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authorUlrich Drepper <drepper@redhat.com>2005-11-01 02:13:41 +0000
committerUlrich Drepper <drepper@redhat.com>2005-11-01 02:13:41 +0000
commit7006f757e6d6f110b88f6a5a7759d1e118870489 (patch)
tree7630af90063c8630ff668bcfb06972db2f5ecdef /sysdeps
parentcb07f6f67db0ef4ccbf3bedfb7c9c4f140773d2c (diff)
* sysdeps/powerpc/powerpc64/Makefile
(sysdep_routines, elide-routines.os): Add hp-timing. * sysdeps/powerpc/powerpc64/hp-timing.c: New file. * sysdeps/powerpc/powerpc64/hp-timing.h: New file. * sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c: New file.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/powerpc/powerpc64/Makefile2
-rw-r--r--sysdeps/powerpc/powerpc64/hp-timing.c25
-rw-r--r--sysdeps/powerpc/powerpc64/hp-timing.h136
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c105
4 files changed, 268 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc64/Makefile b/sysdeps/powerpc/powerpc64/Makefile
index cf29148ff3..cf7c4337e0 100644
--- a/sysdeps/powerpc/powerpc64/Makefile
+++ b/sysdeps/powerpc/powerpc64/Makefile
@@ -11,6 +11,8 @@ pic-ccflag = -fpic
endif
ifeq ($(subdir),csu)
+sysdep_routines += hp-timing
+elide-routines.os += hp-timing
ifneq ($(elf),no)
# The initfini generation code doesn't work in the presence of -fPIC, so
# we use -fpic instead which is much better.
diff --git a/sysdeps/powerpc/powerpc64/hp-timing.c b/sysdeps/powerpc/powerpc64/hp-timing.c
new file mode 100644
index 0000000000..4e54e66e5e
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/hp-timing.c
@@ -0,0 +1,25 @@
+/* Support for high precision, low overhead timing functions.
+ powerpc64 version.
+ Copyright (C) 2005 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. */
+
+#include <hp-timing.h>
+
+/* We have to define the variable for the overhead. */
+hp_timing_t _dl_hp_timing_overhead;
diff --git a/sysdeps/powerpc/powerpc64/hp-timing.h b/sysdeps/powerpc/powerpc64/hp-timing.h
new file mode 100644
index 0000000000..b58cca9003
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/hp-timing.h
@@ -0,0 +1,136 @@
+/* High precision, low overhead timing functions. powerpc64 version.
+ Copyright (C) 2005 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
+
+#include <string.h>
+#include <sys/param.h>
+#include <stdio-common/_itoa.h>
+#include <atomic.h>
+
+/* The macros defined here use the powerpc 64-bit time base register.
+ The time base is nominally clocked at 1/8th the CPU clock, but this
+ can vary.
+
+ 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 assume having the timestamp register. */
+#define HP_TIMING_AVAIL (1)
+
+/* We indeed have inlined functions. */
+#define HP_TIMING_INLINE (1)
+
+/* We use 64bit values for the times. */
+typedef unsigned long long int hp_timing_t;
+
+/* Set timestamp value to zero. */
+#define HP_TIMING_ZERO(Var) (Var) = (0)
+
+/* That's quite simple. Use the `mftb' instruction. Note that the value
+ might not be 100% accurate since there might be some more instructions
+ running in this moment. This could be changed by using a barrier like
+ 'lwsync' right before the `mftb' instruciton. But we are not interested
+ in accurate clock cycles here so we don't do this. */
+#define HP_TIMING_NOW(Var) __asm__ __volatile__ ("mftb %0" : "=r" (Var))
+
+/* Use two 'mftb' instructions in a row to find out how long it takes.
