/**
 * Built-in elements providing WebAssembly core functionality.
 * @module builtins
 *//***/

 import {
  Compiler,
  ConversionKind,

  makeSmallIntegerWrap
} from "./compiler";

import {
  DiagnosticCode
} from "./diagnostics";

import {
  Node,
  NodeKind,
  Expression,
  LiteralKind,
  LiteralExpression,
  StringLiteralExpression
} from "./ast";

import {
  Type,
  TypeKind,
  TypeFlags
} from "./types";

import {
  BinaryOp,
  UnaryOp,
  HostOp,
  NativeType,
  ExpressionRef,
  ExpressionId
} from "./module";

import {
  ElementKind,
  FunctionPrototype,
  Class,
  Field,
  OperatorKind,
  FlowFlags
} from "./program";

/** Compiles a call to a built-in function. */
export function compileCall(
  compiler: Compiler,
  prototype: FunctionPrototype,
  typeArguments: Type[] | null,
  operands: Expression[],
  contextualType: Type,
  reportNode: Node
): ExpressionRef {
  var module = compiler.module;

  var arg0: ExpressionRef,
      arg1: ExpressionRef,
      arg2: ExpressionRef,
      ret: ExpressionRef;

  // NOTE that some implementations below make use of the select expression where straight-forward.
  // whether worth or not should probably be tested once/ it's known if/how embedders handle it.
  // search: createSelect

  switch (prototype.internalName) {

    // types

    case "isInteger": { // isInteger<T!>() / isInteger<T?>(value: T) -> bool
      let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
      compiler.currentType = Type.bool;
      if (!type) return module.createUnreachable();
      return type.is(TypeFlags.INTEGER) && !type.is(TypeFlags.REFERENCE)
        ? module.createI32(1)
        : module.createI32(0);
    }
    case "isFloat": { // isFloat<T!>() / isFloat<T?>(value: T) -> bool
      let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
      compiler.currentType = Type.bool;
      if (!type) return module.createUnreachable();
      return type.is(TypeFlags.FLOAT)
        ? module.createI32(1)
        : module.createI32(0);
    }
    case "isSigned": { // isSigned<T!>() / isSigned<T?>(value: T) -> bool
      let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
      compiler.currentType = Type.bool;
      if (!type) return module.createUnreachable();
      return type.is(TypeFlags.SIGNED)
        ? module.createI32(1)
        : module.createI32(0);
    }
    case "isReference": { // isReference<T!>() / isReference<T?>(value: T) -> bool
      let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
      compiler.currentType = Type.bool;
      if (!type) return module.createUnreachable();
      compiler.currentType = Type.bool;
      return type.is(TypeFlags.REFERENCE)
        ? module.createI32(1)
        : module.createI32(0);
    }
    case "isString": { // isString<T!>() / isString<T?>(value: T) -> bool
      let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
      compiler.currentType = Type.bool;
      if (!type) return module.createUnreachable();
      let classType = type.classReference;
      if (classType) {
        let stringInstance = compiler.program.stringInstance;
        if (stringInstance && classType.isAssignableTo(stringInstance)) return module.createI32(1);
      }
      return module.createI32(0);
    }
    case "isArray": { // isArray<T!>() / isArray<T?>(value: T) -> bool
      let type = evaluateConstantType(compiler, typeArguments, operands, reportNode);
      compiler.currentType = Type.bool;
      if (!type) return module.createUnreachable();
      let classType = type.classReference;
      return classType != null && classType.lookupOverload(OperatorKind.INDEXED_GET) != null
        ? module.createI32(1)
        : module.createI32(0);
    }

