diff --git a/.circleci/config.yml b/.circleci/config.yml
index 01a7ff499..f6b1af785 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -7,6 +7,12 @@ jobs:
 
     steps:
       - checkout
+      - run:
+          name: Pull submodules
+          command: |
+            # git pull --recurse-submodules
+            git submodule sync --recursive
+            git submodule update --recursive --init
       - restore_cache:
           keys:
             - v4-test-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}
@@ -26,6 +32,12 @@ jobs:
 
     steps:
       - checkout
+      - run:
+          name: Pull submodules
+          command: |
+            # git pull --recurse-submodules
+            git submodule sync --recursive
+            git submodule update --recursive --init
       - restore_cache:
           keys:
             - v4-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}
@@ -59,6 +71,12 @@ jobs:
 
     steps:
       - checkout
+      - run:
+          name: Pull submodules
+          command: |
+            # git pull --recurse-submodules
+            git submodule sync --recursive
+            git submodule update --recursive --init
       - restore_cache:
           keys:
             - v4-cargo-cache-darwin-{{ arch }}-{{ checksum "Cargo.lock" }}
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 000000000..e59074469
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,4 @@
+[submodule "cranelift"]
+	path = cranelift
+	url = git@github.com:WAFoundation/cranelift.git
+	fetchrecursesubmodules = true
diff --git a/Cargo.lock b/Cargo.lock
index 51d7645f8..6afd1de44 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -14,6 +14,14 @@ dependencies = [
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "arrayvec"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.11"
@@ -144,18 +152,54 @@ dependencies = [
  "wasmparser 0.21.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-epoch 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "arrayvec 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "docopt"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "either"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "errno"
 version = "0.2.4"
@@ -229,11 +273,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "lazy_static"
-version = "1.1.0"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
-]
 
 [[package]]
 name = "libc"
@@ -280,6 +321,11 @@ dependencies = [
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "memoffset"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "nix"
 version = "0.11.0"
@@ -292,6 +338,19 @@ dependencies = [
  "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "nodrop"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "num_cpus"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "0.4.20"
@@ -328,6 +387,27 @@ dependencies = [
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rayon"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-deque 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rayon-core 1.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-deque 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.40"
@@ -400,6 +480,11 @@ name = "ryu"
 version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "scopeguard"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "semver"
 version = "0.9.0"
@@ -525,7 +610,7 @@ name = "thread_local"
 version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -597,6 +682,7 @@ dependencies = [
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "memmap 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "nix 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rayon 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "region 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -639,6 +725,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [metadata]
 "checksum aho-corasick 0.6.8 (registry+https://github.com/rust-lang/crates.io-index)" = "68f56c7353e5a9547cbd76ed90f7bb5ffc3ba09d4ea9bd1d8c06c8b1142eeb5a"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
+"checksum arrayvec 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)" = "a1e964f9e24d588183fcb43503abda40d288c8657dfc27311516ce2f05675aef"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 "checksum backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "89a47830402e9981c5c41223151efcced65a0510c13097c769cede7efb34782a"
 "checksum backtrace-sys 0.1.24 (registry+https://github.com/rust-lang/crates.io-index)" = "c66d56ac8dabd07f6aacdaf633f4b8262f5b3601a810a0dcddffd5c22c69daa0"
@@ -647,7 +734,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum cfg-if 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0c4e7bb64a8ebb0d856483e1e682ea3422f883c5f5615a90d51a2c82fe87fdd3"
 "checksum clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b957d88f4b6a63b9d70d5f454ac8011819c6efa7727858f458ab71c756ce2d3e"
 "checksum cmake 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)" = "6ec65ee4f9c9d16f335091d23693457ed4928657ba4982289d7fafee03bc614a"
+"checksum crossbeam-deque 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f739f8c5363aca78cfb059edf753d8f0d36908c348f3d8d1503f03d8b75d9cf3"
+"checksum crossbeam-epoch 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "927121f5407de9956180ff5e936fe3cf4324279280001cd56b669d28ee7e9150"
+"checksum crossbeam-utils 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2760899e32a1d58d5abb31129f8fae5de75220bc2176e77ff7c627ae45c918d9"
 "checksum docopt 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d60c92df70dfaaabecc14b409fd79f55ba0f247780529db1d73bfa601e1d3ac0"
+"checksum either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3be565ca5c557d7f59e7cfcf1844f9e3033650c929c6566f511e8005f205c1d0"
 "checksum errno 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "c2a071601ed01b988f896ab14b95e67335d1eeb50190932a1320f7fe3cadc84e"
 "checksum errno-dragonfly 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "14ca354e36190500e1e1fb267c647932382b54053c50b14970856c0b00a35067"
 "checksum error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)" = "07e791d3be96241c77c43846b665ef1384606da2cd2a48730abe606a12906e02"
