alpha.asm
上传用户:qaz666999
上传日期:2022-08-06
资源大小:2570k
文件大小:2k
- dnl Alpha time stamp counter access routine.
- dnl Copyright 2000, 2005 Free Software Foundation, Inc.
- dnl
- dnl This file is part of the GNU MP Library.
- dnl
- dnl The GNU MP Library is free software; you can redistribute it and/or
- dnl modify it under the terms of the GNU Lesser General Public License as
- dnl published by the Free Software Foundation; either version 3 of the
- dnl License, or (at your option) any later version.
- dnl
- dnl The GNU MP Library is distributed in the hope that it will be useful,
- dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
- dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- dnl Lesser General Public License for more details.
- dnl
- dnl You should have received a copy of the GNU Lesser General Public License
- dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
- include(`../config.m4')
- C void speed_cyclecounter (unsigned int p[2]);
- C
- C The rpcc instruction returns a 64-bit value split into two 32-bit fields.
- C The lower 32 bits are set by the hardware, and the upper 32 bits are set
- C by the operating system. The real per-process cycle count is the sum of
- C these halves.
- C Unfortunately, some operating systems don't get this right. NetBSD 1.3 is
- C known to sometimes put garbage in the upper half. Whether newer NetBSD
- C versions get it right, is unknown to us.
- C rpcc measures cycles elapsed in the user program and hence should be very
- C accurate even on a busy system. Losing cache contents due to task
- C switching may have an effect though.
- ASM_START()
- PROLOGUE(speed_cyclecounter)
- rpcc r0
- srl r0,32,r1
- addq r1,r0,r0
- stl r0,0(r16)
- stl r31,4(r16) C zero upper return word
- ret r31,(r26),1
- EPILOGUE(speed_cyclecounter)
- ASM_END()