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Diffstat (limited to 'sysdeps/alpha/hp-timing.h')
| -rw-r--r-- | sysdeps/alpha/hp-timing.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/sysdeps/alpha/hp-timing.h b/sysdeps/alpha/hp-timing.h new file mode 100644 index 0000000000..ccae06b487 --- /dev/null +++ b/sysdeps/alpha/hp-timing.h @@ -0,0 +1,118 @@ +/* High precision, low overhead timing functions. Alpha version. + Copyright (C) 2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Richard Henderson <rth@redhat.com>, 2001. + + 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 + +#include <string.h> +#include <sys/param.h> +#include <stdio-common/_itoa.h> + +/* The macros defined here use the timestamp counter in IA-64. They + provide a very accurate way to measure the time with very little + overhead. The time values themself have no real meaning, only + differences are interesting. + + The list of macros we need includes the following: + + - 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. +*/ + +/* We always have the timestamp register, but it's got only a 4 second + range. Use it for ld.so profiling only. */ +#define HP_TIMING_AVAIL (0) +#define HP_SMALL_TIMING_AVAIL (1) + +/* We indeed have inlined functions. */ +#define HP_TIMING_INLINE (1) + +/* We use 32 bit values for the times. */ +typedef unsigned int hp_timing_t; + +/* Set timestamp value to zero. */ +#define HP_TIMING_ZERO(VAR) (VAR) = (0) + +/* The "rpcc" instruction returns a 32-bit counting half and a 32-bit + "virtual cycle counter displacement". Subtracting the two gives us + a virtual cycle count. */ +#define HP_TIMING_NOW(VAR) \ + do { \ + unsigned long int x_; \ + asm volatile ("rpcc %0" : "=r"(x_)); \ + (VAR) = (int) (x_) - (int) (x_ >> 32); \ + } while (0) + +/* ??? Two rpcc instructions can be scheduled simultaneously. */ +#define HP_TIMING_DIFF_INIT() do { } while (0) + +/* It's simple arithmetic for us. */ +#define HP_TIMING_DIFF(Diff, Start, End) (Diff) = ((End) - (Start)) + +/* ??? Don't bother, since we're only used for ld.so. */ +#define HP_TIMING_ACCUM(Sum, Diff) not implemented + +/* No threads, no extra work. */ +#define HP_TIMING_ACCUM_NT(Sum, Diff) (Sum) += (Diff) + +/* Print the time value. */ +#define HP_TIMING_PRINT(Buf, Len, Val) \ + do { \ + char __buf[20]; \ + char *__cp = _itoa_word (Val, __buf + sizeof (__buf), 10, 0); \ + int __len = (Len); \ + char *__dest = (Buf); \ + while (__len-- > 0 && __cp < __buf + sizeof (__buf)) \ + *__dest++ = *__cp++; \ + memcpy (__dest, " clock cycles", MIN (__len, sizeof (" clock cycles"))); \ + } while (0) + +#endif /* hp-timing.h */ |