google/benchmark

Fail when calculating complexity

Open

#410 创建于 2017年6月30日

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 (3 评论) (0 反应) (0 负责人)C++ (7,968 star) (1,539 fork)batch import
enhancementgood first issuehelp wanted

描述

When calculating time complexity and the range includes 0 it fails upon evaluation.

void BM_Example(benchmark::State& state)
{
  while (state.KeepRunning())
  {
    int i = state.range(0);
  }
  state.SetComplexityN(state.range(0));
}

BENCHMARK(BM_JumpTable)->RangeMultiplier(2)->Range(0, 1)->Complexity(benchmark::o1);

Result

F:\cruft\benchmark\src\complexity.cc:270: benchmark::ComputeBigO: Check (run.complexity_n) > (0)' Failed. Did you forget to call SetComplexityN?

贡献者指南

技术栈
cpp
领域
performance
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
2
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
under 1 hour
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
stale
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
Basic C++ knowledgeGoogle Benchmark library familiarity
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
75
研究方向
The bug is in the ComputeBigO function in complexity.cc (line 270) where an assertion requires complexity n > 0. When the benchmark range includes 0, state.range(0) returns 0, causing the assertion to fail. Investigate whether the assertion should be relaxed to allow 0, or if the benchmark should handle range(0) differently. Check the existing comments for any proposed fixes.