use wasmer_inkwell::{AddressSpace, AtomicOrdering, AtomicRMWBinOp, OptimizationLevel};
use wasmer_inkwell::context::Context;
use wasmer_inkwell::values::BasicValue;

use std::ptr::null;

#[test]
fn test_build_call() {
    let context = Context::create();
    let module = context.create_module("sum");
    let builder = context.create_builder();

    let f32_type = context.f32_type();
    let fn_type = f32_type.fn_type(&[], false);

    let function = module.add_function("get_pi", fn_type, None);
    let basic_block = context.append_basic_block(function, "entry");

    builder.position_at_end(basic_block);

    let pi = f32_type.const_float(::std::f64::consts::PI);

    builder.build_return(Some(&pi));

    let function2 = module.add_function("wrapper", fn_type, None);
    let basic_block2 = context.append_basic_block(function2, "entry");

    builder.position_at_end(basic_block2);

    let pi2_call_site = builder.build_call(function, &[], "get_pi");

    assert!(!pi2_call_site.is_tail_call());

    pi2_call_site.set_tail_call(true);

    assert!(pi2_call_site.is_tail_call());

    let pi2 = pi2_call_site.try_as_basic_value().left().unwrap();

    builder.build_return(Some(&pi2));

    assert!(module.verify().is_ok());

    // Test using function `PointerValue`
    let void_type = context.void_type();
    let fn_type2 = void_type.fn_type(&[], false);
    let function3 = module.add_function("call_fn", fn_type2, None);
    let basic_block3 = context.append_basic_block(function3, "entry");
    let fn_ptr = function3.as_global_value().as_pointer_value();
    let fn_ptr_type = fn_ptr.get_type();

    builder.position_at_end(basic_block3);

    let alloca = builder.build_alloca(fn_ptr_type, "alloca");

    builder.build_store(alloca, fn_ptr);

    let load = builder.build_load(alloca, "load").into_pointer_value();

    builder.build_call(load, &[], "call");
    builder.build_return(None);

    assert!(module.verify().is_ok());
}

#[test]
fn test_null_checked_ptr_ops() {
    let context = Context::create();
    let module = context.create_module("unsafe");
    let builder = context.create_builder();

    // Here we're going to create a function that looks roughly like:
    // fn check_null_index1(ptr: *const i8) -> i8 {
    //     if ptr.is_null() {
    //         -1
    //     } else {
    //         ptr[1]
    //     }
    // }

    let i8_type = context.i8_type();
    let i8_ptr_type = i8_type.ptr_type(AddressSpace::Generic);
    let i64_type = context.i64_type();
    let fn_type = i8_type.fn_type(&[i8_ptr_type.into()], false);
    let neg_one = i8_type.const_all_ones();
    let one = i64_type.const_int(1, false);

    let function = module.add_function("check_null_index1", fn_type, None);
    let entry = context.append_basic_block(function, "entry");

    builder.position_at_end(entry);

    let ptr = function.get_first_param().unwrap().into_pointer_value();

    let is_null = builder.build_is_null(ptr, "is_null");

    let ret_0 = context.append_basic_block(function, "ret_0");
    let ret_idx = context.append_basic_block(function, "ret_idx");

    builder.build_conditional_branch(is_null, ret_0, ret_idx);

    builder.position_at_end(ret_0);
    builder.build_return(Some(&neg_one));

    builder.position_at_end(ret_idx);

    // FIXME: This might not work if compiled on non 64bit devices. Ideally we'd
    // be able to create pointer sized ints easily
    let ptr_as_int = builder.build_ptr_to_int(ptr, i64_type, "ptr_as_int");
    let new_ptr_as_int = builder.build_int_add(ptr_as_int, one, "add");
    let new_ptr = builder.build_int_to_ptr(new_ptr_as_int, i8_ptr_type, "int_as_ptr");
    let index1 = builder.build_load(new_ptr, "deref");

    builder.build_return(Some(&index1));

    // Here we're going to create a function that looks roughly like:
    // fn check_null_index2(ptr: *const i8) -> i8 {
    //     if !ptr.is_null() {
    //         ptr[1]
    //     } else {
    //         -1
    //     }
    // }

    let function = module.add_function("check_null_index2", fn_type, None);
    let entry = context.append_basic_block(function, "entry");

    builder.position_at_end(entry);

    let ptr = function.get_first_param().unwrap().into_pointer_value();

    let is_not_null = builder.build_is_not_null(ptr, "is_not_null");

    let ret_idx = context.append_basic_block(function, "ret_idx");
    let ret_0 = context.append_basic_block(function, "ret_0");

    builder.build_conditional_branch(is_not_null, ret_idx, ret_0);

    builder.position_at_end(ret_0);
    builder.build_return(Some(&neg_one));

    builder.position_at_end(ret_idx);