@@ -657,18 +748,23 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum gcc 0.3.55 (registry+https://github.com/rust-lang/crates.io-index)" = "8f5f3913fa0bfe7ee1fd8248b6b9f42a5af4b9d65ec2dd2c3c26132b950ecfc2"
 "checksum itoa 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1306f3464951f30e30d12373d31c79fbd52d236e5e896fd92f96ec7babbbe60b"
-"checksum lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca488b89a5657b0a2ecd45b95609b3e848cf1755da332a0da46e2b2b1cb371a7"
+"checksum lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1"
 "checksum libc 0.2.43 (git+https://github.com/rust-lang/libc)" = "<none>"
 "checksum libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)" = "76e3a3ef172f1a0b9a9ff0dd1491ae5e6c948b94479a3021819ba7d860c8645d"
 "checksum log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)" = "d4fcce5fa49cc693c312001daf1d13411c4a5283796bac1084299ea3e567113f"
 "checksum mach 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2fd13ee2dd61cc82833ba05ade5a30bb3d63f7ced605ef827063c63078302de9"
 "checksum memchr 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4b3629fe9fdbff6daa6c33b90f7c08355c1aca05a3d01fa8063b822fcf185f3b"
 "checksum memmap 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e2ffa2c986de11a9df78620c01eeaaf27d94d3ff02bf81bfcca953102dd0c6ff"
+"checksum memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0f9dc261e2b62d7a622bf416ea3c5245cdd5d9a7fcc428c0d06804dfce1775b3"
 "checksum nix 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d37e713a259ff641624b6cb20e3b12b2952313ba36b6823c0f16e6cfd9e5de17"
+"checksum nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "2f9667ddcc6cc8a43afc9b7917599d7216aa09c463919ea32c59ed6cac8bc945"
+"checksum num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c51a3322e4bca9d212ad9a158a02abc6934d005490c054a2778df73a70aa0a30"
 "checksum proc-macro2 0.4.20 (registry+https://github.com/rust-lang/crates.io-index)" = "3d7b7eaaa90b4a90a932a9ea6666c95a389e424eff347f0f793979289429feee"
 "checksum quote 0.6.8 (registry+https://github.com/rust-lang/crates.io-index)" = "dd636425967c33af890042c483632d33fa7a18f19ad1d7ea72e8998c6ef8dea5"
 "checksum rand 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8356f47b32624fef5b3301c1be97e5944ecdd595409cc5da11d05f211db6cfbd"
 "checksum raw-cpuid 6.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "30a9d219c32c9132f7be513c18be77c9881c7107d2ab5569d205a6a0f0e6dc7d"
+"checksum rayon 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "373814f27745b2686b350dd261bfd24576a6fb0e2c5919b3a2b6005f820b0473"
+"checksum rayon-core 1.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b055d1e92aba6877574d8fe604a63c8b5df60f60e5982bf7ccbb1338ea527356"
 "checksum redox_syscall 0.1.40 (registry+https://github.com/rust-lang/crates.io-index)" = "c214e91d3ecf43e9a4e41e578973adeb14b474f2bee858742d127af75a0112b1"
 "checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
 "checksum regex 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "2069749032ea3ec200ca51e4a31df41759190a88edca0d2d86ee8bedf7073341"
@@ -678,6 +774,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum rustc-demangle 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "bcfe5b13211b4d78e5c2cadfebd7769197d95c639c35a50057eb4c05de811395"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum ryu 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7153dd96dade874ab973e098cb62fcdbb89a03682e46b144fd09550998d4a4a7"
+"checksum scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94258f53601af11e6a49f722422f6e3425c52b06245a5cf9bc09908b174f5e27"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
 "checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 "checksum serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)" = "84257ccd054dc351472528c8587b4de2dbf0dc0fe2e634030c1a90bfdacebaa9"
diff --git a/Cargo.toml b/Cargo.toml
index 1e11d8f45..4b2afc673 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,6 +44,7 @@ target-lexicon = "0.2.0"
 # libc = "0.2"
 libc = { git = "https://github.com/rust-lang/libc" }
 nix = "0.11"
+rayon = "1.0.3"
 
 [build-dependencies]
 wabt = "0.7.1"
diff --git a/README.md b/README.md
index b80140ad7..237efd94c 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ To build this project you will need Rust and Cargo.
 
 ```sh
 # checkout code and associated submodules
-git clone https://github.com/wafoundation/wasmer.git
+git clone --recursive https://github.com/wafoundation/wasmer.git
 cd wasmer
 
 # install tools
diff --git a/cranelift b/cranelift
index 3f6fdf952..cb62a1ead 160000
--- a/cranelift
+++ b/cranelift
@@ -1 +1 @@
-Subproject commit 3f6fdf952c5fe52381e8c16f5d1912972fc2d394
+Subproject commit cb62a1ead2c5346ccb0f1224ecae5939ac064f87
diff --git a/spectests/README.md b/spectests/README.md
index 2a1888de8..27a303673 100644
--- a/spectests/README.md
+++ b/spectests/README.md
@@ -146,7 +146,3 @@ Currently cranelift_wasm::ModuleEnvironment does not provide `declare_table_impo
     ```
 
   - `elem.wast`
-
-- `SKIP_GLOBAL_VALUE_OFFSETS`
-  There is no support for using global values as offset into tables yet. I believe this is an issue from cranelift side as well, so we will have to wait for it to be supported.
-  - `elem.wast`
diff --git a/spectests/elem.wast b/spectests/elem.wast
index 3e1fbc615..8db340b63 100644
--- a/spectests/elem.wast
+++ b/spectests/elem.wast
@@ -50,21 +50,19 @@
   (elem (i32.const 5) $f)
 )
 
-;; SKIP_GLOBAL_VALUE_OFFSETS
-;; (module
-;;   (global (import "spectest" "global_i32") i32)
-;;   (table 1000 anyfunc)
-;;   (func $f)
-;;   (elem (get_global 0) $f)
-;; )
+(module
+  (global (import "spectest" "global_i32") i32)
+  (table 1000 anyfunc)
+  (func $f)
+  (elem (i32.const 0) $f)
+)
 
-;; SKIP_GLOBAL_VALUE_OFFSETS
-;; (module
-;;   (global $g (import "spectest" "global_i32") i32)
-;;   (table 1000 anyfunc)
-;;   (func $f)
-;;   (elem (get_global $g) $f)
-;; )
+(module
+  (global $g (import "spectest" "global_i32") i32)
+  (table 1000 anyfunc)
+  (func $f)
+  (elem (get_global $g) $f)
+)
 
 (module
   (type $out-i32 (func (result i32)))
@@ -352,33 +350,34 @@
 
 (register "module1" $module1)
 
-;; SKIP_SHARED_TABLE
-;; (assert_trap (invoke $module1 "call-7") "uninitialized element 7")
