Add tvm.testing.run_with_gpu_lock backed by the existing
tvm_ffi.utils.FileLock. Migrate live local GPU tests to acquire the
machine-local lock around device execution, synchronization, host
transfer, and checks while leaving target construction and compilation
outside the critical section.
Replace the custom xdist scheduler with standard xdist_group placement
for the order-dependent test family. RPC tests retain dynamic port
allocation and per-test process isolation rather than gaining a broad
category lock.
## Summary
- Make `PrimExpr` a typed C++ view over `Expr` values whose
`ExprNode::ty` is `PrimType`, instead of using a separate runtime node
class as the proof of primitive-ness.
- Use the shared `ir::Call` node for Relax, TIRX, and primitive-valued
calls, while keeping primitive-only APIs explicit at their semantic
boundaries.
- Keep Python on the general `Expr` surface for primitive-typed values
so `isinstance` behavior does not imply a nominal primitive-expression
subclass.
## Design Rationale
The main advantage of this change is that common expression nodes such
as `Call` can be unified without specializing each one to `PrimType`. A
single `ir::Call` can represent a Relax tensor call, a Relax scalar
call, or a primitive-valued intrinsic call; the result type stored in
`ExprNode::ty` determines whether that particular value can be viewed as
`PrimExpr`.
This keeps the IR node hierarchy focused on expression structure rather
than result-type categories. Nodes that are intrinsically primitive,
such as integer and floating-point literals or TIRX primitive operators,
still have strongly typed C++ APIs and data structures. General nodes
whose result type may vary, such as `Call`, remain general `Expr` nodes
and are narrowed to `PrimExpr` only where primitive-only semantics are
required.
The PR also keeps the compatibility surface practical: C++
primitive-only APIs continue to accept `PrimExpr`, Python exposes a
compatibility predicate for checking the primitive typed category, and
visitors/printers use one natural `Call` path rather than duplicating
Relax and primitive call handling. Missing expression types are
represented explicitly with `Type::Missing()` so constructors can leave
type inference to later analysis without relying on nullable `Type`
values.
This pr modernizes test gating. It replaces the heavy
`tvm.testing.Feature` machinery with a thin `tvm.testing.env` module of
`has_*()` capability probes, used via standard pytest.mark + skipif. And
markers move to `pyproject.toml`
## Summary
Lifts 10 host-toolchain / CLI / process / utility modules from
`python/tvm/contrib/` to a new `python/tvm/support/` package, and
deletes two dead contrib shims.
`tvm.support` is the home for Python helpers that integrate TVM with
external CLIs and host-side tools — compilers, archivers, subprocess
pools, and build-info queries. These are load-bearing internal pieces
that TVM's compile/link/run paths depend on. `tvm.contrib` is reserved
for optional vendor SDK integrations and experimental features. The
distinction is documented in the `tvm.support` package docstring.
Moved (one commit each):
- `tvm.contrib.cc` → `tvm.support.cc`
- `tvm.contrib.nvcc` → `tvm.support.nvcc`
- `tvm.contrib.rocm` → `tvm.support.rocm`
- `tvm.contrib.ndk` → `tvm.support.ndk`
- `tvm.contrib.xcode` → `tvm.support.xcode`
- `tvm.contrib.clang` → `tvm.support.clang`
- `tvm.contrib.emcc` → `tvm.support.emcc`
- `tvm.contrib.popen_pool` → `tvm.support.popen_pool`
- `tvm.contrib.utils` → `tvm.support.utils`
- `tvm.contrib.tar` → `tvm.support.tar`
Deleted:
- `tvm.contrib.spirv` — single `optimize()` wrapping `spirv-opt`; zero
importers.
- `tvm.contrib.rpc` — self-deprecation shim with "removed in 0.5"
banner; honoring it.
Package conversion:
- `python/tvm/support.py` → `python/tvm/support/__init__.py` with
inclusion-rule docstring.
- `libinfo()` extracted into `python/tvm/support/libinfo.py`.
- `FrontendTestModule` dropped (audit confirmed zero callers outside its
own definition).
## Compatibility
Hard break — no `tvm.contrib.<mod>` re-export shims. All callers updated
in this PR.
C++-side FFI registry keys (`tvm.contrib.nvcc.*`, etc.) are unchanged —
only the Python module path moves. Renaming the FFI keys is a separate
follow-up.
This updates CUDA fast math intrinsic lowering to use a PassContext
option instead of a CUDA Target attribute.
The new option is:
```python
with tvm.transform.PassContext(config={"tirx.enable_fast_math": True}):
...
```
When unset or false, CUDA math intrinsics continue to lower to the
precise CUDA math functions such as expf. When true, tirx.LowerIntrin
prioritizes the cuda.fastmath.* lowering rules, producing fast math
intrinsics such as __expf.
Fix CUDA lowering of standard TIR math intrinsics so they use precise
CUDA math functions by default instead of fast-math `__*f` functions.
This fixes the default behavior reported in #19546, where operators such
as `tirx.exp` could lower to `__expf` even though fast math was not
explicitly requested.
This change adds a CUDA target attribute, `enable_fast_math`, which
defaults to `false`. When the attribute is unset or false, standard math
intrinsics lower through the normal CUDA math rule, for example `expf`,
`logf`, `sinf`, `cosf`, `powf`, and `rsqrtf` for `float32`. When users
explicitly enable the attribute on the target, the lowering pass also
checks the `cuda.fastmath.FLowerIntrinsic` rules before the normal CUDA
lowering rules.
Users can opt in to fast math by constructing a CUDA target with the
attribute:
```py
tvm.target.Target({"kind": "cuda", "enable_fast_math": True})
target = tvm.target.Target({
"tag": "nvidia/nvidia-a100",
"enable_fast_math": True,
})
```
The fast-math lowering path currently covers the CUDA math operators
registered with `cuda.fastmath.FLowerIntrinsic`: `tirx.exp`,
`tirx.exp10`, `tirx.log`, `tirx.log2`, `tirx.log10`, `tirx.tan`,
`tirx.cos`, `tirx.sin`, `tirx.tanh`, and `tirx.pow`.
`tirx.rsqrt` is also registered for CUDA lowering so it maps to the CUDA
reciprocal-square-root intrinsic instead of being legalized as `1 /
sqrt(x)`.
Add CUDA codegen tests
`tests/python/codegen/test_target_codegen_cuda_fastmath.py` that check
the lowered IR, generated CUDA source, and runtime results for the
supported math intrinsics across floating point dtypes and both default
and fast-math targets.
Tianqi Chen