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#[cfg(feature = "master")]
use gccjit::Context;
use rustc_codegen_ssa::target_features;
use rustc_session::Session;
use smallvec::{SmallVec, smallvec};
fn gcc_features_by_flags(sess: &Session, features: &mut Vec<String>) {
target_features::retpoline_features_by_flags(sess, features);
// FIXME: LLVM also sets +reserve-x18 here under some conditions.
}
/// The list of GCC features computed from CLI flags (`-Ctarget-cpu`, `-Ctarget-feature`,
/// `--target` and similar).
pub(crate) fn global_gcc_features(sess: &Session, diagnostics: bool) -> Vec<String> {
// Features that come earlier are overridden by conflicting features later in the string.
// Typically we'll want more explicit settings to override the implicit ones, so:
//
// * Features from -Ctarget-cpu=*; are overridden by [^1]
// * Features implied by --target; are overridden by
// * Features from -Ctarget-feature; are overridden by
// * function specific features.
//
// [^1]: target-cpu=native is handled here, other target-cpu values are handled implicitly
// through GCC march implementation.
//
// FIXME(nagisa): it isn't clear what's the best interaction between features implied by
// `-Ctarget-cpu` and `--target` are. On one hand, you'd expect CLI arguments to always
// override anything that's implicit, so e.g. when there's no `--target` flag, features implied
// the host target are overridden by `-Ctarget-cpu=*`. On the other hand, what about when both
// `--target` and `-Ctarget-cpu=*` are specified? Both then imply some target features and both
// flags are specified by the user on the CLI. It isn't as clear-cut which order of precedence
// should be taken in cases like these.
let mut features = vec![];
// Features implied by an implicit or explicit `--target`.
features.extend(sess.target.features.split(',').filter(|v| !v.is_empty()).map(String::from));
// -Ctarget-features
target_features::flag_to_backend_features(
sess,
diagnostics,
|feature| to_gcc_features(sess, feature),
|feature, enable| {
// We run through `to_gcc_features` when
// passing requests down to GCC. This means that all in-language
// features also work on the command line instead of having two
// different names when the GCC name and the Rust name differ.
features.extend(
to_gcc_features(sess, feature)
.iter()
.flat_map(|feat| to_gcc_features(sess, feat).into_iter())
.map(
|feature| {
if !enable { format!("-{}", feature) } else { feature.to_string() }
},
),
);
},
);
gcc_features_by_flags(sess, &mut features);
features
}
// To find a list of GCC's names, check https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
pub fn to_gcc_features<'a>(sess: &Session, s: &'a str) -> SmallVec<[&'a str; 2]> {
let arch = if sess.target.arch == "x86_64" { "x86" } else { &*sess.target.arch };
// cSpell:disable
match (arch, s) {
// FIXME: seems like x87 does not exist?
("x86", "x87") => smallvec![],
("x86", "sse4.2") => smallvec!["sse4.2", "crc32"],
("x86", "pclmulqdq") => smallvec!["pclmul"],
("x86", "rdrand") => smallvec!["rdrnd"],
("x86", "bmi1") => smallvec!["bmi"],
("x86", "cmpxchg16b") => smallvec!["cx16"],
("x86", "avx512vaes") => smallvec!["vaes"],
("x86", "avx512gfni") => smallvec!["gfni"],
("x86", "avx512vpclmulqdq") => smallvec!["vpclmulqdq"],
// NOTE: seems like GCC requires 'avx512bw' for 'avx512vbmi2'.
("x86", "avx512vbmi2") => smallvec!["avx512vbmi2", "avx512bw"],
// NOTE: seems like GCC requires 'avx512bw' for 'avx512bitalg'.
("x86", "avx512bitalg") => smallvec!["avx512bitalg", "avx512bw"],
("aarch64", "rcpc2") => smallvec!["rcpc-immo"],
("aarch64", "dpb") => smallvec!["ccpp"],
("aarch64", "dpb2") => smallvec!["ccdp"],
("aarch64", "frintts") => smallvec!["fptoint"],
("aarch64", "fcma") => smallvec!["complxnum"],
("aarch64", "pmuv3") => smallvec!["perfmon"],
("aarch64", "paca") => smallvec!["pauth"],
("aarch64", "pacg") => smallvec!["pauth"],
// Rust ties fp and neon together. In GCC neon implicitly enables fp,
// but we manually enable neon when a feature only implicitly enables fp
("aarch64", "f32mm") => smallvec!["f32mm", "neon"],
("aarch64", "f64mm") => smallvec!["f64mm", "neon"],
("aarch64", "fhm") => smallvec!["fp16fml", "neon"],
("aarch64", "fp16") => smallvec!["fullfp16", "neon"],
("aarch64", "jsconv") => smallvec!["jsconv", "neon"],
("aarch64", "sve") => smallvec!["sve", "neon"],
("aarch64", "sve2") => smallvec!["sve2", "neon"],
("aarch64", "sve2-aes") => smallvec!["sve2-aes", "neon"],
("aarch64", "sve2-sm4") => smallvec!["sve2-sm4", "neon"],
("aarch64", "sve2-sha3") => smallvec!["sve2-sha3", "neon"],
("aarch64", "sve2-bitperm") => smallvec!["sve2-bitperm", "neon"],
(_, s) => smallvec![s],
}
// cSpell:enable
}
fn arch_to_gcc(name: &str) -> &str {
match name {
"M68000" => "68000",
"M68020" => "68020",
_ => name,
}
}
fn handle_native(name: &str) -> &str {
if name != "native" {
return arch_to_gcc(name);
}
#[cfg(feature = "master")]
{
// Get the native arch.
let context = Context::default();
context.get_target_info().arch().unwrap().to_str().unwrap()
}
#[cfg(not(feature = "master"))]
unimplemented!();
}
pub fn target_cpu(sess: &Session) -> &str {
match sess.opts.cg.target_cpu {
Some(ref name) => handle_native(name),
None => handle_native(sess.target.cpu.as_ref()),
}
}
|
