macOS: enable Accelerate ILP64 through Apple's new interface

.github/actions/setup-randblas-deps-windows/setup.ps1

@@ -81,17 +81,17 @@ function Clone-Pinned {
 
 #------------------------------------------------------------------ pins ------
 # Immutable refs only: a tag or a full commit hash, never a branch. These match
-# install/install.sh and the refs RandLAPACK validated, so the two installers
+# installers/install.sh and the refs RandLAPACK validated, so the two installers
 # and CI cannot disagree about what they built.
 #
-# BLAS++ and LAPACK++ previously came from personal forks carrying one-line
-# MSVC fixes. Both merged upstream on 2026-08-06 (icl-utk-edu/blaspp#132,
-# icl-utk-edu/lapackpp#87), so both now come from icl-utk-edu, pinned to the
-# merge commits: the latest release of each, v2025.05.28, predates the fixes.
+# Pinned to the commits that merged new-Apple-Accelerate support on 2026-08-27
+# (icl-utk-edu/blaspp#134, icl-utk-edu/lapackpp#88); they also contain the MSVC
+# portability fixes (blaspp#132, lapackpp#87). The latest release of each,
+# v2025.05.28, predates all of these.
 $BlasppUrl    = "https://github.com/icl-utk-edu/blaspp.git"
-$BlasppRef    = "30571853f980d3a2a1737124ea4789e025a5e045"
+$BlasppRef    = "2d8d4e937ac46fffab33d4174a4fc7659726dbda"
 $LapackppUrl  = "https://github.com/icl-utk-edu/lapackpp.git"
-$LapackppRef  = "40b9d0daf29b6f1f3fa58bc3f22bd6cfb2c67fe4"
+$LapackppRef  = "b9439cf3c26d1655d88e7f510ae8b4f82fbeb687"
 $Random123Url = "https://github.com/DEShawResearch/Random123.git"
 $Random123Ref = "v1.14.0"
 $GTestUrl     = "https://github.com/google/googletest.git"

.github/actions/setup-randblas-deps/action.yml

@@ -102,7 +102,7 @@ runs:
       uses: actions/cache@v4
       with:
         path: ${{ github.workspace }}/../blaspp-install
-        key: blaspp-mklfix2-${{ runner.os }}-${{ runner.arch }}-${{ inputs.cc }}-${{ inputs.blas-backend }}-${{ steps.blaspp-rev.outputs.sha }}
+        key: blaspp-accel1-${{ runner.os }}-${{ runner.arch }}-${{ inputs.cc }}-${{ inputs.blas-backend }}-${{ steps.blaspp-rev.outputs.sha }}
 
     - name: build blaspp
       if: steps.blaspp-cache.outputs.cache-hit != 'true'
@@ -118,18 +118,24 @@ runs:
         mkdir blaspp-build
         cd blaspp-build
         blas_arg=""
-        # ILP64 only for MKL: it makes MKL_INT 64-bit, which RandBLAS's MKL
+        # ILP64 for MKL: it makes MKL_INT 64-bit, which RandBLAS's MKL
         # spgemm path (test_spgemm, compiled only under RandBLAS_HAS_MKL)
-        # requires to match its int64_t sparse indices. Other backends stay
-        # LP64 -- blaspp's public API is int64_t regardless, so RandBLAS is
-        # unaffected, and this avoids needing ILP64 OpenBLAS/Accelerate libs.
+        # requires to match its int64_t sparse indices. ILP64 for Accelerate:
+        # BLAS++ supports Apple's new interface (icl-utk-edu/blaspp#134), and
+        # macOS >= 13.3 ships ILP64 inside the framework, so these lanes cover
+        # new-Accelerate ILP64 (issue #150) at no extra dependency cost.
+        # OpenBLAS stays LP64 -- blaspp's public API is int64_t regardless, so
+        # RandBLAS is unaffected, and an ILP64 OpenBLAS is a separate library
+        # BLAS++ cannot discover (issue #194).
         blas_int_arg=""
         case "${{ inputs.blas-backend }}" in
           openblas)   blas_arg="-Dblas=openblas" ;;
           mkl)        blas_arg="-Dblas=mkl"; blas_int_arg="-Dblas_int=int64" ;;
-          accelerate) blas_arg="-Dblas=accelerate" ;;
+          accelerate) blas_arg="-Dblas=accelerate"; blas_int_arg="-Dblas_int=int64" ;;
           auto)       blas_arg="" ;;
         esac
+        # A silent fall-back to Apple's legacy interface would test the wrong
+        # BLAS; the generated defines.h is checked after the install below.
         cmake \
           -DCMAKE_C_COMPILER="${CC}" \
           -DCMAKE_CXX_COMPILER="${CXX}" \
@@ -145,14 +151,20 @@ runs:
           jobs="$(nproc)"
         fi
         make -j"${jobs}" install
+        if [[ "${{ inputs.blas-backend }}" == "accelerate" ]]; then
+          grep -q ACCELERATE_NEW_LAPACK ../blaspp-install/include/blas/defines.h \
+            || { echo "::error::BLAS++ did not select Apple's new Accelerate interface"; exit 1; }
+          grep -q '^#define BLAS_ILP64' ../blaspp-install/include/blas/defines.h \
+            || { echo "::error::BLAS++ did not select Accelerate ILP64"; exit 1; }
+        fi
 
