* Add Linux ppc64le (PowerPC64) architecture support using generic targets
Add ppc64le as a new architecture in ISPC, enabling compilation for
POWER8+ (POWER ISA 3.0) processors using the existing generic target
system (generic-i1x4 through generic-i64x4).
Key changes:
- Add Arch::ppc64le enum and parsing/serialization support
- Add CPU_PPC64LE_Generic device type with pwr8 baseline and +vsx features
- Initialize LLVM PowerPC backend when ISPC_PPC64_ENABLED is defined
- Generate ppc64le-linux-gnu triple for the target
- Auto-detect ppc64le host architecture and default to generic-i32x4
- Add PPC64_ENABLED CMake option (OFF by default) with powerpc LLVM component
- Add ppc64le support to builtin generation (GenerateBuiltins.cmake,
GenericTargets.cmake, bitcode2cpp.py)
- Add PowerPC to LLVM_TARGETS_TO_BUILD in alloy.py and superbuild
- Add lit test infrastructure: PPC64_ENABLED feature flag, PPC64LE_HOST
detection, and generic-target-ppc64le.ispc test
- Mark 5 tests UNSUPPORTED on PPC64LE_HOST due to known issues:
gather/scatter assertion, LLVM selection failures, missing rcp stdlib,
and ABI signext mismatch
Tested on Fedora 43 ppc64le (POWER8+) with LLVM 20: 425 tests passed,
267 unsupported, 3 expectedly failed, 0 failures.
* Add ppc64le to supported architectures in documentation
Update ispc.rst to list ppc64le in supported architectures and add
experimental PowerPC64 support entry to v1.31.0 release notes.
* Add ppc64le support to examples timing utility
Add __powerpc64__ to the architecture guard in timing.h so it uses
gettimeofday-based timing instead of x86 inline assembly (rdtsc/cpuid)
on PowerPC64 hosts.
* Add ppc64le support to example CMake build system
Add ppc64le architecture detection and generic target selection to the
example build system. On ppc64le, examples default to generic-i32x4
target. Also guard x86-specific -m32/-m64 compiler flags to only apply
on x86 architectures.
All 15 CPU examples build and pass on ppc64le.
* Fix generic-target build and ppc64le arch inference for cross-compilation
Fix missing build dependencies for the generic-target CMake OBJECT library:
- Add GENERATED property to generated CPP source files
- Add add_dependencies on generic-target-cpp and generic-stdlib-cpp targets
- Move configure_ispc_obj(generic-target) into add_ispc_slim() so include
directories are set in both slim and composite binary paths
Fix lGetArchFromTarget to correctly infer ppc64le architecture when
cross-compiling with --cpu=ppc64le on non-PPC hosts. Previously the arch
inference was entirely host-guarded, causing it to fall through to x86_64.
* Address PR review: fix ppc64le triple, add test runner support and asm test
- Fix ppc64le LLVM triple to use canonical 'powerpc64le' prefix instead
of 'ppc64le' in cmake/GenerateBuiltins.cmake
- Add ppc64le support to scripts/run_tests.py: target config, gcc_arch
flags, and default target/arch detection for ppc64le hosts
- Add ppc64le-vector-asm.ispc lit test verifying PowerPC VSX vector
instructions (xvaddsp, xvmulsp) are generated for generic targets
* Revert autoformatted changes
* Document reasons for ppc64le UNSUPPORTED test skips
Add explanatory comments to all lit tests marked UNSUPPORTED on ppc64le:
- stdlib-short-vec-funcs-3: LLVM 20 can't select froundeven for vectors
- stdlib-short-vec-funcs-6: LLVM 20 can't promote atan2/pow/fmod results
Both are fixed in LLVM 21 (PR llvm/llvm-project#150597)
- fast_math_opt: generic target rcp uses fdiv, failing CHECK_NOFDIV
- num-limits: ABI mismatch for int8/int16 returns between ISPC and clang
- 2169: ISPC assertion in integer divide optimization for generic targets
* Make ppc64le LLVM bug test skips version-conditional
Use 'UNSUPPORTED: PPC64LE_HOST && !LLVM_21_0+' instead of unconditional
'UNSUPPORTED: PPC64LE_HOST' for tests that fail due to LLVM 20 PowerPC
backend bugs fixed in LLVM 21. This automatically re-enables the tests
when ISPC is built with LLVM 21+.
