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JulianKnodtJulianKnodt
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Update with comments
Changing a bunch of struct constructors to `from`, no extra destructuring, getting the type of the discriminant.
1 parent 33b4d20 commit f7cbf2e

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-35
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+41
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‎compiler/rustc_mir/src/transform/large_enums.rs

Lines changed: 41 additions & 35 deletions
Original file line numberDiff line numberDiff line change
@@ -1,8 +1,8 @@
11
use crate::transform::MirPass;
2-
use crate::util::patch::MirPatch;
32
use rustc_data_structures::stable_map::FxHashMap;
43
use rustc_middle::mir::*;
5-
use rustc_middle::ty::{self, Const, List, Ty, TyCtxt};
4+
use rustc_middle::ty::util::IntTypeExt;
5+
use rustc_middle::ty::{self, Const, Ty, TyCtxt};
66
use rustc_span::def_id::DefId;
77
use rustc_target::abi::{Size, TagEncoding, Variants};
88

@@ -60,7 +60,6 @@ impl<const D: u64> EnumSizeOpt<D> {
6060
fn optim(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
6161
let mut alloc_cache = FxHashMap::default();
6262
let body_did = body.source.def_id();
63-
let mut patch = MirPatch::new(body);
6463
let (bbs, local_decls) = body.basic_blocks_and_local_decls_mut();
6564
for bb in bbs {
6665
bb.expand_statements(|st| {
@@ -70,15 +69,17 @@ impl<const D: u64> EnumSizeOpt<D> {
7069
Rvalue::Use(Operand::Copy(rhs) | Operand::Move(rhs)),
7170
)) => {
7271
let ty = lhs.ty(local_decls, tcx).ty;
72+
7373
let source_info = st.source_info;
7474
let span = source_info.span;
7575

7676
let (total_size, num_variants, sizes) =
77-
if let Some((ts, nv, s)) = Self::candidate(tcx, ty, body_did) {
78-
(ts, nv, s)
77+
if let Some(cand) = Self::candidate(tcx, ty, body_did) {
78+
cand
7979
} else {
8080
return None;
8181
};
82+
let adt_def = ty.ty_adt_def().unwrap();
8283

8384
let alloc = if let Some(alloc) = alloc_cache.get(ty) {
8485
alloc
@@ -111,13 +112,13 @@ impl<const D: u64> EnumSizeOpt<D> {
111112
Const::from_usize(tcx, num_variants),
112113
));
113114

114-
let size_array_local = patch.new_temp(tmp_ty, span);
115+
let size_array_local = local_decls.push(LocalDecl::new(tmp_ty, span));
115116
let store_live = Statement {
116117
source_info,
117118
kind: StatementKind::StorageLive(size_array_local),
118119
};
119120

120-
let place = Place { local: size_array_local, projection: List::empty() };
121+
let place = Place::from(size_array_local);
121122
let constant_vals = Constant {
122123
span,
123124
user_ty: None,
@@ -133,11 +134,10 @@ impl<const D: u64> EnumSizeOpt<D> {
133134
kind: StatementKind::Assign(box (place, rval)),
134135
};
135136

136-
let discr_place = Place {
137-
// How do I get the discriminant type?
138-
local: patch.new_temp(tcx.types.isize, span),
139-
projection: List::empty(),
140-
};
137+
let discr_place = Place::from(
138+
local_decls
139+
.push(LocalDecl::new(adt_def.repr.discr_type().to_ty(tcx), span)),
140+
);
141141

142142
let store_discr = Statement {
143143
source_info,
@@ -147,28 +147,40 @@ impl<const D: u64> EnumSizeOpt<D> {
147147
)),
148148
};
149149

150-
// FIXME(jknodt) do I need to add a storage live here for this place?
151-
let size_place = Place {
152-
local: patch.new_temp(tcx.types.usize, span),
153-
projection: List::empty(),
150+
let discr_cast_place =
151+
Place::from(local_decls.push(LocalDecl::new(tcx.types.usize, span)));
152+
153+
let cast_discr = Statement {
154+
source_info,
155+
kind: StatementKind::Assign(box (
156+
discr_cast_place,
157+
Rvalue::Cast(
158+
CastKind::Misc,
159+
Operand::Copy(discr_place),
160+
tcx.types.usize,
161+
),
162+
)),
154163
};
155164

165+
// FIXME(jknodt) do I need to add a storage live here for this place?
166+
let size_place =
167+
Place::from(local_decls.push(LocalDecl::new(tcx.types.usize, span)));
168+
156169
let store_size = Statement {
157170
source_info,
158171
kind: StatementKind::Assign(box (
159172
size_place,
160173
Rvalue::Use(Operand::Copy(Place {
161174
local: size_array_local,
162-
projection: tcx
163-
.intern_place_elems(&[PlaceElem::Index(discr_place.local)]),
175+
projection: tcx.intern_place_elems(&[PlaceElem::Index(
176+
discr_cast_place.local,
177+
)]),
164178
})),
165179
)),
166180
};
167181

168-
let dst = Place {
169-
local: patch.new_temp(tcx.mk_mut_ptr(ty), span),
170-
projection: List::empty(),
171-
};
182+
let dst =
183+
Place::from(local_decls.push(LocalDecl::new(tcx.mk_mut_ptr(ty), span)));
172184

173185
let dst_ptr = Statement {
174186
source_info,
@@ -179,10 +191,8 @@ impl<const D: u64> EnumSizeOpt<D> {
179191
};
180192

181193
let dst_cast_ty = tcx.mk_mut_ptr(tcx.types.u8);
182-
let dst_cast_place = Place {
183-
local: patch.new_temp(dst_cast_ty, span),
184-
projection: List::empty(),
185-
};
194+
let dst_cast_place =
195+
Place::from(local_decls.push(LocalDecl::new(dst_cast_ty, span)));
186196

187197
let dst_cast = Statement {
188198
source_info,
@@ -192,10 +202,8 @@ impl<const D: u64> EnumSizeOpt<D> {
192202
)),
193203
};
194204

195-
let src = Place {
196-
local: patch.new_temp(tcx.mk_imm_ptr(ty), span),
197-
projection: List::empty(),
198-
};
205+
let src =
206+
Place::from(local_decls.push(LocalDecl::new(tcx.mk_imm_ptr(ty), span)));
199207

200208
let src_ptr = Statement {
201209
source_info,
@@ -206,10 +214,8 @@ impl<const D: u64> EnumSizeOpt<D> {
206214
};
207215

208216
let src_cast_ty = tcx.mk_imm_ptr(tcx.types.u8);
209-
let src_cast_place = Place {
210-
local: patch.new_temp(src_cast_ty, span),
211-
projection: List::empty(),
212-
};
217+
let src_cast_place =
218+
Place::from(local_decls.push(LocalDecl::new(src_cast_ty, span)));
213219

214220
let src_cast = Statement {
215221
source_info,
@@ -245,6 +251,7 @@ impl<const D: u64> EnumSizeOpt<D> {
245251
store_live,
246252
const_assign,
247253
store_discr,
254+
cast_discr,
248255
store_size,
249256
dst_ptr,
250257
dst_cast,
@@ -261,6 +268,5 @@ impl<const D: u64> EnumSizeOpt<D> {
261268
}
262269
});
263270
}
264-
patch.apply(body);
265271
}
266272
}

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