Objctive-Cですよ、これは

nanika.m

#import <Foundation/Foundation.h>

#include <objc/runtime.h>

int main( int argc, char *argv[])
{
    id a = [[NSAutoreleasePool alloc] init];

    NSDate *startDate = [NSDate date];

    SEL sel0 = @selector(numberWithInteger:);
    Class CNSNumber = [NSNumber class];
    Method m = class_getClassMethod(CNSNumber ,sel0);
    IMP numberWithInteger = method_getImplementation(m);
    SEL sel1 = @selector(addObject:);
    m = class_getInstanceMethod([NSMutableArray class],sel1);
    IMP addObject = method_getImplementation(m);

    for( int i = 0; i < 1000000; i++) {
        NSMutableArray *array = [NSMutableArray array];
        for( int n = 0; n < 100; n++) {
            addObject(array, sel1, numberWithInteger(CNSNumber, sel0, n));
        }
    }

    NSDate *endDate = [NSDate date];

    NSTimeInterval interval = [endDate timeIntervalSinceDate:startDate];
    NSLog(@"%.3f秒", interval);

    [a release];

    return 0;
}

Original.m

#import <Foundation/Foundation.h>


int main( int argc, char *argv[]) {
	@autoreleasepool {
		NSDate *startDate = [NSDate date];
		
		for(int i = 0; i < 1000000; i++) {
			NSMutableArray *array = [NSMutableArray array];
			for( int n = 0; n < 100; n++) {
				[array addObject:[NSNumber numberWithInteger:n]];
			}
		}
		
		NSDate *endDate = [NSDate date];
		
		NSTimeinterval interval = [endDate timeIntervalSinceDate:startDate];
		NSLog(@"%.3f秒", interval);
	}
	
	return 0;
}