64 lines · cpp
1//===- FormatVariadicBM.cpp - formatv() benchmark ---------- --------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "benchmark/benchmark.h"10#include "llvm/Support/FormatVariadic.h"11#include <algorithm>12#include <string>13#include <vector>14 15using namespace llvm;
16using namespace std;
17
18// Generate a list of format strings that have `NumReplacements` replacements
19// by permuting the replacements and some literal text.
20static vector<string> getFormatStrings(int NumReplacements) {
21 vector<string> Components;
22 for (int I = 0; I < NumReplacements; I++)
23 Components.push_back("{" + to_string(I) + "}");
24 // Intersperse these with some other literal text (_).
25 const string_view Literal = "____";
26 for (char C : Literal)
27 Components.push_back(string(1, C));
28
29 vector<string> Formats;
30 do {
31 string Concat;
32 for (const string &C : Components)
33 Concat += C;
34 Formats.emplace_back(Concat);
35 } while (next_permutation(Components.begin(), Components.end()));
36 return Formats;
37}
38
39// Generate the set of formats to exercise outside the benchmark code.
40static const vector<vector<string>> Formats = {
41 getFormatStrings(1), getFormatStrings(2), getFormatStrings(3),
42 getFormatStrings(4), getFormatStrings(5),
43};
44
45// Benchmark formatv() for a variety of format strings and 1-5 replacements.
46static void BM_FormatVariadic(benchmark::State &state) {
47 for (auto _ : state) {
48 for (const string &Fmt : Formats[0])
49 formatv(Fmt.c_str(), 1).str();
50 for (const string &Fmt : Formats[1])
51 formatv(Fmt.c_str(), 1, 2).str();
52 for (const string &Fmt : Formats[2])
53 formatv(Fmt.c_str(), 1, 2, 3).str();
54 for (const string &Fmt : Formats[3])
55 formatv(Fmt.c_str(), 1, 2, 3, 4).str();
56 for (const string &Fmt : Formats[4])
57 formatv(Fmt.c_str(), 1, 2, 3, 4, 5).str();
58 }
59}
60
61BENCHMARK(BM_FormatVariadic);
62
63BENCHMARK_MAIN();
64