| // Copyright 2014 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| #include "textflag.h" |
| |
| // void runtime·memclr(void*, uintptr) |
| TEXT runtime·memclr(SB), NOSPLIT, $0-8 |
| MOVL ptr+0(FP), DI |
| MOVL n+4(FP), BX |
| XORL AX, AX |
| |
| tail: |
| TESTL BX, BX |
| JEQ _0 |
| CMPL BX, $2 |
| JBE _1or2 |
| CMPL BX, $4 |
| JB _3 |
| JE _4 |
| CMPL BX, $8 |
| JBE _5through8 |
| CMPL BX, $16 |
| JBE _9through16 |
| MOVL BX, CX |
| SHRL $2, CX |
| REP |
| STOSL |
| ANDL $3, BX |
| JNE tail |
| RET |
| |
| _1or2: |
| MOVB AX, (DI) |
| MOVB AX, -1(DI)(BX*1) |
| RET |
| _0: |
| RET |
| _3: |
| MOVW AX, (DI) |
| MOVB AX, 2(DI) |
| RET |
| _4: |
| // We need a separate case for 4 to make sure we clear pointers atomically. |
| MOVL AX, (DI) |
| RET |
| _5through8: |
| MOVL AX, (DI) |
| MOVL AX, -4(DI)(BX*1) |
| RET |
| _9through16: |
| MOVL AX, (DI) |
| MOVL AX, 4(DI) |
| MOVL AX, -8(DI)(BX*1) |
| MOVL AX, -4(DI)(BX*1) |
| RET |
