1 files changed, 61 insertions, 0 deletions
diff --git a/sysdeps/x86/hp-timing.h b/sysdeps/x86/hp-timing.h
new file mode 100644
index 0000000000..a230732baf
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+++ b/sysdeps/x86/hp-timing.h
@@ -0,0 +1,61 @@
+/* High precision, low overhead timing functions.  x86 version.
+   Copyright (C) 2018-2019 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, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _HP_TIMING_H
+#define _HP_TIMING_H	1
+
+#include <isa.h>
+
+#if MINIMUM_ISA == 686 || MINIMUM_ISA == 8664
+/* 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;
+
+/* That's quite simple.  Use the `rdtsc' 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
+   'cpuid' right before the `rdtsc' instruciton.  But we are not interested
+   in accurate clock cycles here so we don't do this.
+
+   NB: Use __builtin_ia32_rdtsc directly since including <x86intrin.h>
+   makes building glibc very slow.  */
+# ifdef USE_RDTSCP
+/* RDTSCP waits until all previous instructions have executed and all
+   previous loads are globally visible before reading the counter.
+   RDTSC doesn't wait until all previous instructions have been executed
+   before reading the counter.  */
+#  define HP_TIMING_NOW(Var) \
+  (__extension__ ({				\
+    unsigned int __aux;				\
+    (Var) = __builtin_ia32_rdtscp (&__aux);	\
+  }))
+# else
+#  define HP_TIMING_NOW(Var) ((Var) = __builtin_ia32_rdtsc ())
+# endif
+
+# include <hp-timing-common.h>
+#else
+/* NB: Undefine _HP_TIMING_H so that <sysdeps/generic/hp-timing.h> will
+   be included.  */
+# undef _HP_TIMING_H
+# include <sysdeps/generic/hp-timing.h>
+#endif
+
+#endif /* hp-timing.h */