    // math

    case "clz": { // clz<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.i32, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) {
        default: { // any integer up to 32-bits incl. bool
          ret = module.createUnary(UnaryOp.ClzI32, arg0);
          break;
        }
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        case TypeKind.ISIZE: {
          ret = module.createUnary(
            compiler.options.isWasm64
              ? UnaryOp.ClzI64
              : UnaryOp.ClzI32,
            arg0
          );
          break;
        }
        case TypeKind.I64:
        case TypeKind.U64: {
          ret = module.createUnary(UnaryOp.ClzI64, arg0);
          break;
        }
        case TypeKind.F32:
        case TypeKind.F64:
        case TypeKind.VOID: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "ctz": { // ctz<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.i32, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) {
        default: { // any integer up to 32-bits incl. bool
          ret = module.createUnary(UnaryOp.CtzI32, arg0);
          break;
        }
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        case TypeKind.ISIZE: {
          ret = module.createUnary(
            compiler.options.isWasm64
              ? UnaryOp.CtzI64
              : UnaryOp.CtzI32,
            arg0
          );
          break;
        }
        case TypeKind.I64:
        case TypeKind.U64: {
          ret = module.createUnary(UnaryOp.CtzI64, arg0);
          break;
        }
        case TypeKind.F32:
        case TypeKind.F64:
        case TypeKind.VOID: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "popcnt": { // popcnt<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.i32, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) {
        default: { // any integer up to 32-bits incl. bool
          ret = module.createUnary(UnaryOp.PopcntI32, arg0);
          break;
        }
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        case TypeKind.ISIZE: {
          ret = module.createUnary(
            compiler.options.isWasm64
              ? UnaryOp.PopcntI64
              : UnaryOp.PopcntI32,
            arg0
          );
          break;
        }
        case TypeKind.I64:
        case TypeKind.U64: {
          ret = module.createUnary(UnaryOp.PopcntI64, arg0);
          break;
        }
        case TypeKind.F32:
        case TypeKind.F64:
        case TypeKind.VOID: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "rotl": { // rotl<T?>(value: T, shift: T) -> T
      if (operands.length != 2) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "2", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.i32, ConversionKind.NONE);
      }
      arg1 = compiler.compileExpression(operands[1], compiler.currentType);
      switch (compiler.currentType.kind) {
        case TypeKind.I8:
        case TypeKind.I16:
        case TypeKind.U8:
        case TypeKind.U16:
        case TypeKind.BOOL: {
          ret = makeSmallIntegerWrap(
            module.createBinary(BinaryOp.RotlI32, arg0, arg1),
            compiler.currentType,
            module
          );
          // fall-through
        }
        case TypeKind.I32:
        case TypeKind.U32: {
          ret = module.createBinary(BinaryOp.RotlI32, arg0, arg1);
          break;
        }
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        case TypeKind.ISIZE: {
          ret = module.createBinary(
            compiler.options.isWasm64
              ? BinaryOp.RotlI64
              : BinaryOp.RotlI32,
            arg0,
            arg1
          );
          break;
        }
        case TypeKind.I64:
        case TypeKind.U64: {
          ret = module.createBinary(BinaryOp.RotlI64, arg0, arg1);
          break;
        }
        default: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "rotr": { // rotr<T?>(value: T, shift: T) -> T
      if (operands.length != 2) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "2", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.i32, ConversionKind.NONE);
      }
      arg1 = compiler.compileExpression(operands[1], compiler.currentType);
      switch (compiler.currentType.kind) {
        case TypeKind.I8:
        case TypeKind.I16:
        case TypeKind.U8:
        case TypeKind.U16:
        case TypeKind.BOOL: {
          ret = makeSmallIntegerWrap(
            module.createBinary(BinaryOp.RotrI32, arg0, arg1),
            compiler.currentType,
            module
          );
          break;
        }
        case TypeKind.I32:
        case TypeKind.U32: {
          ret = module.createBinary(BinaryOp.RotrI32, arg0, arg1);
          break;
        }
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        case TypeKind.ISIZE: {
          ret = module.createBinary(
            compiler.options.isWasm64
              ? BinaryOp.RotrI64
              : BinaryOp.RotrI32,
            arg0,
            arg1
          );
          break;
        }
        case TypeKind.I64:
        case TypeKind.U64: {
          ret = module.createBinary(BinaryOp.RotrI64, arg0, arg1);
          break;
        }
        default: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "abs": { // abs<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) {
        case TypeKind.I8:
        case TypeKind.I16:
          // doesn't need sign-extension here because ifFalse below is either positive
          // or MIN_VALUE (-MIN_VALUE == MIN_VALUE) if selected
        case TypeKind.I32: {
          let tempLocal = compiler.currentFunction.getAndFreeTempLocal(Type.i32);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal.index, arg0),
            module.createBinary(BinaryOp.SubI32, // ifFalse
              module.createI32(0),
              module.createGetLocal(tempLocal.index, NativeType.I32)
            ),
            module.createBinary(BinaryOp.GtI32,
              module.createGetLocal(tempLocal.index, NativeType.I32),
              module.createI32(0)
            )
          );
          break;
        }
        case TypeKind.ISIZE: {
          let tempLocal = compiler.currentFunction.getAndFreeTempLocal(compiler.options.usizeType);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal.index, arg0),
            module.createBinary(
              compiler.options.isWasm64
                ? BinaryOp.SubI64
                : BinaryOp.SubI32,
              compiler.options.usizeType.toNativeZero(module),
              module.createGetLocal(tempLocal.index, compiler.options.nativeSizeType)
            ),
            module.createBinary(
              compiler.options.isWasm64
                ? BinaryOp.GtI64
                : BinaryOp.GtI32,
              module.createGetLocal(tempLocal.index, compiler.options.nativeSizeType),
              compiler.options.usizeType.toNativeZero(module)
            )
          );
          break;
        }
        case TypeKind.I64: {
          let tempLocal = compiler.currentFunction.getAndFreeTempLocal(Type.i64);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal.index, arg0),
            module.createBinary(BinaryOp.SubI64,
              module.createI64(0, 0),
              module.createGetLocal(tempLocal.index, NativeType.I64),
            ),
            module.createBinary(BinaryOp.GtI64,
              module.createGetLocal(tempLocal.index, NativeType.I64),
              module.createI64(0, 0)
            )
          );
          break;
        }
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        case TypeKind.U8:
        case TypeKind.U16:
        case TypeKind.U32:
        case TypeKind.U64:
        case TypeKind.BOOL: {
          ret = arg0;
          break;
        }
        case TypeKind.F32: {
          ret = module.createUnary(UnaryOp.AbsF32, arg0);
          break;
        }
        case TypeKind.F64: {
          ret = module.createUnary(UnaryOp.AbsF64, arg0);
          break;
        }
        case TypeKind.VOID: {
          ret = module.createUnreachable();
          break;
        }
        default: { // void
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "max": { // max<T?>(left: T, right: T) -> T
      if (operands.length != 2) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "2", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      arg1 = compiler.compileExpression(operands[1], compiler.currentType);
      switch (compiler.currentType.kind) {
        case TypeKind.I8:
        case TypeKind.I16:
        case TypeKind.I32: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(Type.i32);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(Type.i32);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(BinaryOp.GtI32,
              module.createGetLocal(tempLocal0.index, NativeType.I32),
              module.createGetLocal(tempLocal1.index, NativeType.I32)
            )
          );
          break;
        }
        case TypeKind.U8:
        case TypeKind.U16:
        case TypeKind.U32:
        case TypeKind.BOOL: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(Type.i32);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(Type.i32);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(BinaryOp.GtU32,
              module.createGetLocal(tempLocal0.index, NativeType.I32),
              module.createGetLocal(tempLocal1.index, NativeType.I32)
            )
          );
          break;
        }
        case TypeKind.I64: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(Type.i64);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(Type.i64);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(BinaryOp.GtI64,
              module.createGetLocal(tempLocal0.index, NativeType.I64),
              module.createGetLocal(tempLocal1.index, NativeType.I64)
            )
          );
          break;
        }
        case TypeKind.U64: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(Type.i64);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(Type.i64);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(BinaryOp.GtU64,
              module.createGetLocal(tempLocal0.index, NativeType.I64),
              module.createGetLocal(tempLocal1.index, NativeType.I64)
            )
          );
          break;
        }
        case TypeKind.ISIZE: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(compiler.options.usizeType);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(compiler.options.usizeType);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(
              compiler.options.isWasm64
                ? BinaryOp.GtI64
                : BinaryOp.GtI32,
              module.createGetLocal(tempLocal0.index, compiler.options.nativeSizeType),
              module.createGetLocal(tempLocal1.index, compiler.options.nativeSizeType)
            )
          );
          break;
        }
