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL

# project. Rights for redistribution and usage in source and binary

# forms are granted according to the OpenSSL license.

# 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
@@ -31,12 +32,12 @@ for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); } 


&function_begin("bn_mul_mont",$sse2?"EXTRN\t_OPENSSL_ia32cap_P:DWORD":"");



$i="ebx";

$i="edx";

$j="ecx";

$ap="esi";

$rp="edi";	$bp="edi";		# overlapping variables!!!

$np="edx";

$num="ebp";

$np="ebp";

$num="ebx";



$_rp=&DWP(4*0,"esp");			# stack top layout

$_ap=&DWP(4*1,"esp");
@@ -45,21 +46,13 @@ $_np=&DWP(4*3,"esp"); 
$_n0=&DWP(4*4,"esp");

$_num=&DWP(4*5,"esp");

$_sp=&DWP(4*6,"esp");

$_bpend=&DWP(4*7,"esp");

$frame=32;				# size of above frame rounded up to 16n



$acc0="mm0";				# mmx register bank layout

$acc1="mm1";

$car0="mm2";

$car1="mm3";

$mul0="mm4";

$mul1="mm5";

$temp="mm6";

$mask="mm7";



if($sse2) {

	&picmeup("eax","OPENSSL_ia32cap_P");

	&bt	(&DWP(0,"eax"),26);

	&jnc	(&label("non_sse2"));

	&xor	("eax","eax");

	&mov	("edi",&wparam(5));	# int num

	&cmp	("edi",3);

	&jb	(&label("just_leave"));



	################################# load argument block...

	&mov	("eax",&wparam(0));	# BN_ULONG *rp
@@ -67,16 +60,14 @@ if($sse2) { 
	&mov	("ecx",&wparam(2));	# const BN_ULONG *bp

	&mov	("edx",&wparam(3));	# const BN_ULONG *np

	&mov	("esi",&wparam(4));	# const BN_ULONG *n0

	&mov	($num,&wparam(5));	# int num

	#&mov	("edi",&wparam(5));	# int num



	&mov	("edi","esp");		# saved stack pointer!

	&add	($num,1);		# extra word on top of tp

	&neg	($num);

	&lea	("esp",&DWP(-$frame,"esp",$num,4));	# alloca($frame+8*($num+1))

	&neg	($num);

	&and	("esp",-1024);		# minimize TLB utilization

	&sub	($num,1);		# num is restored to its original value

					# and will remain constant from now...

	&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");

	&and	("esp",-4096);		# minimize TLB utilization



	&mov	("esi",&DWP(0,"esi"));	# pull n0[0]

	&mov	($_rp,"eax");		# ... save a copy of argument block
@@ -84,8 +75,23 @@ if($sse2) { 
	&mov	($_bp,"ecx");

	&mov	($_np,"edx");

	&mov	($_n0,"esi");

	#&mov	($_num,$num);		# redundant in sse2 context

	&mov	($_sp,"edi");		# saved stack pointer!

	&lea	($num,&DWP(-2,"edi"));	# num is restored to its original value

	#&mov	($_num,$num);		# redundant as $num is not reused

	&mov	($_sp,"ebp");		# saved stack pointer!



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	($mask,"eax");		# mask 32 lower bits
@@ -195,7 +201,153 @@ if($sse2) { 
	&jl	(&label("outer"));



	&emms	();				# done with mmx bank

	&jmp	(&label("common_tail"));



&set_label("non_sse2",16);

}



if (1) {

	&mov	("esp",$_sp);

	&xor	("eax","eax");	# signal "not fast enough [yet]"

	&jmp	(&label("just_leave"));

	# The code below gives ~15% improvement on 512-bit benchmark

	# *only*:-( On all other key lengths it's slower for up to 20%.

	# This is because the original code path holds down the overall

	# amount of multiplications by ~25% by deploying bn_sqr_words.

	# In other words, for the code below to be competitive,

	# dedicated squaring procedure is a must...

} else {

$inp="esi";	# integer path uses these registers differently

$word="edi";

$carry="ebp";



	&sub	($num,1);		# non-SSE2 path uses num-1



	&mov	($inp,$_ap);

	&mov	($word,$_bp);

	&lea	("eax",&DWP(4,$word,$num,4));		# &bp[num]

	&mov	($word,&DWP(0,$word));			# bp[0]

	&mov	($_bpend,"eax");

	&xor	($j,$j);

	&xor	("edx","edx");



&set_label("mull",16);

	&mov	("eax",&DWP(0,$inp,$j,4));		# ap[j]

	&mov	($carry,"edx");

	&mul	($word);				# ap[j]*bp[0]

	&lea	($j,&DWP(1,$j));

	&add	("eax",$carry);

	&adc	("edx",0);

	&mov	(&DWP($frame-4,"esp",$j,4),"eax");	# tp[j]=

	&cmp	($j,$num);

	&jb	(&label("mull"));



	&mov	("eax",&DWP(0,$inp,$num,4));		# ap[num-1]

	&mov	($carry,"edx");

	&mul	($word);				# ap[num-1]*bp[0]

	&add	("eax",$carry);

	&adc	("edx",0);



	&mov	($word,$_n0);

	&mov	($inp,$_np);

