| // 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" | |
| // See memclrNoHeapPointers Go doc for important implementation constraints. | |
| // func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr) | |
| TEXT runtime·memclrNoHeapPointers(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 |