    // FIXME: This might not work if compiled on non 64bit devices. Ideally we'd
    // be able to create pointer sized ints easily
    let ptr_as_int = builder.build_ptr_to_int(ptr, i64_type, "ptr_as_int");
    let new_ptr_as_int = builder.build_int_add(ptr_as_int, one, "add");
    let new_ptr = builder.build_int_to_ptr(new_ptr_as_int, i8_ptr_type, "int_as_ptr");
    let index1 = builder.build_load(new_ptr, "deref");

    builder.build_return(Some(&index1));

    let execution_engine = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();

    unsafe {
        let check_null_index1 = execution_engine.get_function::<unsafe extern "C" fn(*const i8) -> i8>("check_null_index1").unwrap();

        let array = &[100i8, 42i8];

        assert_eq!(check_null_index1.call(null()), -1i8);
        assert_eq!(check_null_index1.call(array.as_ptr()), 42i8);

        let check_null_index2 = execution_engine.get_function::<unsafe extern "C" fn(*const i8) -> i8>("check_null_index2").unwrap();

        assert_eq!(check_null_index2.call(null()), -1i8);
        assert_eq!(check_null_index2.call(array.as_ptr()), 42i8);
    }
}

#[test]
fn test_binary_ops() {
    let context = Context::create();
    let module = context.create_module("unsafe");
    let builder = context.create_builder();
    let execution_engine = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();

    // Here we're going to create an and function which looks roughly like:
    // fn and(left: bool, right: bool) -> bool {
    //     left && right
    // }

    let bool_type = context.bool_type();
    let fn_type = bool_type.fn_type(&[bool_type.into(), bool_type.into()], false);
    let fn_value = module.add_function("and", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let left = fn_value.get_first_param().unwrap().into_int_value();
    let right = fn_value.get_last_param().unwrap().into_int_value();

    let and = builder.build_and(left, right, "and_op");

    builder.build_return(Some(&and));

    // Here we're going to create an or function which looks roughly like:
    // fn or(left: bool, right: bool) -> bool {
    //     left || right
    // }

    let fn_value = module.add_function("or", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let left = fn_value.get_first_param().unwrap().into_int_value();
    let right = fn_value.get_last_param().unwrap().into_int_value();

    let or = builder.build_or(left, right, "or_op");

    builder.build_return(Some(&or));

    // Here we're going to create a xor function which looks roughly like:
    // fn xor(left: bool, right: bool) -> bool {
    //     left || right
    // }

    let fn_value = module.add_function("xor", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let left = fn_value.get_first_param().unwrap().into_int_value();
    let right = fn_value.get_last_param().unwrap().into_int_value();

    let xor = builder.build_xor(left, right, "xor_op");

    builder.build_return(Some(&xor));

    unsafe {
        type BoolFunc = unsafe extern "C" fn(bool, bool) -> bool;

        let and = execution_engine.get_function::<BoolFunc>("and").unwrap();
        let or = execution_engine.get_function::<BoolFunc>("or").unwrap();
        let xor = execution_engine.get_function::<BoolFunc>("xor").unwrap();

        assert!(!and.call(false, false));
        assert!(!and.call(true, false));
        assert!(!and.call(false, true));
        assert!(and.call(true, true));

        assert!(!or.call(false, false));
        assert!(or.call(true, false));
        assert!(or.call(false, true));
        assert!(or.call(true, true));

        assert!(!xor.call(false, false));
        assert!(xor.call(true, false));
        assert!(xor.call(false, true));
        assert!(!xor.call(true, true));
    }
}

#[test]
fn test_switch() {
    let context = Context::create();
    let module = context.create_module("unsafe");
    let builder = context.create_builder();
    let execution_engine = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();

    // Here we're going to create a function which looks roughly like:
    // fn switch(val: u8) -> u8 {
    //     if val == 0 {
    //         1
    //     } else if val == 42 {
    //         255
    //     } else {
    //         val * 2
    //     }
    // }

    let i8_type = context.i8_type();
    let fn_type = i8_type.fn_type(&[i8_type.into()], false);
    let fn_value = module.add_function("switch", fn_type, None);
    let i8_zero = i8_type.const_int(0, false);
    let i8_one = i8_type.const_int(1, false);
    let i8_two = i8_type.const_int(2, false);
    let i8_42 = i8_type.const_int(42, false);
    let i8_255 = i8_type.const_int(255, false);
    let entry = context.append_basic_block(fn_value, "entry");
    let check = context.append_basic_block(fn_value, "check");
    let elif = context.append_basic_block(fn_value, "elif");
    let else_ = context.append_basic_block(fn_value, "else");
    let value = fn_value.get_first_param().unwrap().into_int_value();

    builder.position_at_end(entry);
    builder.build_switch(value, else_, &[(i8_zero, check), (i8_42, elif)]);

    builder.position_at_end(check);
    builder.build_return(Some(&i8_one));

    builder.position_at_end(elif);
    builder.build_return(Some(&i8_255));

    builder.position_at_end(else_);

    let double = builder.build_int_mul(value, i8_two, "double");

    builder.build_return(Some(&double));

    unsafe {
        let switch = execution_engine.get_function::<unsafe extern "C" fn(u8) -> u8>("switch").unwrap();

        assert_eq!(switch.call(0), 1);
        assert_eq!(switch.call(1), 2);
        assert_eq!(switch.call(3), 6);
        assert_eq!(switch.call(10), 20);
        assert_eq!(switch.call(42), 255);
    }
}

