Linux aarch64 wheels

.github/workflows/wheels.yml

@@ -32,7 +32,7 @@ jobs:
 
 
   build_wheels:
-    name: Wheels on ${{ matrix.platform_id }} - ${{ matrix.os }}
+    name: Wheels - ${{ matrix.cibw_archs }} - ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
@@ -43,17 +43,30 @@ jobs:
           - os: windows-latest
             python-version: "3.8"
             platform_id: win_amd64
+            cibw_archs: "auto"
 
           # Linux 64 bit manylinux2014
           - os: ubuntu-latest
             python-version: "3.8"
             platform_id: manylinux_x86_64
             manylinux_image: manylinux2014
+            cibw_archs: "native"
 
-            # Use x86 macOS runner to build both x86 and ARM. GitHub does not offer M1/M2 yet (only self-hosted).
+          # Linux 64 bit manylinux2014 for aarch64
+          # Separate runner because this requires emulation (only x86 runners are available) and is very slow.
+          - os: ubuntu-latest
+            python-version: "3.8"
+            platform_id: manylinux_x86_64
+            manylinux_image: manylinux2014
+            cibw_archs: "aarch64"
+
+          # Use x86 macOS runner to build both x86 and ARM.
+          # GitHub does not offer Apple Silicon yet (only for self-hosted).
+          # See https://github.com/github/roadmap/issues/528
           - os: macos-latest
             python-version: "3.8"
             platform_id: macosx_x86_64
+            cibw_archs: "x86_64 arm64"
 
     steps:
       - uses: actions/checkout@v3
@@ -64,16 +77,31 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
-#      - name: Install tools (macOS)
-#        if: contains(matrix.os, 'macos')
-#        # Install coreutils which includes `nproc` used by `make -j` in suitesparse.sh
-#        #
-#        # GitHub actions comes with libomp already installed, but for its native arch only. Must build universal one
-#        # manually so that both x86 and arm builds can be built.
-#        run: |
-#          brew install coreutils
-#          brew install libomp
-#          sh add_arm_to_libomp_dylib.sh
+      # aarch64 Linux builds are cross-compiled on x86 runners using emulation
+      # see https://cibuildwheel.readthedocs.io/en/stable/faq/#emulation
+      - name: Setup QEMU (for aarch64)
+        if: matrix.cibw_archs == 'aarch64'
+        uses: docker/setup-qemu-action@v2
+        with:
+          platforms: arm64
+
+      - name: Setup env (for aarch64)
+        if: matrix.cibw_archs == 'aarch64'
+        # Ask suitesparse.sh to compile faster by optimizing fewer types. Otherwise, the build takes too long to finish
+        # in 6 hour limit.
+        run: |
+          echo "SUITESPARSE_FAST_BUILD=1" >> $GITHUB_ENV
+
+      - name: Install tools (macOS)
+        if: contains(matrix.os, 'macos')
+        # Install coreutils which includes `nproc` used by `make -j` in suitesparse.sh
+        #
+        # GitHub actions comes with libomp already installed, but for its native arch only. Must build universal one
+        # manually so that both x86 and arm builds can be built.
+        run: |
+          brew install coreutils
+          brew install libomp
+          sh add_arm_to_libomp_dylib.sh
 
       - name: Build Wheels
         env:
@@ -83,6 +111,8 @@ jobs:
           # Build SuiteSparse
           CIBW_BEFORE_ALL: bash suitesparse.sh ${{ github.ref }}
 
+          CIBW_ENVIRONMENT_LINUX: SUITESPARSE_FAST_BUILD=${{ env.SUITESPARSE_FAST_BUILD }}
+
           # CMAKE_GNUtoMS=ON asks suitesparse.sh to build libraries in MSVC style on Windows.
           CIBW_ENVIRONMENT_WINDOWS: CMAKE_GNUtoMS=ON GRAPHBLAS_PREFIX="C:/GraphBLAS"
 
@@ -92,11 +122,11 @@ jobs:
           # Uncomment to only build CPython wheels
 #          CIBW_BUILD: "cp*"
 
-          # macOS: build x86_64 and arm64
-          #CIBW_ARCHS_MACOS: "x86_64 arm64"
+          # Architectures to build specified in matrix
+          CIBW_ARCHS: ${{ matrix.cibw_archs }}
 
-          # No 32-bit builds
-          CIBW_SKIP: "*-win32 *_i686 *musl*"
+          # No 32-bit builds, no musllinux, no PyPy aarch64 (only due to build speed, numpy does not ship aarch64 pypy wheels)
+          CIBW_SKIP: "*-win32 *_i686 *musl* pp*aarch64"
 
