diff --git a/README.md b/README.md
index 87ed8d82..ae999eb9 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@ AssemblyScript NEXT
 
 [![Build Status](https://travis-ci.org/AssemblyScript/next.svg?branch=master)](https://travis-ci.org/AssemblyScript/next)
 
-**AssemblyScript** is a new compiler targeting WebAssembly while utilizing [TypeScript](http://www.typescriptlang.org)'s syntax and [node](https://nodejs.org)'s vibrant ecosystem. Instead of requiring complex toolchains to set up, you can simply `npm install` it - or run it in a browser.
+**AssemblyScript** is a new compiler targeting [WebAssembly](http://webassembly.org) while utilizing [TypeScript](http://www.typescriptlang.org)'s syntax and [node](https://nodejs.org)'s vibrant ecosystem. Instead of requiring complex toolchains to set up, you can simply `npm install` it - or run it in a browser.
 
 By compiling a variant of TypeScript to [Binaryen](https://github.com/WebAssembly/binaryen) IR, the resulting module can be validated, optimized, emitted in WebAssembly text or binary format and converted to [asm.js](http://asmjs.org) as a polyfill.
 
diff --git a/assembly.d.ts b/assembly.d.ts
index c658213b..3adb3865 100644
--- a/assembly.d.ts
+++ b/assembly.d.ts
@@ -90,6 +90,10 @@ declare function isNaN<T = f32 | f64>(value: T): bool;
 declare function isFinite<T = f32 | f64>(value: T): bool;
 /** Traps if the specified value evaluates to `false`. */
 declare function assert(isTrue: bool): void;
+/** Parses an integer string to a 64-bit float. */
+declare function parseInt(str: string, radix?: i32): f64;
+/** Parses a string to a 64-bit float. */
+declare function parseFloat(str: string): f64;
 
 // Internal decorators (not yet implemented)
 
diff --git a/portable.d.ts b/portable.d.ts
index 843a5709..95ce426c 100644
--- a/portable.d.ts
+++ b/portable.d.ts
@@ -52,6 +52,10 @@ declare function unreachable(): any; // sic
 declare function changetype<T1,T2>(value: T1): T2;
 /** Traps if the specified value evaluates to `false`. */
 declare function assert(isTrue: bool): void;
+/** Parses an integer string to a 64-bit float. */
+declare function parseInt(str: string, radix?: i32): f64;
+/** Parses a floating point string to a 64-bit float. */
+declare function parseFloat(str: string): f64;
 
 // Portable standard library
 // Everything marked @deprecated is a temporary filler. Do not use.
@@ -143,6 +147,3 @@ declare namespace console {
   /** @deprecated */
   function log(message: string): void;
 }
-
-/** @deprecated */
-declare function parseFloat(str: string): f64;
diff --git a/src/builtins.ts b/src/builtins.ts
index bcf86ab5..ec94a3c2 100644
--- a/src/builtins.ts
+++ b/src/builtins.ts
@@ -2,7 +2,7 @@ import { Compiler, Target, typeToNativeType, typeToNativeOne } from "./compiler"
 import { DiagnosticCode } from "./diagnostics";
 import { Node, Expression } from "./ast";
 import { Type } from "./types";
-import { Module, ExpressionRef, UnaryOp, BinaryOp, HostOp, NativeType } from "./module";
+import { Module, ExpressionRef, UnaryOp, BinaryOp, HostOp, NativeType, FunctionTypeRef } from "./module";
 import { Program, FunctionPrototype, Local } from "./program";
 
 /** Initializes the specified program with built-in functions. */
@@ -33,23 +33,23 @@ export function initialize(program: Program): void {
   addFunction(program, "isNaN", true);
   addFunction(program, "isFinite", true);
   addFunction(program, "assert");
-  // addFunction(program, "fmod", false, true);
-  // addFunction(program, "pow", true, true);
+  addFunction(program, "parseInt");
+  addFunction(program, "parseFloat");
 }
 
 /** Adds a built-in function to the specified program. */
-function addFunction(program: Program, name: string, isGeneric: bool = false, isImport: bool = false): void {
+function addFunction(program: Program, name: string, isGeneric: bool = false): void {
   let prototype: FunctionPrototype = new FunctionPrototype(program, name, null, null);
   prototype.isBuiltIn = true;
   prototype.isGeneric = isGeneric;
-  prototype.isImport = isImport;
   program.elements.set(name, prototype);
 }
 
