## Rationale
TIRx variables use inherited `ExprNode::ty` as their single semantic
type. Retaining a primitive handle surrogate erases the distinction
between scalar values, typed pointers, and true opaque pointers, then
forces later passes and code generators to reconstruct information that
the IR already owns.
## Changes
- Remove the duplicate reflected `Var::type_annotation` state and
preserve exact `PrimType` or `PointerType` through construction,
visitors, transforms, specialization, builders, printers, and code
generation.
- Keep scalar-only boundaries explicit through `PrimExpr`, `PrimVar`,
and `PrimType`; pointer-capable values remain general `Expr` or `Var`.
- Keep helper boundaries no broader than their contracts: TE tensor
variable indices use `PrimVar`, while expression deep equality recurses
through general `Expr` only where pointer-bearing `Call` arguments
require it and does not generalize private arithmetic subclasses.
- Keep core statement reflection typed as `Expr`, name general
reinterpret targets as `target_ty`, and preserve exact pointer calls in
the general vectorization path with explicit scalarization behavior.
- Delete `PrimType::Handle()` and `PrimType::IsHandle()`. True opaque
pointers use `PointerType::VoidPointerTy()`; TVMScript renders the
canonical global type as `T.handle`, standalone values as `T.handle()`,
and scoped void pointers with a keyword-only storage scope.
- Make `CodeGenSourceBase::SSAGetID` a single `Type` boundary across
source backends, without a separate primitive-type or runtime-dtype
variant.
- Keep WebGPU semantic argument classification type-aware: storage
buffers are identified from `PointerType`, POD arguments from
`PrimType`, and only the final `FunctionInfo` launch ABI is serialized
to `DLDataType`.
- Preserve exact pointer semantics at runtime boundaries, including
access pointers, packed calls and returns, external calls, storage
rewrites, and target-specific lowering.
## Migration guide
- **Variable types:** In C++, replace `var->type_annotation` with
`var->ty`; in Python, replace `var.type_annotation` with `var.ty`. The
result is the exact `Type`: scalar variables carry `PrimType`, while
pointer variables carry `PointerType`.
- **Scalar boundaries:** Use `PrimVar` and `PrimExpr` for variables and
expressions that are semantically scalar. When starting from a general
view, narrow explicitly with `var.as_or_throw<PrimVar>()` or
`expr.as_or_throw<PrimExpr>()`. Keep pointer-capable fields and call
arguments as `Var` or `Expr`. A default-constructed `PrimVar` is
nullable, so construct local scalar variables explicitly, for example
`PrimVar i("i")`.
- **Opaque pointers:** Replace `PrimType::Handle()` with
`PointerType::VoidPointerTy()`. Replace `IsHandle()` tests with explicit
`PointerType` inspection; use `PointerType(element_type, storage_scope)`
when the pointee type is known instead of erasing it to a runtime handle
dtype.
- **TVMScript handles:** Use `arg: T.handle` for a global void-pointer
annotation and `arg = T.handle()` for a standalone value. Use
`T.handle(storage_scope="shared")` for a scoped void pointer. Typed
pointers use forms such as `T.handle("float32")`, `T.handle("float32",
"global")`, or `T.handle("float32", "shared")`. Legacy
`T.handle("void")` input remains parse-compatible, but the printer
canonicalizes it to `T.handle` (or the keyword-only scoped form).
- The separate `tirx.type_annotation` intrinsic used by access-pointer
APIs is unchanged; this migration removes only the duplicate variable
field.
## Validation
- Complete native C++ test executable: 122/122 passed, including
`IRF.CountVar`.
- Relax binding-rewrite suite: 12/12 passed, including transferred-user
bookkeeping.
- Canonical typed/void/scoped TVMScript handle printer and round-trip
checks: 5/5 passed.
## 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.
In the past we have been using `DataType` in PrimExpr.dtype field to
check type information for PrimExpr while still having BaseExpr.ty for
richer type information. DataType is also used both in runtime and
compiler. This PR streamlines the boundary:
- PrimExpr.ty now carries PrimType that replaces original use of
`DataType`
- Runtime use will now favor DLPack DLDataType, removing one layer of
indirection.
- Constants attributes where values are usually runtime values, will use
`DLDataType`
- DataType will be phased out after this PR
We also brings up helper functions in PrimType, but also limits them to
a more concise set so the functions do not grow with the data type codes
in DLPack.
This is a major refactor that changes the IR primitive. It helps to
bring possible future benefits:
- Unified type mechanism through Expr.ty
- Possibility of carry future Type nodes
Migration Guide:
- Use `PrimType` when code reasons about compiler expression types,
tensor element compiler types, or constructs a `PrimExpr`/compiler type.
- Use existing source types such as `expr.ty()`, `ExprOp.expr_ty()`, or
TE tensor element `dtype` where possible instead of rebuilding a type
from dtype text.