+ On current POWER4, POWER5, and 970 processors mftb take ~10 cycles. */
+#define HP_TIMING_DIFF_INIT() \
+ do { \
+ if (GLRO(dl_hp_timing_overhead) == 0) \
+ { \
+ int __cnt = 5; \
+ GLRO(dl_hp_timing_overhead) = ~0ull; \
+ do \
+ { \
+ hp_timing_t __t1, __t2; \
+ HP_TIMING_NOW (__t1); \
+ HP_TIMING_NOW (__t2); \
+ if (__t2 - __t1 < GLRO(dl_hp_timing_overhead)) \
+ GLRO(dl_hp_timing_overhead) = __t2 - __t1; \
+ } \
+ while (--__cnt > 0); \
+ } \
+ } while (0)
+
+/* It's simple arithmetic in 64-bit. */
+#define HP_TIMING_DIFF(Diff, Start, End) (Diff) = ((End) - (Start))
+
+/* We need to insure that this add is atomic in threaded environments. We use
+ __arch_atomic_exchange_and_add_64 from atomic.h to get thread safety. */
+#define HP_TIMING_ACCUM(Sum, Diff) \
+ do { \
+ hp_timing_t __diff = (Diff) - GLRO(dl_hp_timing_overhead); \
+ __arch_atomic_exchange_and_add_64 (&(Sum), __diff); \
+ } while (0)
+
+/* 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 (Val, __buf + sizeof (__buf), 10, 0); \
+ size_t __len = (Len); \
+ char *__dest = (Buf); \
+ while (__len-- > 0 && __cp < __buf + sizeof (__buf)) \
+ *__dest++ = *__cp++; \
+ memcpy (__dest, " ticks", MIN (__len, sizeof (" ticks"))); \
+ } while (0)
+
+#endif /* hp-timing.h */
diff --git a/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c b/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
new file mode 100644
index 0000000000..ddaff303c5
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
@@ -0,0 +1,105 @@
+/* Get frequency of the system processor. powerpc/Linux version.
+ Copyright (C) 2000, 2001, 2005 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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. */
+
+#include <ctype.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <libc-internal.h>
+
+
+hp_timing_t
+__get_clockfreq (void)
+{
+ /* We read the information from the /proc filesystem. /proc/cpuinfo
+ contains at least one line like:
+ timebase : 33333333
+ We search for this line and convert the number into an integer. */
+ static hp_timing_t timebase_freq;
+ hp_timing_t result = 0L;
+
+ /* If this function was called before, we know the result. */
+ if (timebase_freq != 0)
+ return timebase_freq;
+
+ int fd = open ("/proc/cpuinfo", O_RDONLY);
+ if (__builtin_expect (fd != -1, 1))
+ {
+ /* The timebase will be in the 1st 1024 bytes for systems with up
+ to 8 processors. If the first read returns less then 1024
+ bytes read, we have the whole cpuinfo and can start the scan.
+ Otherwise we will have to read more to insure we have the
+ timebase value in the scan. */
+ char buf[1024];
+ ssize_t n;
+
+ n = read (fd, buf, sizeof (buf));
+ if (n == sizeof (buf))
+ {
+ /* We are here because the 1st read returned exactly sizeof
+ (buf) bytes. This implies that we are not at EOF and may
+ not have read the timebase value yet. So we need to read
+ more bytes until we know we have EOF. We copy the lower
+ half of buf to the upper half and read sizeof (buf)/2
+ bytes into the lower half of buf and repeat until we
+ reach EOF. We can assume that the timebase will be in
+ the last 512 bytes of cpuinfo, so two 512 byte half_bufs
+ will be sufficient to contain the timebase and will
+ handle the case where the timebase spans the half_buf
+ boundry. */
+ const ssize_t half_buf = sizeof (buf) / 2;
+ while (n >= half_buf)
+ {
+ memcpy (buf, buf + half_buf, half_buf);
+ n = read (fd, buf + half_buf, half_buf);
+ }
+ if (n >= 0)
+ n += half_buf;
+ }
+
+ if (__builtin_expect (n, 1) > 0)
+ {
+ char *mhz = memmem (buf, n, "timebase", 7);
+
+ if (__builtin_expect (mhz != NULL, 1))
+ {
+ char *endp = buf + n;
+
+ /* Search for the beginning of the string. */
+ while (mhz < endp && (*mhz < '0' || *mhz > '9') && *mhz != '\n')
+ ++mhz;
+
+ while (mhz < endp && *mhz != '\n')
+ {
+ if (*mhz >= '0' && *mhz <= '9')
+ {
+ result *= 10;
+ result += *mhz - '0';
+ }
+
+ ++mhz;
+ }
+ }
+ timebase_freq = result;
+ }
+ close (fd);
+ }
+
+ return timebase_freq;
+}