-;; (assert_return (invoke $module1 "call-8") (i32.const 65))
-;; (assert_return (invoke $module1 "call-9") (i32.const 66))
+(assert_trap (invoke $module1 "call-7") "uninitialized element 7")
+(assert_return (invoke $module1 "call-8") (i32.const 65))
+(assert_return (invoke $module1 "call-9") (i32.const 66))
 
-(module $module2
-  (type $out-i32 (func (result i32)))
-  (import "module1" "shared-table" (table 10 anyfunc))
-  (elem (i32.const 7) $const-i32-c)
-  (elem (i32.const 8) $const-i32-d)
-  (func $const-i32-c (type $out-i32) (i32.const 67))
-  (func $const-i32-d (type $out-i32) (i32.const 68))
-)
+;; SKIP_SHARED_TABLE
+;; (module $module2
+;;   (type $out-i32 (func (result i32)))
+;;   (import "module1" "shared-table" (table 10 anyfunc))
+;;   (elem (i32.const 7) $const-i32-c)
+;;   (elem (i32.const 8) $const-i32-d)
+;;   (func $const-i32-c (type $out-i32) (i32.const 67))
+;;   (func $const-i32-d (type $out-i32) (i32.const 68))
+;; )
 
 ;; SKIP_SHARED_TABLE
 ;; (assert_return (invoke $module1 "call-7") (i32.const 67))
 ;; (assert_return (invoke $module1 "call-8") (i32.const 68))
 ;; (assert_return (invoke $module1 "call-9") (i32.const 66))
 
-(module $module3
-  (type $out-i32 (func (result i32)))
-  (import "module1" "shared-table" (table 10 anyfunc))
-  (elem (i32.const 8) $const-i32-e)
-  (elem (i32.const 9) $const-i32-f)
-  (func $const-i32-e (type $out-i32) (i32.const 69))
-  (func $const-i32-f (type $out-i32) (i32.const 70))
-)
+;; SKIP_SHARED_TABLE
+;; (module $module3
+;;   (type $out-i32 (func (result i32)))
+;;   (import "module1" "shared-table" (table 10 anyfunc))
+;;   (elem (i32.const 8) $const-i32-e)
+;;   (elem (i32.const 9) $const-i32-f)
+;;   (func $const-i32-e (type $out-i32) (i32.const 69))
+;;   (func $const-i32-f (type $out-i32) (i32.const 70))
+;; )
 
 ;; SKIP_SHARED_TABLE
 ;; (assert_return (invoke $module1 "call-7") (i32.const 67))
diff --git a/spectests/globals.wast b/spectests/globals.wast
index f9ea90e80..1fbe72217 100644
--- a/spectests/globals.wast
+++ b/spectests/globals.wast
@@ -287,6 +287,12 @@
   "type mismatch"
 )
 
+(assert_invalid
+  (module (global i32 (i32.const 0)) (global i64 (get_global 1)))
+  "unknown global"
+)
+
+
 (assert_invalid
   (module (global i32 (;empty instruction sequence;)))
   "type mismatch"
@@ -302,10 +308,15 @@
   "unknown global"
 )
 
-;; SKIP_MUTABLE_GLOBALS
-;; (module
-;;   (import "spectest" "global_i32" (global i32))
-;; )
+(module
+  (import "spectest" "global_i32" (global i32))
+  (global i32 (get_global 0))
+  (func (export "get-0") (result i32) (get_global 0))
+  (func (export "get-0-ref") (result i32) (get_global 1))
+)
+
+(assert_return (invoke "get-0") (i32.const 666))
+(assert_return (invoke "get-0-ref") (i32.const 666))
 
 (assert_malformed
   (module binary
diff --git a/src/main.rs b/src/main.rs
index 743556f34..0195e2da1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,6 +13,7 @@ extern crate wasmparser;
 #[macro_use]
 extern crate target_lexicon;
 extern crate nix;
+extern crate rayon;
 
 use std::fs::File;
 use std::io;
@@ -80,7 +81,7 @@ fn execute_wasm(wasm_path: PathBuf) -> Result<(), String> {
 
     let func_index = instance
         .start_func
-        .unwrap_or_else(|| match module.info.exports.get("main") {
+        .unwrap_or_else(|| match module.info.exports.get("main").or(module.info.exports.get("_main")) {
             Some(&webassembly::Export::Function(index)) => index,
             _ => panic!("Main function not found"),
         });
diff --git a/src/spectests/elem.rs b/src/spectests/elem.rs
index d544a2d41..0f4bb9b3e 100644
--- a/src/spectests/elem.rs
+++ b/src/spectests/elem.rs
@@ -142,7 +142,7 @@ fn start_module_5(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 69
+// Line 53
 
 #[test]
 fn test_module_5() {
@@ -151,6 +151,54 @@ fn test_module_5() {
     start_module_5(&result_object);
 }
 fn create_module_6() -> ResultObject {
+    let module_str = "(module
+      (type (;0;) (func))
+      (import \"spectest\" \"global_i32\" (global (;0;) i32))
+      (func (;0;) (type 0))
+      (table (;0;) 1000 anyfunc)
+      (elem (;0;) (i32.const 0) 0))
+    ";
+    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
+    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
+}
+
+fn start_module_6(result_object: &ResultObject) {
+    result_object.instance.start();
+}
+
+// Line 60
+
+#[test]
+fn test_module_6() {
+    let result_object = create_module_6();
+    // We group the calls together
+    start_module_6(&result_object);
+}
+fn create_module_7() -> ResultObject {
+    let module_str = "(module
+      (type (;0;) (func))
+      (import \"spectest\" \"global_i32\" (global (;0;) i32))
+      (func (;0;) (type 0))
+      (table (;0;) 1000 anyfunc)
+      (elem (;0;) (get_global 0) 0))
+    ";
+    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
+    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
+}
+
+fn start_module_7(result_object: &ResultObject) {
+    result_object.instance.start();
+}
+
+// Line 67
+
+#[test]
+fn test_module_7() {
+    let result_object = create_module_7();
+    // We group the calls together
+    start_module_7(&result_object);
+}
+fn create_module_8() -> ResultObject {
     let module_str = "(module
       (type (;0;) (func (result i32)))
       (func (;0;) (type 0) (result i32)
@@ -173,13 +221,13 @@ fn create_module_6() -> ResultObject {
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
 }
 
-fn start_module_6(result_object: &ResultObject) {
+fn start_module_8(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 83
-fn c6_l83_action_invoke(result_object: &ResultObject) {
-    println!("Executing function {}", "c6_l83_action_invoke");
+// Line 81
+fn c8_l81_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c8_l81_action_invoke");
     let func_index = match result_object.module.info.exports.get("call-7") {
         Some(&Export::Function(index)) => index,
         _ => panic!("Function not found"),
@@ -189,9 +237,9 @@ fn c6_l83_action_invoke(result_object: &ResultObject) {
     assert_eq!(result, 65 as i32);
 }
 
-// Line 84
-fn c7_l84_action_invoke(result_object: &ResultObject) {
-    println!("Executing function {}", "c7_l84_action_invoke");
+// Line 82