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          let tempLocal0 = compiler.currentFunction.getTempLocal(compiler.options.usizeType);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(compiler.options.usizeType);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(
              compiler.options.isWasm64
                ? BinaryOp.GtU64
                : BinaryOp.GtU32,
              module.createGetLocal(tempLocal0.index, compiler.options.nativeSizeType),
              module.createGetLocal(tempLocal1.index, compiler.options.nativeSizeType)
            )
          );
          break;
        }
        case TypeKind.F32: {
          ret = module.createBinary(BinaryOp.MaxF32, arg0, arg1);
          break;
        }
        case TypeKind.F64: {
          ret = module.createBinary(BinaryOp.MaxF64, arg0, arg1);
          break;
        }
        default: { // void
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "min": { // min<T?>(left: T, right: T) -> T
      if (operands.length != 2) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "2", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      arg1 = compiler.compileExpression(operands[1], compiler.currentType);
      switch (compiler.currentType.kind) {
        case TypeKind.I8:
        case TypeKind.I16:
        case TypeKind.I32: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(Type.i32);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(Type.i32);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(BinaryOp.LtI32,
              module.createGetLocal(tempLocal0.index, NativeType.I32),
              module.createGetLocal(tempLocal1.index, NativeType.I32)
            )
          );
          break;
        }
        case TypeKind.U8:
        case TypeKind.U16:
        case TypeKind.U32:
        case TypeKind.BOOL: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(Type.i32);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(Type.i32);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(BinaryOp.LtU32,
              module.createGetLocal(tempLocal0.index, NativeType.I32),
              module.createGetLocal(tempLocal1.index, NativeType.I32)
            )
          );
          break;
        }
        case TypeKind.I64: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(Type.i64);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(Type.i64);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(BinaryOp.LtI64,
              module.createGetLocal(tempLocal0.index, NativeType.I64),
              module.createGetLocal(tempLocal1.index, NativeType.I64)
            )
          );
          break;
        }
        case TypeKind.U64: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(Type.i64);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(Type.i64);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(BinaryOp.LtU64,
              module.createGetLocal(tempLocal0.index, NativeType.I64),
              module.createGetLocal(tempLocal1.index, NativeType.I64)
            )
          );
          break;
        }
        case TypeKind.ISIZE: {
          let tempLocal0 = compiler.currentFunction.getTempLocal(compiler.options.usizeType);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(compiler.options.usizeType);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(
              compiler.options.isWasm64
                ? BinaryOp.LtI64
                : BinaryOp.LtI32,
              module.createGetLocal(tempLocal0.index, compiler.options.nativeSizeType),
              module.createGetLocal(tempLocal1.index, compiler.options.nativeSizeType)
            )
          );
          break;
        }
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          let tempLocal0 = compiler.currentFunction.getTempLocal(compiler.options.usizeType);
          let tempLocal1 = compiler.currentFunction.getAndFreeTempLocal(compiler.options.usizeType);
          compiler.currentFunction.freeTempLocal(tempLocal0);
          ret = module.createSelect(
            module.createTeeLocal(tempLocal0.index, arg0),
            module.createTeeLocal(tempLocal1.index, arg1),
            module.createBinary(
              compiler.options.isWasm64
                ? BinaryOp.LtU64
                : BinaryOp.LtU32,
              module.createGetLocal(tempLocal0.index, compiler.options.nativeSizeType),
              module.createGetLocal(tempLocal1.index, compiler.options.nativeSizeType)
            )
          );
          break;
        }
        case TypeKind.F32: {
          ret = module.createBinary(BinaryOp.MinF32, arg0, arg1);
          break;
        }
        case TypeKind.F64: {
          ret = module.createBinary(BinaryOp.MinF64, arg0, arg1);
          break;
        }
        default: { // void
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "ceil": { // ceil<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) {
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        default: { // any integer
          ret = arg0;
          break;
        }
        case TypeKind.F32: {
          ret = module.createUnary(UnaryOp.CeilF32, arg0);
          break;
        }
        case TypeKind.F64: {
          ret = module.createUnary(UnaryOp.CeilF64, arg0);
          break;
        }
        case TypeKind.VOID: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "floor": { // floor<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) {
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        default: { // any integer
          ret = arg0;
          break;
        }
        case TypeKind.F32: {
          ret = module.createUnary(UnaryOp.FloorF32, arg0);
          break;
        }
        case TypeKind.F64: {
          ret = module.createUnary(UnaryOp.FloorF64, arg0);
          break;
        }
        case TypeKind.VOID: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "copysign": { // copysign<T?>(left: T, right: T) -> T
      if (operands.length != 2) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "2", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      arg1 = compiler.compileExpression(operands[1], compiler.currentType);
      switch (compiler.currentType.kind) { // TODO: does an integer version make sense?
        case TypeKind.F32: {
          ret = module.createBinary(BinaryOp.CopysignF32, arg0, arg1);
          break;
        }
        case TypeKind.F64: {
          ret = module.createBinary(BinaryOp.CopysignF64, arg0, arg1);
          break;
        }
        default: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "nearest": { // nearest<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) {
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        default: { // any integer
          ret = arg0;
          break;
        }
        case TypeKind.F32: {
          ret = module.createUnary(UnaryOp.NearestF32, arg0);
          break;
        }
        case TypeKind.F64: {
          ret = module.createUnary(UnaryOp.NearestF64, arg0);
          break;
        }
        case TypeKind.VOID: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "reinterpret": { // reinterpret<T!>(value: *) -> T
      if (operands.length != 1) {
        if (!(typeArguments && typeArguments.length == 1)) {
          if (typeArguments && typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
          );
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (!(typeArguments && typeArguments.length == 1)) {
        if (typeArguments && typeArguments.length) compiler.currentType = typeArguments[0];
        compiler.error(
          DiagnosticCode.Expected_0_type_arguments_but_got_1,
          reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
        );
        return module.createUnreachable();
      }
      switch (typeArguments[0].kind) {
        case TypeKind.I32:
        case TypeKind.U32: {
          arg0 = compiler.compileExpression(operands[0], Type.f32);
          ret = module.createUnary(UnaryOp.ReinterpretF32, arg0);
          break;
        }
        case TypeKind.I64:
        case TypeKind.U64: {
          arg0 = compiler.compileExpression(operands[0], Type.f64);
          ret = module.createUnary(UnaryOp.ReinterpretF64, arg0);
          break;
        }
        case TypeKind.USIZE: {
          if (typeArguments[0].is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            compiler.currentType = typeArguments[0];
            return module.createUnreachable();
          }
          // fall-through
        }
        case TypeKind.ISIZE: {
          arg0 = compiler.compileExpression(
            operands[0],
            compiler.options.isWasm64
              ? Type.f64
              : Type.f32
            );
          ret = module.createUnary(
            compiler.options.isWasm64
              ? UnaryOp.ReinterpretF64
              : UnaryOp.ReinterpretF32,
            arg0
          );
          break;
        }
        case TypeKind.F32: {
          arg0 = compiler.compileExpression(operands[0], Type.u32);
          ret = module.createUnary(UnaryOp.ReinterpretI32, arg0);
          break;
        }
        case TypeKind.F64: {
          arg0 = compiler.compileExpression(operands[0], Type.u64);
          ret = module.createUnary(UnaryOp.ReinterpretI64, arg0);
          break;
        }
        default: { // small integers and void
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      compiler.currentType = typeArguments[0];
      return ret;
    }
    case "sqrt": { // sqrt<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) { // TODO: integer versions (that return f64 or convert)?
        case TypeKind.F32: {
          ret = module.createUnary(UnaryOp.SqrtF32, arg0);
          break;
        }
        case TypeKind.F64: {
          ret = module.createUnary(UnaryOp.SqrtF64, arg0);
          break;
        }
        // case TypeKind.VOID:
        default: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "trunc": { // trunc<T?>(value: T) -> T
      if (operands.length != 1) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments && typeArguments.length) {
        compiler.currentType = typeArguments[0];
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.f64, ConversionKind.NONE);
      }
      switch (compiler.currentType.kind) {
        case TypeKind.USIZE: {
          if (compiler.currentType.is(TypeFlags.REFERENCE)) {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = module.createUnreachable();
            break;
          }
          // fall-through
        }
        default: { // any integer
          ret = arg0;
          break;
        }
        // TODO: truncate to contextual type directly (if not void etc.)?
        case TypeKind.F32: {
          ret = module.createUnary(UnaryOp.TruncF32, arg0);
          break;
        }
        case TypeKind.F64: {
          ret = module.createUnary(UnaryOp.TruncF64, arg0);
          break;
        }
        case TypeKind.VOID: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }

