x86_64-mont.pl readability improvement. (7a2f4cbf) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP OpenSSL

crypto/bn/asm/x86_64-mont.pl

+14 −15

Original line number	Diff line number	Diff line
		@@ -97,8 +97,8 @@ bn_mul_mont:
		xor %rdx,%rdx
		add $hi0,$hi1
		adc \$0,%rdx
		mov $hi1,-8(%rsp,$j,8)
		mov %rdx,(%rsp,$j,8)
		mov $hi1,-8(%rsp,$num,8)
		mov %rdx,(%rsp,$num,8) # store upmost overflow bit

		lea 1($i),$i # i++
		.align 4
		@@ -146,26 +146,25 @@ bn_mul_mont:
		cmp $num,$j
		jl .Linner

		xor %rdx,%rdx # $j equals to num here...
		xor %rdx,%rdx
		add $hi0,$hi1
		adc \$0,%rdx
		add (%rsp,$j,8),$hi1 # pull upmost overflow bit
		add (%rsp,$num,8),$hi1 # pull upmost overflow bit
		adc \$0,%rdx
		mov $hi1,-8(%rsp,$j,8)
		mov %rdx,(%rsp,$j,8) # store upmost overflow bit
		mov $hi1,-8(%rsp,$num,8)
		mov %rdx,(%rsp,$num,8) # store upmost overflow bit

		lea 1($i),$i # i++
		cmp $num,$i
		jl .Louter

		sub $i,$i # clear CF at once
		cmp \$0,%rdx # %rdx still holds upmost overflow bit
		jnz .Lsub # ... and $j still equals to num
		mov -8(%rsp,$num,8),%rax
		cmp -8($np,$num,8),%rax # tp[num-1]-np[num-1]
		jae .Lsub

		xor $i,$i # i=0
		lea -1($num),$j # j=num-1
		cmp \$0,%rdx # %rdx still holds upmost overflow bit
		jnz .Lsub # CF is cleared by compare with 0
		mov (%rsp,$j,8),%rax
		cmp ($np,$j,8),%rax # tp[num-1]-np[num-1]
		jae .Lsub # if taken CF was cleared by above cmp
		.align 4
		.Lcopy:
		mov (%rsp,$j,8),%rax
		@@ -190,8 +189,8 @@ bn_mul_mont:
		sbb ($np,$i,8),%rax
		mov %rax,($rp,$i,8) # rp[i]=tp[i]-np[j]
		lea 1($i),$i # i++
		dec $j # doesn't affect cf!
		jg .Lsub
		dec $j # doesn't affect CF!
		jge .Lsub
		lea -1($num),$j # j=num-1
		sbb \$0,%rdx
		jc .Lcopy # tp was less than np