root/tests/bcj_test.c

DEFINITIONS

1. call
2. jump
3. main

///////////////////////////////////////////////////////////////////////////////
//
/// \file       bcj_test.c
/// \brief      Source code of compress_prepared_bcj_*
///
/// This is a simple program that should make the compiler to generate
/// PC-relative branches, jumps, and calls. The compiled files can then
/// be used to test the branch conversion filters. Note that this program
/// itself does nothing useful.
///
/// Compiling: gcc -std=c99 -fPIC -c bcj_test.c
/// Don't optimize or strip.
//
//  Author:     Lasse Collin
//
//  This file has been put into the public domain.
//  You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////

extern int jump(int a, int b);


extern int
call(int a, int b)
{
        if (a < b)
                a = jump(a, b);

        return a;
}


extern int
jump(int a, int b)
{
        // The loop generates conditional jump backwards.
        while (1) {
                if (a < b) {
                        a *= 2;
                        a += 3 * b;
                        break;
                } else {
                        // Put enough code here to prevent JMP SHORT on x86.
                        a += b;
                        a /= 2;
                        b += b % 5;
                        a -= b / 3;
                        b = 2 * b + a - 1;
                        a *= b + a + 1;
                        b += a - 1;
                        a += b * 2 - a / 5;
                }
        }

        return a;
}


int
main(int argc, char **argv)
{
        int a = call(argc, argc + 1);
        return a == 0;
}