[libc-commits] [libc] [libc] NVPTX Profiling Draft (PR #92009)

[via libc-commits]

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@@ -0,0 +1,92 @@
+#include "LibcGpuBenchmark.h"
+#include "src/__support/CPP/algorithm.h"
+#include "src/__support/FPUtil/sqrt.h"
+#include "src/time/gpu/time_utils.h"
+
+namespace LIBC_NAMESPACE {
+namespace benchmarks {
+
+FixedVector<Benchmark *, 64> benchmarks_to_run;
+
+void Benchmark::add_benchmark(Benchmark *benchmark) {
+  benchmarks_to_run.push_back(benchmark);
+}
+
+int Benchmark::run_benchmarks() {
+  for (auto it = benchmarks_to_run.rbegin(), e = benchmarks_to_run.rend();
+       it != e; ++it)
+    (*it)->run();
+  return 0;
+}
+
+BenchmarkResult benchmark(const BenchmarkOptions &options,
+                          cpp::function<uint64_t(void)> wrapper_func) {
+  BenchmarkResult result;
+  RuntimeEstimationProgression rep;
+  uint32_t total_iterations = 0;
+  uint32_t iterations = options.initial_iterations;
+  if (iterations < 1u)
+    iterations = 1;
+
+  uint32_t samples = 0;
+  uint64_t total_time = 0;
+  uint64_t best_guess = 0;
+  uint64_t total_cycles = 0;
+  uint64_t cycles_squared = 0;
+  uint64_t min = UINT64_MAX;
+  uint64_t max = 0;
+
+  uint64_t overhead = UINT64_MAX;
+  int overhead_iterations = 10;
+  for (int i = 0; i < overhead_iterations; i++)
+    overhead = cpp::min(overhead, LIBC_NAMESPACE::overhead());
+
+  for (uint64_t time_budget = options.max_duration; time_budget >= 0;) {
+    uint64_t sample_cycles = 0;
+    const clock_t start = static_cast<double>(clock());
+    for (uint32_t i = 0; i < iterations; i++) {
+      auto wrapper_intermediate = wrapper_func();
+      uint64_t result = wrapper_intermediate - overhead;
+      max = cpp::max(max, result);
+      min = cpp::min(min, result);
+      sample_cycles += result;
+    }
+    const clock_t end = clock();
+    const clock_t duration_ns =
+        ((end - start) * 1000 * 1000 * 1000) / CLOCKS_PER_SEC;
+    total_time += duration_ns;
+    time_budget -= duration_ns;
+    samples++;
+    total_cycles += sample_cycles;
+    cycles_squared += sample_cycles * sample_cycles;
+
+    total_iterations += iterations;
+    const double change_ratio =
+        rep.compute_improvement({iterations, sample_cycles});
+    best_guess = rep.current_estimation;
+
+    if (samples >= options.max_samples ||
+        iterations >= options.max_iterations) {
+      break;
+    } else if (total_time >= options.min_duration &&
+               samples >= options.min_samples &&
+               change_ratio < options.epsilon) {
+      break;
+    }
+
+    iterations *= options.scaling_factor;
----------------
jameshu15869 wrote:

which for loop are you referring to? I think my original intent was to increase the number of iterations executed per sample after each sample (i.e. group of iterations) executes. Do you mean moving it to the for loop on line 47?



https://github.com/llvm/llvm-project/pull/92009