#[test]
fn test_bit_shifts() {
    let context = Context::create();
    let module = context.create_module("unsafe");
    let builder = context.create_builder();
    let execution_engine = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();

    // Here we're going to create a function which looks roughly like:
    // fn left_shift(value: u8, bits: u8) -> u8 {
    //     value << bits
    // }
    let i8_type = context.i8_type();
    let fn_type = i8_type.fn_type(&[i8_type.into(), i8_type.into()], false);
    let fn_value = module.add_function("left_shift", fn_type, None);
    let value = fn_value.get_first_param().unwrap().into_int_value();
    let bits = fn_value.get_nth_param(1).unwrap().into_int_value();

    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let shift = builder.build_left_shift(value, bits, "shl");

    builder.build_return(Some(&shift));

    // Here we're going to create a function which looks roughly like:
    // fn right_shift(value: u8, bits: u8) -> u8 {
    //     value >> bits
    // }
    let fn_value = module.add_function("right_shift", fn_type, None);
    let value = fn_value.get_first_param().unwrap().into_int_value();
    let bits = fn_value.get_nth_param(1).unwrap().into_int_value();

    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let shift = builder.build_right_shift(value, bits, false, "shr");

    builder.build_return(Some(&shift));

    // Here we're going to create a function which looks roughly like:
    // fn right_shift(value: u8, bits: u8) -> u8 {
    //     value >> bits
    // }
    let fn_value = module.add_function("right_shift_sign_extend", fn_type, None);
    let value = fn_value.get_first_param().unwrap().into_int_value();
    let bits = fn_value.get_nth_param(1).unwrap().into_int_value();

    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let shift = builder.build_right_shift(value, bits, true, "shr");

    builder.build_return(Some(&shift));

    unsafe {
        let left_shift = execution_engine.get_function::<unsafe extern "C" fn(u8, u8) -> u8>("left_shift").unwrap();
        let right_shift  = execution_engine.get_function::<unsafe extern "C" fn(u8, u8) -> u8>("right_shift").unwrap();
        let right_shift_sign_extend = execution_engine.get_function::<unsafe extern "C" fn(i8, u8) -> i8>("right_shift_sign_extend").unwrap();

        assert_eq!(left_shift.call(0, 0), 0);
        assert_eq!(left_shift.call(0, 4), 0);
        assert_eq!(left_shift.call(1, 0), 1);
        assert_eq!(left_shift.call(1, 1), 2);
        assert_eq!(left_shift.call(1, 2), 4);
        assert_eq!(left_shift.call(1, 3), 8);
        assert_eq!(left_shift.call(64, 1), 128);

        assert_eq!(right_shift.call(128, 1), 64);
        assert_eq!(right_shift.call(8, 3), 1);
        assert_eq!(right_shift.call(4, 2), 1);
        assert_eq!(right_shift.call(2, 1), 1);
        assert_eq!(right_shift.call(1, 0), 1);
        assert_eq!(right_shift.call(0, 4), 0);
        assert_eq!(right_shift.call(0, 0), 0);

        assert_eq!(right_shift_sign_extend.call(8, 3), 1);
        assert_eq!(right_shift_sign_extend.call(4, 2), 1);
        assert_eq!(right_shift_sign_extend.call(2, 1), 1);
        assert_eq!(right_shift_sign_extend.call(1, 0), 1);
        assert_eq!(right_shift_sign_extend.call(0, 4), 0);
        assert_eq!(right_shift_sign_extend.call(0, 0), 0);
        assert_eq!(right_shift_sign_extend.call(-127, 1), -64);
        assert_eq!(right_shift_sign_extend.call(-127, 8), -1);
        assert_eq!(right_shift_sign_extend.call(-65, 3), -9);
        assert_eq!(right_shift_sign_extend.call(-64, 3), -8);
        assert_eq!(right_shift_sign_extend.call(-63, 3), -8);
    }
}

#[test]
fn test_unconditional_branch() {
    let context = Context::create();
    let builder = context.create_builder();
    let module = context.create_module("my_mod");
    let void_type = context.void_type();
    let fn_type = void_type.fn_type(&[], false);
    let fn_value = module.add_function("my_fn", fn_type, None);
    let entry_bb = context.append_basic_block(fn_value, "entry");
    let skipped_bb = context.append_basic_block(fn_value, "skipped");
    let end_bb = context.append_basic_block(fn_value, "end");

    builder.position_at_end(entry_bb);
    builder.build_unconditional_branch(end_bb);

    builder.position_at_end(skipped_bb);
    builder.build_unreachable();
}

#[test]
fn test_no_builder_double_free() {
    let context = Context::create();
    let builder = context.create_builder();

    drop(builder);
    drop(context);
}

// TODO: Compile-fail test this:
// let builder = {
//     let context = Context::create();
//
//     context.create_builder()
// };