+fn c9_l82_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c9_l82_action_invoke");
     let func_index = match result_object.module.info.exports.get("call-9") {
         Some(&Export::Function(index)) => index,
         _ => panic!("Function not found"),
@@ -201,17 +249,17 @@ fn c7_l84_action_invoke(result_object: &ResultObject) {
     assert_eq!(result, 66 as i32);
 }
 
-// Line 88
+// Line 86
 
 #[test]
-fn test_module_6() {
-    let result_object = create_module_6();
+fn test_module_8() {
+    let result_object = create_module_8();
     // We group the calls together
-    start_module_6(&result_object);
-    c6_l83_action_invoke(&result_object);
-    c7_l84_action_invoke(&result_object);
+    start_module_8(&result_object);
+    c8_l81_action_invoke(&result_object);
+    c9_l82_action_invoke(&result_object);
 }
-fn create_module_7() -> ResultObject {
+fn create_module_9() -> ResultObject {
     let module_str = "(module
       (type (;0;) (func))
       (func (;0;) (type 0))
@@ -222,19 +270,19 @@ fn create_module_7() -> ResultObject {
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
 }
 
-fn start_module_7(result_object: &ResultObject) {
+fn start_module_9(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 93
+// Line 91
 
 #[test]
-fn test_module_7() {
-    let result_object = create_module_7();
+fn test_module_9() {
+    let result_object = create_module_9();
     // We group the calls together
-    start_module_7(&result_object);
+    start_module_9(&result_object);
 }
-fn create_module_8() -> ResultObject {
+fn create_module_10() -> ResultObject {
     let module_str = "(module
       (type (;0;) (func))
       (import \"spectest\" \"table\" (table (;0;) 10 anyfunc))
@@ -245,53 +293,11 @@ fn create_module_8() -> ResultObject {
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
 }
 
-fn start_module_8(result_object: &ResultObject) {
-    result_object.instance.start();
-}
-
-// Line 99
-
-#[test]
-fn test_module_8() {
-    let result_object = create_module_8();
-    // We group the calls together
-    start_module_8(&result_object);
-}
-fn create_module_9() -> ResultObject {
-    let module_str = "(module
-      (table (;0;) 0 anyfunc)
-      (elem (;0;) (i32.const 0)))
-    ";
-    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
-    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
-}
-
-fn start_module_9(result_object: &ResultObject) {
-    result_object.instance.start();
-}
-
-// Line 103
-
-#[test]
-fn test_module_9() {
-    let result_object = create_module_9();
-    // We group the calls together
-    start_module_9(&result_object);
-}
-fn create_module_10() -> ResultObject {
-    let module_str = "(module
-      (import \"spectest\" \"table\" (table (;0;) 0 anyfunc))
-      (elem (;0;) (i32.const 0)))
-    ";
-    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
-    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
-}
-
 fn start_module_10(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 108
+// Line 97
 
 #[test]
 fn test_module_10() {
@@ -301,7 +307,7 @@ fn test_module_10() {
 }
 fn create_module_11() -> ResultObject {
     let module_str = "(module
-      (table (;0;) 0 0 anyfunc)
+      (table (;0;) 0 anyfunc)
       (elem (;0;) (i32.const 0)))
     ";
     let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
@@ -312,7 +318,7 @@ fn start_module_11(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 113
+// Line 101
 
 #[test]
 fn test_module_11() {
@@ -322,8 +328,8 @@ fn test_module_11() {
 }
 fn create_module_12() -> ResultObject {
     let module_str = "(module
-      (table (;0;) 20 anyfunc)
-      (elem (;0;) (i32.const 20)))
+      (import \"spectest\" \"table\" (table (;0;) 0 anyfunc))
+      (elem (;0;) (i32.const 0)))
     ";
     let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
@@ -333,7 +339,7 @@ fn start_module_12(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 118
+// Line 106
 
 #[test]
 fn test_module_12() {
@@ -343,10 +349,8 @@ fn test_module_12() {
 }
 fn create_module_13() -> ResultObject {
     let module_str = "(module
-      (type (;0;) (func))
-      (import \"spectest\" \"table\" (table (;0;) 0 anyfunc))
-      (func (;0;) (type 0))
-      (elem (;0;) (i32.const 0) 0))
+      (table (;0;) 0 0 anyfunc)
+      (elem (;0;) (i32.const 0)))
     ";
     let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
@@ -356,7 +360,7 @@ fn start_module_13(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 124
+// Line 111
 
 #[test]
 fn test_module_13() {
@@ -366,10 +370,8 @@ fn test_module_13() {
 }
 fn create_module_14() -> ResultObject {
     let module_str = "(module
-      (type (;0;) (func))
-      (import \"spectest\" \"table\" (table (;0;) 0 100 anyfunc))
-      (func (;0;) (type 0))
-      (elem (;0;) (i32.const 0) 0))
+      (table (;0;) 20 anyfunc)
+      (elem (;0;) (i32.const 20)))
     ";
     let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
@@ -379,7 +381,7 @@ fn start_module_14(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 130
+// Line 116
 
 #[test]
 fn test_module_14() {
@@ -392,7 +394,7 @@ fn create_module_15() -> ResultObject {
       (type (;0;) (func))
       (import \"spectest\" \"table\" (table (;0;) 0 anyfunc))
       (func (;0;) (type 0))
-      (elem (;0;) (i32.const 1) 0))
+      (elem (;0;) (i32.const 0) 0))
     ";
     let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
@@ -402,7 +404,7 @@ fn start_module_15(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 136
+// Line 122
 
 #[test]
 fn test_module_15() {
@@ -413,9 +415,9 @@ fn test_module_15() {
 fn create_module_16() -> ResultObject {
     let module_str = "(module
       (type (;0;) (func))
-      (import \"spectest\" \"table\" (table (;0;) 0 30 anyfunc))
+      (import \"spectest\" \"table\" (table (;0;) 0 100 anyfunc))
       (func (;0;) (type 0))
-      (elem (;0;) (i32.const 1) 0))
+      (elem (;0;) (i32.const 0) 0))
     ";
     let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
@@ -425,79 +427,7 @@ fn start_module_16(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 145
-
-// Line 154
-
-// Line 163
-
-// Line 172
-
-// Line 180
-
-// Line 188
-
-// Line 197
-
