a61b747a29
db07f91 Assert that what might look like a possible division by zero is actually unreachable (practicalswift) Tree-SHA512: f1652eb37196a5b72f356503a1fbb44fb98aa8a94954ad1765f86d81ebf41a2337d4eb58c4f19937fda3752f5d2d642756e44afdbd438015b87ac20801246bff
105 lines
3.5 KiB
C++
105 lines
3.5 KiB
C++
// Copyright (c) 2015 The Bitcoin Core developers
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// Distributed under the MIT software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#include "bench.h"
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#include "perf.h"
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#include <iostream>
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#include <iomanip>
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#include <sys/time.h>
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benchmark::BenchRunner::BenchmarkMap &benchmark::BenchRunner::benchmarks() {
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static std::map<std::string, benchmark::BenchFunction> benchmarks_map;
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return benchmarks_map;
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}
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static double gettimedouble(void) {
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struct timeval tv;
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gettimeofday(&tv, NULL);
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return tv.tv_usec * 0.000001 + tv.tv_sec;
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}
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benchmark::BenchRunner::BenchRunner(std::string name, benchmark::BenchFunction func)
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{
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benchmarks().insert(std::make_pair(name, func));
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}
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void
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benchmark::BenchRunner::RunAll(double elapsedTimeForOne)
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{
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perf_init();
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std::cout << "#Benchmark" << "," << "count" << "," << "min" << "," << "max" << "," << "average" << ","
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<< "min_cycles" << "," << "max_cycles" << "," << "average_cycles" << "\n";
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for (const auto &p: benchmarks()) {
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State state(p.first, elapsedTimeForOne);
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p.second(state);
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}
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perf_fini();
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}
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bool benchmark::State::KeepRunning()
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{
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if (count & countMask) {
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++count;
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return true;
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}
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double now;
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uint64_t nowCycles;
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if (count == 0) {
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lastTime = beginTime = now = gettimedouble();
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lastCycles = beginCycles = nowCycles = perf_cpucycles();
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}
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else {
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now = gettimedouble();
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double elapsed = now - lastTime;
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double elapsedOne = elapsed * countMaskInv;
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if (elapsedOne < minTime) minTime = elapsedOne;
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if (elapsedOne > maxTime) maxTime = elapsedOne;
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// We only use relative values, so don't have to handle 64-bit wrap-around specially
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nowCycles = perf_cpucycles();
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uint64_t elapsedOneCycles = (nowCycles - lastCycles) * countMaskInv;
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if (elapsedOneCycles < minCycles) minCycles = elapsedOneCycles;
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if (elapsedOneCycles > maxCycles) maxCycles = elapsedOneCycles;
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if (elapsed*128 < maxElapsed) {
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// If the execution was much too fast (1/128th of maxElapsed), increase the count mask by 8x and restart timing.
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// The restart avoids including the overhead of this code in the measurement.
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countMask = ((countMask<<3)|7) & ((1LL<<60)-1);
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countMaskInv = 1./(countMask+1);
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count = 0;
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minTime = std::numeric_limits<double>::max();
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maxTime = std::numeric_limits<double>::min();
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minCycles = std::numeric_limits<uint64_t>::max();
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maxCycles = std::numeric_limits<uint64_t>::min();
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return true;
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}
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if (elapsed*16 < maxElapsed) {
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uint64_t newCountMask = ((countMask<<1)|1) & ((1LL<<60)-1);
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if ((count & newCountMask)==0) {
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countMask = newCountMask;
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countMaskInv = 1./(countMask+1);
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}
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}
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}
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lastTime = now;
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lastCycles = nowCycles;
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++count;
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if (now - beginTime < maxElapsed) return true; // Keep going
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--count;
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assert(count != 0 && "count == 0 => (now == 0 && beginTime == 0) => return above");
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// Output results
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double average = (now-beginTime)/count;
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int64_t averageCycles = (nowCycles-beginCycles)/count;
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std::cout << std::fixed << std::setprecision(15) << name << "," << count << "," << minTime << "," << maxTime << "," << average << ","
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<< minCycles << "," << maxCycles << "," << averageCycles << "\n";
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return false;
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}
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