     - name: cache lapackpp install
       if: inputs.install-lapackpp == 'true'
       id: lapackpp-cache
       uses: actions/cache@v4
       with:
         path: ${{ github.workspace }}/../lapackpp-install
-        key: lapackpp-mklfix2-${{ runner.os }}-${{ runner.arch }}-${{ inputs.cc }}-${{ inputs.blas-backend }}-${{ steps.blaspp-rev.outputs.sha }}-${{ steps.lapackpp-rev.outputs.sha }}
+        key: lapackpp-accel1-${{ runner.os }}-${{ runner.arch }}-${{ inputs.cc }}-${{ inputs.blas-backend }}-${{ steps.blaspp-rev.outputs.sha }}-${{ steps.lapackpp-rev.outputs.sha }}
 
     - name: build lapackpp
       if: inputs.install-lapackpp == 'true' && steps.lapackpp-cache.outputs.cache-hit != 'true'
@@ -167,9 +179,10 @@ runs:
         git clone --depth 1 https://github.com/icl-utk-edu/lapackpp.git
         mkdir lapackpp-build
         cd lapackpp-build
-        # Match the int width of the blaspp we link against (ILP64 only for MKL).
+        # Match the int width of the blaspp we link against (ILP64 for MKL
+        # and Accelerate, per the blaspp step above).
         blas_int_arg=""
-        if [[ "${{ inputs.blas-backend }}" == "mkl" ]]; then
+        if [[ "${{ inputs.blas-backend }}" == "mkl" || "${{ inputs.blas-backend }}" == "accelerate" ]]; then
           blas_int_arg="-Dblas_int=int64"
         fi
         cmake \

.github/scripts/windows/toolchain-arch.ps1

@@ -1,4 +1,4 @@
-# Toolchain architecture detection, shared by install/install.ps1 (user-facing
+# Toolchain architecture detection, shared by installers/install.ps1 (user-facing
 # preflight) and .github/actions/setup-randlapack-deps-windows/setup.ps1 (which
 # also runs standalone in CI). Dot-source it; it defines functions only.
 #

