arm64_multiply_constants.obs

#~
# ARM64 Multiply-by-Constant Test
# Tests multiply-by-constant optimization (especially multiply-by-6)
# Related commit: cc65c18b7 - Fixed multiply-by-6 using LSL #1 instead of LSL #2
~#

class ARM64MultiplyConstantsTest {
    function : Main(args : String[]) ~ Nil {
        "Testing ARM64 multiply-by-constant optimization..."->PrintLine();

        pass := true;

        # Test multiply by various constants that use shift-add optimization
        constants := Int->New[6];
        constants[0] := 3;
        constants[1] := 5;
        constants[2] := 6;  # This was broken (LSL #1 instead of LSL #2)
        constants[3] := 7;
        constants[4] := 9;
        constants[5] := 10;

        for(c_idx := 0; c_idx < constants->Size(); c_idx += 1;) {
            multiplier := constants[c_idx];

            for(i := 0; i < 10; i += 1;) {
                result := i * multiplier;
                expected := i * multiplier;  # Compute expected value

                if(result <> expected) {
                    pass := false;
                    "  FAIL: {$i} * {$multiplier} = {$result}, expected {$expected}"->PrintLine();
                };
            };
        };

        # Specific test for multiply-by-6 (the critical bug)
        test_values := Int->New[5];
        test_values[0] := 5;
        test_values[1] := 10;
        test_values[2] := 15;
        test_values[3] := 100;
        test_values[4] := 1000;

        for(idx := 0; idx < test_values->Size(); idx += 1;) {
            val := test_values[idx];
            result := val * 6;
            expected := val + val + val + val + val + val;  # 6x via addition

            if(result <> expected) {
                pass := false;
                "  FAIL: {$val} * 6 = {$result}, expected {$expected}"->PrintLine();
            };
        };

        # Edge cases
        zero := 0;
        result_zero := zero * 6;
        if(result_zero <> 0) {
            pass := false;
            "  FAIL: 0 * 6, expected 0"->PrintLine();
        };

        neg_five := -5;
        result_neg := neg_five * 6;
        if(result_neg <> -30) {
            pass := false;
            "  FAIL: (-5) * 6, expected -30"->PrintLine();
        };

        if(pass) {
            "PASS: ARM64 multiply-by-constant optimization"->PrintLine();
        } else {
            "FAIL: ARM64 multiply-by-constant optimization"->PrintLine();
        };
    }
}