    // memory access

    case "load": { // load<T!>(offset: usize, constantOffset?: usize) -> *
      if (operands.length < 1 || operands.length > 2) {
        if (!(typeArguments && typeArguments.length == 1)) {
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
          );
        }
        if (operands.length < 1) {
          compiler.error(
            DiagnosticCode.Expected_at_least_0_arguments_but_got_1,
            reportNode.range, "1", operands.length.toString(10)
          );
        } else {
          compiler.error(
            DiagnosticCode.Expected_0_arguments_but_got_1,
            reportNode.range, "2", operands.length.toString(10)
          );
        }
        return module.createUnreachable();
      }
      if (!(typeArguments && typeArguments.length == 1)) {
        if (typeArguments && typeArguments.length) compiler.currentType = typeArguments[0];
        compiler.error(
          DiagnosticCode.Expected_0_type_arguments_but_got_1,
          reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
        );
        return module.createUnreachable();
      }
      arg0 = compiler.compileExpression(operands[0], compiler.options.usizeType);
      let offset = operands.length == 2 ? evaluateConstantOffset(compiler, operands[1]) : 0; // reports
      if (offset < 0) { // reported in evaluateConstantOffset
        return module.createUnreachable();
      }
      compiler.currentType = typeArguments[0];
      return module.createLoad(
        typeArguments[0].byteSize,
        typeArguments[0].is(TypeFlags.SIGNED | TypeFlags.INTEGER),
        arg0,
        typeArguments[0].is(TypeFlags.INTEGER) &&
        contextualType.is(TypeFlags.INTEGER) &&
        contextualType.size > typeArguments[0].size
          ? (compiler.currentType = contextualType).toNativeType()
          : (compiler.currentType = typeArguments[0]).toNativeType(),
        offset
      );
    }
    case "store": { // store<T!>(offset: usize, value: *, constantOffset?: usize) -> void
      compiler.currentType = Type.void;
      if (operands.length < 2 || operands.length > 3) {
        if (!(typeArguments && typeArguments.length == 1)) {
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
          );
        }
        if (operands.length < 2) {
          compiler.error(
            DiagnosticCode.Expected_at_least_0_arguments_but_got_1,
            reportNode.range, "2", operands.length.toString(10)
          );
        } else {
          compiler.error(
            DiagnosticCode.Expected_0_arguments_but_got_1,
            reportNode.range, "3", operands.length.toString(10)
          );
        }
        return module.createUnreachable();
      }
      if (!(typeArguments && typeArguments.length == 1)) {
        compiler.error(
          DiagnosticCode.Expected_0_type_arguments_but_got_1,
          reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
        );
        return module.createUnreachable();
      }
      arg0 = compiler.compileExpression(operands[0], compiler.options.usizeType);
      arg1 = compiler.compileExpression(
        operands[1],
        typeArguments[0],
        typeArguments[0].is(TypeFlags.INTEGER)
          ? ConversionKind.NONE // wraps a larger integer type to a smaller one, i.e. i32.store8
          : ConversionKind.IMPLICIT
      );
      let type: Type;
      if (
        compiler.currentType.is(TypeFlags.INTEGER) &&
        typeArguments[0].is(TypeFlags.INTEGER) &&
        typeArguments[0].size > compiler.currentType.size
      ) {
        arg1 = compiler.convertExpression(
          arg1,
          compiler.currentType, typeArguments[0],
          ConversionKind.IMPLICIT,
          operands[1]
        );
        type = typeArguments[0];
      } else {
        type = compiler.currentType;
      }
      let offset = operands.length == 3 ? evaluateConstantOffset(compiler, operands[2]) : 0; // reports
      if (offset < 0) { // reported in evaluateConstantOffset
        return module.createUnreachable();
      }
      compiler.currentType = Type.void;
      return module.createStore(typeArguments[0].byteSize, arg0, arg1, type.toNativeType(), offset);
    }
    case "sizeof": { // sizeof<T!>() -> usize
      compiler.currentType = compiler.options.usizeType;
      if (operands.length != 0) {
        if (!(typeArguments && typeArguments.length == 1)) {
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
          );
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "0", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (!(typeArguments && typeArguments.length == 1)) {
        compiler.error(
          DiagnosticCode.Expected_0_type_arguments_but_got_1,
          reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
        );
      }
      let byteSize = (<Type[]>typeArguments)[0].byteSize;
      if (compiler.options.isWasm64) {
        // implicitly wrap if contextual type is a 32-bit integer
        if (contextualType.is(TypeFlags.INTEGER) && contextualType.size <= 32) {
          compiler.currentType = Type.u32;
          ret = module.createI32(byteSize);
        } else {
          ret = module.createI64(byteSize, 0);
        }
      } else {
        // implicitly extend if contextual type is a 64-bit integer
        if (contextualType.is(TypeFlags.INTEGER) && contextualType.size == 64) {
          compiler.currentType = Type.u64;
          ret = module.createI64(byteSize, 0);
        } else {
          ret = module.createI32(byteSize);
        }
      }
      return ret;
    }
    case "alignof": { // alignof<T!>() -> usize
      compiler.currentType = compiler.options.usizeType;
      if (operands.length != 0) {
        if (!(typeArguments && typeArguments.length == 1)) {
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
          );
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "0", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (!(typeArguments && typeArguments.length == 1)) {
        compiler.error(
          DiagnosticCode.Expected_0_type_arguments_but_got_1,
          reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
