github.com/stingnevermore/go@v0.0.0-20180120041312-3810f5bfed72/src/runtime/memclr_plan9_386.s (about)

     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  // void runtime·memclrNoHeapPointers(void*, uintptr)
     8  TEXT runtime·memclrNoHeapPointers(SB), NOSPLIT, $0-8
     9  	MOVL	ptr+0(FP), DI
    10  	MOVL	n+4(FP), BX
    11  	XORL	AX, AX
    12  
    13  tail:
    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