From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001
From: root <root@artemis.panaceas.org>
Date: Fri, 25 Dec 2015 04:40:36 +0000
Subject: initial_commit

---
 arch/alpha/lib/strncpy.S | 81 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 arch/alpha/lib/strncpy.S

(limited to 'arch/alpha/lib/strncpy.S')

diff --git a/arch/alpha/lib/strncpy.S b/arch/alpha/lib/strncpy.S
new file mode 100644
index 00000000..a46f7f3a
--- /dev/null
+++ b/arch/alpha/lib/strncpy.S
@@ -0,0 +1,81 @@
+/*
+ * arch/alpha/lib/strncpy.S
+ * Contributed by Richard Henderson (rth@tamu.edu)
+ *
+ * Copy no more than COUNT bytes of the null-terminated string from
+ * SRC to DST.  If SRC does not cover all of COUNT, the balance is
+ * zeroed.
+ *
+ * Or, rather, if the kernel cared about that weird ANSI quirk.  This
+ * version has cropped that bit o' nastiness as well as assuming that
+ * __stxncpy is in range of a branch.
+ */
+
+	.set noat
+	.set noreorder
+
+	.text
+
+	.align 4
+	.globl strncpy
+	.ent strncpy
+strncpy:
+	.frame $30, 0, $26
+	.prologue 0
+
+	mov	$16, $0		# set return value now
+	beq	$18, $zerolen
+	unop
+	bsr	$23, __stxncpy	# do the work of the copy
+
+	unop
+	bne	$18, $multiword	# do we have full words left?
+	subq	$24, 1, $3	# nope
+	subq	$27, 1, $4
+
+	or	$3, $24, $3	# clear the bits between the last
+	or	$4, $27, $4	# written byte and the last byte in COUNT
+	andnot	$3, $4, $4
+	zap	$1, $4, $1
+
+	stq_u	$1, 0($16)
+	ret
+
+	.align	4
+$multiword:
+	subq	$27, 1, $2	# clear the final bits in the prev word
+	or	$2, $27, $2
+	zapnot	$1, $2, $1
+	subq	$18, 1, $18
+
+	stq_u	$1, 0($16)
+	addq	$16, 8, $16
+	unop
+	beq	$18, 1f
+
+	nop
+	unop
+	nop
+	blbc	$18, 0f
+
+	stq_u	$31, 0($16)	# zero one word
+	subq	$18, 1, $18
+	addq	$16, 8, $16
+	beq	$18, 1f
+
+0:	stq_u	$31, 0($16)	# zero two words
+	subq	$18, 2, $18
+	stq_u	$31, 8($16)
+	addq	$16, 16, $16
+	bne	$18, 0b
+
+1:	ldq_u	$1, 0($16)	# clear the leading bits in the final word
+	subq	$24, 1, $2
+	or	$2, $24, $2
+
+	zap	$1, $2, $1
+	stq_u	$1, 0($16)
+$zerolen:
+	ret
+
+	.end	strncpy
-- 
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