Repository navigation
Conversation
Signed-off-by: Raul Estrada <raulestradaa@gmail.com>
9 tasks done
uurl
marked this pull request as ready for review
October 26, 2026 06:53
nihalpasham
added
the
cuda-oxide
Collaborator
nihalpasham
added a commit
that referenced
this pull request
Oct 29, 2026
…120 libm exports (#1660) ## What This PR Does Implements `#1224` across the 9-commit `libdevice_math` series (`#1638`, `#1645`, `#1646`, `#1649`, `#1650`, `#1651`, `#1652`, `#1653`, `#1660`), replacing hand-maintained math dispatch tables across three crates with a single generated table backed by `libdevice.10.bc` evidence and expanding `libm 0.2.16` coverage from 72 to **120 of 124 `f32`/`f64` exports**: 1. **Add `intrinsics/overlay/libdevice_math.toml` + `libdevice.10.bc` signature verification and generate `dialect-mir` math dispatch (`cuda-intrinsics-gen`, `dialect-mir`, `mir-importer`, `rustc-codegen-cuda`)** 2. **Extract float-math lowering into `mir-lower/src/convert/ops/float_math.rs` driven by generated `RustFloatMathLowering` (`mir-lower`)** 3. **Lower scalar aliases (`tgamma`, `ilogb`, `ldexp`, `erf`, `j0`, `y0`, ...), entry-block out-parameter adapters (`frexp`, `modf`, `remquo`), `lgamma_r`, C23 `fmaximum`/`fminimum`, and `j1` (`mir-lower`, `examples/math_special`)** --- ### 1. Generated `libm -> libdevice` Dispatch (`#1224`) Previously, wiring a single `libm` or `std::sys::cmath` function required hand-editing ~10 sites across `rustc-codegen-cuda/src/collector.rs`, `mir-importer`, `dialect-mir`, and `mir-lower`: ```text BEFORE (hand-maintained across 4 crates): collector.rs ──► hardcoded `std::sys::cmath::*` match list mir-importer ──► hand-written `RustFloatMathIntrinsic` enum + `from_core_path` / `from_libm_path` dialect-mir ──► hand-written `CALLEE_*` constants + `is_libdevice_backed_placeholder` mir-lower ──► hand-written placeholder -> `__nv_*` match table AFTER (`intrinsics/overlay/libdevice_math.toml` -> `cuda-intrinsics-gen`): libdevice_math.toml + cuda-13.0.json (102 signatures verified against libdevice.10.bc) │ ▼ crates/dialect-mir/src/generated/libdevice_math.rs ├──► collector.rs `is_intrinsic_lowered_cmath_shim(fn_path)` ├──► mir-importer `from_core_path` + `from_libm_path` -> `CALLEE_*` ├──► codegen `link_requirement()` -> `MathLink::{Always, Libnvvm, Never}` └──► mir-lower `RustFloatMathIntrinsic::lowering(self) -> RustFloatMathLowering` ``` --- ### 2. Entry-Block Out-Parameter Adapters & IEEE Edge-Case Lowerings (`mir-lower`) ```text Function Family Lowering in `mir-lower/src/convert/ops/float_math.rs` ───────────────────────────── ────────────────────────────────────────────────────────────────────────── `frexp`, `modf`, `remquo` Hoists `llvm.alloca` to function entry block (`0` `.local` traffic after `opt -O2` SROA); normalizes `frexp(+-inf/NaN) -> (x, 0)` and `remquo` NaN -> `quo = 0` `lgamma_r`, `lgammaf_r` Composes `__nv_lgamma`, `__nv_floor`, and `__nv_fmod(floor(x), 2.0)` with `-0.0 -> (+inf, -1)`, negative integer poles `-> (+inf, +1)`, `-inf -> (+inf, +1)` C23 `fmaximum*` / `fminimum*` Pure LLVM `fcmp` (empty fast-math flags) + sign-bit tie-break (`-0.0 < +0.0`) `j1`, `j1f` Calls `__nv_j1{,f}` and normalizes `|x| == inf -> +0.0` ``` --- ## Verification * **RTX 5090 (`sm_120a`) GPU Execution & Sanitizer**: * `cargo oxide run math_special`: **2,822 / 2,822 `f32` and `f64` checks PASS** (`compute-sanitizer --tool memcheck`: `0 errors`, `0` `.local` instructions emitted for `frexp`, `modf`, `remquo`, `lgamma_r`, and C23 `minmax`). * `cargo oxide run libm_math` & `cargo oxide run libdevice_math`: **PASS**. * **Generator & Bitcode Verification**: * `cargo run -p cuda-intrinsics-gen -- check` & `verify-libdevice`: **PASS** (`102` `libdevice.10.bc` signatures verified). * **Tests, Lints & Guards**: * `cargo test -p cuda-intrinsics-gen -p dialect-mir -p mir-importer -p mir-lower -p cuda-oxide-codegen --all-targets`: **3,494 tests PASS** * `just fmt-check`, `just clippy`, `scripts/sync-example-locks.sh --check`, and all 18 `scripts/check-*.sh` guards: **all PASS** Closes #1224 --------- Signed-off-by: Raul Estrada <raulestradaa@gmail.com> Signed-off-by: nihalpasham <nihalp@nvidia.com> Co-authored-by: nihalpasham <nihalp@nvidia.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Introduce a dedicated
libdevice_mathshard and deterministic renderer as infrastructure for the libm coverage work in #1224.The initial shard reproduces the existing 72 f32/f64 libm mappings. Compiler dispatch, handwritten mapping tables, and linking behavior remain unchanged; their migration follows in a separate PR.
Refs #1224 .
Changes
intrinsics/overlay/libdevice_math.toml.generateandcheckcommands.extract-libdeviceandverify-libdevicecommands to validate exported definitions and signatures against real bitcode.This PR targets
mainindependently of #1638 and #1645. The compiler-table migration follows after those PRs and this infrastructure land.Testing
Run from
cuda-oxide/:just check: formatting, Clippy, tests, guards, generated outputs, ABI history, documentation, and doctests passed.cargo test -p cuda-intrinsics-gen --locked --all-targets: 333 tests passed.cargo clippy -p cuda-intrinsics-gen --locked --all-targets -- -D warnings.cargo run -p cuda-intrinsics-gen --locked -- check.verify-libdeviceagainst locally installed CUDA bitcode: all 64 signatures verified.--skip-terminal.A new GPU example is not applicable to this generator-only change.
Checklist
git commit -s).