Rollup merge of #138689 - jedbrown:jed/nvptx-target-feature, r=ZuseZ4

add nvptx_target_feature

Tracking issue: #141468 (nvptx), which is part of #44839 (catch-all arches)
The feature gate is `#![feature(nvptx_target_feature)]`

This exposes the target features `sm_20` through `sm_120a` [as defined](https://github.com/llvm/llvm-project/blob/llvmorg-20.1.1/llvm/lib/Target/NVPTX/NVPTX.td#L59-L85) by LLVM.

Cc: ``````@gonzalobg``````
``````@rustbot`````` label +O-NVPTX +A-target-feature
This commit is contained in:
Stuart Cook
2025-08-07 20:49:36 +10:00
committed by GitHub
11 changed files with 222 additions and 10 deletions

View File

@@ -262,6 +262,15 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
// Filter out features that are not supported by the current LLVM version
("aarch64", "fpmr") => None, // only existed in 18
("arm", "fp16") => Some(LLVMFeature::new("fullfp16")),
// NVPTX targets added in LLVM 20
("nvptx64", "sm_100") if get_version().0 < 20 => None,
("nvptx64", "sm_100a") if get_version().0 < 20 => None,
("nvptx64", "sm_101") if get_version().0 < 20 => None,
("nvptx64", "sm_101a") if get_version().0 < 20 => None,
("nvptx64", "sm_120") if get_version().0 < 20 => None,
("nvptx64", "sm_120a") if get_version().0 < 20 => None,
("nvptx64", "ptx86") if get_version().0 < 20 => None,
("nvptx64", "ptx87") if get_version().0 < 20 => None,
// Filter out features that are not supported by the current LLVM version
("loongarch64", "div32" | "lam-bh" | "lamcas" | "ld-seq-sa" | "scq")
if get_version().0 < 20 =>
@@ -324,15 +333,12 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
///
/// We do not have to worry about RUSTC_SPECIFIC_FEATURES here, those are handled outside codegen.
pub(crate) fn target_config(sess: &Session) -> TargetConfig {
// Add base features for the target.
// We do *not* add the -Ctarget-features there, and instead duplicate the logic for that below.
// The reason is that if LLVM considers a feature implied but we do not, we don't want that to
// show up in `cfg`. That way, `cfg` is entirely under our control -- except for the handling of
// the target CPU, that is still expanded to target features (with all their implied features)
// by LLVM.
let target_machine = create_informational_target_machine(sess, true);
let (unstable_target_features, target_features) = cfg_target_feature(sess, |feature| {
// This closure determines whether the target CPU has the feature according to LLVM. We do
// *not* consider the `-Ctarget-feature`s here, as that will be handled later in
// `cfg_target_feature`.
if let Some(feat) = to_llvm_features(sess, feature) {
// All the LLVM features this expands to must be enabled.
for llvm_feature in feat {