| Austin Schuh | dace2a6 | 2020-08-18 10:56:48 -0700 | [diff] [blame] | 1 | dnl Alpha time stamp counter access routine. |
| 2 | |
| 3 | dnl Copyright 2000, 2005 Free Software Foundation, Inc. |
| 4 | |
| 5 | dnl This file is part of the GNU MP Library. |
| 6 | dnl |
| 7 | dnl The GNU MP Library is free software; you can redistribute it and/or modify |
| 8 | dnl it under the terms of either: |
| 9 | dnl |
| 10 | dnl * the GNU Lesser General Public License as published by the Free |
| 11 | dnl Software Foundation; either version 3 of the License, or (at your |
| 12 | dnl option) any later version. |
| 13 | dnl |
| 14 | dnl or |
| 15 | dnl |
| 16 | dnl * the GNU General Public License as published by the Free Software |
| 17 | dnl Foundation; either version 2 of the License, or (at your option) any |
| 18 | dnl later version. |
| 19 | dnl |
| 20 | dnl or both in parallel, as here. |
| 21 | dnl |
| 22 | dnl The GNU MP Library is distributed in the hope that it will be useful, but |
| 23 | dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 24 | dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 25 | dnl for more details. |
| 26 | dnl |
| 27 | dnl You should have received copies of the GNU General Public License and the |
| 28 | dnl GNU Lesser General Public License along with the GNU MP Library. If not, |
| 29 | dnl see https://www.gnu.org/licenses/. |
| 30 | |
| 31 | include(`../config.m4') |
| 32 | |
| 33 | |
| 34 | C void speed_cyclecounter (unsigned int p[2]); |
| 35 | C |
| 36 | |
| 37 | C The rpcc instruction returns a 64-bit value split into two 32-bit fields. |
| 38 | C The lower 32 bits are set by the hardware, and the upper 32 bits are set |
| 39 | C by the operating system. The real per-process cycle count is the sum of |
| 40 | C these halves. |
| 41 | |
| 42 | C Unfortunately, some operating systems don't get this right. NetBSD 1.3 is |
| 43 | C known to sometimes put garbage in the upper half. Whether newer NetBSD |
| 44 | C versions get it right, is unknown to us. |
| 45 | |
| 46 | C rpcc measures cycles elapsed in the user program and hence should be very |
| 47 | C accurate even on a busy system. Losing cache contents due to task |
| 48 | C switching may have an effect though. |
| 49 | |
| 50 | ASM_START() |
| 51 | PROLOGUE(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 |
| 58 | EPILOGUE(speed_cyclecounter) |
| 59 | ASM_END() |