diff --git a/src/librustc_mir/transform/instcombine.rs b/src/librustc_mir/transform/instcombine.rs
index a016892d982d1..7967137e01e54 100644
--- a/src/librustc_mir/transform/instcombine.rs
+++ b/src/librustc_mir/transform/instcombine.rs
@@ -1,11 +1,12 @@
//! Performs various peephole optimizations.
use crate::transform::{MirPass, MirSource};
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_hir::Mutability;
use rustc_index::vec::Idx;
use rustc_middle::mir::visit::{MutVisitor, Visitor};
use rustc_middle::mir::{
- Body, Constant, Local, Location, Mutability, Operand, Place, PlaceRef, ProjectionElem, Rvalue,
+ Body, Constant, Local, Location, Operand, Place, PlaceRef, ProjectionElem, Rvalue,
};
use rustc_middle::ty::{self, TyCtxt};
use std::mem;
@@ -39,7 +40,7 @@ impl<'tcx> MutVisitor<'tcx> for InstCombineVisitor<'tcx> {
}
fn visit_rvalue(&mut self, rvalue: &mut Rvalue<'tcx>, location: Location) {
- if let Some(mtbl) = self.optimizations.and_stars.remove(&location) {
+ if self.optimizations.and_stars.remove(&location) {
debug!("replacing `&*`: {:?}", rvalue);
let new_place = match rvalue {
Rvalue::Ref(_, _, place) => {
@@ -57,10 +58,7 @@ impl<'tcx> MutVisitor<'tcx> for InstCombineVisitor<'tcx> {
}
_ => bug!("Detected `&*` but didn't find `&*`!"),
};
- *rvalue = Rvalue::Use(match mtbl {
- Mutability::Mut => Operand::Move(new_place),
- Mutability::Not => Operand::Copy(new_place),
- });
+ *rvalue = Rvalue::Use(Operand::Copy(new_place))
}
if let Some(constant) = self.optimizations.arrays_lengths.remove(&location) {
@@ -93,8 +91,8 @@ impl Visitor<'tcx> for OptimizationFinder<'b, 'tcx> {
{
// The dereferenced place must have type `&_`.
let ty = Place::ty_from(local, proj_base, self.body, self.tcx).ty;
- if let ty::Ref(_, _, mtbl) = ty.kind {
- self.optimizations.and_stars.insert(location, mtbl);
+ if let ty::Ref(_, _, Mutability::Not) = ty.kind {
+ self.optimizations.and_stars.insert(location);
}
}
}
@@ -114,6 +112,6 @@ impl Visitor<'tcx> for OptimizationFinder<'b, 'tcx> {
#[derive(Default)]
struct OptimizationList<'tcx> {
- and_stars: FxHashMap<Location, Mutability>,
+ and_stars: FxHashSet<Location>,
arrays_lengths: FxHashMap<Location, Constant<'tcx>>,
}
diff --git a/src/test/mir-opt/inline/issue-58867-inline-as-ref-as-mut/rustc.a.Inline.after.mir b/src/test/mir-opt/inline/issue-58867-inline-as-ref-as-mut/rustc.a.Inline.after.mir
index 8751469d265a2..44f412c2e2674 100644
--- a/src/test/mir-opt/inline/issue-58867-inline-as-ref-as-mut/rustc.a.Inline.after.mir
+++ b/src/test/mir-opt/inline/issue-58867-inline-as-ref-as-mut/rustc.a.Inline.after.mir
@@ -8,6 +8,7 @@ fn a(_1: &mut [T]) -> &mut [T] {
let mut _4: &mut [T]; // in scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:6
scope 1 {
debug self => _4; // in scope 1 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
+ let mut _5: &mut [T]; // in scope 1 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:15
}
bb0: {
@@ -15,7 +16,10 @@ fn a(_1: &mut [T]) -> &mut [T] {
StorageLive(_3); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:15
StorageLive(_4); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:6
_4 = &mut (*_1); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:6
- _3 = move _4; // scope 1 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
+ StorageLive(_5); // scope 1 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
+ _5 = &mut (*_4); // scope 1 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
