1dnl  x86 pentium time stamp counter access routine.
2
3dnl  Copyright 1999, 2000, 2003-2005 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
31
32include(`../config.m4')
33
34
35C void speed_cyclecounter (unsigned p[2]);
36C
37C Get the pentium rdtsc cycle counter, storing the least significant word in
38C p[0] and the most significant in p[1].
39C
40C cpuid is used to serialize execution.  On big measurements this won't be
41C significant but it may help make small single measurements more accurate.
42
43PROLOGUE(speed_cyclecounter)
44
45	C rdi	p
46
47	movq	%rbx, %r10
48	xorl	%eax, %eax
49	cpuid
50	rdtsc
51	movl	%eax, (%rdi)
52	movl	%edx, 4(%rdi)
53	movq	%r10, %rbx
54	ret
55EPILOGUE()
56