#[test]
fn test_no_builder_double_free2() {
    let context = Context::create();
    let builder = context.create_builder();

    // Builder continues to function with different context
    let context = Context::create();
    let module = context.create_module("my_mod");
    let void_type = context.void_type();
    let fn_type = void_type.fn_type(&[], false);
    let fn_value = module.add_function("my_fn", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);
    // FIXME: Builder segfaults when making build calls with different context
    // as of newer rust versions(late 2018+?). Maybe this isn't actually something
    // you're suppose to do in LLVM and LTO(?) has made it a more prominent issue?
    // builder.build_unreachable();

    // #[cfg(any(feature = "llvm3-6", feature = "llvm3-7", feature = "llvm3-8"))]
    // assert_eq!(*module.print_to_string(), *CString::new("; ModuleID = \'my_mod\'\n\ndefine void @my_fn() {\nentry:\n  unreachable\n}\n").unwrap());
    // #[cfg(not(any(feature = "llvm3-6", feature = "llvm3-7", feature = "llvm3-8")))]
    // assert_eq!(*module.print_to_string(), *CString::new("; ModuleID = \'my_mod\'\nsource_filename = \"my_mod\"\n\ndefine void @my_fn() {\nentry:\n  unreachable\n}\n").unwrap());

    // 2nd Context drops fine
    // Builder drops fine
}

#[test]
fn test_vector_convert_ops() {
    let context = Context::create();
    let module = context.create_module("test");
    let int8_vec_type = context.i8_type().vec_type(3);
    let int32_vec_type = context.i32_type().vec_type(3);
    let float32_vec_type = context.f32_type().vec_type(3);
    let float16_vec_type = context.f16_type().vec_type(3);

    // Here we're building a function that takes in a <3 x i8> and returns it casted to and from a <3 x i32>
    // Casting to and from means we can ensure the cast build functions return a vector when one is provided.
    let fn_type = int32_vec_type.fn_type(&[int8_vec_type.into()], false);
    let fn_value = module.add_function("test_int_vec_cast", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();

    builder.position_at_end(entry);
    let in_vec = fn_value.get_first_param().unwrap().into_vector_value();
    let casted_vec = builder.build_int_cast(in_vec, int32_vec_type, "casted_vec");
    let _uncasted_vec = builder.build_int_cast(casted_vec, int8_vec_type, "uncasted_vec");
    builder.build_return(Some(&casted_vec));
    assert!(fn_value.verify(true));

    // Here we're building a function that takes in a <3 x f32> and returns it casted to and from a <3 x f16>
    let fn_type = float16_vec_type.fn_type(&[float32_vec_type.into()], false);
    let fn_value = module.add_function("test_float_vec_cast", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();

    builder.position_at_end(entry);
    let in_vec = fn_value.get_first_param().unwrap().into_vector_value();
    let casted_vec = builder.build_float_cast(in_vec, float16_vec_type, "casted_vec");
    let _uncasted_vec = builder.build_float_cast(casted_vec, float32_vec_type, "uncasted_vec");
    builder.build_return(Some(&casted_vec));
    assert!(fn_value.verify(true));

    // Here we're building a function that takes in a <3 x f32> and returns it casted to and from a <3 x i32>
    let fn_type = int32_vec_type.fn_type(&[float32_vec_type.into()], false);
    let fn_value = module.add_function("test_float_to_int_vec_cast", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();

    builder.position_at_end(entry);
    let in_vec = fn_value.get_first_param().unwrap().into_vector_value();
    let casted_vec = builder.build_float_to_signed_int(in_vec, int32_vec_type, "casted_vec");
    let _uncasted_vec = builder.build_signed_int_to_float(casted_vec, float32_vec_type, "uncasted_vec");
    builder.build_return(Some(&casted_vec));
    assert!(fn_value.verify(true));
}

#[test]
fn test_vector_binary_ops() {
    let context = Context::create();
    let module = context.create_module("test");
    let int32_vec_type = context.i32_type().vec_type(2);
    let float32_vec_type = context.f32_type().vec_type(2);
    let bool_vec_type = context.bool_type().vec_type(2);

    // Here we're building a function that takes in three <2 x i32>s and returns them added together as a <2 x i32>
    let fn_type = int32_vec_type.fn_type(&[int32_vec_type.into(), int32_vec_type.into(), int32_vec_type.into()], false);
    let fn_value = module.add_function("test_int_vec_add", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();

    builder.position_at_end(entry);
    let p1_vec = fn_value.get_first_param().unwrap().into_vector_value();
    let p2_vec = fn_value.get_nth_param(1).unwrap().into_vector_value();
    let p3_vec = fn_value.get_nth_param(2).unwrap().into_vector_value();
    let added_vec = builder.build_int_add(p1_vec, p2_vec, "added_vec");
    let added_vec = builder.build_int_add(added_vec, p3_vec, "added_vec");
    builder.build_return(Some(&added_vec));
    assert!(fn_value.verify(true));

