[Fix] Remove unused let_bindings_ in CodeGenC to fix #1300

[kurisu6912]

This pr remove unused let_bindings_ in tvm CodeGen to fix #1300

[github-actions]

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[coderabbitai]

Walkthrough

These changes introduce a new Ref type for macro argument annotations as a replacement for Var (with deprecation warning), expand the dtype system with eight new 2-width integer vector types, add corresponding test coverage, and update the TVM submodule.

Changes

Cohort / File(s)	Summary
Type System Enhancements tilelang/language/proxy.py, tilelang/language/__init__.py	Introduce generic Ref type with TYPE_CHECKING support for type-safe macro argument annotations; expose Ref in public API alongside existing symbols.
Macro Argument Handling tilelang/language/v2/builder.py	Extend macro_arg to accept Ref annotations alongside existing Var, add deprecation warning recommending T.Ref, update shadow variable warning message to suggest T.alloc_var.
Data Type Extensions tilelang/language/v2/dtypes.py	Add int_ type alias, introduce eight new 2-width vector integer types (int8x2, int16x2, int32x2, int64x2, uint8x2, uint16x2, uint32x2, uint64x2), register types in public API.
Test Coverage testing/python/language/test_tilelang_intimm.py, testing/python/language/test_tilelang_language_frontend_v2.py	Add new test file validating boundary values and bitwise operations on integer types; add test blocks verifying T.Ref macro parameter handling with success and error paths.
Dependency Update 3rdparty/tvm	Update TVM submodule pointer from 713e6ade56eaa72cc85d58d9228dd9f34cc2d03e to bc31e7ad9f9fafd7659dfabafe359fd55a0ffc1e.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

• tilelang/language/v2/builder.py: Verify that the deprecation warning for Var is appropriately logged and that runtime checks remain consistent for both Var and Ref cases.
• tilelang/language/v2/dtypes.py: Confirm that all eight new vector types are correctly registered in runtime and TYPE_CHECKING branches, and that the int_ handling in __dtype_call__ correctly constructs TVM constants.
• tilelang/language/proxy.py: Ensure generic Ref type definition and non-generic runtime fallback work correctly across both type-checking and runtime paths.
• Test files: Verify that test logic properly exercises macro argument handling with T.Ref and that boundary value tests for integer types are comprehensive.

Possibly related PRs

• [Feat] Add missing support to pass reference by T.Var annotation #1291: Modifies macro argument handling in builder.py and related tests to change how Var/Ref annotated parameters are processed—related to reference semantics restoration.

Suggested reviewers

• tzj-fxz
• LeiWang1999

Poem

🐰 A rabbit hops through types so bright,
With Ref reborn and Var in flight,
Vector types in twos now gleam,
Eight new friends join tilelang's dream! ✨

Pre-merge checks and finishing touches

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Title check	⚠️ Warning	The PR title claims to remove unused let_bindings_ in CodeGenC, but the raw_summary shows changes to TVM submodule, test files, dtype enhancements, Ref type support, and macro handling—none of which relate to CodeGenC or let_bindings_ removal.	Update the PR title to accurately reflect the actual changes: focus on the primary changes such as Ref type introduction, dtype vector support, or test additions, rather than the CodeGenC fix claim.
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (1 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (2)

tilelang/language/v2/builder.py (1)

477-492: LGTM! Ref support added with appropriate deprecation warning.

The macro_arg function now accepts both Var and Ref annotations, with a deprecation warning for Var guiding users to the new T.Ref pattern. The validation logic correctly ensures the argument is a local.var-allocated buffer.

Consider moving the Ref import to the module level (line 1-23) rather than importing locally within the function:

 from tvm.tir.expr import EqualOp, FloatImm, IntImm, NotEqualOp, PrimExpr, StringImm, Var
+from tilelang.language.proxy import Ref

Then remove line 478. This is a minor style preference—local imports are acceptable, but module-level imports improve discoverability.

testing/python/language/test_tilelang_language_frontend_v2.py (1)

397-428: LGTM! Comprehensive T.Ref test coverage.

The new test blocks validate T.Ref macro annotations with both successful (alloc_var) and error (plain int) cases, providing parity with the existing T.Var tests. The tests confirm proper script generation and error handling.

The exception message at line 425 could be extracted to a constant to address the static analysis hint (TRY003), though this is consistent with the pattern used at line 393:

ERROR_MSG = "Expect to report an error, x should not be passed as T.Var"

However, this is a minor style preference and not a blocker.

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between d4b6d09 and 07e650c.

