1 /* High precision, low overhead timing functions.  powerpc64 version.
2    Copyright (C) 2005-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _HP_TIMING_H
20 #define _HP_TIMING_H	1
21 
22 /* We indeed have inlined functions.  */
23 #define HP_TIMING_INLINE	(1)
24 
25 /* We use 64bit values for the times.  */
26 typedef unsigned long long int hp_timing_t;
27 
28 /* That's quite simple.  Use the `mftb' instruction.  Note that the value
29    might not be 100% accurate since there might be some more instructions
30    running in this moment.  This could be changed by using a barrier like
31    'lwsync' right before the `mftb' instruction.  But we are not interested
32    in accurate clock cycles here so we don't do this.  */
33 
34 #define HP_TIMING_NOW(Var)						\
35   do {									\
36     unsigned int hi, lo, tmp;						\
37     __asm__ __volatile__ ("1:	mfspr	%0,269;"			\
38 			  "	mfspr	%1,268;"			\
39 			  "	mfspr	%2,269;"			\
40 			  "	cmpw	%0,%2;"				\
41 			  "	bne	1b;"				\
42 			  : "=&r" (hi), "=&r" (lo), "=&r" (tmp)		\
43 			  : : "cr0");					\
44     Var = ((hp_timing_t) hi << 32) | lo;				\
45   } while (0)
46 
47 #include <hp-timing-common.h>
48 
49 #endif	/* hp-timing.h */
50