+ _3 = &mut (*_5); // scope 1 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
+ StorageDead(_5); // scope 1 at $SRC_DIR/libcore/convert/mod.rs:LL:COL
_2 = &mut (*_3); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:15
StorageDead(_4); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:14: 3:15
_0 = &mut (*_2); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:3:5: 3:15
diff --git a/src/test/mir-opt/inline/issue-58867-inline-as-ref-as-mut/rustc.b.Inline.after.mir b/src/test/mir-opt/inline/issue-58867-inline-as-ref-as-mut/rustc.b.Inline.after.mir
index 743da27a049f9..48e48f989bd94 100644
--- a/src/test/mir-opt/inline/issue-58867-inline-as-ref-as-mut/rustc.b.Inline.after.mir
+++ b/src/test/mir-opt/inline/issue-58867-inline-as-ref-as-mut/rustc.b.Inline.after.mir
@@ -9,6 +9,7 @@ fn b(_1: &mut std::boxed::Box<T>) -> &mut T {
scope 1 {
debug self => _4; // in scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
let mut _5: &mut T; // in scope 1 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
+ let mut _6: &mut T; // in scope 1 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
}
bb0: {
@@ -17,8 +18,11 @@ fn b(_1: &mut std::boxed::Box<T>) -> &mut T {
StorageLive(_4); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:6
_4 = &mut (*_1); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:6
StorageLive(_5); // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
- _5 = &mut (*(*_4)); // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
- _3 = move _5; // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
+ StorageLive(_6); // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
+ _6 = &mut (*(*_4)); // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
+ _5 = &mut (*_6); // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
+ _3 = &mut (*_5); // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
+ StorageDead(_6); // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
StorageDead(_5); // scope 1 at $SRC_DIR/liballoc/boxed.rs:LL:COL
_2 = &mut (*_3); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:5: 8:15
StorageDead(_4); // scope 0 at $DIR/issue-58867-inline-as-ref-as-mut.rs:8:14: 8:15
diff --git a/src/test/mir-opt/nrvo-simple/rustc.nrvo.RenameReturnPlace.diff b/src/test/mir-opt/nrvo-simple/rustc.nrvo.RenameReturnPlace.diff
index 79d92897cb572..4511470f3a50f 100644
--- a/src/test/mir-opt/nrvo-simple/rustc.nrvo.RenameReturnPlace.diff
+++ b/src/test/mir-opt/nrvo-simple/rustc.nrvo.RenameReturnPlace.diff
@@ -26,12 +26,17 @@
// + span: $DIR/nrvo-simple.rs:3:20: 3:21
// + literal: Const { ty: u8, val: Value(Scalar(0x00)) }
StorageLive(_3); // scope 1 at $DIR/nrvo-simple.rs:4:5: 4:19
+ StorageLive(_5); // scope 1 at $DIR/nrvo-simple.rs:4:10: 4:18
+ StorageLive(_6); // scope 1 at $DIR/nrvo-simple.rs:4:10: 4:18
- _6 = &mut _2; // scope 1 at $DIR/nrvo-simple.rs:4:10: 4:18
+ _6 = &mut _0; // scope 1 at $DIR/nrvo-simple.rs:4:10: 4:18
- _3 = move _1(move _6) -> bb1; // scope 1 at $DIR/nrvo-simple.rs:4:5: 4:19
+ _5 = &mut (*_6); // scope 1 at $DIR/nrvo-simple.rs:4:10: 4:18
+ _3 = move _1(move _5) -> bb1; // scope 1 at $DIR/nrvo-simple.rs:4:5: 4:19
}
bb1: {
+ StorageDead(_5); // scope 1 at $DIR/nrvo-simple.rs:4:18: 4:19
+ StorageDead(_6); // scope 1 at $DIR/nrvo-simple.rs:4:19: 4:20
StorageDead(_3); // scope 1 at $DIR/nrvo-simple.rs:4:19: 4:20
- _0 = _2; // scope 1 at $DIR/nrvo-simple.rs:5:5: 5:8
- StorageDead(_2); // scope 0 at $DIR/nrvo-simple.rs:6:1: 6:2