📒 Files selected for processing (7)

• 3rdparty/tvm (1 hunks)
• testing/python/language/test_tilelang_intimm.py (1 hunks)
• testing/python/language/test_tilelang_language_frontend_v2.py (1 hunks)
• tilelang/language/__init__.py (1 hunks)
• tilelang/language/proxy.py (2 hunks)
• tilelang/language/v2/builder.py (2 hunks)
• tilelang/language/v2/dtypes.py (7 hunks)

🧰 Additional context used

🧬 Code graph analysis (4)

testing/python/language/test_tilelang_language_frontend_v2.py (2)

tilelang/language/v2/builder.py (4)

• macro (159-169)
• macro (553-590)
• prim_func (152-156)
• prim_func (659-752)

tilelang/language/proxy.py (2)

• Ref (269-270)
• Ref (278-279)

tilelang/language/__init__.py (1)

tilelang/language/proxy.py (2)

• Ref (269-270)
• Ref (278-279)

tilelang/language/v2/builder.py (1)

tilelang/language/proxy.py (2)

• Ref (269-270)
• Ref (278-279)

testing/python/language/test_tilelang_intimm.py (1)

tilelang/language/v2/dtypes.py (4)

• int32 (156-156)
• uint32 (184-184)
• int64 (157-157)
• uint64 (185-185)

🪛 Ruff (0.14.5)

testing/python/language/test_tilelang_language_frontend_v2.py

425-425: Avoid specifying long messages outside the exception class

(TRY003)

tilelang/language/__init__.py

25-25: Unused noqa directive (non-enabled: F401)

Remove unused noqa directive

(RUF100)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: Quick Lint

🔇 Additional comments (10)

3rdparty/tvm (1)

1-1: Verify submodule commit aligns with PR objectives and contains intended changes.

The submodule pointer has been updated from 713e6ade56eaa72cc85d58d9228dd9f34cc2d03e to bc31e7ad9f9fafd7659dfabafe359fd55a0ffc1e. However, there's a discrepancy between the PR title ("Remove unused let_bindings_ in CodeGenC to fix #1300") and the AI summary (which describes new Ref type, dtype system changes, and test coverage).

Without access to the external TVM repository commit details, I cannot verify:

• What changes this commit introduces
• Whether it addresses the stated goal of fixing #1300
• How it relates to the other changes mentioned in the AI summary

Please confirm that this specific commit contains the intended changes and aligns with the PR's goal. You can verify this by:

1. Checking the TVM commit details at bc31e7ad9f9fafd7659dfabafe359fd55a0ffc1e
2. Confirming it addresses the let_bindings_ removal mentioned in #1300
3. Clarifying whether the AI summary describes changes in the main repository (outside the TVM submodule) or if there's a mismatch in the summaries

tilelang/language/__init__.py (1)

25-25: LGTM! Ref export added correctly.

The new Ref symbol is imported from .proxy and re-exported to support macro argument annotations. The static analysis hint about unused noqa is a false positive—the F401 suppression is valid for re-exported symbols in __init__.py.

testing/python/language/test_tilelang_intimm.py (1)

6-25: LGTM! Comprehensive integer immediate tests.

The test exercises boundary values for signed and unsigned 32/64-bit integers and confirms bitwise operations work correctly. The test validates int32, uint32, int64, and uint64 constructors with edge cases and operator support.

tilelang/language/proxy.py (2)

4-4: LGTM! Import additions for generic Ref type.

Generic and TypeVar are added to support the new parameterized Ref type used in macro annotations.

---

267-279: LGTM! Ref type follows established pattern.

The Ref type is defined as Generic[_T] with tir.Var for type checking, and as a placeholder at runtime, mirroring the existing pattern used for Tensor classes (lines 216-265). This dual definition enables proper static type checking while maintaining runtime compatibility.

tilelang/language/v2/builder.py (1)

338-338: LGTM! Clearer warning message.

The updated warning now explicitly suggests T.alloc_var, making it more actionable for developers encountering variable shadowing.

tilelang/language/v2/dtypes.py (4)

90-95: LGTM! int_ alias is necessary to avoid shadowing.

The int_ alias captures Python's built-in int type before it's shadowed by dtype('int32') at line 314. This allows isinstance(expr, int_) checks in __dtype_call__ to work correctly after the module-level int reassignment. The implementation correctly returns a constant via tvm.tir.const for integer literals.

---

158-161: LGTM! TYPE_CHECKING stubs for new vector dtypes.

The new 2-width integer vector type stubs (int8x2, int16x2, int32x2, int64x2, uint8x2, uint16x2, uint32x2, uint64x2) follow the established pattern for existing vector types (x4, x8, x16, etc.) and enable proper static type checking.

Also applies to: 186-189

---

323-326: LGTM! Runtime dtype definitions for new vector types.

The runtime definitions for the 2-width integer vector dtypes are consistent with the TYPE_CHECKING stubs and follow the established pattern used for other vector widths.

Also applies to: 351-354

---

487-490: LGTM! Public API exposure updated.

The _all_dtypes set and public API exposure are correctly updated to include the new 2-width integer vector dtype names, making them accessible throughout the codebase.

Also applies to: 515-518