1dnl Alpha time stamp counter access routine. 2 3dnl Copyright 2000, 2005 Free Software Foundation, Inc. 4dnl 5dnl This file is part of the GNU MP Library. 6dnl 7dnl The GNU MP Library is free software; you can redistribute it and/or 8dnl modify it under the terms of the GNU Lesser General Public License as 9dnl published by the Free Software Foundation; either version 3 of the 10dnl License, or (at your option) any later version. 11dnl 12dnl The GNU MP Library is distributed in the hope that it will be useful, 13dnl but WITHOUT ANY WARRANTY; without even the implied warranty of 14dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15dnl Lesser General Public License for more details. 16dnl 17dnl You should have received a copy of the GNU Lesser General Public License 18dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. 19 20include(`../config.m4') 21 22 23C void speed_cyclecounter (unsigned int p[2]); 24C 25 26C The rpcc instruction returns a 64-bit value split into two 32-bit fields. 27C The lower 32 bits are set by the hardware, and the upper 32 bits are set 28C by the operating system. The real per-process cycle count is the sum of 29C these halves. 30 31C Unfortunately, some operating systems don't get this right. NetBSD 1.3 is 32C known to sometimes put garbage in the upper half. Whether newer NetBSD 33C versions get it right, is unknown to us. 34 35C rpcc measures cycles elapsed in the user program and hence should be very 36C accurate even on a busy system. Losing cache contents due to task 37C switching may have an effect though. 38 39ASM_START() 40PROLOGUE(speed_cyclecounter) 41 rpcc r0 42 srl r0,32,r1 43 addq r1,r0,r0 44 stl r0,0(r16) 45 stl r31,4(r16) C zero upper return word 46 ret r31,(r26),1 47EPILOGUE(speed_cyclecounter) 48ASM_END() 49