powdr/test_data/std/split_gl_test.asm

use std::split::split_gl::SplitGL;


machine Main {
    reg pc[@pc];
    reg X0[<=];
    reg X1[<=];
    reg X2[<=];
    reg low;
    reg high;

    degree 65536;

    SplitGL split_machine;

    instr split X0 -> X1, X2 = split_machine.split;

    instr assert_eq X0, X1 {
        X0 = X1
    }

    instr loop { pc' = pc }

    function main {

        // Min value
        // Note that this has two byte decompositions, 0x and p = 0xffffffff00000001.
        // The second would lead to a different split value, but should be ruled
        // out by the overflow check.
        low, high <== split(0);
        assert_eq low, 0;
        assert_eq high, 0;

        // Max value
        // On Goldilocks, this is 0xffffffff00000000.
        low, high <== split(-1);
        assert_eq low, 0;
        assert_eq high, 0xffffffff;

        // Max low value
        low, high <== split(0xfffffffeffffffff);
        assert_eq low, 0xffffffff;
        assert_eq high, 0xfffffffe;

        // Some other value
        low, high <== split(0xabcdef0123456789);
        assert_eq low, 0x23456789;
        assert_eq high, 0xabcdef01;

        return;
    }
}