dnl  x86 pentium time stamp counter access routine.

dnl  Copyright 1999, 2000, 2003-2005 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 p[2]);

C

C Get the pentium rdtsc cycle counter, storing the least significant word in

C p[0] and the most significant in p[1].

C

C cpuid is used to serialize execution.  On big measurements this won't be

C significant but it may help make small single measurements more accurate.

PROLOGUE(speed_cyclecounter)

	C rdi	p

	movq	%rbx, %r10

	xorl	%eax, %eax

	cpuid

	rdtsc

	movl	%eax, (%rdi)

	movl	%edx, 4(%rdi)

	movq	%r10, %rbx

	ret

EPILOGUE()