 /** Compiles a call to a built-in function. */
-export function compileCall(compiler: Compiler, internalName: string, typeArguments: Type[], operands: Expression[], reportNode: Node): ExpressionRef {
+export function compileCall(compiler: Compiler, prototype: FunctionPrototype, typeArguments: Type[], operands: Expression[], reportNode: Node): ExpressionRef {
   const module: Module = compiler.module;
   const usizeType: Type = select<Type>(Type.usize64, Type.usize32, compiler.options.target == Target.WASM64);
+  const nativeUsizeType: NativeType = select<NativeType>(NativeType.I64, NativeType.I32, compiler.options.target == Target.WASM64);
 
   let arg0: ExpressionRef,
       arg1: ExpressionRef,
@@ -59,8 +59,9 @@ export function compileCall(compiler: Compiler, internalName: string, typeArgume
   let tempLocal1: Local;
 
   let type: Type;
+  var ftype: FunctionTypeRef;
 
-  switch (internalName) {
+  switch (prototype.internalName) {
 
     case "clz": // clz<T>(value: T) -> T
       if (!validateCall(compiler, typeArguments, 1, operands, 1, reportNode))
@@ -498,8 +499,42 @@ export function compileCall(compiler: Compiler, internalName: string, typeArgume
             module.createUnreachable()
           );
 
-    // case "fmod":
-    // case "pow":
+    case "parseInt": // takes a pointer to the string
+      compiler.currentType = Type.f64;
+      if (typeArguments.length != 0) {
+        compiler.error(DiagnosticCode.Expected_0_type_arguments_but_got_1, reportNode.range, "0", typeArguments.length.toString(10));
+        return module.createUnreachable();
+      }
+      if (operands.length < 1) {
+        compiler.error(DiagnosticCode.Expected_at_least_0_arguments_but_got_1, reportNode.range, "1", operands.length.toString(10));
+        return module.createUnreachable();
+      }
+      if (operands.length > 2) {
+        compiler.error(DiagnosticCode.Expected_0_arguments_but_got_1, reportNode.range, "2", operands.length.toString(10));
+        return module.createUnreachable();
+      }
+      if (!prototype.isCompiled) {
+        if (!(ftype = module.getFunctionTypeBySignature(NativeType.F64, [ nativeUsizeType, NativeType.I32 ])))
+              ftype = module.addFunctionType(nativeUsizeType == NativeType.I64 ? "FIi" : "Fii", NativeType.F64, [ nativeUsizeType, NativeType.I32 ]);
+        module.addFunctionImport("parseInt", "env", "parseInt", ftype); // FIXME: can't call with i64 pointers (WASM64)
+        prototype.isCompiled = true;
+      }
+      arg0 = compiler.compileExpression(operands[0], usizeType); // reports
+      arg1 = operands.length == 2 ? compiler.compileExpression(operands[1], Type.i32) : module.createI32(-1); // -1 marks omitted
+      return module.createCallImport("parseInt", [ arg0, arg1 ], NativeType.F64);
+
+    case "parseFloat": // takes a pointer to the string
+      compiler.currentType = Type.f64;
+      if (!validateCall(compiler, typeArguments, 0, operands, 1, reportNode))
+        return module.createUnreachable();
+      if (!prototype.isCompiled) {
+        if (!(ftype = module.getFunctionTypeBySignature(NativeType.F64, [ nativeUsizeType ])))
+              ftype = module.addFunctionType(nativeUsizeType == NativeType.I64 ? "FI" : "Fi", NativeType.F64, [ nativeUsizeType ]);
+        module.addFunctionImport("parseFloat", "env", "parseFloat", ftype); // FIXME: can't call with i64 pointers (WASM64)
+        prototype.isCompiled = true;
+      }
+      arg0 = compiler.compileExpression(operands[0], usizeType); // reports
+      return module.createCallImport("parseFloat", [ arg0 ], NativeType.F64);
   }
   return 0;
 }
diff --git a/src/compiler.ts b/src/compiler.ts
index b044b644..9e84eeda 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -1673,7 +1673,7 @@ export class Compiler extends DiagnosticEmitter {
         functionInstance = <Function | null>functionPrototype.instances.get(sb.join(","));
         if (!functionInstance) {
           this.currentType = contextualType;
-          let expr: ExpressionRef = compileBuiltinCall(this, functionPrototype.internalName, resolvedTypeArguments, expression.arguments, expression);
+          let expr: ExpressionRef = compileBuiltinCall(this, functionPrototype, resolvedTypeArguments, expression.arguments, expression);
           if (!expr) {
             this.error(DiagnosticCode.Operation_not_supported, expression.range);
             return this.module.createUnreachable();
diff --git a/tests/compiler/assert.wast b/tests/compiler/assert.wast
index 010cb566..7920843f 100644
--- a/tests/compiler/assert.wast
+++ b/tests/compiler/assert.wast
@@ -41,6 +41,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
 [program.exports]
   