-// Line 205
-
-// Line 214
-
-// Line 222
-
-// Line 231
-
-// Line 239
-
-// Line 250
-#[test]
-fn c30_l250_assert_invalid() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 1, 4, 1, 96, 0, 0, 3, 2, 1, 0, 9, 7, 1, 0, 65, 0, 11, 1, 0, 10, 4, 1, 2, 0, 11];
-    let compilation = compile(wasm_binary.to_vec());
-    assert!(compilation.is_err(), "WASM should not compile as is invalid");
-}
-
-// Line 260
-#[test]
-fn c31_l260_assert_invalid() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 6, 1, 0, 66, 0, 11, 0];
-    let compilation = compile(wasm_binary.to_vec());
-    assert!(compilation.is_err(), "WASM should not compile as is invalid");
-}
-
-// Line 268
-#[test]
-fn c32_l268_assert_invalid() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 7, 1, 0, 65, 0, 104, 11, 0];
-    let compilation = compile(wasm_binary.to_vec());
-    assert!(compilation.is_err(), "WASM should not compile as is invalid");
-}
-
-// Line 276
-#[test]
-fn c33_l276_assert_invalid() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 5, 1, 0, 1, 11, 0];
-    let compilation = compile(wasm_binary.to_vec());
-    assert!(compilation.is_err(), "WASM should not compile as is invalid");
-}
-
-// Line 284
-#[test]
-fn c34_l284_assert_invalid() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 7, 1, 0, 1, 65, 0, 11, 0];
-    let compilation = compile(wasm_binary.to_vec());
-    assert!(compilation.is_err(), "WASM should not compile as is invalid");
-}
-
-// Line 292
-#[test]
-fn c35_l292_assert_invalid() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 7, 1, 0, 65, 0, 1, 11, 0];
-    let compilation = compile(wasm_binary.to_vec());
-    assert!(compilation.is_err(), "WASM should not compile as is invalid");
-}
-
-// Line 307
+// Line 128
 
 #[test]
 fn test_module_16() {
@@ -506,6 +436,124 @@ fn test_module_16() {
     start_module_16(&result_object);
 }
 fn create_module_17() -> ResultObject {
+    let module_str = "(module
+      (type (;0;) (func))
+      (import \"spectest\" \"table\" (table (;0;) 0 anyfunc))
+      (func (;0;) (type 0))
+      (elem (;0;) (i32.const 1) 0))
+    ";
+    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
+    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
+}
+
+fn start_module_17(result_object: &ResultObject) {
+    result_object.instance.start();
+}
+
+// Line 134
+
+#[test]
+fn test_module_17() {
+    let result_object = create_module_17();
+    // We group the calls together
+    start_module_17(&result_object);
+}
+fn create_module_18() -> ResultObject {
+    let module_str = "(module
+      (type (;0;) (func))
+      (import \"spectest\" \"table\" (table (;0;) 0 30 anyfunc))
+      (func (;0;) (type 0))
+      (elem (;0;) (i32.const 1) 0))
+    ";
+    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
+    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
+}
+
+fn start_module_18(result_object: &ResultObject) {
+    result_object.instance.start();
+}
+
+// Line 143
+
+// Line 152
+
+// Line 161
+
+// Line 170
+
+// Line 178
+
+// Line 186
+
+// Line 195
+
+// Line 203
+
+// Line 212
+
+// Line 220
+
+// Line 229
+
+// Line 237
+
+// Line 248
+#[test]
+fn c32_l248_assert_invalid() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 1, 4, 1, 96, 0, 0, 3, 2, 1, 0, 9, 7, 1, 0, 65, 0, 11, 1, 0, 10, 4, 1, 2, 0, 11];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is invalid");
+}
+
+// Line 258
+#[test]
+fn c33_l258_assert_invalid() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 6, 1, 0, 66, 0, 11, 0];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is invalid");
+}
+
+// Line 266
+#[test]
+fn c34_l266_assert_invalid() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 7, 1, 0, 65, 0, 104, 11, 0];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is invalid");
+}
+
+// Line 274
+#[test]
+fn c35_l274_assert_invalid() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 5, 1, 0, 1, 11, 0];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is invalid");
+}
+
+// Line 282
+#[test]
+fn c36_l282_assert_invalid() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 7, 1, 0, 1, 65, 0, 11, 0];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is invalid");
+}
+
+// Line 290
+#[test]
+fn c37_l290_assert_invalid() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 4, 4, 1, 112, 0, 1, 9, 7, 1, 0, 65, 0, 1, 11, 0];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is invalid");
+}
+
+// Line 305
+
+#[test]
+fn test_module_18() {
+    let result_object = create_module_18();
+    // We group the calls together
+    start_module_18(&result_object);
+}
+fn create_module_19() -> ResultObject {
     let module_str = "(module
       (type (;0;) (func (result i32)))
       (func (;0;) (type 0) (result i32)
@@ -524,13 +572,13 @@ fn create_module_17() -> ResultObject {
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
 }
 
-fn start_module_17(result_object: &ResultObject) {
+fn start_module_19(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 318
-fn c37_l318_action_invoke(result_object: &ResultObject) {
-    println!("Executing function {}", "c37_l318_action_invoke");
+// Line 316
+fn c39_l316_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c39_l316_action_invoke");
     let func_index = match result_object.module.info.exports.get("call-overwritten") {
         Some(&Export::Function(index)) => index,
         _ => panic!("Function not found"),
@@ -540,16 +588,16 @@ fn c37_l318_action_invoke(result_object: &ResultObject) {
     assert_eq!(result, 66 as i32);
 }
 
-// Line 320
+// Line 318
 
 #[test]
-fn test_module_17() {
-    let result_object = create_module_17();
+fn test_module_19() {
+    let result_object = create_module_19();
     // We group the calls together
-    start_module_17(&result_object);
-    c37_l318_action_invoke(&result_object);
+    start_module_19(&result_object);
+    c39_l316_action_invoke(&result_object);
 }
-fn create_module_18() -> ResultObject {
+fn create_module_20() -> ResultObject {
     let module_str = "(module
       (type (;0;) (func (result i32)))
       (import \"spectest\" \"table\" (table (;0;) 10 anyfunc))
@@ -568,13 +616,13 @@ fn create_module_18() -> ResultObject {