.github/workflows/install-script.yml

@@ -1,4 +1,4 @@
-# Exercises install/install.sh itself -- the one artifact the core workflows
+# Exercises installers/install.sh itself -- the one artifact the core workflows
 # never run, since they hand-replicate the build recipe instead. What each lane
 # proves:
 #   1. a fresh checkout run non-interactively builds, and its tests pass;
@@ -96,7 +96,7 @@ jobs:
       - name: run the installer, capturing output for the escape-sequence check
         run: |
           set -euo pipefail
-          bash RandBLAS/install/install.sh --yes \
+          bash RandBLAS/installers/install.sh --yes \
             --blas=${{ matrix.backend }} \
             --project-dir "$GITHUB_WORKSPACE/RandNLA-project" \
             2>&1 | tee installer.out
@@ -135,7 +135,7 @@ jobs:
       - name: re-run the installer in place (idempotency)
         run: |
           set -euo pipefail
-          bash RandBLAS/install/install.sh --yes \
+          bash RandBLAS/installers/install.sh --yes \
             --blas=${{ matrix.backend }} \
             --project-dir "$GITHUB_WORKSPACE/RandNLA-project" | tee rerun.out
           grep -q 'already built' rerun.out \
@@ -147,7 +147,7 @@ jobs:
           BLASPP_INSTALL_DIR="$GITHUB_WORKSPACE/RandNLA-project/install/blaspp-${{ matrix.backend }}-install" \
           RANDOM123_INSTALL_DIR="$GITHUB_WORKSPACE/RandNLA-project/install/Random123-install" \
           GTEST_ROOT="$GITHUB_WORKSPACE/RandNLA-project/install/googletest-install" \
-          bash RandBLAS-discovery/install/install.sh --yes \
+          bash RandBLAS-discovery/installers/install.sh --yes \
             --blas=${{ matrix.backend }} \
             --project-dir "$GITHUB_WORKSPACE/RandNLA-project-discovery" | tee discovery.out
           grep -q 'external install' discovery.out \
@@ -169,30 +169,36 @@ jobs:
       - name: install libomp
         run: brew install libomp
 
-      # Accelerate is the default on macOS and is LP64-only: BLAS++ implements
-      # only Apple's legacy interface, so there is no ILP64 lane to run here.
+      # Accelerate is the default on macOS. The pinned BLAS++ supports Apple's
+      # new interface (icl-utk-edu/blaspp#134), which carries ILP64 on
+      # macOS >= 13.3, so the width default resolves to ILP64 here just like
+      # MKL on Linux -- and the summary line proves it, rather than trusting
+      # what was requested.
       - name: run the installer
         run: |
           set -euo pipefail
-          bash RandBLAS/install/install.sh --yes \
+          bash RandBLAS/installers/install.sh --yes \
             --project-dir "$GITHUB_WORKSPACE/RandNLA-project" | tee installer.out
-          grep -qE '^  Backend  *accelerate' installer.out
+          grep -qE '^  Backend  *accelerate, ILP64' installer.out
 
       - name: run the test suite
         run: ctest --test-dir RandNLA-project/build/RandBLAS-build --output-on-failure
 
       - name: re-run the installer in place (idempotency)
         run: |
-          bash RandBLAS/install/install.sh --yes \
+          bash RandBLAS/installers/install.sh --yes \
             --project-dir "$GITHUB_WORKSPACE/RandNLA-project"
 
-      - name: asking for ILP64 on Accelerate is refused, not silently downgraded
+      # The explicit-LP64 route stays supported and stays tested: with every
+      # auto run now resolving to ILP64, this is the one place the legacy
+      # 32-bit-integer width on Accelerate is still exercised.
+      - name: explicit --blas-int=lp64 still builds LP64
         run: |
-          if bash RandBLAS/install/install.sh --yes --blas=accelerate --blas-int=ilp64 \
-               --project-dir "$GITHUB_WORKSPACE/RandNLA-project-ilp64" > refuse.out 2>&1; then
-            echo "The installer accepted an impossible configuration."; cat refuse.out; exit 1
-          fi
-          grep -q 'not available with Accelerate' refuse.out
+          set -euo pipefail
+          bash RandBLAS/installers/install.sh --yes --blas=accelerate --blas-int=lp64 \
+            --project-dir "$GITHUB_WORKSPACE/RandNLA-project-lp64" | tee lp64.out
+          grep -qE '^  Backend  *accelerate, LP64' lp64.out
+          ctest --test-dir RandNLA-project-lp64/build/RandBLAS-build --output-on-failure
 
   packager:
     # The contract conda-forge and Spack rely on: dependencies already