        );
        return module.createUnreachable();
      }
      let byteSize = (<Type[]>typeArguments)[0].byteSize;
      let alignLog2: i32;
      switch (byteSize) {
        case 1: { alignLog2 = 0; break; }
        case 2: { alignLog2 = 1; break; }
        case 4: { alignLog2 = 2; break; }
        case 8: { alignLog2 = 3; break; }
        default: { assert(false); return module.createUnreachable(); }
      }
      if (compiler.options.isWasm64) {
        // implicitly wrap if contextual type is a 32-bit integer
        if (contextualType.is(TypeFlags.INTEGER) && contextualType.size <= 32) {
          compiler.currentType = Type.u32;
          ret = module.createI32(alignLog2);
        } else {
          ret = module.createI64(alignLog2, 0);
        }
      } else {
        // implicitly extend if contextual type is a 64-bit integer
        if (contextualType.is(TypeFlags.INTEGER) && contextualType.size == 64) {
          compiler.currentType = Type.u64;
          ret = module.createI64(alignLog2, 0);
        } else {
          ret = module.createI32(alignLog2);
        }
      }
      return ret;
    }
    case "offsetof": { // offsetof<T!>(fieldName?: string) -> usize
      compiler.currentType = compiler.options.usizeType;
      if (operands.length > 1) {
        if (!(typeArguments && typeArguments.length == 1)) {
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
          );
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (!(typeArguments && typeArguments.length == 1)) {
        compiler.error(
          DiagnosticCode.Expected_0_type_arguments_but_got_1,
          reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
        );
        return module.createUnreachable();
      }
      let classType = typeArguments[0].classReference;
      if (!classType) {
        compiler.error( // TODO: better error
          DiagnosticCode.Operation_not_supported,
          reportNode.range
        );
        return module.createUnreachable();
      }
      let offset: i32;
      if (operands.length) {
        if (
          operands[0].kind != NodeKind.LITERAL ||
          (<LiteralExpression>operands[0]).literalKind != LiteralKind.STRING
        ) {
          compiler.error(
            DiagnosticCode.String_literal_expected,
            operands[0].range
          );
          return module.createUnreachable();
        }
        let fieldName = (<StringLiteralExpression>operands[0]).value;
        let field = classType.members ? classType.members.get(fieldName) : null;
        if (!(field && field.kind == ElementKind.FIELD)) {
          compiler.error(
            DiagnosticCode.Type_0_has_no_property_1,
            operands[0].range, classType.internalName, fieldName
          );
          return module.createUnreachable();
        }
        offset = (<Field>field).memoryOffset;
      } else {
        offset = classType.currentMemoryOffset;
      }
      if (compiler.options.isWasm64) {
        // implicitly wrap if contextual type is a 32-bit integer
        if (contextualType.is(TypeFlags.INTEGER) && contextualType.size <= 32) {
          compiler.currentType = Type.u32;
          return module.createI32(offset);
        } else {
          return module.createI64(offset);
        }
      } else {
        // implicitly extend if contextual type is a 64-bit integer
        if (contextualType.is(TypeFlags.INTEGER) && contextualType.size == 64) {
          compiler.currentType = Type.u64;
          return module.createI64(offset);
        } else {
          return module.createI32(offset);
        }
      }
    }
    case "i32.load8_s": return compileLoadInstruction(compiler, Type.i8, operands, Type.i32, reportNode);
    case "i32.load8_u": return compileLoadInstruction(compiler, Type.u8, operands, Type.u32, reportNode);
    case "i32.load16_s": return compileLoadInstruction(compiler, Type.i16, operands, Type.i32, reportNode);
    case "i32.load16_u": return compileLoadInstruction(compiler, Type.u16, operands, Type.u32, reportNode);
    case "i32.load": return compileLoadInstruction(compiler, Type.i32, operands, Type.i32, reportNode);
    case "i64.load8_s": return compileLoadInstruction(compiler, Type.i8, operands, Type.i64, reportNode);
    case "i64.load8_u": return compileLoadInstruction(compiler, Type.u8, operands, Type.u64, reportNode);
    case "i64.load16_s": return compileLoadInstruction(compiler, Type.i16, operands, Type.i64, reportNode);
    case "i64.load16_u": return compileLoadInstruction(compiler, Type.u16, operands, Type.u64, reportNode);
    case "i64.load32_s": return compileLoadInstruction(compiler, Type.i32, operands, Type.i64, reportNode);
    case "i64.load32_u": return compileLoadInstruction(compiler, Type.u32, operands, Type.u64, reportNode);
    case "i64.load": return compileLoadInstruction(compiler, Type.i64, operands, Type.i64, reportNode);
    case "f32.load": return compileLoadInstruction(compiler, Type.f32, operands, Type.f32, reportNode);
    case "f64.load": return compileLoadInstruction(compiler, Type.f64, operands, Type.f64, reportNode);
    case "i32.store8": return compileStoreInstruction(compiler, Type.i8, operands, Type.i32, reportNode);
    case "i32.store16": return compileStoreInstruction(compiler, Type.i16, operands, Type.i32, reportNode);
    case "i32.store": return compileStoreInstruction(compiler, Type.i32, operands, Type.i32, reportNode);
    case "i64.store8": return compileStoreInstruction(compiler, Type.i8, operands, Type.i64, reportNode);
    case "i64.store16": return compileStoreInstruction(compiler, Type.i16, operands, Type.i64, reportNode);
    case "i64.store32": return compileStoreInstruction(compiler, Type.i32, operands, Type.i64, reportNode);
    case "i64.store": return compileStoreInstruction(compiler, Type.i64, operands, Type.i64, reportNode);
    case "f32.store": return compileStoreInstruction(compiler, Type.f32, operands, Type.f32, reportNode);
    case "f64.store": return compileStoreInstruction(compiler, Type.f64, operands, Type.f64, reportNode);