 ;)
diff --git a/tests/compiler/binary.wast b/tests/compiler/binary.wast
index c492c038..fdc93e6b 100644
--- a/tests/compiler/binary.wast
+++ b/tests/compiler/binary.wast
@@ -844,6 +844,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   binary/b
   binary/i
   binary/I
diff --git a/tests/compiler/builtins.ts b/tests/compiler/builtins.ts
index 5b27fd12..da7ace9d 100644
--- a/tests/compiler/builtins.ts
+++ b/tests/compiler/builtins.ts
@@ -1,6 +1,6 @@
 let b: bool;
 
-// integer builtins
+// integers
 
 let i: i32;
 
@@ -40,7 +40,7 @@ I = abs<i64>(-42); assert(I == 42);
 I = max<i64>(1, 2); assert(I == 2);
 I = min<i64>(1, 2); assert(i == 1);
 
-// floating point builtins
+// floats
 
 let f: f32;
 
@@ -104,7 +104,7 @@ F = trunc<f64>(1.25);
 b = isNaN<f64>(1.25);
 b = isFinite<f64>(1.25);
 
-// load and store builtins
+// load and store
 
 i = load<i32>(8); store<i32>(8, i);
 store<i32>(8, load<i32>(8));
@@ -115,7 +115,7 @@ store<f32>(8, load<f32>(8));
 F = load<f64>(8); store<f64>(8, F);
 store<f64>(8, load<f64>(8));
 
-// reinterpretation builtins
+// reinterpretation
 
 reinterpret<f32,i32>(1.25);
 reinterpret<i32,f32>(25);
@@ -127,7 +127,7 @@ f = reinterpret<i32,f32>(25);
 I = reinterpret<f64,i64>(1.25);
 F = reinterpret<i64,f64>(25);
 
-// host builtins
+// host
 
 let s: usize;
 
@@ -137,7 +137,7 @@ grow_memory(1);
 s = current_memory();
 s = grow_memory(1);
 
-// other builtins
+// other
 
 select<i32>(10, 20, true);
 select<i64>(100, 200, false);
@@ -151,7 +151,7 @@ F = select<f64>(12.5, 25.0, false);
 
 if (0) unreachable();
 
-// AS specific builtins
+// AS specific
 
 sizeof<u8>();
 sizeof<u16>();
@@ -176,3 +176,11 @@ assert(!isFinite<f64>(NaN));
 assert(!isFinite<f64>(Infinity));
 assert(isFinite<f32>(0));
 assert(isFinite<f64>(0));
+
+// imported
+
+// TODO: Can't be interpreted due to 'Fatal: callImport: unknown import: env.parseInt'
+
+// parseInt(0);
+// parseInt(0, 10);
+// parseFloat(0);
diff --git a/tests/compiler/builtins.wast b/tests/compiler/builtins.wast
index a9a67297..ce16ba57 100644
--- a/tests/compiler/builtins.wast
+++ b/tests/compiler/builtins.wast
@@ -1087,6 +1087,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   builtins/b
   builtins/i
   builtins/I
diff --git a/tests/compiler/declare.wast b/tests/compiler/declare.wast
index 0699e334..a5532316 100644
--- a/tests/compiler/declare.wast
+++ b/tests/compiler/declare.wast
@@ -34,6 +34,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   declare/external
 [program.exports]
   declare/external
diff --git a/tests/compiler/do.wast b/tests/compiler/do.wast
index 2790cf61..f85f728d 100644
--- a/tests/compiler/do.wast
+++ b/tests/compiler/do.wast
@@ -79,6 +79,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   do/loopDo
   do/loopDoInDo
 [program.exports]
diff --git a/tests/compiler/enum.wast b/tests/compiler/enum.wast
index aa5ef2f9..9f571813 100644
--- a/tests/compiler/enum.wast
+++ b/tests/compiler/enum.wast
@@ -64,6 +64,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   enum/Implicit
   enum/Explicit
   enum/Mixed
diff --git a/tests/compiler/export.wast b/tests/compiler/export.wast
index 7dfbc78b..a3cfe3d4 100644
--- a/tests/compiler/export.wast
+++ b/tests/compiler/export.wast
@@ -54,6 +54,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   export/add
   export/sub
   export/a
diff --git a/tests/compiler/for.wast b/tests/compiler/for.wast
index 199f0f88..bee6a79d 100644
--- a/tests/compiler/for.wast
+++ b/tests/compiler/for.wast
@@ -175,6 +175,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   for/i
 [program.exports]
   