* s/UNSUPPORTED/XFAIL
* Add -mcpu
* Update docs
* Add PPC64 CI workflow with Ubuntu + QEMU for lit tests
* Fix check_isa to guard PPC64LE detection with endianness check
* Re-align with default target
* Revert all changes made to docs/ispc.rst
* Add functional tests to PPC64 CI workflow via QEMU
* Disable ispcrt build in PPC64 CI to avoid TBB dependency
* Install libtbb-dev instead of disabling ispcrt in PPC64 CI
* Disable X86 and ARM targets in PPC64 CI to avoid missing 32-bit headers
* Install gcc-multilib and re-enable all targets in PPC64 CI
* Install python3-dev for examples build in PPC64 CI
* Switch PPC64 CI to Ubuntu 25.10 with native LLVM 20 packages
* Fix LLVM tools package name to llvm-20-tools for Ubuntu 25.10
* Replace gcc-multilib with cross-compilation headers in PPC64 CI
Use libc6-dev-i386-cross and libc6-dev-armhf-cross instead of gcc-multilib
to provide 32-bit headers for builtin compilation. This avoids the package
conflict between gcc-multilib and gcc-powerpc64le-linux-gnu on Ubuntu 25.10.
* Add libstdc++-15-dev for host C++ linking in PPC64 CI
clang++ needs libstdc++-dev to link C++ programs on the host. Previously
gcc-multilib pulled this in as a dependency; now that we use cross packages
instead, we need to install it explicitly.
* Create FileCheck symlink for unversioned lookup in PPC64 CI
Ubuntu 25.10 installs FileCheck as FileCheck-20 (versioned), but ISPC's
CMake FindLLVM.cmake looks for the unversioned name. Create a symlink
to resolve this.
Tested locally: full build + lit tests pass in Ubuntu 25.10 Docker.
* Revert configure_ispc_obj(generic-target) move, no longer needed after #3739
* Fix PPC64 CI: build only PPC64 target, remove unnecessary cross-compilation packages
Disable ARM and x86 targets in the PPC64 CI workflow since they are
not needed and cause build failures due to missing cross-compilation
headers in the container. Also remove libc6-dev-i386-cross and
libc6-dev-armhf-cross packages that were only needed for those targets.
* Fix PPC64 CI: keep X86 enabled for host lit tests, remove build artifacts
Remove -DX86_ENABLED=OFF from the PPC64 CI cmake command since lit tests
use --target=host which detects x86 on the CI runner.
Remove set_source_files_properties and add_dependencies lines from
GenericTargets.cmake that were artifacts of the configure_ispc_obj move
reverted in c1a2b488.
* fix: Fix PPC64LE pipeline
* Add pipeline running on native runner
* Add sudo to apt-get install commands in workflow
* Consolidate pipelines
* Skip miscompiled float16 tests on ppc64le and fix native runner
- Add '// rule: skip on arch=ppc64le' to 54 float16/f16 functional tests
that fail compilation on ppc64le
- Drop g++-multilib from native runner (unavailable on ppc64le)
- Add -DX86_ENABLED=OFF to native runner cmake to avoid x86 dependencies
* Refactor ppc64le arch inference out of lGetArchFromTarget
Revert lGetArchFromTarget to its original single-parameter signature and
move the cross-compilation arch fix-up for ppc64le to the call site.
This keeps the function focused on target-to-arch mapping and handles
the CPU-based override separately.
* Rename ppc64le CPU identifier to pwr8
Use 'pwr8' instead of 'ppc64le' as the CPU name for the generic PPC64LE
target, aligning the --cpu flag value with the actual LLVM CPU name that
was already being set internally.
* Skip float16 func tests on ppc64le due to missing fp16 support
* Install LLVM 19 packages for native ppc64le CI runner
* fix: clean up
* fix: install libclang-19-dev
* fix: s/generic/pwr8
* func-tests: skip round() varying float tests on ppc64le
LLVM PowerPC backend (POWER8) cannot lower @llvm.roundeven for vector
types (v4f32), which the generic builtin path uses for round(). Skip
these tests on ppc64le until a target-specific implementation is added.
* doc: clean up
* doc: move PowerPC support to new ISPC 1.31.0 section
Trung Lê
b72df90271