    // control flow

    case "select": { // select<T?>(ifTrue: T, ifFalse: T, condition: bool) -> T
      if (operands.length != 3) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "3", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length != 1) {
          if (typeArguments.length) compiler.currentType = typeArguments[0];
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.i32, ConversionKind.NONE);
      }
      let type = compiler.currentType;
      arg1 = compiler.compileExpression(operands[1], type);
      arg2 = compiler.compileExpression(operands[2], Type.i32);
      compiler.currentType = type;
      switch (compiler.currentType.kind) {
        default: { // any value type
          ret = module.createSelect(arg0, arg1, arg2);
          break;
        }
        case TypeKind.VOID: {
          compiler.error(
            DiagnosticCode.Operation_not_supported,
            reportNode.range
          );
          ret = module.createUnreachable();
          break;
        }
      }
      return ret;
    }
    case "unreachable": { // unreachable() -> *
      if (operands.length != 0) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "0", operands.length.toString(10)
        );
      }
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      return module.createUnreachable();
    }

    // host operations

    case "current_memory": { // current_memory() -> i32
      compiler.currentType = Type.i32;
      if (operands.length != 0) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "0", operands.length.toString(10)
        );
      }
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      return module.createHost(HostOp.CurrentMemory);
    }
    case "grow_memory": { // grow_memory(pages: i32) -> i32
      compiler.currentType = Type.i32;
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "0", operands.length.toString(10)
        );
        arg0 = module.createUnreachable();
      } else {
        arg0 = compiler.compileExpression(operands[0], Type.i32);
      }
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      return module.createHost(HostOp.GrowMemory, null, [ arg0 ]);
    }
    // see: https://github.com/WebAssembly/bulk-memory-operations
    case "move_memory": { // move_memory(dest: usize, src: usize: n: usize) -> void
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 3) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "3", operands.length.toString(10)
        );
        compiler.currentType = Type.void;
        return module.createUnreachable();
      }
      arg0 = compiler.compileExpression(operands[0], compiler.options.usizeType);
      arg1 = compiler.compileExpression(operands[1], compiler.options.usizeType);
      arg2 = compiler.compileExpression(operands[2], compiler.options.usizeType);
      compiler.currentType = Type.void;
      throw new Error("not implemented");
      // return module.createHost(HostOp.MoveMemory, null, [ arg0, arg1, arg2 ]);
    }
    case "set_memory": { // set_memory(dest: usize, value: u32, n: usize) -> void
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 3) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "3", operands.length.toString(10)
        );
        compiler.currentType = Type.void;
        return module.createUnreachable();
      }
      arg0 = compiler.compileExpression(operands[0], compiler.options.usizeType);
      arg1 = compiler.compileExpression(operands[1], Type.u32);
      arg2 = compiler.compileExpression(operands[2], compiler.options.usizeType);
      compiler.currentType = Type.void;
      throw new Error("not implemented");
      // return module.createHost(HostOp.SetMemory, null, [ arg0, arg1, arg2 ]);
    }

    // other

    case "changetype": { // changetype<T!>(value: *) -> T
      if (!(typeArguments && typeArguments.length == 1)) {
        if (typeArguments && typeArguments.length) compiler.currentType = typeArguments[0];
        compiler.error(
          DiagnosticCode.Expected_0_type_arguments_but_got_1,
          reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
        );
        return module.createUnreachable();
      } else if (typeArguments[0].kind != TypeKind.USIZE) { // any usize
        compiler.error(
          DiagnosticCode.Operation_not_supported,
          reportNode.range
        );
        compiler.currentType = typeArguments[0];
        return module.createUnreachable();
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = typeArguments[0];
        return module.createUnreachable();
      }
      arg0 = compiler.compileExpression(
        operands[0],
        compiler.options.usizeType,
        ConversionKind.NONE
      );
      compiler.currentType = typeArguments[0];
      if (compiler.currentType.kind != TypeKind.USIZE) {
        compiler.error(
          DiagnosticCode.Operation_not_supported,
          reportNode.range
        );
        return module.createUnreachable();
      }
      // if (reportNode.range.source.sourceKind != SourceKind.STDLIB)
      //  compiler.warning(DiagnosticCode.Operation_is_unsafe, reportNode.range);
      return arg0; // any usize to any usize
    }
    case "assert": { // assert<T?>(isTrueish: T, message?: string) -> T with T != null
      if (operands.length < 1 || operands.length > 2) {
        if (typeArguments) {
          if (typeArguments.length) compiler.currentType = typeArguments[0].nonNullableType;
          if (typeArguments.length != 1) {
            compiler.error(
              DiagnosticCode.Expected_0_type_arguments_but_got_1,
              reportNode.range, "1", typeArguments.length.toString(10)
            );
          }
        }
        if (operands.length < 1) {
          compiler.error(
            DiagnosticCode.Expected_at_least_0_arguments_but_got_1,
            reportNode.range, "1", operands.length.toString(10)
          );
        } else if (operands.length > 2) {
          compiler.error(
            DiagnosticCode.Expected_0_arguments_but_got_1,
            reportNode.range, "2", operands.length.toString(10)
          );
        }
        return module.createUnreachable();
      }
      if (typeArguments) {
        if (typeArguments.length) compiler.currentType = typeArguments[0].nonNullableType;
        if (typeArguments.length != 1) {
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return module.createUnreachable();
        }
        arg0 = compiler.compileExpression(operands[0], typeArguments[0]);
      } else {
        arg0 = compiler.compileExpressionRetainType(operands[0], Type.i32);
      }

      let type = compiler.currentType;
      compiler.currentType = type.nonNullableType;

