patch-2.4.0-test12 linux/arch/alpha/lib/memmove.S

• Lines: 104
• Date: Mon Dec 11 13:46:26 2000
• Orig file: v2.4.0-test11/linux/arch/alpha/lib/memmove.S
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test11/linux/arch/alpha/lib/memmove.S linux/arch/alpha/lib/memmove.S
@@ -0,0 +1,103 @@
+/*
+ * arch/alpha/lib/memmove.S
+ *
+ * Barely optimized memmove routine for Alpha EV5.
+ *
+ * This is hand-massaged output from the original memcpy.c.  We defer to
+ * memcpy whenever possible; the backwards copy loops are not unrolled.
+ */
+        
+	.set noat
+	.set noreorder
+	.text
+
+	.align 4
+	.globl memmove
+	.ent memmove
+memmove:
+	addq $16,$18,$4
+	addq $17,$18,$5
+	cmpule $4,$17,$1		/*  dest + n <= src  */
+	cmpule $5,$16,$2		/*  dest >= src + n  */
+
+	bis $1,$2,$1
+	mov $16,$0
+	xor $16,$17,$2
+	bne $1,memcpy
+
+	and $2,7,$2			/* Test for src/dest co-alignment.  */
+	bne $2,$misaligned
+
+	and $4,7,$1
+	beq $1,$skip_aligned_byte_loop_head
+
+$aligned_byte_loop_head:
+	lda $4,-1($4)
+	lda $5,-1($5)
+	unop
+	ble $18,$egress
+
+	ldq_u $3,0($5)
+	ldq_u $2,0($4)
+	lda $18,-1($18)
+	extbl $3,$5,$1
+
+	insbl $1,$4,$1
+	mskbl $2,$4,$2
+	bis $1,$2,$1
+	and $4,7,$6
+
+	stq_u $1,0($4)
+	bne $6,$aligned_byte_loop_head
+
+$skip_aligned_byte_loop_head:
+	lda $18,-8($18)
+	blt $18,$skip_aligned_word_loop
+
+$aligned_word_loop:
+	ldq $1,-8($5)
+	nop
+	lda $5,-8($5)
+	lda $18,-8($18)
+
+	stq $1,-8($4)
+	nop
+	lda $4,-8($4)
+	bge $18,$aligned_word_loop
+
+$skip_aligned_word_loop:
+	lda $18,8($18)
+	bgt $18,$byte_loop_tail
+	unop
+	ret $31,($26),1
+
+	.align 4
+$misaligned:
+	nop
+	fnop
+	unop
+	beq $18,$egress
+
+$byte_loop_tail:
+	ldq_u $3,-1($5)
+	ldq_u $2,-1($4)
+	lda $5,-1($5)
+	lda $4,-1($4)
+
+	lda $18,-1($18)
+	extbl $3,$5,$1
+	insbl $1,$4,$1
+	mskbl $2,$4,$2
+
+	bis $1,$2,$1
+	stq_u $1,0($4)
+	nop
+	bgt $18,$byte_loop_tail
+
+$egress:
+	ret $31,($26),1
+	nop
+	nop
+	nop
+
+	.end memmove