Commit 7fb37eed authored by Andy Polyakov's avatar Andy Polyakov
Browse files

ec/asm/ecp_nistz256-x86_64.pl: minor sqr_montx cleanup. 



Drop some redundant instructions in reduction in ecp_nistz256_sqr_montx.

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
(cherry picked from commit 8fc063dc)
parent c8ec3410

crypto/ec/asm/ecp_nistz256-x86_64.pl

+9 −13
Original line number Diff line number Diff line
@@ -1185,19 +1185,18 @@ __ecp_nistz256_sqr_montx: 
	adox	$t1, $acc5

	.byte	0x67,0x67

	mulx	%rdx, $t0, $t4

	 mov	$acc0, %rdx

	 mov	.Lpoly+8*3(%rip), %rdx

	adox	$t0, $acc6

	 shlx	$a_ptr, $acc0, $t0

	adox	$t4, $acc7

	 shrx	$a_ptr, $acc0, $t4

	 mov	.Lpoly+8*3(%rip), $t1

	mov	%rdx,$t1



	# reduction step 1

	add	$t0, $acc1

	adc	$t4, $acc2



	mulx	$t1, $t0, $acc0

	 mov	$acc1, %rdx

	mulx	$acc0, $t0, $acc0

	adc	$t0, $acc3

	 shlx	$a_ptr, $acc1, $t0

	adc	\$0, $acc0
@@ -1207,8 +1206,7 @@ __ecp_nistz256_sqr_montx: 
	add	$t0, $acc2

	adc	$t4, $acc3



	mulx	$t1, $t0, $acc1

	 mov	$acc2, %rdx

	mulx	$acc1, $t0, $acc1

	adc	$t0, $acc0

	 shlx	$a_ptr, $acc2, $t0

	adc	\$0, $acc1
@@ -1218,8 +1216,7 @@ __ecp_nistz256_sqr_montx: 
	add	$t0, $acc3

	adc	$t4, $acc0



	mulx	$t1, $t0, $acc2

	 mov	$acc3, %rdx

	mulx	$acc2, $t0, $acc2

	adc	$t0, $acc1

	 shlx	$a_ptr, $acc3, $t0

	adc	\$0, $acc2
@@ -1229,12 +1226,12 @@ __ecp_nistz256_sqr_montx: 
	add	$t0, $acc0

	adc	$t4, $acc1



	mulx	$t1, $t0, $acc3

	mulx	$acc3, $t0, $acc3

	adc	$t0, $acc2

	adc	\$0, $acc3



	xor	$t3, $t3		# cf=0

	adc	$acc0, $acc4		# accumulate upper half

	xor	$t3, $t3

	add	$acc0, $acc4		# accumulate upper half

	 mov	.Lpoly+8*1(%rip), $a_ptr

	adc	$acc1, $acc5

	 mov	$acc4, $acc0
@@ -1243,8 +1240,7 @@ __ecp_nistz256_sqr_montx: 
	 mov	$acc5, $acc1

	adc	\$0, $t3



	xor	%eax, %eax		# cf=0

	sbb	\$-1, $acc4		# .Lpoly[0]

	sub	\$-1, $acc4		# .Lpoly[0]

	 mov	$acc6, $acc2

	sbb	$a_ptr, $acc5		# .Lpoly[1]

	sbb	\$0, $acc6		# .Lpoly[2]