diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 0950dff14adfa..9ca46da5c1f08 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1,6 +1,9 @@
 name: CI
 
 on:
+  push:
+    branches:
+    - swiftwasm
   pull_request:
     branches:
     - swiftwasm
@@ -13,59 +16,7 @@ jobs:
     steps:
     - uses: actions/checkout@v1
     - name: Run a multi-line script
-      run: |
-        sudo apt update
-        sudo apt install \
-          git ninja-build clang python \
-          uuid-dev libicu-dev icu-devtools libbsd-dev \
-          libedit-dev libxml2-dev libsqlite3-dev swig \
-          libpython-dev libncurses5-dev pkg-config \
-          libblocksruntime-dev libcurl4-openssl-dev \
-          systemtap-sdt-dev tzdata rsync
-
-        ./utils/update-checkout --clone --scheme wasm
-        git checkout $GITHUB_SHA
-        export sourcedir=$PWD/..
-        cd $sourcedir
-
-        wget -O install_cmake.sh "https://github.com/Kitware/CMake/releases/download/v3.15.3/cmake-3.15.3-Linux-x86_64.sh"
-        chmod +x install_cmake.sh
-        sudo mkdir -p /opt/cmake
-        sudo ./install_cmake.sh --skip-license --prefix=/opt/cmake
-        sudo ln -sf /opt/cmake/bin/* /usr/local/bin
-        cmake --version
-
-        wget -O wasi-sdk.tar.gz https://github.com/swiftwasm/wasi-sdk/releases/download/20190421.6/wasi-sdk-3.19gefb17cb478f9.m-linux.tar.gz
-        tar xfz wasi-sdk.tar.gz
-        mv wasi-sdk-3.19gefb17cb478f9+m/opt/wasi-sdk ./wasi-sdk
-
-        wget -O icu.tar.xz "https://github.com/swiftwasm/icu4c-wasi/releases/download/20190421.3/icu4c-wasi.tar.xz"
-        tar xf icu.tar.xz
-
-        cd swift
-        utils/build-script --release --wasm --verbose \
-          --skip-build-benchmarks \
-          --extra-cmake-options=" \
-            -DSWIFT_SDKS='WASM;LINUX' \
-            -DSWIFT_BUILD_SOURCEKIT=FALSE \
-            -DSWIFT_ENABLE_SOURCEKIT_TESTS=FALSE \
-            -DCMAKE_AR='$sourcedir/wasi-sdk/bin/llvm-ar' \
-            -DCMAKE_RANLIB='$sourcedir/wasi-sdk/bin/llvm-ranlib' \
-          " \
-          --build-stdlib-deployment-targets "wasm-wasm32" \
-          --build-swift-static-stdlib \
-          --install-destdir="$sourcedir/install" \
-          --install-prefix="/opt/swiftwasm-sdk" \
-          --install-swift \
-          --installable-package="$sourcedir/swiftwasm.tar.gz" \
-          --llvm-targets-to-build "X86;WebAssembly" \
-          --stdlib-deployment-targets "wasm-wasm32" \
-          --wasm-icu-data "todo-icu-data" \
-          --wasm-icu-i18n "$sourcedir/icu_out/lib" \
-          --wasm-icu-i18n-include "$sourcedir/icu_out/include" \
-          --wasm-icu-uc "$sourcedir/icu_out/lib" \
-          --wasm-icu-uc-include "$sourcedir/icu_out/include" \
-          --wasm-wasi-sdk "$sourcedir/wasi-sdk"
+      run: ./ci-linux.sh
 
   macos_build:
     timeout-minutes: 0
@@ -74,42 +25,4 @@ jobs:
     steps:
     - uses: actions/checkout@v1
     - name: Run a multi-line script
-      run: |
-        brew install cmake ninja llvm
-        ./utils/update-checkout --clone --scheme wasm
-        git checkout $GITHUB_SHA
-        export sourcedir=$PWD/..
