diff --git a/.circleci/config.yml b/.circleci/config.yml
index 3490bf6b539..c588234dc03 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -21,7 +21,8 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - v6-lint-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-lint-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-lint-{{ arch }}
       - <<: *run_install_dependencies
       - run:
           name: Install lint deps
@@ -40,7 +41,7 @@ jobs:
             - target/debug/.fingerprint
             - target/debug/build
             - target/debug/deps
-          key: v6-test-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}
+          key: v8-lint-{{ arch }}-{{ checksum "Cargo.lock" }}
 
   test:
     docker:
@@ -50,14 +51,17 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - v6-test-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-test-cargo-cache-linux-stable-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-test-cargo-cache-linux-stable-{{ arch }}
       - <<: *run_install_dependencies
       - run:
           name: Tests
           command: make test
       - run:
           name: Emscripten Tests
-          command: make test-emscripten
+          command: |
+            make test-emscripten-clif
+            make test-emscripten-llvm
       - run:
           name: Integration Tests
           command: make integration-tests
@@ -67,7 +71,7 @@ jobs:
             - target/debug/.fingerprint
             - target/debug/build
             - target/debug/deps
-          key: v6-test-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}
+          key: v8-test-cargo-cache-linux-stable-{{ arch }}-{{ checksum "Cargo.lock" }}
 
   test-macos:
     macos:
@@ -76,7 +80,8 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - v6-cargo-cache-darwin-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-cargo-cache-darwin-stable-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-cargo-cache-darwin-stable-{{ arch }}
       - run:
           name: Install crate dependencies
           command: |
@@ -112,7 +117,8 @@ jobs:
             # We increase the ulimit for fixing cargo unclosed files in mac
             ulimit -n 8000
             sudo sysctl -w kern.maxfiles=655360 kern.maxfilesperproc=327680
-            make test-emscripten
+            make test-emscripten-clif
+            make test-emscripten-llvm
       - run:
           name: Integration Tests
           command: |
@@ -129,7 +135,7 @@ jobs:
             - target/release/.fingerprint
             - target/release/build
             - target/release/deps
-          key: v6-cargo-cache-darwin-{{ arch }}-{{ checksum "Cargo.lock" }}
+          key: v8-cargo-cache-darwin-stable-{{ arch }}-{{ checksum "Cargo.lock" }}
 
   test-and-build:
     docker:
@@ -138,13 +144,16 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - v6-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-cargo-cache-linux-nightly-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-cargo-cache-linux-nightly-{{ arch }}
       - run:
           name: Install dependencies
           command: |
             sudo apt-get install -y cmake
             curl -O https://releases.llvm.org/7.0.0/clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz
             tar xf clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz
+      # Use rust nightly (for dynasm, for now)
+      - run: rustup default nightly-2019-04-11
       - run:
           name: Tests
           command: |
@@ -154,7 +163,8 @@ jobs:
           name: Emscripten Tests
           command: |
             export LLVM_SYS_70_PREFIX="`pwd`/clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04/"
-            make test-emscripten
+            make test-emscripten-clif
+            make test-emscripten-llvm
       - run:
           name: Release Build
           command: |
@@ -183,7 +193,7 @@ jobs:
             - target/release/.fingerprint
             - target/release/build
             - target/release/deps
-          key: v6-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}
+          key: v8-cargo-cache-linux-nightly-{{ arch }}-{{ checksum "Cargo.lock" }}
 
   test-and-build-macos:
     macos:
@@ -192,7 +202,8 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - v6-cargo-cache-darwin-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-cargo-cache-darwin-nightly-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-cargo-cache-darwin-nightly-{{ arch }}
       - run:
           name: Install crate dependencies
           command: |
@@ -209,6 +220,8 @@ jobs:
             curl https://sh.rustup.rs -sSf | sh -s -- -y
             export PATH="$HOME/.cargo/bin:$PATH"
             cargo --version
+      # Use rust nightly (for dynasm, for now)
+      - run: rustup default nightly-2019-04-11
       - run:
           name: Tests
           command: |
@@ -228,7 +241,8 @@ jobs:
             # We increase the ulimit for fixing cargo unclosed files in mac
             ulimit -n 8000
             sudo sysctl -w kern.maxfiles=655360 kern.maxfilesperproc=327680
-            make test-emscripten
+            make test-emscripten-clif
+            make test-emscripten-dynasm
       - run:
           name: Release Build
           command: |
@@ -253,7 +267,7 @@ jobs:
             - target/release/.fingerprint
             - target/release/build
             - target/release/deps
-          key: v6-cargo-cache-darwin-{{ arch }}-{{ checksum "Cargo.lock" }}
+          key: v8-cargo-cache-darwin-nightly-{ arch }}-{{ checksum "Cargo.lock" }}
 
   test-rust-nightly:
     docker:
@@ -262,27 +276,28 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - v6-test-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}-nightly
+            - v8-cargo-cache-linux-nightly-{{ arch }}-{{ checksum "Cargo.lock" }}
+            - v8-cargo-cache-linux-nightly-{{ arch }}
       - run:
           name: Install dependencies
           command: |
             sudo apt-get install -y cmake
             curl -O https://releases.llvm.org/7.0.0/clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz
             tar xf clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz
-      - run: rustup default nightly-2019-02-27
+      - run: rustup default nightly-2019-04-11
       - run: |
           export LLVM_SYS_70_PREFIX="`pwd`/clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04/"
           make test
-          make test-nightly
+          make test-dynasm
           make test-emscripten-clif
-          make test-emscripten-nightly
+          make test-emscripten-dynasm
       - save_cache:
           paths:
             - /usr/local/cargo/registry
             - target/debug/.fingerprint
             - target/debug/build
             - target/debug/deps
-          key: v6-test-cargo-cache-linux-{{ arch }}-{{ checksum "Cargo.lock" }}-nightly
+          key: v8-cargo-cache-linux-nightly-{{ arch }}-{{ checksum "Cargo.lock" }}-nightly
 
   publish-github-release:
     docker:
diff --git a/Cargo.lock b/Cargo.lock
index 5f111b7b8f5..1e81b086e0b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2274,6 +2274,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "nix 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 0.6.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "wasmer-runtime-core 0.2.1",
  "wasmparser 0.28.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/Makefile b/Makefile
index 383d4ccf4ab..947032873ce 100644
--- a/Makefile
+++ b/Makefile
@@ -41,17 +41,16 @@ test:
 	cargo build -p wasmer-runtime-c-api
 	cargo test -p wasmer-runtime-c-api -- --nocapture
 
-test-nightly:
+test-dynasm:
 	cargo test --manifest-path lib/spectests/Cargo.toml --features dynasm
 
-test-emscripten:
-	cargo test --manifest-path lib/emscripten/Cargo.toml --features clif -- --test-threads=1 $(runargs)
+test-emscripten-llvm:
 	cargo test --manifest-path lib/emscripten/Cargo.toml --features llvm -- --test-threads=1 $(runargs)
 
 test-emscripten-clif:
 	cargo test --manifest-path lib/emscripten/Cargo.toml --features clif -- --test-threads=1 $(runargs)
 
-test-emscripten-nightly:
+test-emscripten-dynasm:
 	cargo test --manifest-path lib/emscripten/Cargo.toml --features dynasm -- --test-threads=1 $(runargs)
 
 dynasm-debug-release: