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| author | David Robillard <d@drobilla.net> | 2021-07-02 13:54:45 -0400 |
|---|---|---|
| committer | David Robillard <d@drobilla.net> | 2021-07-17 19:58:17 -0400 |
| commit | 5942e985c6ac9b18090ec92b11aa8a586b6365c5 (patch) | |
| tree | ce66d68e863df9ecba01c16dfe1a5bc7100068f0 /benchmark | |
| parent | bc264ab6f58177124d49a72b4a808eb97fa2cb25 (diff) | |
| download | zix-5942e985c6ac9b18090ec92b11aa8a586b6365c5.tar.gz zix-5942e985c6ac9b18090ec92b11aa8a586b6365c5.tar.bz2 zix-5942e985c6ac9b18090ec92b11aa8a586b6365c5.zip | |
Avoid use of rand()
Diffstat (limited to 'benchmark')
| -rw-r--r-- | benchmark/.clang-tidy | 4 | ||||
| -rw-r--r-- | benchmark/dict_bench.c | 16 | ||||
| -rw-r--r-- | benchmark/tree_bench.c | 18 |
3 files changed, 14 insertions, 24 deletions
diff --git a/benchmark/.clang-tidy b/benchmark/.clang-tidy index 06febc0..2c16e13 100644 --- a/benchmark/.clang-tidy +++ b/benchmark/.clang-tidy @@ -7,10 +7,6 @@ Checks: > -bugprone-suspicious-string-compare, -cert-dcl37-c, -cert-dcl51-cpp, - -cert-msc30-c, - -cert-msc32-c, - -cert-msc50-cpp, - -cert-msc51-cpp, -clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling, -hicpp-multiway-paths-covered, -llvm-header-guard, diff --git a/benchmark/dict_bench.c b/benchmark/dict_bench.c index 4a82a8f..4a77257 100644 --- a/benchmark/dict_bench.c +++ b/benchmark/dict_bench.c @@ -39,6 +39,16 @@ typedef struct { size_t len; } ZixChunk; +/// Linear Congruential Generator for making random 64-bit integers +static inline uint64_t +lcg64(const uint64_t i) +{ + static const uint64_t a = 6364136223846793005ull; + static const uint64_t c = 1ull; + + return (a * i) + c; +} + static uint32_t zix_chunk_hash(const ZixChunk* const chunk) { @@ -151,10 +161,9 @@ main(int argc, char** argv) // Benchmark search // GHashTable - srand(seed); struct timespec search_start = bench_start(); for (size_t i = 0; i < n; ++i) { - const size_t index = rand() % n; + const size_t index = lcg64(seed + i) % n; char* match = (char*)g_hash_table_lookup(hash, strings[index]); if (strcmp(match, strings[index])) { return test_fail("Bad match for `%s'\n", strings[index]); @@ -163,10 +172,9 @@ main(int argc, char** argv) fprintf(search_dat, "\t%lf", bench_end(&search_start)); // ZixHash - srand(seed); search_start = bench_start(); for (size_t i = 0; i < n; ++i) { - const size_t index = rand() % n; + const size_t index = lcg64(seed + i) % n; const ZixChunk key = {strings[index], lengths[index] + 1}; const ZixChunk* match = NULL; if (!(match = (const ZixChunk*)zix_hash_find(zhash, &key))) { diff --git a/benchmark/tree_bench.c b/benchmark/tree_bench.c index bd274b1..9e399ba 100644 --- a/benchmark/tree_bench.c +++ b/benchmark/tree_bench.c @@ -17,6 +17,8 @@ #include "bench.h" #include "warnings.h" +#include "../test/test_data.h" + #include "zix/btree.h" #include "zix/common.h" #include "zix/tree.h" @@ -35,22 +37,6 @@ ZIX_RESTORE_WARNINGS // #define BENCH_SORTED_ARRAY 1 -// Return a pseudo-pseudo-pseudo-random-ish integer with no duplicates -static size_t -unique_rand(size_t i) -{ - i ^= 0x5CA1AB1Eu; // Juggle bits to avoid linear clumps - - // Largest prime < 2^32 which satisfies (2^32 = 3 mod 4) - static const size_t prime = 4294967291; - if (i >= prime) { - return i; // Values >= prime are mapped to themselves - } - - const size_t residue = ((uint64_t)i * i) % prime; - return (i <= prime / 2) ? residue : prime - residue; -} - static int int_cmp(const void* a, const void* b, const void* ZIX_UNUSED(user_data)) { |