-        cd $sourcedir
-        wget -O wasi-sdk.tar.gz https://github.com/swiftwasm/wasi-sdk/releases/download/20190421.6/wasi-sdk-3.19gefb17cb478f9.m-linux.tar.gz
-        tar xfz wasi-sdk.tar.gz
-        mv wasi-sdk-3.19gefb17cb478f9+m/opt/wasi-sdk ./wasi-sdk
-        # Link sysroot/usr/include to sysroot/include because Darwin sysroot doesn't 
-        # find header files in sysroot/include but sysroot/usr/include
-        mkdir wasi-sdk/share/sysroot/usr/
-        ln -s ../include wasi-sdk/share/sysroot/usr/include
-        wget -O icu.tar.xz "https://github.com/swiftwasm/icu4c-wasi/releases/download/20190421.3/icu4c-wasi.tar.xz"
-        tar xf icu.tar.xz
-        cd swift
-        ./utils/build-script --release --wasm --verbose \
-          --skip-build-benchmarks \
-          --extra-cmake-options=" \
-            -DSWIFT_PRIMARY_VARIANT_SDK:STRING=WASM \
-            -DSWIFT_PRIMARY_VARIANT_ARCH:STRING=wasm32 \
-            -DSWIFT_OSX_x86_64_ICU_STATICLIB=TRUE \
-            -DSWIFT_BUILD_SOURCEKIT=FALSE \
-            -DSWIFT_ENABLE_SOURCEKIT_TESTS=FALSE \
-            -DCMAKE_AR='/usr/local/opt/llvm/bin/llvm-ar' \
-            -DCMAKE_RANLIB='/usr/local/opt/llvm/bin/llvm-ranlib' \
-          " \
-          --build-stdlib-deployment-targets "wasm-wasm32" \
-          --build-swift-dynamic-sdk-overlay false \
-          --build-swift-static-sdk-overlay false \
-          --build-swift-static-stdlib \
-          --llvm-targets-to-build "X86;WebAssembly" \
-          --stdlib-deployment-targets "wasm-wasm32" \
-          --wasm-icu-data "todo-icu-data" \
-          --wasm-icu-i18n "$sourcedir/icu_out/lib" \
-          --wasm-icu-i18n-include "$sourcedir/icu_out/include" \
-          --wasm-icu-uc "$sourcedir/icu_out/lib" \
-          --wasm-icu-uc-include "$sourcedir/icu_out/include" \
-          --wasm-wasi-sdk "$sourcedir/wasi-sdk"
+      run: ./ci-mac.sh
diff --git a/build-linux.sh b/build-linux.sh
new file mode 100755
index 0000000000000..7d91a1abd9b57
--- /dev/null
+++ b/build-linux.sh
@@ -0,0 +1,25 @@
+#/bin/bash
+
+utils/build-script --release --wasm --verbose \
+  --skip-build-benchmarks \
+  --extra-cmake-options=" \
+    -DSWIFT_SDKS='WASM;LINUX' \
+    -DSWIFT_BUILD_SOURCEKIT=FALSE \
+    -DSWIFT_ENABLE_SOURCEKIT_TESTS=FALSE \
+    -DCMAKE_AR='$sourcedir/wasi-sdk/bin/llvm-ar' \
+    -DCMAKE_RANLIB='$sourcedir/wasi-sdk/bin/llvm-ranlib' \
+  " \
+  --build-stdlib-deployment-targets "wasm-wasm32" \
+  --build-swift-static-stdlib \
+  --install-destdir="$sourcedir/install" \
+  --install-prefix="/opt/swiftwasm-sdk" \
+  --install-swift \
+  --installable-package="$sourcedir/swiftwasm.tar.gz" \
+  --llvm-targets-to-build "X86;WebAssembly" \
+  --stdlib-deployment-targets "wasm-wasm32" \
+  --wasm-icu-data "todo-icu-data" \
+  --wasm-icu-i18n "$sourcedir/icu_out/lib" \
+  --wasm-icu-i18n-include "$sourcedir/icu_out/include" \
+  --wasm-icu-uc "$sourcedir/icu_out/lib" \
+  --wasm-icu-uc-include "$sourcedir/icu_out/include" \
+  --wasm-wasi-sdk "$sourcedir/wasi-sdk"
diff --git a/build-mac.sh b/build-mac.sh
new file mode 100755
index 0000000000000..741b394981492
--- /dev/null
+++ b/build-mac.sh
@@ -0,0 +1,25 @@
+#/bin/bash
+
