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authorWilco Dijkstra <wdijkstr@arm.com>2015-09-18 16:02:38 +0100
committerWilco Dijkstra <wdijkstr@arm.com>2015-09-18 16:02:38 +0100
commitcb2f668d4692df8d31b2ccf9b18b86bebe2d9174 (patch)
treea573cb40e143d907c480181e8edfb62951258816 /benchtests/bench-util.c
parente2b918d05db58248d5a61427e9f1416ccce782c9 (diff)
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Add a new benchmark for isinf/isnan/isnormal/isfinite/fpclassify. The test uses 2 arrays with 1024 doubles, one with 99% finite FP numbers (10% zeroes, 10% negative) and 1% inf/NaN, the other with 50% inf, and 50% Nan.
ChangeLog:
2015-09-18  Wilco Dijkstra  <wdijkstr@arm.com>

	* benchtests/Makefile: Add bench-math-inlines, link with libm.
	* benchtests/bench-math-inlines.c: New benchmark.
	* benchtests/bench-util.h: New file.
	* benchtests/bench-util.c: New file.
	* benchtests/bench-skeleton.c: Add include of bench-util.c/h.
Diffstat (limited to 'benchtests/bench-util.c')
-rw-r--r--benchtests/bench-util.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/benchtests/bench-util.c b/benchtests/bench-util.c
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+++ b/benchtests/bench-util.c
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+/* Benchmark utility functions.
+   Copyright (C) 2015 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
+   <http://www.gnu.org/licenses/>.  */
+
+
+static volatile unsigned int dontoptimize = 0;
+
+void
+bench_start (void)
+{
+  /* This loop should cause CPU to switch to maximal freqency.
+     This makes subsequent measurement more accurate.  We need a side effect
+     to prevent the loop being deleted by compiler.
+     This should be enough to cause CPU to speed up and it is simpler than
+     running loop for constant time.  This is used when user does not have root
+     access to set a constant freqency.  */
+
+  for (int k = 0; k < START_ITER; k++)
+    dontoptimize += 23 * dontoptimize + 2;
+}