    // Here we're building a function that takes in three <2 x f32>s and returns x * y / z as an
    // <2 x f32>
    let fn_type = float32_vec_type.fn_type(&[float32_vec_type.into(), float32_vec_type.into(), float32_vec_type.into()], false);
    let fn_value = module.add_function("test_float_vec_mul", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();

    builder.position_at_end(entry);
    let p1_vec = fn_value.get_first_param().unwrap().into_vector_value();
    let p2_vec = fn_value.get_nth_param(1).unwrap().into_vector_value();
    let p3_vec = fn_value.get_nth_param(2).unwrap().into_vector_value();
    let multiplied_vec = builder.build_float_mul(p1_vec, p2_vec, "multipled_vec");
    let divided_vec = builder.build_float_div(multiplied_vec, p3_vec, "divided_vec");
    builder.build_return(Some(&divided_vec));
    assert!(fn_value.verify(true));

    // Here we're building a function that takes two <2 x f32>s and a <2 x bool> and returns (x < y) * z
    // as a <2 x bool>
    let fn_type = bool_vec_type.fn_type(&[float32_vec_type.into(), float32_vec_type.into(), bool_vec_type.into()], false);
    let fn_value = module.add_function("test_float_vec_compare", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();

    builder.position_at_end(entry);
    let p1_vec = fn_value.get_first_param().unwrap().into_vector_value();
    let p2_vec = fn_value.get_nth_param(1).unwrap().into_vector_value();
    let p3_vec = fn_value.get_nth_param(2).unwrap().into_vector_value();
    let compared_vec = builder.build_float_compare(wasmer_inkwell::FloatPredicate::OLT, p1_vec, p2_vec, "compared_vec");
    let multiplied_vec = builder.build_int_mul(compared_vec, p3_vec, "multiplied_vec");
    builder.build_return(Some(&multiplied_vec));
    assert!(fn_value.verify(true));
}

#[test]
fn test_vector_pointer_ops() {
    let context = Context::create();
    let module = context.create_module("test");
    let int32_vec_type = context.i32_type().vec_type(4);
    let i8_ptr_vec_type = context.i8_type().ptr_type(AddressSpace::Generic).vec_type(4);
    let bool_vec_type = context.bool_type().vec_type(4);

    // Here we're building a function that takes a <4 x i32>, converts it to a <4 x i8*> and returns a
    // <4 x bool> if the pointer is null
    let fn_type = bool_vec_type.fn_type(&[int32_vec_type.into()], false);
    let fn_value = module.add_function("test_ptr_null", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();

    builder.position_at_end(entry);
    let in_vec = fn_value.get_first_param().unwrap().into_vector_value();
    let ptr_vec = builder.build_int_to_ptr(in_vec, i8_ptr_vec_type, "ptr_vec");
    let is_null_vec = builder.build_is_null(ptr_vec, "is_null_vec");
    builder.build_return(Some(&is_null_vec));
    assert!(fn_value.verify(true));
}

#[test]
fn test_insert_value() {
    let context = Context::create();
    let module = context.create_module("av");
    let void_type = context.void_type();
    let f32_type = context.f32_type();
    let i32_type = context.i32_type();
    let struct_type = context.struct_type(&[i32_type.into(), f32_type.into()], false);
    let array_type = i32_type.array_type(3);
    let fn_type = void_type.fn_type(&[], false);
    let fn_value = module.add_function("av_fn", fn_type, None);
    let builder = context.create_builder();
    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let array_alloca = builder.build_alloca(array_type, "array_alloca");
    let array = builder.build_load(array_alloca, "array_load").into_array_value();
    let const_int1 = i32_type.const_int(2, false);
    let const_int2 = i32_type.const_int(5, false);
    let const_int3 = i32_type.const_int(6, false);
    let const_float = f32_type.const_float(3.14);

    assert!(builder.build_insert_value(array, const_int1, 0, "insert").unwrap().is_array_value());
    assert!(builder.build_insert_value(array, const_int2, 1, "insert").unwrap().is_array_value());
    assert!(builder.build_insert_value(array, const_int3, 2, "insert").unwrap().is_array_value());
    assert!(builder.build_insert_value(array, const_int3, 3, "insert").is_none());
    assert!(builder.build_insert_value(array, const_int3, 4, "insert").is_none());

    assert!(builder.build_extract_value(array, 0, "extract").unwrap().is_int_value());
    assert!(builder.build_extract_value(array, 1, "extract").unwrap().is_int_value());
    assert!(builder.build_extract_value(array, 2, "extract").unwrap().is_int_value());
    assert!(builder.build_extract_value(array, 3, "extract").is_none());