+./utils/build-script --release --wasm --verbose \
+  --skip-build-benchmarks \
+  --extra-cmake-options=" \
+    -DSWIFT_PRIMARY_VARIANT_SDK:STRING=WASM \
+    -DSWIFT_PRIMARY_VARIANT_ARCH:STRING=wasm32 \
+    -DSWIFT_OSX_x86_64_ICU_STATICLIB=TRUE \
+    -DSWIFT_BUILD_SOURCEKIT=FALSE \
+    -DSWIFT_ENABLE_SOURCEKIT_TESTS=FALSE \
+    -DCMAKE_AR='/usr/local/opt/llvm/bin/llvm-ar' \
+    -DCMAKE_RANLIB='/usr/local/opt/llvm/bin/llvm-ranlib' \
+  " \
+  --build-stdlib-deployment-targets "wasm-wasm32" \
+  --build-swift-dynamic-sdk-overlay false \
+  --build-swift-static-sdk-overlay false \
+  --build-swift-static-stdlib \
+  --llvm-targets-to-build "X86;WebAssembly" \
+  --stdlib-deployment-targets "wasm-wasm32" \
+  --wasm-icu-data "todo-icu-data" \
+  --wasm-icu-i18n "$sourcedir/icu_out/lib" \
+  --wasm-icu-i18n-include "$sourcedir/icu_out/include" \
+  --wasm-icu-uc "$sourcedir/icu_out/lib" \
+  --wasm-icu-uc-include "$sourcedir/icu_out/include" \
+  --wasm-wasi-sdk "$sourcedir/wasi-sdk"
diff --git a/ci-linux.sh b/ci-linux.sh
new file mode 100755
index 0000000000000..18953fb7ce1f5
--- /dev/null
+++ b/ci-linux.sh
@@ -0,0 +1,33 @@
+#/bin/bash
+
+sudo apt update
+sudo apt install \
+  git ninja-build clang python \
+  uuid-dev libicu-dev icu-devtools libbsd-dev \
+  libedit-dev libxml2-dev libsqlite3-dev swig \
+  libpython-dev libncurses5-dev pkg-config \
+  libblocksruntime-dev libcurl4-openssl-dev \
+  systemtap-sdt-dev tzdata rsync
+
+export current_sha=`git rev-parse HEAD`
+./utils/update-checkout --clone --scheme wasm
+git checkout $current_sha
+export sourcedir=$PWD/..
+cd $sourcedir
+
+wget -O install_cmake.sh "https://github.com/Kitware/CMake/releases/download/v3.15.3/cmake-3.15.3-Linux-x86_64.sh"
+chmod +x install_cmake.sh
+sudo mkdir -p /opt/cmake
+sudo ./install_cmake.sh --skip-license --prefix=/opt/cmake
+sudo ln -sf /opt/cmake/bin/* /usr/local/bin
+cmake --version
+
+wget -O wasi-sdk.tar.gz https://github.com/swiftwasm/wasi-sdk/releases/download/20190421.6/wasi-sdk-3.19gefb17cb478f9.m-linux.tar.gz
+tar xfz wasi-sdk.tar.gz
+mv wasi-sdk-3.19gefb17cb478f9+m/opt/wasi-sdk ./wasi-sdk
+
+wget -O icu.tar.xz "https://github.com/swiftwasm/icu4c-wasi/releases/download/20190421.3/icu4c-wasi.tar.xz"
+tar xf icu.tar.xz
+
+cd swift
+./build-linux.sh
diff --git a/ci-mac.sh b/ci-mac.sh
new file mode 100755
index 0000000000000..dc8bab5527073
--- /dev/null
+++ b/ci-mac.sh
@@ -0,0 +1,20 @@
+#/bin/bash
+
+brew install cmake ninja llvm
+export current_sha=`git rev-parse HEAD`
+./utils/update-checkout --clone --scheme wasm
+git checkout $current_sha
+export sourcedir=$PWD/..
+cd $sourcedir
+wget -O wasi-sdk.tar.gz https://github.com/swiftwasm/wasi-sdk/releases/download/20190421.6/wasi-sdk-3.19gefb17cb478f9.m-linux.tar.gz
+tar xfz wasi-sdk.tar.gz
+mv wasi-sdk-3.19gefb17cb478f9+m/opt/wasi-sdk ./wasi-sdk
+# Link sysroot/usr/include to sysroot/include because Darwin sysroot doesn't 
+# find header files in sysroot/include but sysroot/usr/include
+mkdir wasi-sdk/share/sysroot/usr/
+ln -s ../include wasi-sdk/share/sysroot/usr/include
+wget -O icu.tar.xz "https://github.com/swiftwasm/icu4c-wasi/releases/download/20190421.3/icu4c-wasi.tar.xz"
+tar xf icu.tar.xz
+
+cd swift
+./build-mac.sh