      // just return ifTrueish if assertions are disabled, or simplify if dropped anyway
      if (compiler.options.noAssert) {
        if (contextualType == Type.void) {
          compiler.currentType = Type.void;
          return module.createNop();
        }
        return arg0;
      }

      let abort = compileAbort(compiler, operands.length == 2 ? operands[1] : null, reportNode);

      compiler.currentType = type.nonNullableType;

      if (contextualType == Type.void) { // simplify if dropped anyway
        switch (compiler.currentType.kind) {
          default: { // any integer up to 32-bits incl. bool
            ret = module.createIf(
              module.createUnary(UnaryOp.EqzI32,
                arg0
              ),
              abort
            );
            break;
          }
          case TypeKind.I64:
          case TypeKind.U64: {
            ret = module.createIf(
              module.createUnary(UnaryOp.EqzI64,
                arg0
              ),
              abort
            );
            break;
          }
          case TypeKind.ISIZE:
          case TypeKind.USIZE: {
            ret = module.createIf(
              module.createUnary(
                compiler.options.isWasm64
                  ? UnaryOp.EqzI64
                  : UnaryOp.EqzI32,
                arg0
              ),
              abort
            );
            break;
          }
          // TODO: also check for NaN in float assertions, as in `Boolean(NaN) -> false`?
          case TypeKind.F32: {
            ret = module.createIf(
              module.createBinary(BinaryOp.EqF32,
                arg0,
                module.createF32(0)
              ),
              abort
            );
            break;
          }
          case TypeKind.F64: {
            ret = module.createIf(
              module.createBinary(BinaryOp.EqF64,
                arg0,
                module.createF64(0)
              ),
              abort
            );
            break;
          }
          case TypeKind.VOID: {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = abort;
            break;
          }
        }
        compiler.currentType = Type.void;
      } else {
        switch (compiler.currentType.kind) {
          default: { // any integer up to 32-bits incl. bool
            let tempLocal = compiler.currentFunction.getAndFreeTempLocal(Type.i32);
            ret = module.createIf(
              module.createUnary(UnaryOp.EqzI32,
                module.createTeeLocal(tempLocal.index, arg0)
              ),
              abort,
              module.createGetLocal(tempLocal.index, NativeType.I32)
            );
            break;
          }
          case TypeKind.I64:
          case TypeKind.U64: {
            let tempLocal = compiler.currentFunction.getAndFreeTempLocal(Type.i64);
            ret = module.createIf(
              module.createUnary(UnaryOp.EqzI64,
                module.createTeeLocal(tempLocal.index, arg0)
              ),
              abort,
              module.createGetLocal(tempLocal.index, NativeType.I64)
            );
            break;
          }
          case TypeKind.ISIZE:
          case TypeKind.USIZE: {
            let tempLocal = compiler.currentFunction.getAndFreeTempLocal(compiler.options.usizeType);
            ret = module.createIf(
              module.createUnary(
                compiler.options.isWasm64
                  ? UnaryOp.EqzI64
                  : UnaryOp.EqzI32,
                module.createTeeLocal(tempLocal.index, arg0)
              ),
              abort,
              module.createGetLocal(tempLocal.index, compiler.options.nativeSizeType)
            );
            break;
          }
          case TypeKind.F32: {
            let tempLocal = compiler.currentFunction.getAndFreeTempLocal(Type.f32);
            ret = module.createIf(
              module.createBinary(BinaryOp.EqF32,
                module.createTeeLocal(tempLocal.index, arg0),
                module.createF32(0)
              ),
              abort,
              module.createGetLocal(tempLocal.index, NativeType.F32)
            );
            break;
          }
          case TypeKind.F64: {
            let tempLocal = compiler.currentFunction.getAndFreeTempLocal(Type.f64);
            ret = module.createIf(
              module.createBinary(BinaryOp.EqF64,
                module.createTeeLocal(tempLocal.index, arg0),
                module.createF64(0)
              ),
              abort,
              module.createGetLocal(tempLocal.index, NativeType.F64)
            );
            break;
          }
          case TypeKind.VOID: {
            compiler.error(
              DiagnosticCode.Operation_not_supported,
              reportNode.range
            );
            ret = abort;
            break;
          }
        }
      }
      return ret;
    }
    case "unchecked": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        return module.createUnreachable();
      }
      let flow = compiler.currentFunction.flow;
      flow.set(FlowFlags.UNCHECKED_CONTEXT);
      ret = compiler.compileExpressionRetainType(operands[0], contextualType, false);
      flow.unset(FlowFlags.UNCHECKED_CONTEXT);
      return ret;
    }

    // conversions

    case "i8": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.i8;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.i8, ConversionKind.EXPLICIT);
    }
    case "i16": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.i16;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.i16, ConversionKind.EXPLICIT);
    }
    case "i32": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.i32;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.i32, ConversionKind.EXPLICIT);
    }
    case "i64": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.i64;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.i64, ConversionKind.EXPLICIT);
    }
    case "isize": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = compiler.options.isWasm64
          ? Type.isize64
          : Type.isize32;
        return module.createUnreachable();
      }
      return compiler.compileExpression(
        operands[0],
        compiler.options.isWasm64
          ? Type.isize64
          : Type.isize32,
        ConversionKind.EXPLICIT
      );
    }
    case "u8": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.u8;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.u8, ConversionKind.EXPLICIT);
    }
    case "u16": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.u16;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.u16, ConversionKind.EXPLICIT);
    }
    case "u32": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.u32;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.u32, ConversionKind.EXPLICIT);
    }
    case "u64": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.u64;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.u64, ConversionKind.EXPLICIT);
    }
    case "usize": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = compiler.options.usizeType;
        return module.createUnreachable();
      }
      return compiler.compileExpression(
        operands[0],
        compiler.options.usizeType,
        ConversionKind.EXPLICIT
      );
    }
    case "bool": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.bool;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.bool, ConversionKind.EXPLICIT);
    }
    case "f32": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.f32;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.f32, ConversionKind.EXPLICIT);
    }
    case "f64": {
      if (typeArguments) {
        compiler.error(
          DiagnosticCode.Type_0_is_not_generic,
          reportNode.range, prototype.internalName
        );
      }
      if (operands.length != 1) {
        compiler.error(
          DiagnosticCode.Expected_0_arguments_but_got_1,
          reportNode.range, "1", operands.length.toString(10)
        );
        compiler.currentType = Type.f64;
        return module.createUnreachable();
      }
      return compiler.compileExpression(operands[0], Type.f64, ConversionKind.EXPLICIT);
    }
  }
  compiler.error(
    DiagnosticCode.Operation_not_supported,
    reportNode.range
  );
  return module.createUnreachable();
}

function evaluateConstantType(
  compiler: Compiler,
  typeArguments: Type[] | null,
  operands: Expression[],
  reportNode: Node
): Type | null {
  if (operands.length == 0) { // requires type argument
    if (!typeArguments || typeArguments.length != 1) {
      compiler.error(
        DiagnosticCode.Expected_0_type_arguments_but_got_1,
        reportNode.range, "1", typeArguments ? typeArguments.length.toString(10) : "0"
      );
      return null;
    }
    return typeArguments[0];
  }
  if (operands.length == 1) { // optional type argument
    if (typeArguments) {
      if (typeArguments.length == 1) {
        compiler.compileExpression(operands[0], typeArguments[0], ConversionKind.IMPLICIT, false);
      } else {
        if (typeArguments.length) {
          compiler.error(
            DiagnosticCode.Expected_0_type_arguments_but_got_1,
            reportNode.range, "1", typeArguments.length.toString(10)
          );
          return null;
        }
        compiler.compileExpressionRetainType(operands[0], Type.i32, false);
      }
    } else {
      compiler.compileExpressionRetainType(operands[0], Type.i32, false);
    }
    return compiler.currentType;
  }
  if (typeArguments && typeArguments.length > 1) {
    compiler.error(
      DiagnosticCode.Expected_0_type_arguments_but_got_1,
      reportNode.range, "1", typeArguments.length.toString(10)
    );
  }
  compiler.error(
    DiagnosticCode.Expected_0_arguments_but_got_1,
    reportNode.range, "1", operands.length.toString(10)
  );
  return null;
}

function evaluateConstantOffset(compiler: Compiler, expression: Expression): i32 {
  var expr: ExpressionRef;
  var value: i32;
  if (compiler.options.isWasm64) {
    expr = compiler.precomputeExpression(expression, Type.usize64);
    if (
      _BinaryenExpressionGetId(expr) != ExpressionId.Const ||
      _BinaryenExpressionGetType(expr) != NativeType.I64 ||
      _BinaryenConstGetValueI64High(expr) != 0 ||
      (value = _BinaryenConstGetValueI64Low(expr)) < 0
    ) {
      compiler.error(
        DiagnosticCode.Operation_not_supported,
        expression.range
      );
      value = -1;
    }
  } else {
    expr = compiler.precomputeExpression(expression, Type.usize32);
    if (
      _BinaryenExpressionGetId(expr) != ExpressionId.Const ||
      _BinaryenExpressionGetType(expr) != NativeType.I32 ||
      (value = _BinaryenConstGetValueI32(expr)) < 0
    ) {
      compiler.error(
        DiagnosticCode.Operation_not_supported,
        expression.range
      );
      value = -1;
    }
  }
  return value;
}

const allocateInternalName = "allocate_memory";

/** Compiles a memory allocation for an instance of the specified class. */
export function compileAllocate(
  compiler: Compiler,
  classInstance: Class,
  reportNode: Node
): ExpressionRef {
  var program = compiler.program;
  assert(classInstance.program == program);
  var module = compiler.module;
  var options = compiler.options;

  var allocatePrototype = program.elementsLookup.get(allocateInternalName);
  if (!allocatePrototype) {
    program.error(
      DiagnosticCode.Cannot_find_name_0,
      reportNode.range, allocateInternalName
    );
    return module.createUnreachable();
  }
  if (allocatePrototype.kind != ElementKind.FUNCTION_PROTOTYPE) {
    program.error(
      DiagnosticCode.Cannot_invoke_an_expression_whose_type_lacks_a_call_signature_Type_0_has_no_compatible_call_signatures,
      reportNode.range, allocatePrototype.internalName
    );
    return module.createUnreachable();
  }

  var allocateInstance = (<FunctionPrototype>allocatePrototype).resolve(); // reports
  if (!(allocateInstance && compiler.compileFunction(allocateInstance))) return module.createUnreachable();

  compiler.currentType = classInstance.type;
  return module.createCall(
    allocateInstance.internalName, [
      options.isWasm64
        ? module.createI64(classInstance.currentMemoryOffset)
        : module.createI32(classInstance.currentMemoryOffset)
    ],
    options.nativeSizeType
  );
}

const abortInternalName = "abort";

/** Compiles an abort wired to the conditionally imported 'abort' function. */
export function compileAbort(
  compiler: Compiler,
  message: Expression | null,
  reportNode: Node
): ExpressionRef {
  var program = compiler.program;
  var module = compiler.module;

  var stringType = program.typesLookup.get("string"); // might be intended
  if (!stringType) return module.createUnreachable();

  var abortPrototype = program.elementsLookup.get(abortInternalName); // might be intended
  if (!abortPrototype || abortPrototype.kind != ElementKind.FUNCTION_PROTOTYPE) return module.createUnreachable();

  var abortInstance = (<FunctionPrototype>abortPrototype).resolve(); // reports
  if (!(abortInstance && compiler.compileFunction(abortInstance))) return module.createUnreachable();

  var messageArg = message != null
    ? compiler.compileExpression(message, stringType)
    : stringType.toNativeZero(module);

  var filenameArg = compiler.compileStaticString(reportNode.range.source.normalizedPath);

  compiler.currentType = Type.void;
  return module.createBlock(null, [
    module.createCallImport(
      abortInstance.internalName, [
        messageArg,
        filenameArg,
        module.createI32(reportNode.range.line),
        module.createI32(reportNode.range.column)
      ],
      NativeType.None
    ),
    module.createUnreachable()
  ]);
}

/** Explicitly compiles a specific load instruction. */
export function compileLoadInstruction(
  compiler: Compiler,
  loadType: Type,
  loadOperands: Expression[],
  valueType: Type,
  reportNode: Node
): ExpressionRef { // transform to a `<valueType>load<loadType>(offset)` call
  var loadPrototype = assert(compiler.program.elementsLookup.get("load"));
  assert(loadPrototype.kind == ElementKind.FUNCTION_PROTOTYPE);
  return compileCall(compiler, <FunctionPrototype>loadPrototype, [ loadType ], loadOperands, valueType, reportNode);
}

/** Explicitly compiles a specific store instruction. */
export function compileStoreInstruction(
  compiler: Compiler,
  storeType: Type,
  storeOperands: Expression[],
  valueType: Type,
  reportNode: Node
): ExpressionRef { // transform to a `store<storeType>(offset, <valueType>value)` call
  var storePrototype = assert(compiler.program.elementsLookup.get("store"));
  assert(storePrototype.kind == ElementKind.FUNCTION_PROTOTYPE);
  return compileCall(compiler, <FunctionPrototype>storePrototype, [ storeType ], storeOperands, valueType, reportNode);
}