           # Use delvewheel on Windows.
           # This copies graphblas.dll into the wheel. "repair" in cibuildwheel parlance includes copying any shared

add_arm_to_libomp_dylib.sh

@@ -1,4 +1,23 @@
 #!/bin/sh
+# Construct a universal2 version of homebrew's libomp.
+#
+# Homebrew's libomp works well to patch Apple clang's missing OpenMP support. The problem is a combination of:
+# - Brew installs libomp built for x86 *or* ARM, matching the architecture of the machine it is running on.
+# - GitHub Actions only has x86 runners as of now. Check back in Q4 2023. https://github.com/github/roadmap/issues/528
+# - The linker will select the first found libomp, and if that version does not include the expected architecture then
+#   linking will fail.
+#
+# One solution is to build a universal2 version of libomp that includes both architectures. That's what this script
+# does. It adds the ARM version of libomp to the x86 version.
+#
+# This script assumes it is running on x86 with x86 libomp already installed.
+
+if [ "$(arch)" != "x86_64" ] && [ "$(arch)" != "i386" ]; then
+    echo "Not running on x86 as expected. Running on:"
+    arch
+    echo "If the above says arm64 then this hack is no longer necessary. Remove this script from the build."
+    exit 1;
+fi
 
 #mkdir x86lib
 mkdir armlib
@@ -11,8 +30,21 @@ brew fetch --force --bottle-tag=arm64_big_sur libomp
 #tar -xzf $(brew --cache --bottle-tag=x86_64_monterey libomp) --strip-components 2 -C x86lib
 tar -xzf $(brew --cache --bottle-tag=arm64_big_sur libomp) --strip-components 2 -C armlib
 
-# merge
+# ARM and x86 dylibs have different install names due to different brew install directories.
+# The x86 install name will be expected so make the ARM install name match.
+X86_INSTALL_NAME="$(otool -X -D $(brew --prefix libomp)/lib/libomp.dylib)"
+install_name_tool -id "${X86_INSTALL_NAME}" armlib/lib/libomp.dylib
+codesign --force -s - armlib/lib/libomp.dylib
+
+# merge the downloaded (arm) libomp with the already installed (x86) libomp to create a universal libomp
 lipo armlib/lib/libomp.dylib $(brew --prefix libomp)/lib/libomp.dylib -output libomp.dylib -create
+
+# print contents of universal library for reference
+otool -arch all -L libomp.dylib
+
+# replace the x86-only libomp with the newly-created universal one
 cp -f libomp.dylib $(brew --prefix libomp)/lib
+
+# clean up
 rm libomp.dylib
 rm -rf armlib

suitesparse.sh

@@ -25,9 +25,8 @@ if [ -n "${BREW_LIBOMP}" ]; then
     cmake_params+=(-DOpenMP_libomp_LIBRARY="omp")
     export LDFLAGS="-L$(brew --prefix libomp)/lib"
 
-    export CFLAGS="-arch x86_64"
-#    # build both x86 and ARM
-#    export CFLAGS="-arch x86_64 -arch arm64"
+    # build both x86 and ARM
+    export CFLAGS="-arch x86_64 -arch arm64"
 fi
 
 if [ -n "${CMAKE_GNUtoMS}" ]; then
@@ -63,6 +62,26 @@ echo "#define GxB_NO_UINT32    1" >> ../Source/GB_control.h
 # echo "#define GxB_NO_UINT64    1" >> ../Source/GB_control.h #
 echo "#define GxB_NO_UINT8     1" >> ../Source/GB_control.h
 
+if [ -n "${SUITESPARSE_FAST_BUILD}" ]; then
+    echo "suitesparse.sh: Fast build requested."
+    # Disable optimizing even more types. This is for builds that don't finish in runner resource limits,
+    # such as emulated aarm64.
+
+    echo "#define GxB_NO_BOOL      1" >> ../Source/GB_control.h
+#    echo "#define GxB_NO_FP32      1" >> ../Source/GB_control.h
+#    echo "#define GxB_NO_FP64      1" >> ../Source/GB_control.h
+    echo "#define GxB_NO_FC32      1" >> ../Source/GB_control.h
+    echo "#define GxB_NO_FC64      1" >> ../Source/GB_control.h
+    echo "#define GxB_NO_INT16     1" >> ../Source/GB_control.h
+    echo "#define GxB_NO_INT32     1" >> ../Source/GB_control.h
+#    echo "#define GxB_NO_INT64     1" >> ../Source/GB_control.h
+#    echo "#define GxB_NO_INT8      1" >> ../Source/GB_control.h
+    echo "#define GxB_NO_UINT16    1" >> ../Source/GB_control.h
+    echo "#define GxB_NO_UINT32    1" >> ../Source/GB_control.h
+    echo "#define GxB_NO_UINT64    1" >> ../Source/GB_control.h
+    echo "#define GxB_NO_UINT8     1" >> ../Source/GB_control.h
+fi
+
 # Disable all Source/Generated2 kernels. For workflow development only.
 #cmake_params+=(-DCMAKE_CUDA_DEV=1)