A C89 standard compliant, single header, nostdlib (no C Standard Library) simple performance profiler.
For more information please look at the "perf.h" file or take a look at the "examples" or "tests" folder.
Warning
THIS PROJECT IS A WORK IN PROGRESS! ANYTHING CAN CHANGE AT ANY MOMENT WITHOUT ANY NOTICE! USE THIS PROJECT AT YOUR OWN RISK!
- C89 compliant — portable and legacy-friendly
- Single-header API — just include
perf.h - nostdlib — no dependency on the C Standard Library
- Minimal binary size — optimized for small executables
- Cross-platform — Windows, Linux, MacOs
- Strict compilation — built with aggressive warnings & safety checks
Download or clone perf.h and include it in your project.
#define PERF_STATS_ENABLE /* Enable aggregated profiling statistics */
#include "perf.h" /* Performance Profiler */
/* Just an example function that does some operations */
void test_function(double a, double b)
{
int i;
for (i = 0; i < 100; ++i)
{
a += a + b;
}
}
int main() {
/* Simply wrap your function or void block in a PERF_PROFILE call */
PERF_PROFILE(test_function(5.0, 2.23));
/* In this example we also profile the perf function calls themselv and give it a name */
PERF_PROFILE_WITH_NAME(
{
PERF_PROFILE(test_function(1.0, 3.0));
PERF_PROFILE_WITH_NAME(test_function(1.0, 3.0), "custom_name");
},
"profile_perf_calls");
/* If PERF_STATS_ENABLE is set you can print the aggregated statistics
* or access the perf_stats_entries & perf_stats_entry_count vars
*/
perf_print_stats();
return 0;
}The profiling results are then printed out like this (the bottom shows the collected statistic values):
perf_test.c:27 [perf] 51 cycles, 0.000001 ms, "test_function(5.0, 2.23)"
perf_test.c:31 [perf] 49 cycles, 0.000000 ms, "test_function(1.0, 3.0)"
perf_test.c:32 [perf] 82 cycles, 0.000003 ms, "custom_name"
perf_test.c:29 [perf] 1985457 cycles, 0.707300 ms, "profile_perf_calls"
perf_test.c:32 [perf]
perf_test.c:32 [perf] +---------------------------------------+-------------------------------------------------------+
perf_test.c:32 [perf] | cylces | time_ms |
perf_test.c:32 [perf] +---------+---------+---------+---------+-------------+-------------+-------------+-------------+
perf_test.c:32 [perf] | min | max | avg | sum | min | max | avg | sum |
perf_test.c:32 [perf] +---------+---------+---------+---------+-------------+-------------+-------------+-------------+
perf_test.c:32 [perf] | 43 | 56 | 46 | 460 | 0.0000 | 0.0001 | 0.0000 | 0.0004 | 10 x test_function(5.0, 2.23)
perf_test.c:39 [perf] | 42 | 48 | 44 | 134 | 0.0000 | 0.0001 | 0.0000 | 0.0001 | 3 x test_function(1.0, 3.0)
perf_test.c:40 [perf] | 44 | 44 | 44 | 132 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 3 x custom_name
perf_test.c:37 [perf] | 892923 | 1115842 | 1000412 | 3001238 | 0.3181 | 0.3975 | 0.3565 | 1.0695 | 3 x profile_perf_calls
perf_test.c:37 [perf] +---------+---------+---------+---------+-------------+-------------+-------------+-------------+If you want to turn on collecting statistics you can specify -DPERF_STATS_ENABLE or #define it like the following example.
#define PERF_STATS_ENABLE /* Enable statistics collecting */
#define PERF_STATS_ENTRIES_MAX 1024 /* Optional: Default 1024, max unique (file+line+function name) combinations to store */
#define PERF_STATS_NAME_MAX 512 /* Optional: Default 512, max length of the function name */
#include "perf.h"In your code you can then print the statics like min/max/avg/sum/count cycles and time in milliseconds.
perf_print_stats();If you want to turn of printing perf results for each call you can specify -DPERF_DISBALE_INTERMEDIATE_PRINT or #define it like the following example.
#define PERF_DISBALE_INTERMEDIATE_PRINT
#include "perf.h"If you placed the PERF_ calls in your code base but want to switch off the functionality without loosing any performance you can specify -DPERF_DISABLE or #define it like the following example.
#define PERF_DISABLE
#include "perf.h"In this repo you will find the "examples/perf_win32_nostdlib.c" with the corresponding "build.bat" file which creates an executable only linked to "kernel32" and is not using the C standard library and executes the program afterwards.
nostdlib is a lightweight, minimalistic approach to C development that removes dependencies on the standard library. The motivation behind this project is to provide developers with greater control over their code by eliminating unnecessary overhead, reducing binary size, and enabling deployment in resource-constrained environments.
Many modern development environments rely heavily on the standard library, which, while convenient, introduces unnecessary bloat, security risks, and unpredictable dependencies. nostdlib aims to give developers fine-grained control over memory management, execution flow, and system calls by working directly with the underlying platform.
By removing the standard library, nostdlib significantly reduces runtime overhead, allowing for faster execution and smaller binary sizes.
Standard libraries often include unnecessary functions that increase the attack surface of an application. nostdlib mitigates security risks by removing unused and potentially vulnerable components.
Without linking to the standard library, binaries are smaller, making them ideal for embedded systems, bootloaders, and operating systems where storage is limited.
Direct control over system calls and memory management leads to performance gains by eliminating abstraction layers imposed by standard libraries.
By relying only on fundamental system interfaces, nostdlib allows for easier porting across different platforms without worrying about standard library availability.