1// Copyright 2014 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5#include "textflag.h"
6
7// func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr)
8TEXT runtime·memclrNoHeapPointers(SB), NOSPLIT, $0-8
9	MOVL	ptr+0(FP), DI
10	MOVL	n+4(FP), BX
11	XORL	AX, AX
12
13tail:
14	TESTL	BX, BX
15	JEQ	_0
16	CMPL	BX, $2
17	JBE	_1or2
18	CMPL	BX, $4
19	JB	_3
20	JE	_4
21	CMPL	BX, $8
22	JBE	_5through8
23	CMPL	BX, $16
24	JBE	_9through16
25	MOVL	BX, CX
26	SHRL	$2, CX
27	REP
28	STOSL
29	ANDL	$3, BX
30	JNE	tail
31	RET
32
33_1or2:
34	MOVB	AX, (DI)
35	MOVB	AX, -1(DI)(BX*1)
36	RET
37_0:
38	RET
39_3:
40	MOVW	AX, (DI)
41	MOVB	AX, 2(DI)
42	RET
43_4:
44	// We need a separate case for 4 to make sure we clear pointers atomically.
45	MOVL	AX, (DI)
46	RET
47_5through8:
48	MOVL	AX, (DI)
49	MOVL	AX, -4(DI)(BX*1)
50	RET
51_9through16:
52	MOVL	AX, (DI)
53	MOVL	AX, 4(DI)
54	MOVL	AX, -8(DI)(BX*1)
55	MOVL	AX, -4(DI)(BX*1)
56	RET
57