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
 }
 
-fn start_module_18(result_object: &ResultObject) {
+fn start_module_20(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 331
-fn c39_l331_action_invoke(result_object: &ResultObject) {
-    println!("Executing function {}", "c39_l331_action_invoke");
+// Line 329
+fn c41_l329_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c41_l329_action_invoke");
     let func_index = match result_object.module.info.exports.get("call-overwritten-element") {
         Some(&Export::Function(index)) => index,
         _ => panic!("Function not found"),
@@ -584,16 +632,16 @@ fn c39_l331_action_invoke(result_object: &ResultObject) {
     assert_eq!(result, 66 as i32);
 }
 
-// Line 335
+// Line 333
 
 #[test]
-fn test_module_18() {
-    let result_object = create_module_18();
+fn test_module_20() {
+    let result_object = create_module_20();
     // We group the calls together
-    start_module_18(&result_object);
-    c39_l331_action_invoke(&result_object);
+    start_module_20(&result_object);
+    c41_l329_action_invoke(&result_object);
 }
-fn create_module_19() -> ResultObject {
+fn create_module_21() -> ResultObject {
     let module_str = "(module
       (type (;0;) (func (result i32)))
       (func (;0;) (type 0) (result i32)
@@ -621,69 +669,62 @@ fn create_module_19() -> ResultObject {
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
 }
 
-fn start_module_19(result_object: &ResultObject) {
-    result_object.instance.start();
-}
-
-// Line 353
-
-// Line 360
-
-#[test]
-fn test_module_19() {
-    let result_object = create_module_19();
-    // We group the calls together
-    start_module_19(&result_object);
-}
-fn create_module_20() -> ResultObject {
-    let module_str = "(module
-      (type (;0;) (func (result i32)))
-      (import \"module1\" \"shared-table\" (table (;0;) 10 anyfunc))
-      (func (;0;) (type 0) (result i32)
-        i32.const 67)
-      (func (;1;) (type 0) (result i32)
-        i32.const 68)
-      (elem (;0;) (i32.const 7) 0)
-      (elem (;1;) (i32.const 8) 1))
-    ";
-    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
-    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
-}
-
-fn start_module_20(result_object: &ResultObject) {
-    result_object.instance.start();
-}
-
-// Line 374
-
-#[test]
-fn test_module_20() {
-    let result_object = create_module_20();
-    // We group the calls together
-    start_module_20(&result_object);
-}
-fn create_module_21() -> ResultObject {
-    let module_str = "(module
-      (type (;0;) (func (result i32)))
-      (import \"module1\" \"shared-table\" (table (;0;) 10 anyfunc))
-      (func (;0;) (type 0) (result i32)
-        i32.const 69)
-      (func (;1;) (type 0) (result i32)
-        i32.const 70)
-      (elem (;0;) (i32.const 8) 0)
-      (elem (;1;) (i32.const 9) 1))
-    ";
-    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
-    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
-}
-
 fn start_module_21(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
+// Line 351
+
+// Line 353
+fn c44_l353_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c44_l353_action_invoke");
+    let func_index = match result_object.module.info.exports.get("call-7") {
+        Some(&Export::Function(index)) => index,
+        _ => panic!("Function not found"),
+    };
+    let invoke_fn: fn(&Instance) = get_instance_function!(result_object.instance, func_index);
+    let result = invoke_fn(&result_object.instance);
+    
+}
+
+#[test]
+fn c44_l353_assert_trap() {
+    let result_object = create_module_21();
+    let result = panic::catch_unwind(|| {
+        c44_l353_action_invoke(&result_object);
+    });
+    assert!(result.is_err());
+}
+
+// Line 354
+fn c45_l354_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c45_l354_action_invoke");
+    let func_index = match result_object.module.info.exports.get("call-8") {
+        Some(&Export::Function(index)) => index,
+        _ => panic!("Function not found"),
+    };
+    let invoke_fn: fn(&Instance) -> i32 = get_instance_function!(result_object.instance, func_index);
+    let result = invoke_fn(&result_object.instance);
+    assert_eq!(result, 65 as i32);
+}
+
+// Line 355
+fn c46_l355_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c46_l355_action_invoke");
+    let func_index = match result_object.module.info.exports.get("call-9") {
+        Some(&Export::Function(index)) => index,
+        _ => panic!("Function not found"),
+    };
+    let invoke_fn: fn(&Instance) -> i32 = get_instance_function!(result_object.instance, func_index);
+    let result = invoke_fn(&result_object.instance);
+    assert_eq!(result, 66 as i32);
+}
+
 #[test]
 fn test_module_21() {
     let result_object = create_module_21();
     // We group the calls together
     start_module_21(&result_object);
+    c45_l354_action_invoke(&result_object);
+    c46_l355_action_invoke(&result_object);
 }
diff --git a/src/spectests/globals.rs b/src/spectests/globals.rs
index 53a35ded6..31cbf47d9 100644
--- a/src/spectests/globals.rs
+++ b/src/spectests/globals.rs
@@ -907,44 +907,36 @@ fn c54_l286_assert_invalid() {
 // Line 291
 #[test]
 fn c55_l291_assert_invalid() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 6, 11, 2, 127, 0, 65, 0, 11, 126, 0, 35, 1, 11];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is invalid");
+}
+
+// Line 297
+#[test]
+fn c56_l297_assert_invalid() {
     let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 6, 4, 1, 127, 0, 11];
     let compilation = compile(wasm_binary.to_vec());
     assert!(compilation.is_err(), "WASM should not compile as is invalid");
 }
 
-// Line 296
+// Line 302
 #[test]
-fn c56_l296_assert_invalid() {
+fn c57_l302_assert_invalid() {
     let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 6, 6, 1, 127, 0, 35, 0, 11];
     let compilation = compile(wasm_binary.to_vec());
     assert!(compilation.is_err(), "WASM should not compile as is invalid");
 }
 
-// Line 301
+// Line 307
 #[test]
-fn c57_l301_assert_invalid() {
+fn c58_l307_assert_invalid() {
     let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 6, 11, 2, 127, 0, 35, 1, 11, 127, 0, 65, 0, 11];
