1. Remove quotes from strings in yaml file for better consistency.

2. Use MAKEFLAGS env variable to limit build parallelism so that mlir installation script remains clean.

.circleci/config.yml

@@ -7,25 +7,26 @@ jobs:
     steps:
       - checkout
       - run:
-          name: "Pull Submodules"
+          name: Pull Submodules
           command: |
             git submodule update --init --recursive
       - run:
           name: Installing GCC, CMake, Ninja, Protobuf
-          command: 'sudo apt-get update && sudo apt-get install -y gcc g++ cmake ninja-build protobuf-compiler'
+          command: sudo apt-get update && sudo apt-get install -y gcc g++ cmake ninja-build protobuf-compiler
       # Use cached mlir installation if possible.
       - restore_cache:
-          key: V1-LLVM-PROJECT-{{ arch }}
+          key: V2-LLVM-PROJECT-{{ arch }}
       - run:
           name: Install MLIR
           command: |
             # Check whether cache restoration succeeds by checking whether
             # mlir-opt executable exists.
             if [ ! -f llvm-project/build/bin/mlir-opt ]; then
-              sh .circleci/install-mlir.sh
+              export MAKEFLAGS=-j4
+              source .circleci/install-mlir.sh
             fi
       - save_cache:
-          key: V1-LLVM-PROJECT-{{ arch }}
+          key: V2-LLVM-PROJECT-{{ arch }}
           paths:
             - llvm-project
       - run:

.circleci/install-mlir.sh

@@ -8,5 +8,5 @@ cmake -G Ninja ../llvm \
    -DCMAKE_BUILD_TYPE=Release \
    -DLLVM_ENABLE_ASSERTIONS=ON \
    -DLLVM_ENABLE_RTTI=ON
-# TODO(tjingrant): why is RTTI necessary?
-cmake --build . --target check-mlir -- -j ${PARALLEL_JOBS_LIMIT:-4}
+
+cmake --build . --target check-mlir