bjoernager/rust
bjoernager/rust
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Shrink TyKind::FnPtr.

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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.
This commit is contained in:
Nicholas Nethercote 2024-08-08 17:18:20 +10:00
parent 8640998869
commit c4717cc9d1
89 changed files with 298 additions and 201 deletions
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17
compiler/rustc_passes/src/abi_test.rs
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,