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Auto merge of #128812 - nnethercote:shrink-TyKind-FnPtr, r=compiler-errors

Shrink `TyKind::FnPtr`.

By splitting the `FnSig` within `TyKind::FnPtr` into `FnSigTys` and `FnHeader`, which can be packed more efficiently. This reduces the size of the hot `TyKind` type from 32 bytes to 24 bytes on 64-bit platforms. This reduces peak memory usage by a few percent on some benchmarks. It also reduces cache misses and page faults similarly, though this doesn't translate to clear cycles or wall-time improvements on CI.

r? `@compiler-errors`
This commit is contained in:
bors 2024-08-14 00:56:53 +00:00
commit e9c965df7b
89 changed files with 315 additions and 231 deletions

View file

@ -127,14 +127,17 @@ fn dump_abi_of_fn_type(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribut
for meta_item in meta_items {
match meta_item.name_or_empty() {
sym::debug => {
let ty::FnPtr(sig) = ty.kind() else {
let ty::FnPtr(sig_tys, hdr) = ty.kind() else {
span_bug!(
meta_item.span(),
"`#[rustc_abi(debug)]` on a type alias requires function pointer type"
);
};
let abi = unwrap_fn_abi(
tcx.fn_abi_of_fn_ptr(param_env.and((*sig, /* extra_args */ ty::List::empty()))),
tcx.fn_abi_of_fn_ptr(
param_env
.and((sig_tys.with(*hdr), /* extra_args */ ty::List::empty())),
),
tcx,
item_def_id,
);
@ -155,7 +158,7 @@ fn dump_abi_of_fn_type(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribut
"`#[rustc_abi(assert_eq)]` on a type alias requires pair type"
);
};
let ty::FnPtr(sig1) = field1.kind() else {
let ty::FnPtr(sig_tys1, hdr1) = field1.kind() else {
span_bug!(
meta_item.span(),
"`#[rustc_abi(assert_eq)]` on a type alias requires pair of function pointer types"
@ -163,12 +166,13 @@ fn dump_abi_of_fn_type(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribut
};
let abi1 = unwrap_fn_abi(
tcx.fn_abi_of_fn_ptr(
param_env.and((*sig1, /* extra_args */ ty::List::empty())),
param_env
.and((sig_tys1.with(*hdr1), /* extra_args */ ty::List::empty())),
),
tcx,
item_def_id,
);
let ty::FnPtr(sig2) = field2.kind() else {
let ty::FnPtr(sig_tys2, hdr2) = field2.kind() else {
span_bug!(
meta_item.span(),
"`#[rustc_abi(assert_eq)]` on a type alias requires pair of function pointer types"
@ -176,7 +180,8 @@ fn dump_abi_of_fn_type(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribut
};
let abi2 = unwrap_fn_abi(
tcx.fn_abi_of_fn_ptr(
param_env.and((*sig2, /* extra_args */ ty::List::empty())),
param_env
.and((sig_tys2.with(*hdr2), /* extra_args */ ty::List::empty())),
),
tcx,
item_def_id,