- Use raw `DLDataType` for runtime constants, ABI paths, dtype-valued
attrs, and storage/runtime helper logic.
- Prefer direct `PrimType` equality, `MatchesCode(...)`,
`MatchesElementType(...)`, and `WithCode(...)` over local wrappers or
string dtype checks.
Performance:
Using Object type instead of DLDataType would indeed bring some
performance impact to the IR. We have done the following performance
optimizations:
- Make sure most of the outputs reuse one of the PrimType from inputs
- Cache a thread local PrimType based on input so we don't repeatly
realloc
We did benchmarks show that rewrite simplify operation stays within
+-10% overhead of original one. Which merits the refactor given the
benefit the unfication brings
## Summary
Follow-up work on top of the TIRx infrastructure bring-up (#19581). It
extends the TIRx operator-dispatch, codegen, and TVMScript surfaces with
the next batch of low-level programming features for Blackwell-class
GPUs, while keeping `s_tir` script support intact.
## Main Changes
- **op-dispatch**: warp `ldmatrix`/`stmatrix` copy dispatch; split CUDA
copy into register / gmem-smem / `ldgsts` paths; `tcgen05.ld/st`
`.16x{64,128,256}b` dispatch with a factory and M=128 layout;
element-wise broadcast at the layout level with a copy vec-alignment
fix.
- **gemm**: CUDA synchronous `mma.sync` tensor-core dispatch; accept a
Layout F C operand for M=64 MMAs.
- **op**: add the `permute_layout` primitive (replaces `permute_dims`).
- **tvmscript**: add the `Tx.jit` decorator, `Tx.constexpr` compile-time
params, and `Tx.wg_reg_tile`.
- **lower-tirx**: introduce the `Tx.device_entry()` marker (replacing
`ScopeKind::kKernel`); canonical thread filters that drop the
`Tx.filter` wrapper.
- **codegen**: add a typed-pointer byte-offset intrinsic; remove the
`entry_cluster_sync` codegen attribute.
## Validation
- `pre-commit run` (changed files) — clean
- `ninja -C build -j$(nproc)` — builds
- `pytest tests/python/tirx/ -n 16`
- `1997 passed, 39 skipped, 3 xpassed`
- `python -m pytest tests/python/all-platform-minimal-test`
- `37 passed, 105 skipped`
- `TVM_TEST_TARGETS=llvm pytest tests/python/tirx-analysis
tests/python/tirx-base tests/python/tirx-transform -n 16`
- `630 passed, 25 skipped, 8 xfailed, 1 xpassed`
## Local CI Notes
Several full CI-equivalent jobs are not locally reproducible because
this machine is missing parts of the Apache TVM CI environment (e.g.,
specific `llvm-config` versions, Vulkan, ROCm, ARM/QEMU cross-toolchain,
and web/wasm components). The Blackwell/Trainium kernel tests are
maintained downstream and are intentionally not part of this PR.
## Summary
This PR adds the initial TIRx support needed for low-level programming
of Blackwell-class GPU architectures. As part of the ongoing TIRx
refactor, it introduces TVMScript support for directly scripting
advanced hardware features without relying on scheduling as the primary
programming interface.
The change keeps existing `s_tir` script support intact while making
direct scripting a first-class path for TIRx programs.
## Main Changes
- Add TIRx operator dispatch and layout infrastructure.
- Add TVMScript support for new low-level TIRx operations.
- Add analysis, transform, and lowering support for TIRx IR nodes.
- Add CUDA/Blackwell-oriented codegen and intrinsic coverage.
- Add Python and C++ integration points for TIRx scripting and runtime
support.
## Validation
- `pre-commit run --all-files`
- `ninja -C build -j32`
- `CUDA_VISIBLE_DEVICES=2 pytest tests/python/tirx/ -n 16`
- `1723 passed, 47 skipped, 32 warnings`
- `CUDA_VISIBLE_DEVICES=2 python -m pytest -v
tests/python/all-platform-minimal-test`
- `37 passed, 105 skipped`
- `TVM_TEST_TARGETS=llvm python -m pytest -v tests/python/tirx-analysis
tests/python/tirx-base tests/python/tirx-transform -n 16`
- `664 passed, 25 skipped, 9 xfailed, 1 xpassed`
## Local CI Notes
Some full CI-equivalent jobs were not locally reproducible because this
machine is missing parts of the Apache TVM CI environment, including
`llvm-config-15/17`, Vulkan, ROCm, Maven, Sphinx, Doxygen, Emscripten,
and ARM/QEMU cross-toolchain components. Metal-specific tests were
skipped locally because no Metal runtime is available.
This PR brings up the tirx namespace. We have been spliting out the
original tir namespace to include high-level component s_tir and this PR
updates the remaining low-level part as tirx namespace
Tianqi Chen