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Diffstat (limited to 'src/runtime/memclr_arm.s')
| -rw-r--r-- | src/runtime/memclr_arm.s | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/src/runtime/memclr_arm.s b/src/runtime/memclr_arm.s new file mode 100644 index 0000000..f02d058 --- /dev/null +++ b/src/runtime/memclr_arm.s @@ -0,0 +1,91 @@ +// Inferno's libkern/memset-arm.s +// https://bitbucket.org/inferno-os/inferno-os/src/master/libkern/memset-arm.s +// +// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. +// Revisions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com). All rights reserved. +// Portions Copyright 2009 The Go Authors. All rights reserved. +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. + +#include "textflag.h" + +#define TO R8 +#define TOE R11 +#define N R12 +#define TMP R12 /* N and TMP don't overlap */ + +// See memclrNoHeapPointers Go doc for important implementation constraints. + +// func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr) +// Also called from assembly in sys_windows_arm.s without g (but using Go stack convention). +TEXT runtime·memclrNoHeapPointers(SB),NOSPLIT,$0-8 + MOVW ptr+0(FP), TO + MOVW n+4(FP), N + MOVW $0, R0 + + ADD N, TO, TOE /* to end pointer */ + + CMP $4, N /* need at least 4 bytes to copy */ + BLT _1tail + +_4align: /* align on 4 */ + AND.S $3, TO, TMP + BEQ _4aligned + + MOVBU.P R0, 1(TO) /* implicit write back */ + B _4align + +_4aligned: + SUB $31, TOE, TMP /* do 32-byte chunks if possible */ + CMP TMP, TO + BHS _4tail + + MOVW R0, R1 /* replicate */ + MOVW R0, R2 + MOVW R0, R3 + MOVW R0, R4 + MOVW R0, R5 + MOVW R0, R6 + MOVW R0, R7 + +_f32loop: + CMP TMP, TO + BHS _4tail + + MOVM.IA.W [R0-R7], (TO) + B _f32loop + +_4tail: + SUB $3, TOE, TMP /* do remaining words if possible */ +_4loop: + CMP TMP, TO + BHS _1tail + + MOVW.P R0, 4(TO) /* implicit write back */ + B _4loop + +_1tail: + CMP TO, TOE + BEQ _return + + MOVBU.P R0, 1(TO) /* implicit write back */ + B _1tail + +_return: + RET |