memclr_plan9_386.s

Documentation: runtime

     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// See memclrNoHeapPointers Go doc for important implementation constraints.
     8
     9// func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr)
    10TEXT runtime·memclrNoHeapPointers(SB), NOSPLIT, $0-8
    11	MOVL	ptr+0(FP), DI
    12	MOVL	n+4(FP), BX
    13	XORL	AX, AX
    14
    15tail:
    16	TESTL	BX, BX
    17	JEQ	_0
    18	CMPL	BX, $2
    19	JBE	_1or2
    20	CMPL	BX, $4
    21	JB	_3
    22	JE	_4
    23	CMPL	BX, $8
    24	JBE	_5through8
    25	CMPL	BX, $16
    26	JBE	_9through16
    27	MOVL	BX, CX
    28	SHRL	$2, CX
    29	REP
    30	STOSL
    31	ANDL	$3, BX
    32	JNE	tail
    33	RET
    34
    35_1or2:
    36	MOVB	AX, (DI)
    37	MOVB	AX, -1(DI)(BX*1)
    38	RET
    39_0:
    40	RET
    41_3:
    42	MOVW	AX, (DI)
    43	MOVB	AX, 2(DI)
    44	RET
    45_4:
    46	// We need a separate case for 4 to make sure we clear pointers atomically.
    47	MOVL	AX, (DI)
    48	RET
    49_5through8:
    50	MOVL	AX, (DI)
    51	MOVL	AX, -4(DI)(BX*1)
    52	RET
    53_9through16:
    54	MOVL	AX, (DI)
    55	MOVL	AX, 4(DI)
    56	MOVL	AX, -8(DI)(BX*1)
    57	MOVL	AX, -4(DI)(BX*1)
    58	RET
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