diff --git a/tests/compiler/game-of-life.wast b/tests/compiler/game-of-life.wast
index 0705d873..74ce6de2 100644
--- a/tests/compiler/game-of-life.wast
+++ b/tests/compiler/game-of-life.wast
@@ -336,6 +336,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   game-of-life/w
   game-of-life/h
   game-of-life/s
diff --git a/tests/compiler/i64.optimized.wast b/tests/compiler/i64.optimized.wast
index 76f88806..181bd820 100644
--- a/tests/compiler/i64.optimized.wast
+++ b/tests/compiler/i64.optimized.wast
@@ -22,8 +22,8 @@
  (export "or" (func $i64/or))
  (export "xor" (func $i64/xor))
  (export "shl" (func $i64/shl))
- (export "shr_u" (func $i64/shr_u))
  (export "shr_s" (func $i64/shr_s))
+ (export "shr_u" (func $i64/shr_u))
  (export "rotl" (func $i64/rotl_))
  (export "rotr" (func $i64/rotr_))
  (export "eq" (func $i64/eq))
@@ -580,12 +580,12 @@
    )
   )
  )
- (func $i64/shr_u (; 17 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
+ (func $i64/shr_s (; 17 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
   (local $4 i64)
   (set_global $i64/lo
    (i32.wrap/i64
     (tee_local $4
-     (i64.shr_u
+     (i64.shr_s
       (i64.or
        (i64.extend_u/i32
         (get_local $0)
@@ -621,12 +621,12 @@
    )
   )
  )
- (func $i64/shr_s (; 18 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
+ (func $i64/shr_u (; 18 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
   (local $4 i64)
   (set_global $i64/lo
    (i32.wrap/i64
     (tee_local $4
-     (i64.shr_s
+     (i64.shr_u
       (i64.or
        (i64.extend_u/i32
         (get_local $0)
diff --git a/tests/compiler/i64.ts b/tests/compiler/i64.ts
index c5cc4cc6..540a535c 100644
--- a/tests/compiler/i64.ts
+++ b/tests/compiler/i64.ts
@@ -102,14 +102,14 @@ export function shl(loLeft: u32, hiLeft: u32, loRight: u32, hiRight: u32): void
   hi = <u32>(ret >>> 32);
 }
 
-export function shr_u(loLeft: u32, hiLeft: u32, loRight: u32, hiRight: u32): void {
-  const ret: u64 = (<u64>loLeft | <u64>hiLeft << 32) >> (<u64>loRight | <u64>hiRight << 32);
+export function shr_s(loLeft: u32, hiLeft: u32, loRight: u32, hiRight: u32): void {
+  const ret: u64 = <u64>(<i64>(<u64>loLeft | <u64>hiLeft << 32) >> <i64>(<u64>loRight | <u64>hiRight << 32));
   lo = <u32>ret;
   hi = <u32>(ret >>> 32);
 }
 
