buildtools/gcc/gmp/tune/alpha.asm
Fredrik Holmqvist f133d007f9 Upgrade GMP from 5.0.5 to 6.1.2 (2016-12-16)
Old version was from 2012-05-06, 6.1.2 is from 2016-12-16
A lot of support for newer processors and speedups since then
See gmp/NEWS for details
2018-07-04 20:20:59 +02:00

60 lines
2.0 KiB
NASM

dnl Alpha time stamp counter access routine.
dnl Copyright 2000, 2005 Free Software Foundation, Inc.
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 modify
dnl it under the terms of either:
dnl
dnl * the GNU Lesser General Public License as published by the Free
dnl Software Foundation; either version 3 of the License, or (at your
dnl option) any later version.
dnl
dnl or
dnl
dnl * the GNU General Public License as published by the Free Software
dnl Foundation; either version 2 of the License, or (at your option) any
dnl later version.
dnl
dnl or both in parallel, as here.
dnl
dnl The GNU MP Library is distributed in the hope that it will be useful, but
dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
dnl for more details.
dnl
dnl You should have received copies of the GNU General Public License and the
dnl GNU Lesser General Public License along with the GNU MP Library. If not,
dnl see https://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()