Build llvm with clang since gcc on ppc64le doesn't support __builtin_thread_pointer

docker/Dockerfile.llvm-project

@@ -28,8 +28,8 @@ RUN distro=$(cat /etc/os-release|grep -Po '(?<=^ID=").*(?=")|(?<=^ID=)[^"].*[^"]
           ln -sf /usr/share/zoneinfo/${TZ} /etc/localtime && \
           dpkg-reconfigure -f noninteractive tzdata && \
           apt-get install -qq -y --no-install-recommends \
-                  autoconf automake ca-certificates cmake cppcheck curl \
-                  default-jdk-headless gcc g++ git libncurses-dev \
+                  autoconf automake ca-certificates clang cmake cppcheck \
+                  curl default-jdk-headless gcc g++ git libncurses-dev \
                   libtool make maven ninja-build openjdk-11-jdk-headless \
                   python3 python3-dev python3-distutils python3-numpy \
                   python3-pip python3-pytest-xdist python3-setuptools \
@@ -44,7 +44,7 @@ RUN distro=$(cat /etc/os-release|grep -Po '(?<=^ID=").*(?=")|(?<=^ID=)[^"].*[^"]
               https://dl.fedoraproject.org/pub/epel/epel-release-latest-${RHEL_VERSION}.noarch.rpm && \
           yum update -q -y && \
           yum install -q -y \
-              autoconf automake ca-certificates cmake diffutils \
+              autoconf automake ca-certificates clang cmake diffutils \
               file java-11-openjdk-devel java-11-openjdk-headless \
               gcc gcc-c++ git libtool make ncurses-devel \
               python39 python39-devel python39-numpy python39-pip \
@@ -84,7 +84,9 @@ RUN git clone -n https://github.com/llvm/llvm-project.git \
     && cd llvm-project \
     && git checkout ${LLVM_PROJECT_SHA1} \
     && mkdir -p build && cd build \
-    && cmake -G Ninja ../llvm \
+# Build with clang since gcc on ppc64le doesn't support __builtin_thread_pointer
+    && CC=clang CXX=clang++ \
+       cmake -G Ninja ../llvm \
              -DLLVM_ENABLE_PROJECTS=mlir \
              -DLLVM_TARGETS_TO_BUILD="host" \
              -DCMAKE_BUILD_TYPE=Release \

docker/Dockerfile.onnx-mlir

@@ -40,7 +40,8 @@ RUN LLVM_PROJECT_ROOT=${WORK_DIR}/llvm-project \
     && rm -rf build && mkdir -p build && cd build \
 # NNPA acclerator is built on all archs to enable lit tests
 # (dependent libzdnn is built on s390x only)
-    && cmake -DMLIR_DIR=${LLVM_PROJECT_ROOT}/build/lib/cmake/mlir \
+    && CC=clang CXX=clang++ \
+       cmake -DMLIR_DIR=${LLVM_PROJECT_ROOT}/build/lib/cmake/mlir \
              -DCMAKE_BUILD_TYPE=Release \
              -DCMAKE_INSTALL_MESSAGE=NEVER \
              -DONNX_MLIR_ACCELERATORS=${ACCEL} .. \
@@ -79,8 +80,8 @@ RUN LLVM_PROJECT_ROOT=${WORK_DIR}/llvm-project \
           pip3 uninstall -q -y Cython pybind11 pytest pytest-forked \
                pytest-xdist typing-extensions && \
           yum remove -q -y \
-              adwaita-icon-theme autoconf automake cmake diffutils file \
-              git libtool make python39 && \
+              adwaita-icon-theme autoconf automake cmake file \
+              git libtool python39 && \
           rm -rf /var/cache/dnf/* /usr/local/bin/ninja; \
        fi \
     && rm -rf /tmp/* /usr/bin/python \

docker/Dockerfile.onnx-mlir-dev

@@ -29,7 +29,8 @@ RUN LLVM_PROJECT_ROOT=${WORK_DIR}/llvm-project \
     && rm -rf build && mkdir -p build && cd build \
 # NNPA acclerator is built on all archs to enable lit tests
 # (dependent libzdnn is built on s390x only)
-    && cmake -DMLIR_DIR=${LLVM_PROJECT_ROOT}/build/lib/cmake/mlir \
+    && CC=clang CXX=clang++ \
+       cmake -DMLIR_DIR=${LLVM_PROJECT_ROOT}/build/lib/cmake/mlir \
              -DCMAKE_BUILD_TYPE=Debug \
              -DONNX_MLIR_TEST_OPTLEVEL=0 \
              -DONNX_MLIR_ACCELERATORS=${ACCEL} .. \