1dnl Alpha time stamp counter access routine. 2 3dnl Copyright 2000, 2005 Free Software Foundation, Inc. 4 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 modify 8dnl it under the terms of either: 9dnl 10dnl * the GNU Lesser General Public License as published by the Free 11dnl Software Foundation; either version 3 of the License, or (at your 12dnl option) any later version. 13dnl 14dnl or 15dnl 16dnl * the GNU General Public License as published by the Free Software 17dnl Foundation; either version 2 of the License, or (at your option) any 18dnl later version. 19dnl 20dnl or both in parallel, as here. 21dnl 22dnl The GNU MP Library is distributed in the hope that it will be useful, but 23dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 24dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 25dnl for more details. 26dnl 27dnl You should have received copies of the GNU General Public License and the 28dnl GNU Lesser General Public License along with the GNU MP Library. If not, 29dnl see https://www.gnu.org/licenses/. 30 31include(`../config.m4') 32 33 34C void speed_cyclecounter (unsigned int p[2]); 35C 36 37C The rpcc instruction returns a 64-bit value split into two 32-bit fields. 38C The lower 32 bits are set by the hardware, and the upper 32 bits are set 39C by the operating system. The real per-process cycle count is the sum of 40C these halves. 41 42C Unfortunately, some operating systems don't get this right. NetBSD 1.3 is 43C known to sometimes put garbage in the upper half. Whether newer NetBSD 44C versions get it right, is unknown to us. 45 46C rpcc measures cycles elapsed in the user program and hence should be very 47C accurate even on a busy system. Losing cache contents due to task 48C switching may have an effect though. 49 50ASM_START() 51PROLOGUE(speed_cyclecounter) 52 rpcc r0 53 srl r0,32,r1 54 addq r1,r0,r0 55 stl r0,0(r16) 56 stl r31,4(r16) C zero upper return word 57 ret r31,(r26),1 58EPILOGUE(speed_cyclecounter) 59ASM_END() 60