-export function shr_s(loLeft: u32, hiLeft: u32, loRight: u32, hiRight: u32): void {
-  const ret: u64 = <u64>(<i64>(<u64>loLeft | <u64>hiLeft << 32) >> <i64>(<u64>loRight | <u64>hiRight << 32));
+export function shr_u(loLeft: u32, hiLeft: u32, loRight: u32, hiRight: u32): void {
+  const ret: u64 = (<u64>loLeft | <u64>hiLeft << 32) >> (<u64>loRight | <u64>hiRight << 32);
   lo = <u32>ret;
   hi = <u32>(ret >>> 32);
 }
diff --git a/tests/compiler/i64.wast b/tests/compiler/i64.wast
index 5f171edf..617225ad 100644
--- a/tests/compiler/i64.wast
+++ b/tests/compiler/i64.wast
@@ -23,8 +23,8 @@
  (export "or" (func $i64/or))
  (export "xor" (func $i64/xor))
  (export "shl" (func $i64/shl))
- (export "shr_u" (func $i64/shr_u))
  (export "shr_s" (func $i64/shr_s))
+ (export "shr_u" (func $i64/shr_u))
  (export "rotl" (func $i64/rotl_))
  (export "rotr" (func $i64/rotr_))
  (export "eq" (func $i64/eq))
@@ -642,11 +642,11 @@
    )
   )
  )
- (func $i64/shr_u (; 17 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
+ (func $i64/shr_s (; 17 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
   (local $4 i64)
   (block
    (set_local $4
-    (i64.shr_u
+    (i64.shr_s
      (i64.or
       (i64.extend_u/i32
        (get_local $0)
@@ -686,11 +686,11 @@
    )
   )
  )
- (func $i64/shr_s (; 18 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
+ (func $i64/shr_u (; 18 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
   (local $4 i64)
   (block
    (set_local $4
-    (i64.shr_s
+    (i64.shr_u
      (i64.or
       (i64.extend_u/i32
        (get_local $0)
@@ -1217,6 +1217,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   i64/lo
   i64/hi
   i64/getLo
@@ -1236,8 +1238,8 @@
   i64/or
   i64/xor
   i64/shl
-  i64/shr_u
   i64/shr_s
+  i64/shr_u
   i64/rotl_
   i64/rotr_
   i64/eq
@@ -1268,8 +1270,8 @@
   i64/or
   i64/xor
   i64/shl
-  i64/shr_u
   i64/shr_s
+  i64/shr_u
   i64/rotl
   i64/rotr
   i64/eq
diff --git a/tests/compiler/if.wast b/tests/compiler/if.wast
index 611ff45f..01bcb40a 100644
--- a/tests/compiler/if.wast
+++ b/tests/compiler/if.wast
@@ -74,6 +74,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   if/ifThenElse
   if/ifThen
   if/ifThenElseBlock
diff --git a/tests/compiler/import.wast b/tests/compiler/import.wast
index 74c7a514..166928a5 100644
--- a/tests/compiler/import.wast
+++ b/tests/compiler/import.wast
@@ -66,6 +66,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   export/add
   export/sub
   export/a
diff --git a/tests/compiler/literals.wast b/tests/compiler/literals.wast
index 073ad016..65aef3c2 100644
--- a/tests/compiler/literals.wast
+++ b/tests/compiler/literals.wast
@@ -167,6 +167,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
 [program.exports]
   
 ;)
diff --git a/tests/compiler/logical.wast b/tests/compiler/logical.wast
index e1c71a3a..813531b4 100644
--- a/tests/compiler/logical.wast
+++ b/tests/compiler/logical.wast
@@ -295,6 +295,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   logical/i
   logical/I
   logical/f
diff --git a/tests/compiler/memcpy.wast b/tests/compiler/memcpy.wast
index f73c111a..61e17427 100644
--- a/tests/compiler/memcpy.wast
+++ b/tests/compiler/memcpy.wast
@@ -2161,6 +2161,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   memcpy/memcpy
   memcpy/base
   memcpy/dest
diff --git a/tests/compiler/reexport.wast b/tests/compiler/reexport.wast
index 6ad55032..1d3b1c74 100644
--- a/tests/compiler/reexport.wast
+++ b/tests/compiler/reexport.wast
@@ -72,6 +72,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   export/add
   export/sub
   export/a
diff --git a/tests/compiler/switch.wast b/tests/compiler/switch.wast
index 474af8cc..955c09f7 100644
--- a/tests/compiler/switch.wast
+++ b/tests/compiler/switch.wast
@@ -173,6 +173,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   switch/doSwitch
   switch/doSwitchDefaultFirst
   switch/doSwitchDefaultOmitted
diff --git a/tests/compiler/ternary.wast b/tests/compiler/ternary.wast
index 231a3500..20243729 100644
--- a/tests/compiler/ternary.wast
+++ b/tests/compiler/ternary.wast
@@ -61,6 +61,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   ternary/a
 [program.exports]
   
diff --git a/tests/compiler/tlsf.wast b/tests/compiler/tlsf.wast
index 2bcb0764..4b248c29 100644
--- a/tests/compiler/tlsf.wast
+++ b/tests/compiler/tlsf.wast
@@ -356,6 +356,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   tlsf/fls
   tlsf/ffs
   tlsf/ALIGN_SIZE_LOG2
diff --git a/tests/compiler/unary.wast b/tests/compiler/unary.wast
index 0c89f319..6695638a 100644
--- a/tests/compiler/unary.wast
+++ b/tests/compiler/unary.wast
@@ -661,6 +661,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   unary/i
   unary/I
   unary/f
diff --git a/tests/compiler/while.wast b/tests/compiler/while.wast
index 65d9f503..c9350a90 100644
--- a/tests/compiler/while.wast
+++ b/tests/compiler/while.wast
@@ -88,6 +88,8 @@
   isNaN
   isFinite
   assert
+  parseInt
+  parseFloat
   while/loopWhile
   while/loopWhileInWhile
 [program.exports]