    let struct_alloca = builder.build_alloca(struct_type, "struct_alloca");
    let struct_value = builder.build_load(struct_alloca, "struct_load").into_struct_value();

    assert!(builder.build_insert_value(struct_value, const_int2, 0, "insert").unwrap().is_struct_value());
    assert!(builder.build_insert_value(struct_value, const_float, 1, "insert").unwrap().is_struct_value());
    assert!(builder.build_insert_value(struct_value, const_float, 2, "insert").is_none());
    assert!(builder.build_insert_value(struct_value, const_float, 3, "insert").is_none());

    assert!(builder.build_extract_value(struct_value, 0, "extract").unwrap().is_int_value());
    assert!(builder.build_extract_value(struct_value, 1, "extract").unwrap().is_float_value());
    assert!(builder.build_extract_value(struct_value, 2, "extract").is_none());
    assert!(builder.build_extract_value(struct_value, 3, "extract").is_none());

    builder.build_return(None);

    assert!(module.verify().is_ok());
}

fn is_alignment_ok(align: u32) -> bool {
    // This replicates the assertions LLVM runs.
    //
    // See https://github.com/TheDan64/inkwell/issues/168
    align > 0 && align.is_power_of_two() && (align as f64).log2() < 64.0
}

#[llvm_versions(8.0..=latest)]
#[test]
fn test_alignment_bytes() {
    let verify_alignment = |alignment: u32| {
        let context = Context::create();
        let module = context.create_module("av");
        let result = run_memcpy_on(&context, &module, alignment);

        if is_alignment_ok(alignment) {
            assert!(result.is_ok() && module.verify().is_ok(), "alignment of {} was a power of 2 under 2^64, but did not verify for memcpy.", alignment);
        } else {
            assert!(result.is_err(), "alignment of {} was a power of 2 under 2^64, yet verification passed for memcpy when it should not have.", alignment);
        }

        let result = run_memmove_on(&context, &module, alignment);

        if is_alignment_ok(alignment) {
            assert!(result.is_ok() && module.verify().is_ok(), "alignment of {} was a power of 2 under 2^64, but did not verify for memmove.", alignment);
        } else {
            assert!(result.is_err(), "alignment of {} was a power of 2 under 2^64, yet verification passed for memmove when it should not have.", alignment);
        }
    };

    for alignment in 0..32 {
        verify_alignment(alignment);
    }

    verify_alignment(u32::max_value());
}

#[llvm_versions(8.0..=latest)]
fn run_memcpy_on<'ctx>(context: &'ctx Context, module: &wasmer_inkwell::module::Module<'ctx>, alignment: u32) -> Result<(), &'static str> {
    let i32_type = context.i32_type();
    let i64_type = context.i64_type();
    let array_len = 4;
    let fn_type = i32_type.ptr_type(AddressSpace::Generic).fn_type(&[], false);
    let fn_value = module.add_function("test_fn", fn_type, None);
    let builder = context.create_builder();
    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let len_value = i64_type.const_int(array_len as u64, false);
    let array_ptr = builder.build_array_malloc(i32_type, len_value, "array_ptr").unwrap();

    // Initialize the array with the values [1, 2, 3, 4]
    for index in 0..4 {
        let index_val = i32_type.const_int(index, false);
        let elem_ptr = unsafe { builder.build_in_bounds_gep(array_ptr, &[index_val], "index") };
        let int_val = i32_type.const_int(index + 1, false);

        builder.build_store(elem_ptr, int_val);
    }

    // Memcpy the first half of the array over the second half of the array.
    let elems_to_copy = 2;
    let bytes_to_copy = elems_to_copy * std::mem::size_of::<i32>();
    let size_val = i64_type.const_int(bytes_to_copy as u64, false);
    let index_val = i32_type.const_int(2, false);
    let dest_ptr = unsafe { builder.build_in_bounds_gep(array_ptr, &[index_val], "index") };

    builder.build_memcpy(dest_ptr, alignment, array_ptr, alignment, size_val)?;

    builder.build_return(Some(&array_ptr));

    Ok(())
}

#[llvm_versions(8.0..=latest)]
#[test]
fn test_memcpy() {
    // 1. Allocate an array with a few elements.
    // 2. Memcpy from the first half of the array to the second half.
    // 3. Run the code in an execution engine and verify the array's contents.
    let context = Context::create();
    let module = context.create_module("av");

    assert!(run_memcpy_on(&context, &module, 8).is_ok());