INSTALL.md

@@ -9,11 +9,11 @@ builds RandBLAS and every dependency it needs into a self-contained
 and does not touch your shell configuration.
 
 ```bash
-bash install/install.sh            # Linux and macOS
+bash installers/install.sh            # Linux and macOS
 ```
 
 ```powershell
-powershell -ExecutionPolicy Bypass -File install\install.ps1    # Windows
+powershell -ExecutionPolicy Bypass -File installers\install.ps1    # Windows
 ```
 
 **You supply the toolchain; the installer supplies everything above it.** You
@@ -472,8 +472,9 @@ Anything not listed may well work; it is simply untested.
 | Ubuntu (latest) | gcc | OpenBLAS | LP64 | yes | release, debug+ASan, release+UBSan |
 | Ubuntu (latest) | gcc | oneMKL | ILP64 | yes | enables the MKL sparse path |
 | Ubuntu (latest) | clang | OpenBLAS | LP64 | yes | release, ASan, TSan |
-| macOS 14 | Apple Clang | Accelerate | LP64 | **no** | Apple Clang ships no OpenMP runtime |
-| macOS 15 | Homebrew LLVM | Accelerate | LP64 | yes | via Homebrew `libomp` |
+| macOS 14 | Apple Clang | Accelerate (new interface) | ILP64 | **no** | Apple Clang ships no OpenMP runtime |
+| macOS 15 | Homebrew LLVM | Accelerate (new interface) | ILP64 | yes | via Homebrew `libomp` |
+| macOS (latest) | Apple Clang | Accelerate (new interface) | LP64 | **no** | installer lane, explicit `--blas-int=lp64` |
 | Windows | MSVC | oneMKL | ILP64 | yes (`/openmp:llvm`) | x64 only |
 
 Compiler floor: RandBLAS uses C++20 [concepts](https://en.cppreference.com/w/cpp/language/constraints),
@@ -498,7 +499,7 @@ provide it, and falls back to LP64 with a warning where it cannot**:
 |---|---|---|
 | oneMKL | ILP64 | `mkl_intel_ilp64` is a distinct library, so the choice is real and verifiable |
 | OpenBLAS | LP64 | see below |
-| Accelerate | LP64 | BLAS++ implements only Apple's legacy interface ([lapackpp#43](https://github.com/icl-utk-edu/lapackpp/issues/43)) |
+| Accelerate | ILP64 | Apple's new interface (macOS ≥ 13.3) ships ILP64 inside the framework; BLAS++ supports it as of [blaspp#134](https://github.com/icl-utk-edu/blaspp/pull/134). On older macOS the `int64` probe fails and `auto` falls back to LP64 with a warning |
 
 **OpenBLAS is the subtle one.** BLAS++ probes `int32` before `int64` and uses
 `blas_int` only to filter library *names*. For MKL that is enough. For
@@ -508,7 +509,7 @@ nothing. If you have an ILP64 OpenBLAS (on Debian or Ubuntu,
 `libopenblas64-dev`), point at it explicitly rather than hoping it is found:
 
 ```bash
-bash install/install.sh --blas=custom --blas-int=ilp64 \
+bash installers/install.sh --blas=custom --blas-int=ilp64 \
   --blas-libraries=/usr/lib/x86_64-linux-gnu/libopenblas64.so
 ```
 

install/install.sh → installers/install.sh

@@ -22,15 +22,15 @@ usage() {
     # the latter silently starts printing unrelated code the moment anyone
     # adds a line above it.
     cat <<'USAGE'
-Usage: bash install/install.sh [options]
+Usage: bash installers/install.sh [options]
 
 Backend selection:
   --blas=BACKEND        auto | openblas | mkl | accelerate | custom
                         (default: auto -- Accelerate on macOS, MKL on Linux
                         when MKLROOT is set, otherwise OpenBLAS)
   --blas-int=WIDTH      ilp64 | lp64. Default is ilp64 wherever the backend
                         can provide it, falling back to lp64 with a warning.
-                        Accelerate is lp64-only and rejects ilp64.
+                        Accelerate ILP64 requires macOS 13.3 or newer.
   --blas-libraries=L    Link line for --blas=custom, e.g.
                         "/opt/aocl/lib/libblis.so;/opt/aocl/lib/libflame.so"
 
