summary refs log tree commit diff
path: root/sysdeps/alpha/alphaev5/add_n.s
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/alpha/alphaev5/add_n.s')
-rw-r--r--sysdeps/alpha/alphaev5/add_n.s175
1 files changed, 102 insertions, 73 deletions
diff --git a/sysdeps/alpha/alphaev5/add_n.s b/sysdeps/alpha/alphaev5/add_n.s
index 2aaf041774..66cf82b3c3 100644
--- a/sysdeps/alpha/alphaev5/add_n.s
+++ b/sysdeps/alpha/alphaev5/add_n.s
@@ -35,84 +35,113 @@
 __mpn_add_n:
 	.frame	$30,0,$26,0
 
-	ldq	$3,0($17)
-	ldq	$4,0($18)
-
-	subq	$19,1,$19
-	and	$19,4-1,$2	# number of limbs in first loop
-	bis	$31,$31,$0
-	beq	$2,.L0		# if multiple of 4 limbs, skip first loop
-
-	subq	$19,$2,$19
-
-.Loop0:	subq	$2,1,$2
+	or	$31,$31,$25		# clear cy
+	subq	$19,4,$19		# decr loop cnt
+	blt	$19,.Lend2		# if less than 4 limbs, goto 2nd loop
+ # Start software pipeline for 1st loop
+	ldq	$0,0($18)
+	ldq	$1,8($18)
+	ldq	$4,0($17)
 	ldq	$5,8($17)
-	addq	$4,$0,$4
-	ldq	$6,8($18)
-	cmpult	$4,$0,$1
-	addq	$3,$4,$4
-	cmpult	$4,$3,$0
-	stq	$4,0($16)
-	or	$0,$1,$0
-
-	addq	$17,8,$17
-	addq	$18,8,$18
-	bis	$5,$5,$3
-	bis	$6,$6,$4
-	addq	$16,8,$16
-	bne	$2,.Loop0
-
-.L0:	beq	$19,.Lend
-
+	addq	$17,32,$17		# update s1_ptr
+	ldq	$2,16($18)
+	addq	$0,$4,$20		# 1st main add
+	ldq	$3,24($18)
+	subq	$19,4,$19		# decr loop cnt
+	ldq	$6,-16($17)
+	cmpult	$20,$0,$25		# compute cy from last add
+	ldq	$7,-8($17)
+	addq	$1,$25,$28		# cy add
+	addq	$18,32,$18		# update s2_ptr
+	addq	$5,$28,$21		# 2nd main add
+	cmpult	$28,$25,$8		# compute cy from last add
+	blt	$19,.Lend1		# if less than 4 limbs remain, jump
+ # 1st loop handles groups of 4 limbs in a software pipeline
 	.align	4
-.Loop:	subq	$19,4,$19
-	unop
-
-	ldq	$6,8($18)
-	addq	$4,$0,$0
+.Loop:	cmpult	$21,$28,$25		# compute cy from last add
+	ldq	$0,0($18)
+	or	$8,$25,$25		# combine cy from the two adds
+	ldq	$1,8($18)
+	addq	$2,$25,$28		# cy add
+	ldq	$4,0($17)
+	addq	$28,$6,$22		# 3rd main add
 	ldq	$5,8($17)
-	cmpult	$0,$4,$1
-	ldq	$4,16($18)
-	addq	$3,$0,$20
-	cmpult	$20,$3,$0
-	ldq	$3,16($17)
-	or	$0,$1,$0
-	addq	$6,$0,$0
-	cmpult	$0,$6,$1
-	ldq	$6,24($18)
-	addq	$5,$0,$21
-	cmpult	$21,$5,$0
-	ldq	$5,24($17)
-	or	$0,$1,$0
-	addq	$4,$0,$0
-	cmpult	$0,$4,$1
-	ldq	$4,32($18)
-	addq	$3,$0,$22
-	cmpult	$22,$3,$0
-	ldq	$3,32($17)
-	or	$0,$1,$0
-	addq	$6,$0,$0
-	cmpult	$0,$6,$1
-	addq	$5,$0,$23
-	cmpult	$23,$5,$0
-	or	$0,$1,$0
-
+	cmpult	$28,$25,$8		# compute cy from last add
+	cmpult	$22,$28,$25		# compute cy from last add
 	stq	$20,0($16)
+	or	$8,$25,$25		# combine cy from the two adds
 	stq	$21,8($16)