    // Verify the module
    if let Err(errors) = module.verify() {
        panic!("Errors defining module: {:?}", errors);
    }

    let execution_engine = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();

    unsafe {
        let func = execution_engine.get_function::<unsafe extern "C" fn() -> *const i32>("test_fn").unwrap();
        let actual = std::slice::from_raw_parts(func.call(), 4);

        assert_eq!(&[1, 2, 1, 2], actual);
    }
}

#[llvm_versions(8.0..=latest)]
fn run_memmove_on<'ctx>(context: &'ctx Context, module: &wasmer_inkwell::module::Module<'ctx>, alignment: u32) -> Result<(), &'static str> {
    let i32_type = context.i32_type();
    let i64_type = context.i64_type();
    let array_len = 4;
    let fn_type = i32_type.ptr_type(AddressSpace::Generic).fn_type(&[], false);
    let fn_value = module.add_function("test_fn", fn_type, None);
    let builder = context.create_builder();
    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let len_value = i64_type.const_int(array_len as u64, false);
    let array_ptr = builder.build_array_malloc(i32_type, len_value, "array_ptr").unwrap();

    // Initialize the array with the values [1, 2, 3, 4]
    for index in 0..4 {
        let index_val = i32_type.const_int(index, false);
        let elem_ptr = unsafe { builder.build_in_bounds_gep(array_ptr, &[index_val], "index") };
        let int_val = i32_type.const_int(index + 1, false);

        builder.build_store(elem_ptr, int_val);
    }

    // Memcpy the first half of the array over the second half of the array.
    let elems_to_copy = 2;
    let bytes_to_copy = elems_to_copy * std::mem::size_of::<i32>();
    let size_val = i64_type.const_int(bytes_to_copy as u64, false);
    let index_val = i32_type.const_int(2, false);
    let dest_ptr = unsafe { builder.build_in_bounds_gep(array_ptr, &[index_val], "index") };

    builder.build_memmove(dest_ptr, alignment, array_ptr, alignment, size_val)?;

    builder.build_return(Some(&array_ptr));

    Ok(())
}

#[llvm_versions(8.0..=latest)]
#[test]
fn test_memmove() {
    // 1. Allocate an array with a few elements.
    // 2. Memmove from the first half of the array to the second half.
    // 3. Run the code in an execution engine and verify the array's contents.
    let context = Context::create();
    let module = context.create_module("av");

    assert!(run_memcpy_on(&context, &module, 8).is_ok());

    // Verify the module
    if let Err(errors) = module.verify() {
        panic!("Errors defining module: {:?}", errors);
    }

    let execution_engine = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();

    unsafe {
        let func = execution_engine.get_function::<unsafe extern "C" fn() -> *const i32>("test_fn").unwrap();
        let actual = std::slice::from_raw_parts(func.call(), 4);

        assert_eq!(&[1, 2, 1, 2], actual);
    }
}

#[test]
fn test_bitcast() {
    let context = Context::create();
    let module = context.create_module("bc");
    let void_type = context.void_type();
    let f32_type = context.f32_type();
    let i32_type = context.i32_type();
    let f64_type = context.f64_type();
    let i64_type = context.i64_type();
    let i32_ptr_type = i32_type.ptr_type(AddressSpace::Generic);
    let i64_ptr_type = i64_type.ptr_type(AddressSpace::Generic);
    let i32_vec_type = i32_type.vec_type(2);
    let arg_types = [
        i32_type.into(),
        f32_type.into(),
        i32_vec_type.into(),
        i32_ptr_type.into(),
        f64_type.into(),
    ];
    let fn_type = void_type.fn_type(&arg_types, false);
    let fn_value = module.add_function("bc", fn_type, None);
    let builder = context.create_builder();
    let entry = context.append_basic_block(fn_value, "entry");
    let i32_arg = fn_value.get_first_param().unwrap();
    let f32_arg = fn_value.get_nth_param(1).unwrap();
    let i32_vec_arg = fn_value.get_nth_param(2).unwrap();
    let i32_ptr_arg = fn_value.get_nth_param(3).unwrap();
    let f64_arg = fn_value.get_nth_param(4).unwrap();

    builder.position_at_end(entry);

    let cast = builder.build_bitcast(i32_arg, f32_type, "i32tof32");

    builder.build_bitcast(f32_arg, f32_type, "f32tof32");
    builder.build_bitcast(i32_vec_arg, i64_type, "2xi32toi64");
    builder.build_bitcast(i32_ptr_arg, i64_ptr_type, "i32*toi64*");

    builder.build_return(None);

    assert!(module.verify().is_ok(), module.print_to_string().to_string());

    let first_iv = cast.as_instruction_value().unwrap();

    builder.position_before(&first_iv);
    builder.build_bitcast(f64_arg, i64_type, "f64toi64");

    assert!(module.verify().is_ok());
}

#[test]
fn test_atomicrmw() {
    let context = Context::create();
    let module = context.create_module("rmw");

    let void_type = context.void_type();
    let fn_type = void_type.fn_type(&[], false);
    let fn_value = module.add_function("", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();
    builder.position_at_end(entry);

    let i32_type = context.i32_type();
    let i64_type = context.i64_type();
    let i31_type = context.custom_width_int_type(31);
    let i4_type = context.custom_width_int_type(4);

    let ptr_value = i32_type.ptr_type(AddressSpace::Generic).get_undef();
    let zero_value = i32_type.const_zero();
    let result = builder.build_atomicrmw(AtomicRMWBinOp::Add, ptr_value, zero_value, AtomicOrdering::Unordered);
    assert!(result.is_ok());