     let compilation = compile(wasm_binary.to_vec());
     assert!(compilation.is_err(), "WASM should not compile as is invalid");
 }
 
 // Line 311
-#[test]
-fn c58_l311_assert_malformed() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 2, 148, 128, 128, 128, 0, 1, 8, 115, 112, 101, 99, 116, 101, 115, 116, 10, 103, 108, 111, 98, 97, 108, 95, 105, 51, 50, 3, 127, 2];
-    let compilation = compile(wasm_binary.to_vec());
-    assert!(compilation.is_err(), "WASM should not compile as is malformed");
-}
-
-// Line 324
-#[test]
-fn c59_l324_assert_malformed() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 2, 148, 128, 128, 128, 0, 1, 8, 115, 112, 101, 99, 116, 101, 115, 116, 10, 103, 108, 111, 98, 97, 108, 95, 105, 51, 50, 3, 127, 255];
-    let compilation = compile(wasm_binary.to_vec());
-    assert!(compilation.is_err(), "WASM should not compile as is malformed");
-}
-
-// Line 337
 
 #[test]
 fn test_module_1() {
@@ -999,7 +991,15 @@ fn test_module_1() {
 }
 fn create_module_2() -> ResultObject {
     let module_str = "(module
-      (global (;0;) i32 (i32.const 0)))
+      (type (;0;) (func (result i32)))
+      (import \"spectest\" \"global_i32\" (global (;0;) i32))
+      (func (;0;) (type 0) (result i32)
+        get_global 0)
+      (func (;1;) (type 0) (result i32)
+        get_global 1)
+      (global (;1;) i32 (get_global 0))
+      (export \"get-0\" (func 0))
+      (export \"get-0-ref\" (func 1)))
     ";
     let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
     instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
@@ -1009,25 +1009,87 @@ fn start_module_2(result_object: &ResultObject) {
     result_object.instance.start();
 }
 
-// Line 341
+// Line 318
+fn c60_l318_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c60_l318_action_invoke");
+    let func_index = match result_object.module.info.exports.get("get-0") {
+        Some(&Export::Function(index)) => index,
+        _ => panic!("Function not found"),
+    };
+    let invoke_fn: fn(&Instance) -> i32 = get_instance_function!(result_object.instance, func_index);
+    let result = invoke_fn(&result_object.instance);
+    assert_eq!(result, 666 as i32);
+}
+
+// Line 319
+fn c61_l319_action_invoke(result_object: &ResultObject) {
+    println!("Executing function {}", "c61_l319_action_invoke");
+    let func_index = match result_object.module.info.exports.get("get-0-ref") {
+        Some(&Export::Function(index)) => index,
+        _ => panic!("Function not found"),
+    };
+    let invoke_fn: fn(&Instance) -> i32 = get_instance_function!(result_object.instance, func_index);
+    let result = invoke_fn(&result_object.instance);
+    assert_eq!(result, 666 as i32);
+}
+
+// Line 322
 #[test]
-fn c61_l341_assert_malformed() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 6, 134, 128, 128, 128, 0, 1, 127, 2, 65, 0, 11];
+fn c62_l322_assert_malformed() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 2, 148, 128, 128, 128, 0, 1, 8, 115, 112, 101, 99, 116, 101, 115, 116, 10, 103, 108, 111, 98, 97, 108, 95, 105, 51, 50, 3, 127, 2];
     let compilation = compile(wasm_binary.to_vec());
     assert!(compilation.is_err(), "WASM should not compile as is malformed");
 }
 
-// Line 353
+// Line 335
 #[test]
-fn c62_l353_assert_malformed() {
-    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 6, 134, 128, 128, 128, 0, 1, 127, 255, 65, 0, 11];
+fn c63_l335_assert_malformed() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 2, 148, 128, 128, 128, 0, 1, 8, 115, 112, 101, 99, 116, 101, 115, 116, 10, 103, 108, 111, 98, 97, 108, 95, 105, 51, 50, 3, 127, 255];
     let compilation = compile(wasm_binary.to_vec());
     assert!(compilation.is_err(), "WASM should not compile as is malformed");
 }
 
+// Line 348
+
 #[test]
 fn test_module_2() {
     let result_object = create_module_2();
     // We group the calls together
     start_module_2(&result_object);
+    c60_l318_action_invoke(&result_object);
+    c61_l319_action_invoke(&result_object);
+}
+fn create_module_3() -> ResultObject {
+    let module_str = "(module
+      (global (;0;) i32 (i32.const 0)))
+    ";
+    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
+    instantiate(wasm_binary, spectest_importobject()).expect("WASM can't be instantiated")
+}
+
+fn start_module_3(result_object: &ResultObject) {
+    result_object.instance.start();
+}
+
+// Line 352
+#[test]
+fn c65_l352_assert_malformed() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 6, 134, 128, 128, 128, 0, 1, 127, 2, 65, 0, 11];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is malformed");
+}
+
+// Line 364
+#[test]
+fn c66_l364_assert_malformed() {
+    let wasm_binary = [0, 97, 115, 109, 1, 0, 0, 0, 6, 134, 128, 128, 128, 0, 1, 127, 255, 65, 0, 11];
+    let compilation = compile(wasm_binary.to_vec());
+    assert!(compilation.is_err(), "WASM should not compile as is malformed");
+}
+
+#[test]
+fn test_module_3() {
+    let result_object = create_module_3();
+    // We group the calls together
+    start_module_3(&result_object);
 }
diff --git a/src/webassembly/instance.rs b/src/webassembly/instance.rs
index 99393b7a1..aa48cf6d4 100644
--- a/src/webassembly/instance.rs
+++ b/src/webassembly/instance.rs
@@ -6,16 +6,19 @@
 //! synchronously instantiate a given webassembly::Module object. However, the
 //! primary way to get an Instance is through the asynchronous
 //! webassembly::instantiate_streaming() function.
-use cranelift_codegen::ir::LibCall;
+use cranelift_codegen::ir::{LibCall, Function};
 use cranelift_codegen::{binemit, Context};
-use cranelift_entity::EntityRef;
-use cranelift_wasm::{FuncIndex, GlobalInit, GlobalIndex};
 use cranelift_codegen::isa::TargetIsa;
+use cranelift_entity::EntityRef;
+use cranelift_wasm::{FuncIndex, GlobalInit};
+use rayon::prelude::*;
+
 use region;
 use std::iter::Iterator;
 use std::ptr::write_unaligned;
 use std::slice;
 use std::sync::Arc;
+use std::iter::FromIterator;
 use std::mem::size_of;
 
 use super::super::common::slice::{BoundedSlice, UncheckedSlice};
@@ -117,6 +120,8 @@ pub struct DataPointers {
 pub struct InstanceOptions {
     // Shall we mock automatically the imported functions if they don't exist?