	&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]

	&adc	("edx",0);

	&mov	($j,1);



	&jmp	(&label("2ndmadd"));



&set_label("1stmadd",16);

	&mov	("eax",&DWP(0,$inp,$j,4));		# ap[j]

	&mov	($carry,"edx");

	&mul	($word);				# ap[j]*bp[i]

	&lea	($j,&DWP(1,$j));

	&add	("eax",&DWP($frame-4,"esp",$j,4));	# +=tp[j]

	&adc	("edx",0);

	&add	("eax",$carry);

	&adc	("edx",0);

	&mov	(&DWP($frame-4,"esp",$j,4),"eax");	# tp[j]=

	&cmp	($j,$num);

	&jb	(&label("1stmadd"));



	&mov	("eax",&DWP(0,$inp,$num,4));		# ap[num-1]

	&mov	($carry,"edx");

	&mul	($word);				# ap[num-1]*bp[i]

	&add	("eax",&DWP($frame,"esp",$num,4));	# +=tp[num-1]

	&adc	("edx",0);

	&add	("eax",$carry);

	&adc	("edx",0);



	&mov	($word,$_n0);

	&mov	($inp,$_np);

	&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),"eax");	# tp[num-1]=

	&adc	($j,0);

	&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]

	&adc	("edx",0);

	&mov	($j,1);



&set_label("2ndmadd",16);

	&mov	("eax",&DWP(0,$inp,$j,4));		# np[j]

	&mov	($carry,"edx");

	&mul	($word);				# np[j]*m

	&lea	($j,&DWP(1,$j));

	&add	("eax",&DWP($frame-4,"esp",$j,4));	# +=tp[j]

	&adc	("edx",0);

	&add	("eax",$carry);

	&adc	("edx",0);

	&mov	(&DWP($frame-8,"esp",$j,4),"eax");	# tp[j-1]=

	&cmp	($j,$num);

	&jb	(&label("2ndmadd"));



	&mov	("eax",&DWP(0,$inp,$num,4));		# np[num-1]

	&mov	($carry,"edx");

	&mul	($word);				# np[num-1]*m

	&add	("eax",&DWP($frame,"esp",$num,4));	# +=tp[num-1]

	&adc	("edx",0);

	&add	("eax",$carry);

	&adc	("edx",0);

	&mov	(&DWP($frame-4,"esp",$num,4),"eax");	# tp[num-2]=



	&xor	("eax","eax");

	&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]=

	&mov	(&DWP($frame+4,"esp",$num,4),"eax");	# tp[num]=



	&mov	($carry,$_bp);				# &bp[i]

	&add	($carry,4);

	&cmp	($carry,$_bpend);

	&je	(&label("x86done"));

	&mov	($word,&DWP(0,$carry));			# bp[i]

	&mov	($inp,$_ap);

	&mov	($_bp,$carry);				# &bp[++i]

	&xor	($j,$j);

	&xor	("edx","edx");

	&jmp	(&label("1stmadd"));



&set_label("x86done",16);

	&mov	($np,$_np);	# make adjustments for tail processing

	&add	($num,1);

}



&set_label("common_tail",16);

	&mov	("esi",&DWP($frame,"esp",$num,4));# load upmost overflow bit

	&mov	($rp,$_rp);			# load result pointer

						# [$ap and $bp are zapped]
@@ -206,15 +358,15 @@ if($sse2) { 
	&mov	("eax",&DWP($frame,"esp",$j,4));

	&cmp	("eax",&DWP(0,$np,$j,4));	# tp[num-1]-np[num-1]?

	&jae	(&label("sub"));		# if taken CF is cleared

&set_label("copy");

&set_label("copy",16);

	&mov	("eax",&DWP($frame,"esp",$j,4));

	&mov	(&DWP(0,$rp,$j,4),"eax");	# rp[i]=tp[i]

	&mov	(&DWP($frame,"esp",$j,4),$j);	# zap temporary vector

	&dec	($j);

	&jge	(&label("copy"));

	&jmp	(&label("exit_sse2"));

	&jmp	(&label("exit"));



&set_label("sub",4);

&set_label("sub",16);

	&mov	("eax",&DWP($frame,"esp",$i,4));

	&sbb	("eax",&DWP(0,$np,$i,4));

	&mov	(&DWP(0,$rp,$i,4),"eax");	# rp[i]=tp[i]-np[i]
@@ -224,21 +376,15 @@ if($sse2) { 
	&lea	($j,&DWP(-1,$num));		# j=num-1

	&sbb	("esi",0);			# esi holds upmost overflow bit

	&jc	(&label("copy"));

&set_label("zap");

&set_label("zap",16);

	&mov	(&DWP($frame,"esp",$j,4),$i);	# zap temporary vector

	&dec	($j);

	&jge	(&label("zap"));



&set_label("exit_sse2");

&set_label("exit",4);

	&mov	("esp",$_sp);		# pull saved stack pointer

	&mov	("eax",1);

	&jmp	(&label("leave"));

&set_label("non_sse2");

}



	&xor	("eax","eax");	# zero signals "not implemented [yet]"



&set_label("leave");

&set_label("just_leave");

&function_end("bn_mul_mont");



&asm_finish();