    let ptr_value = i64_type.ptr_type(AddressSpace::Generic).get_undef();
    let zero_value = i32_type.const_zero();
    let result = builder.build_atomicrmw(AtomicRMWBinOp::Add, ptr_value, zero_value, AtomicOrdering::Unordered);
    assert!(result.is_err());

    let ptr_value = i31_type.ptr_type(AddressSpace::Generic).get_undef();
    let zero_value = i31_type.const_zero();
    let result = builder.build_atomicrmw(AtomicRMWBinOp::Add, ptr_value, zero_value, AtomicOrdering::Unordered);
    assert!(result.is_err());

    let ptr_value = i4_type.ptr_type(AddressSpace::Generic).get_undef();
    let zero_value = i4_type.const_zero();
    let result = builder.build_atomicrmw(AtomicRMWBinOp::Add, ptr_value, zero_value, AtomicOrdering::Unordered);
    assert!(result.is_err());
}

#[llvm_versions(3.9..=latest)]
#[test]
fn test_cmpxchg() {
    let context = Context::create();
    let module = context.create_module("cmpxchg");

    let void_type = context.void_type();
    let fn_type = void_type.fn_type(&[], false);
    let fn_value = module.add_function("", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");
    let builder = context.create_builder();
    builder.position_at_end(entry);

    let i32_type = context.i32_type();
    let i64_type = context.i64_type();
    let i32_ptr_type = i32_type.ptr_type(AddressSpace::Generic);
    let i32_ptr_ptr_type = i32_ptr_type.ptr_type(AddressSpace::Generic);

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i32_type.const_zero();
    let neg_one_value = i32_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::Monotonic);
    assert!(result.is_ok());

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i32_type.const_zero();
    let neg_one_value = i32_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Unordered, AtomicOrdering::Monotonic);
    assert!(result.is_err());

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i32_type.const_zero();
    let neg_one_value = i32_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::Unordered);
    assert!(result.is_err());

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i32_type.const_zero();
    let neg_one_value = i32_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::Release);
    assert!(result.is_err());

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i32_type.const_zero();
    let neg_one_value = i32_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::AcquireRelease);
    assert!(result.is_err());

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i32_type.const_zero();
    let neg_one_value = i32_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::SequentiallyConsistent);
    assert!(result.is_err());

    let ptr_value = i32_ptr_ptr_type.get_undef();
    let zero_value = i32_type.const_zero();
    let neg_one_value = i32_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::Monotonic);
    assert!(result.is_err());

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i64_type.const_zero();
    let neg_one_value = i32_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::Monotonic);
    assert!(result.is_err());

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i32_type.const_zero();
    let neg_one_value = i64_type.const_all_ones();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::Monotonic);
    assert!(result.is_err());

    let ptr_value = i32_ptr_ptr_type.get_undef();
    let zero_value = i32_ptr_type.const_zero();
    let neg_one_value = i32_ptr_type.const_zero();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::Monotonic);
    assert!(result.is_ok());

    let ptr_value = i32_ptr_type.get_undef();
    let zero_value = i32_ptr_type.const_zero();
    let neg_one_value = i32_ptr_type.const_zero();
    let result = builder.build_cmpxchg(ptr_value, zero_value, neg_one_value, AtomicOrdering::Monotonic, AtomicOrdering::Monotonic);
    assert!(result.is_err());
}

#[test]
fn test_safe_struct_gep() {
    let context = Context::create();
    let builder = context.create_builder();
    let module = context.create_module("struct_gep");
    let void_type = context.void_type();
    let i32_ty = context.i32_type();
    let i32_ptr_ty = i32_ty.ptr_type(AddressSpace::Generic);
    let field_types = &[i32_ty.into(), i32_ty.into()];
    let struct_ty = context.struct_type(field_types, false);
    let struct_ptr_ty = struct_ty.ptr_type(AddressSpace::Generic);
    let fn_type = void_type.fn_type(&[i32_ptr_ty.into(), struct_ptr_ty.into()], false);
    let fn_value = module.add_function("", fn_type, None);
    let entry = context.append_basic_block(fn_value, "entry");

    builder.position_at_end(entry);

    let i32_ptr = fn_value.get_first_param().unwrap().into_pointer_value();
    let struct_ptr = fn_value.get_last_param().unwrap().into_pointer_value();

    assert!(builder.build_struct_gep(i32_ptr, 0, "struct_gep").is_err());
    assert!(builder.build_struct_gep(i32_ptr, 10, "struct_gep").is_err());
    assert!(builder.build_struct_gep(struct_ptr, 0, "struct_gep").is_ok());
    assert!(builder.build_struct_gep(struct_ptr, 1, "struct_gep").is_ok());
    assert!(builder.build_struct_gep(struct_ptr, 2, "struct_gep").is_err());
}