-	stq	$22,16($16)
-	stq	$23,24($16)
-
-	addq	$17,32,$17
-	addq	$18,32,$18
-	addq	$16,32,$16
-	bne	$19,.Loop
+	addq	$3,$25,$28		# cy add
+	addq	$28,$7,$23		# 4th main add
+	cmpult	$28,$25,$8		# compute cy from last add
+	cmpult	$23,$28,$25		# compute cy from last add
+	addq	$17,32,$17		# update s1_ptr
+	or	$8,$25,$25		# combine cy from the two adds
+	addq	$16,32,$16		# update res_ptr
+	addq	$0,$25,$28		# cy add
+	ldq	$2,16($18)
+	addq	$4,$28,$20		# 1st main add
+	ldq	$3,24($18)
+	cmpult	$28,$25,$8		# compute cy from last add
+	ldq	$6,-16($17)
+	cmpult	$20,$28,$25		# compute cy from last add
+	ldq	$7,-8($17)
+	or	$8,$25,$25		# combine cy from the two adds
+	subq	$19,4,$19		# decr loop cnt
+	stq	$22,-16($16)
+	addq	$1,$25,$28		# cy add
+	stq	$23,-8($16)
+	addq	$5,$28,$21		# 2nd main add
+	addq	$18,32,$18		# update s2_ptr
+	cmpult	$28,$25,$8		# compute cy from last add
+	bge	$19,.Loop
+ # Finish software pipeline for 1st loop
+.Lend1:	cmpult	$21,$28,$25		# compute cy from last add
+	or	$8,$25,$25		# combine cy from the two adds
+	addq	$2,$25,$28		# cy add
+	addq	$28,$6,$22		# 3rd main add
+	cmpult	$28,$25,$8		# compute cy from last add
+	cmpult	$22,$28,$25		# compute cy from last add
+	stq	$20,0($16)
+	or	$8,$25,$25		# combine cy from the two adds
+	stq	$21,8($16)
+	addq	$3,$25,$28		# cy add
+	addq	$28,$7,$23		# 4th main add
+	cmpult	$28,$25,$8		# compute cy from last add
+	cmpult	$23,$28,$25		# compute cy from last add
+	or	$8,$25,$25		# combine cy from the two adds
+	addq	$16,32,$16		# update res_ptr
+	stq	$22,-16($16)
+	stq	$23,-8($16)
+.Lend2:	addq	$19,4,$19		# restore loop cnt
+	beq	$19,.Lret
+ # Start software pipeline for 2nd loop
+	ldq	$0,0($18)
+	ldq	$4,0($17)
+	subq	$19,1,$19
+	beq	$19,.Lend0
+ # 2nd loop handles remaining 1-3 limbs
+	.align	4
+.Loop0:	addq	$0,$25,$28		# cy add
+	ldq	$0,8($18)
+	addq	$4,$28,$20		# main add
+	ldq	$4,8($17)
+	addq	$18,8,$18
+	cmpult	$28,$25,$8		# compute cy from last add
+	addq	$17,8,$17
+	stq	$20,0($16)
+	cmpult	$20,$28,$25		# compute cy from last add
+	subq	$19,1,$19		# decr loop cnt
+	or	$8,$25,$25		# combine cy from the two adds
+	addq	$16,8,$16
+	bne	$19,.Loop0
+.Lend0:	addq	$0,$25,$28		# cy add
+	addq	$4,$28,$20		# main add
+	cmpult	$28,$25,$8		# compute cy from last add
+	cmpult	$20,$28,$25		# compute cy from last add
+	stq	$20,0($16)
+	or	$8,$25,$25		# combine cy from the two adds
 
-.Lend:	addq	$4,$0,$4
-	cmpult	$4,$0,$1
-	addq	$3,$4,$4
-	cmpult	$4,$3,$0
-	stq	$4,0($16)
-	or	$0,$1,$0
+.Lret:	or	$25,$31,$0		# return cy
 	ret	$31,($26),1
-
 	.end	__mpn_add_n