@@ -438,13 +438,16 @@ source_is_current() {  # <dest> <url> <ref>
 # branch name. These match the refs RandLAPACK's Windows provisioner validated.
 #==============================================================================
 BLASPP_URL="https://github.com/icl-utk-edu/blaspp.git"
-# The commit that merged the MSVC portability fix (blaspp PR #132, 2026-08-06).
-# Not in a release yet -- the latest tag, v2025.05.28, predates it. Move to a
-# tag once one includes it.
-BLASPP_REF="30571853f980d3a2a1737124ea4789e025a5e045"
+# The commit that merged new-Apple-Accelerate support (blaspp PR #134,
+# 2026-08-27); also contains the MSVC portability fix (PR #132). Not in a
+# release yet -- the latest tag, v2025.05.28, predates both. Move to a tag
+# once one includes them.
+BLASPP_REF="2d8d4e937ac46fffab33d4174a4fc7659726dbda"
 
 LAPACKPP_URL="https://github.com/icl-utk-edu/lapackpp.git"
-LAPACKPP_REF="40b9d0daf29b6f1f3fa58bc3f22bd6cfb2c67fe4"
+# The commit that merged the LAPACK++ half of new-Accelerate support
+# (lapackpp PR #88, 2026-08-27).
+LAPACKPP_REF="b9439cf3c26d1655d88e7f510ae8b4f82fbeb687"
 
 RANDOM123_URL="https://github.com/DEShawResearch/Random123.git"
 RANDOM123_REF="v1.14.0"
@@ -487,26 +490,18 @@ fi
 # int64_t regardless of the underlying width -- so this choice is about what
 # the BLAS underneath can represent, not about RandBLAS's interface.
 #
-# Accelerate is the one backend with no ILP64 route at all. Apple has shipped
-# an ILP64 interface since macOS 13.3, behind ACCELERATE_NEW_LAPACK and
-# ACCELERATE_LAPACK_ILP64, but BLAS++ does not implement it: BLASFinder.cmake
-# emits only "-framework Accelerate", the legacy LP64 path. Tracked upstream as
-# icl-utk-edu/lapackpp#43.
+# Accelerate: Apple has shipped an ILP64 interface since macOS 13.3, behind
+# ACCELERATE_NEW_LAPACK and ACCELERATE_LAPACK_ILP64, and BLAS++ implements it
+# as of the pinned commit (icl-utk-edu/blaspp#134: requesting int64 with the
+# new interface defines ACCELERATE_LAPACK_ILP64 in blas/config.h). On macOS
+# older than 13.3 the int64 probe fails and "auto" falls back to LP64 with the
+# usual warning; an explicit --blas-int=ilp64 fails the build rather than
+# silently downgrading.
 WIDTH_ORDER=()
-case "$BLAS_BACKEND" in
-    accelerate)
-        if [[ "$BLAS_INT_CHOICE" == "ilp64" ]]; then
-            die "--blas-int=ilp64 is not available with Accelerate: BLAS++ implements only Apple's legacy LP64 interface (see icl-utk-edu/lapackpp#43). Use --blas=openblas or --blas=mkl for ILP64."
-        fi
-        WIDTH_ORDER=(int32)
-        ;;
-    *)
-        case "$BLAS_INT_CHOICE" in
-            ilp64) WIDTH_ORDER=(int64) ;;
-            lp64)  WIDTH_ORDER=(int32) ;;
-            auto)  WIDTH_ORDER=(int64 int32) ;;   # ILP64 first, LP64 as fallback
-        esac
-        ;;
+case "$BLAS_INT_CHOICE" in
+    ilp64) WIDTH_ORDER=(int64) ;;
+    lp64)  WIDTH_ORDER=(int32) ;;
+    auto)  WIDTH_ORDER=(int64 int32) ;;   # ILP64 first, LP64 as fallback
 esac
 
 # blaspp's own backend selector. Its matcher accepts "apple" or "accelerate".