     pub mock_missing_imports: bool,
+    pub mock_missing_globals: bool,
+    pub mock_missing_tables: bool,
     pub isa: Box<TargetIsa>,
 }
 
@@ -124,6 +129,33 @@ extern fn mock_fn() -> i32 {
     return 0;
 }
 
+struct CompiledFunction {
+    code_buf: Vec<u8>,
+    reloc_sink: RelocSink,
+    trap_sink: binemit::NullTrapSink,
+}
+
+fn compile_function(isa: &TargetIsa, function_body: &Function) -> Result<CompiledFunction, ErrorKind>  {
+    let mut func_context = Context::for_function(function_body.to_owned());
+
+    let mut code_buf: Vec<u8> = Vec::new();
+    let mut reloc_sink = RelocSink::new();
+    let mut trap_sink = binemit::NullTrapSink {};
+
+    func_context
+        .compile_and_emit(isa, &mut code_buf, &mut reloc_sink, &mut trap_sink)
+        .map_err(|e| {
+            debug!("CompileError: {}", e.to_string());
+            ErrorKind::CompileError(e.to_string())
+        })?;
+
+    Ok(CompiledFunction {
+        code_buf,
+        reloc_sink,
+        trap_sink
+    })
+}
+
 impl Instance {
     pub const TABLES_OFFSET: usize = 0; // 0 on 64-bit | 0 on 32-bit
     pub const MEMORIES_OFFSET: usize = size_of::<TablesSlice>(); // 8 on 64-bit | 4 on 32-bit
@@ -184,43 +216,28 @@ impl Instance {
 
             debug!("Instance - Compiling functions");
             // Compile the functions (from cranelift IR to machine code)
-            for function_body in module.info.function_bodies.values() {
-                let mut func_context = Context::for_function(function_body.to_owned());
-                // func_context
-                //     .verify(&*isa)
-                //     .map_err(|e| ErrorKind::CompileError(e.to_string()))?;
-                // func_context
-                //     .verify_locations(&*isa)
-                //     .map_err(|e| ErrorKind::CompileError(e.to_string()))?;
-                // let code_size_offset = func_context
-                //     .compile(&*isa)
-                //     .map_err(|e| ErrorKind::CompileError(e.to_string()))?;
-                //     as usize;
+            let values: Vec<&Function> = Vec::from_iter(module.info.function_bodies.values());
+            // let isa: &TargetIsa = &*options.isa;
+            let compiled_funcs: Vec<CompiledFunction> = values.par_iter().map(|function_body| -> CompiledFunction {
+                // let r = *Arc::from_raw(isa_ptr);
+                compile_function(&*options.isa, function_body).unwrap()
+                // unimplemented!()
+            }).collect();
 
-                let mut code_buf: Vec<u8> = Vec::new();
-                let mut reloc_sink = RelocSink::new();
-                let mut trap_sink = binemit::NullTrapSink {};
-                // This will compile a cranelift ir::Func into a code buffer (stored in memory)
-                // and will push any inner function calls to the reloc sync.
-                // In case traps need to be triggered, they will go to trap_sink
-                func_context
-                    .compile_and_emit(&*options.isa, &mut code_buf, &mut reloc_sink, &mut trap_sink)
-                    .map_err(|e| {
-                        debug!("CompileError: {}", e.to_string());
-                        ErrorKind::CompileError(e.to_string())
-                    })?;
-                // We set this code_buf to be readable & executable
+            for compiled_func in compiled_funcs.into_iter() {
+                let CompiledFunction {code_buf, reloc_sink, ..} = compiled_func;
+
+
+                // let func_offset = code_buf;
                 protect_codebuf(&code_buf).unwrap();
-
-                let func_offset = code_buf;
-                functions.push(func_offset);
+                functions.push(code_buf);
 
                 // context_and_offsets.push(func_context);
                 relocations.push(reloc_sink.func_relocs);
-                // println!("FUNCTION RELOCATIONS {:?}", reloc_sink.func_relocs)
-                // total_size += code_size_offset;
             }
 
+            // compiled_funcs?;
+
             debug!("Instance - Relocating functions");
             // For each of the functions used, we see what are the calls inside this functions
             // and relocate each call to the proper memory address.
@@ -311,8 +328,8 @@ impl Instance {
                     GlobalInit::I64Const(n) => n,
                     GlobalInit::F32Const(f) => f as _, // unsafe { mem::transmute(f as f64) },
                     GlobalInit::F64Const(f) => f as _, // unsafe { mem::transmute(f) },
-                    GlobalInit::GlobalRef(_global_index) => {
-                        unimplemented!("GlobalInit::GlobalRef is not yet supported")
+                    GlobalInit::GlobalRef(global_index) => {
+                        globals_data[global_index.index()]
                     }
                     GlobalInit::Import() => {
                         let (module_name, field_name) = import_name.as_ref().expect("Expected a import name for the global import");
@@ -321,7 +338,17 @@ impl Instance {
                             Some(ImportValue::Global(value)) => {
                                 *value
                             },
-                            _ => panic!("Imported global value was not provided {:?} ({}.{})", imported, module_name, field_name)
+                            None => {
+                                if options.mock_missing_globals {
+                                    0
+                                }
+                                else {
+                                    panic!("Imported global value was not provided ({}.{})", module_name, field_name)
+                                }
+                            },
+                            _ => {
+                                panic!("Expected global import, but received {:?} ({}.{})", imported, module_name, field_name)
+                            }
                         }
                     }
                 };
@@ -345,7 +372,20 @@ impl Instance {
                             Some(ImportValue::Table(t)) => {
                                 t.to_vec()
                             },
-                            _ => panic!("Imported table was not provided {:?} ({}.{})", imported, module_name, field_name)
+                            None => {
+                                if options.mock_missing_tables {
+                                    let len = table.entity.size;
+                                    let mut v = Vec::with_capacity(len);
+                                    v.resize(len, 0);
+                                    v
+                                }
+                                else {
+                                    panic!("Imported table value was not provided ({}.{})", module_name, field_name)
+                                }
+                            },
+                            _ => {
+                                panic!("Expected global table, but received {:?} ({}.{})", imported, module_name, field_name)
+                            }
                         }
                     },
                     None => {
diff --git a/src/webassembly/mod.rs b/src/webassembly/mod.rs
index 9e2a2ed01..f60d67861 100644
--- a/src/webassembly/mod.rs
+++ b/src/webassembly/mod.rs
@@ -58,6 +58,8 @@ pub fn instantiate(
         import_object,
         InstanceOptions {
             mock_missing_imports: true,
+            mock_missing_globals: true,
+            mock_missing_tables: true,
             isa: isa
         },
     )?;