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-rw-r--r--libc/sysdeps/linux/common/hp-timing.h83
1 files changed, 83 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/common/hp-timing.h b/libc/sysdeps/linux/common/hp-timing.h
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+/* High precision, low overhead timing functions. Generic version.
+ Copyright (C) 1998, 2000 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#ifndef _HP_TIMING_H
+#define _HP_TIMING_H 1
+
+
+/* There are no generic definitions for the times. We could write something
+ using the `gettimeofday' system call where available but the overhead of
+ the system call might be too high.
+
+ In case a platform supports timers in the hardware the following macros
+ and types must be defined:
+
+ - HP_TIMING_AVAIL: test for availability.
+
+ - HP_TIMING_INLINE: this macro is non-zero if the functionality is not
+ implemented using function calls but instead uses some inlined code
+ which might simply consist of a few assembler instructions. We have to
+ know this since we might want to use the macros here in places where we
+ cannot make function calls.
+
+ - hp_timing_t: This is the type for variables used to store the time
+ values.
+
+ - HP_TIMING_ZERO: clear `hp_timing_t' object.
+
+ - HP_TIMING_NOW: place timestamp for current time in variable given as
+ parameter.
+
+ - HP_TIMING_DIFF_INIT: do whatever is necessary to be able to use the
+ HP_TIMING_DIFF macro.
+
+ - HP_TIMING_DIFF: compute difference between two times and store it
+ in a third. Source and destination might overlap.
+
+ - HP_TIMING_ACCUM: add time difference to another variable. This might
+ be a bit more complicated to implement for some platforms as the
+ operation should be thread-safe and 64bit arithmetic on 32bit platforms
+ is not.
+
+ - HP_TIMING_ACCUM_NT: this is the variant for situations where we know
+ there are no threads involved.
+
+ - HP_TIMING_PRINT: write decimal representation of the timing value into
+ the given string. This operation need not be inline even though
+ HP_TIMING_INLINE is specified.
+
+*/
+
+/* Provide dummy definitions. */
+#define HP_TIMING_AVAIL (0)
+#define HP_TIMING_INLINE (0)
+typedef int hp_timing_t;
+#define HP_TIMING_ZERO(Var)
+#define HP_TIMING_NOW(var)
+#define HP_TIMING_DIFF_INIT()
+#define HP_TIMING_DIFF(Diff, Start, End)
+#define HP_TIMING_ACCUM(Sum, Diff)
+#define HP_TIMING_ACCUM_NT(Sum, Diff)
+#define HP_TIMING_PRINT(Buf, Len, Val)
+
+/* Since this implementation is not available we tell the user about it. */
+#define HP_TIMING_NONAVAIL 1
+
+#endif /* hp-timing.h */