benchtests: Add benchtests for dl_elf_hash, dl_new_hash and nss_hash

Benchtests are for throughput and include random / fixed size
benchmarks.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

1 files changed, 86 insertions, 0 deletions

diff --git a/benchtests/bench-hash-funcs-kernel.h b/benchtests/bench-hash-funcs-kernel.h
new file mode 100644
index 0000000000..83995cc0ae
--- /dev/null
+++ b/benchtests/bench-hash-funcs-kernel.h
@@ -0,0 +1,86 @@
+/* Actual benchmark kernels used by bench-hash-funcs.h
+   Copyright (C) 2022 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/>.  */
+
+
+
+/* We go through the trouble of using macros here because many of the
+   hash functions are meant to be inlined so its not fair to benchmark
+   them with a function pointer where they won't be inlinable. */
+#undef RUN_FUNC
+#undef POSTFIX
+#ifdef SIMPLE
+# define RUN_FUNC SIMPLE_TEST_FUNC
+# define POSTFIX _simple
+#else
+# define RUN_FUNC TEST_FUNC
+# define POSTFIX _optimized
+#endif
+
+#define PRIMITIVE_CAT(x, y) x ## y
+#define CAT(x, y) PRIMITIVE_CAT (x, y)
+
+static double __attribute__ ((noinline, noclone))
+CAT (do_one_test_kernel, POSTFIX) (const char *s, size_t len)
+{
+
+  unsigned int iters;
+  timing_t start, stop, cur;
+
+  /* Warmup.  */
+  for (iters = NFIXED_ITERS / 32; iters; --iters)
+    DO_NOT_OPTIMIZE_OUT (RUN_FUNC (s, len));
+
+  TIMING_NOW (start);
+  for (iters = NFIXED_ITERS; iters; --iters)
+    DO_NOT_OPTIMIZE_OUT (RUN_FUNC (s, len));
+
+  TIMING_NOW (stop);
+
+  TIMING_DIFF (cur, start, stop);
+
+  (void) (len);
+  return (double) cur / (double) NFIXED_ITERS;
+}
+
+static double __attribute__ ((noinline, noclone))
+CAT (do_rand_test_kernel, POSTFIX) (char const *bufs,
+				    unsigned int const *sizes)
+{
+  unsigned int i, iters;
+  size_t offset;
+  timing_t start, stop, cur;
+
+  /* Warmup.  */
+  for (i = 0, offset = 0; i < NRAND_BUFS; ++i, offset += RAND_BENCH_MAX_LEN)
+    DO_NOT_OPTIMIZE_OUT (RUN_FUNC (bufs + offset, sizes[i]));
+
+  TIMING_NOW (start);
+  for (iters = NRAND_ITERS; iters; --iters)
+    {
+      for (i = 0, offset = 0; i < NRAND_BUFS;
+	   ++i, offset += RAND_BENCH_MAX_LEN)
+	DO_NOT_OPTIMIZE_OUT (RUN_FUNC (bufs + offset, sizes[i]));
+
+    }
+  TIMING_NOW (stop);
+
+  TIMING_DIFF (cur, start, stop);
+
+  (void) (sizes);
+  return (double) cur / (double) (NRAND_ITERS * NRAND_BUFS);
+}