strptime_l vs. NSDateFormatter Benchmarks

gistfile1.m

#import <Foundation/Foundation.h>

int main(int argc, char *argv[]) {
    @autoreleasepool {
        static size_t const iterations = 10000;
        
        uint64_t t_0 = dispatch_benchmark(iterations, ^{
            @autoreleasepool {
                NSString *dateStr = @"Sat Sep 15 05:52:10 +0000 2012";

                const char *str = [dateStr UTF8String];
                const char *fmt = [@"%a %b %d %H:%M:%S %z %Y" UTF8String];
                struct tm timeinfo;
                memset(&timeinfo, 0, sizeof(timeinfo));
                char *ret = strptime_l(str, fmt, &timeinfo, NULL);

                NSDate *date = nil;

                if (ret) {
                    time_t time = mktime(&timeinfo);

                    date = [NSDate dateWithTimeIntervalSince1970:time];
                }
            }
        });
        
        NSLog(@"strptime_l Avg. Runtime: %llu ns", t_0);
        
        uint64_t t_1 = dispatch_benchmark(iterations, ^{
            @autoreleasepool {
                NSString *dateStr = @"Sat Sep 15 05:52:10 +0000 2012";

                NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
                [dateFormat setDateFormat:@"EE LLLL d HH:mm:ss Z yyyy"];
                NSDate *date = [dateFormat dateFromString:dateStr];
            }
        });
        
        NSLog(@"NSDateFormatter Avg. Runtime: %llu ns", t_1);
    }
}

This gives the following result on a reasonably new MacBook Pro:

strptime_l Avg. Runtime: 21919 ns
NSDateFormatter Avg. Runtime: 405682 ns