From 4b96e44ebbf42dc8b6f3e5ac4894739adc17d826 Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Thu, 30 May 2024 22:05:30 -0700 Subject: [PATCH] Also InstSimplify `&raw*` We do this for `&*` and `&mut*` already; might as well do it for raw pointers too. --- .../rustc_mir_transform/src/instsimplify.rs | 2 +- .../ref_of_deref.pointers.InstSimplify.diff | 58 +++++++++++++++++++ .../ref_of_deref.references.InstSimplify.diff | 58 +++++++++++++++++++ tests/mir-opt/instsimplify/ref_of_deref.rs | 40 +++++++++++++ 4 files changed, 157 insertions(+), 1 deletion(-) create mode 100644 tests/mir-opt/instsimplify/ref_of_deref.pointers.InstSimplify.diff create mode 100644 tests/mir-opt/instsimplify/ref_of_deref.references.InstSimplify.diff create mode 100644 tests/mir-opt/instsimplify/ref_of_deref.rs diff --git a/compiler/rustc_mir_transform/src/instsimplify.rs b/compiler/rustc_mir_transform/src/instsimplify.rs index a54332b6f2571..40db3e38fd32b 100644 --- a/compiler/rustc_mir_transform/src/instsimplify.rs +++ b/compiler/rustc_mir_transform/src/instsimplify.rs @@ -123,7 +123,7 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> { /// Transform `&(*a)` ==> `a`. fn simplify_ref_deref(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) { - if let Rvalue::Ref(_, _, place) = rvalue { + if let Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) = rvalue { if let Some((base, ProjectionElem::Deref)) = place.as_ref().last_projection() { if rvalue.ty(self.local_decls, self.tcx) != base.ty(self.local_decls, self.tcx).ty { return; diff --git a/tests/mir-opt/instsimplify/ref_of_deref.pointers.InstSimplify.diff b/tests/mir-opt/instsimplify/ref_of_deref.pointers.InstSimplify.diff new file mode 100644 index 0000000000000..52b3d1e1d40b3 --- /dev/null +++ b/tests/mir-opt/instsimplify/ref_of_deref.pointers.InstSimplify.diff @@ -0,0 +1,58 @@ +- // MIR for `pointers` before InstSimplify ++ // MIR for `pointers` after InstSimplify + + fn pointers(_1: *const [i32], _2: *mut i32) -> () { + debug const_ptr => _1; + debug mut_ptr => _2; + let mut _0: (); + let _3: &[i32]; + scope 1 { + debug _a => _3; + let _4: &i32; + scope 2 { + debug _b => _4; + let _5: &mut i32; + scope 3 { + debug _c => _5; + let _6: *const [i32]; + scope 4 { + debug _d => _6; + let _7: *const i32; + scope 5 { + debug _e => _7; + let _8: *mut i32; + scope 6 { + debug _f => _8; + } + } + } + } + } + } + + bb0: { + StorageLive(_3); + _3 = &(*_1); + StorageLive(_4); + _4 = &(*_2); + StorageLive(_5); + _5 = &mut (*_2); + StorageLive(_6); +- _6 = &raw const (*_1); ++ _6 = _1; + StorageLive(_7); + _7 = &raw const (*_2); + StorageLive(_8); +- _8 = &raw mut (*_2); ++ _8 = _2; + _0 = const (); + StorageDead(_8); + StorageDead(_7); + StorageDead(_6); + StorageDead(_5); + StorageDead(_4); + StorageDead(_3); + return; + } + } + diff --git a/tests/mir-opt/instsimplify/ref_of_deref.references.InstSimplify.diff b/tests/mir-opt/instsimplify/ref_of_deref.references.InstSimplify.diff new file mode 100644 index 0000000000000..ca0828a225a01 --- /dev/null +++ b/tests/mir-opt/instsimplify/ref_of_deref.references.InstSimplify.diff @@ -0,0 +1,58 @@ +- // MIR for `references` before InstSimplify ++ // MIR for `references` after InstSimplify + + fn references(_1: &i32, _2: &mut [i32]) -> () { + debug const_ref => _1; + debug mut_ref => _2; + let mut _0: (); + let _3: &i32; + scope 1 { + debug _a => _3; + let _4: &[i32]; + scope 2 { + debug _b => _4; + let _5: &mut [i32]; + scope 3 { + debug _c => _5; + let _6: *const i32; + scope 4 { + debug _d => _6; + let _7: *const [i32]; + scope 5 { + debug _e => _7; + let _8: *mut [i32]; + scope 6 { + debug _f => _8; + } + } + } + } + } + } + + bb0: { + StorageLive(_3); +- _3 = &(*_1); ++ _3 = _1; + StorageLive(_4); + _4 = &(*_2); + StorageLive(_5); +- _5 = &mut (*_2); ++ _5 = _2; + StorageLive(_6); + _6 = &raw const (*_1); + StorageLive(_7); + _7 = &raw const (*_2); + StorageLive(_8); + _8 = &raw mut (*_2); + _0 = const (); + StorageDead(_8); + StorageDead(_7); + StorageDead(_6); + StorageDead(_5); + StorageDead(_4); + StorageDead(_3); + return; + } + } + diff --git a/tests/mir-opt/instsimplify/ref_of_deref.rs b/tests/mir-opt/instsimplify/ref_of_deref.rs new file mode 100644 index 0000000000000..37e164bc17f18 --- /dev/null +++ b/tests/mir-opt/instsimplify/ref_of_deref.rs @@ -0,0 +1,40 @@ +//@ test-mir-pass: InstSimplify +#![crate_type = "lib"] +#![feature(raw_ref_op)] + +// For each of these, only 2 of the 6 should simplify, +// as the others have the wrong types. + +// EMIT_MIR ref_of_deref.references.InstSimplify.diff +// CHECK-LABEL: references +pub fn references(const_ref: &i32, mut_ref: &mut [i32]) { + // CHECK: _3 = _1; + let _a = &*const_ref; + // CHECK: _4 = &(*_2); + let _b = &*mut_ref; + // CHECK: _5 = _2; + let _c = &mut *mut_ref; + // CHECK: _6 = &raw const (*_1); + let _d = &raw const *const_ref; + // CHECK: _7 = &raw const (*_2); + let _e = &raw const *mut_ref; + // CHECK: _8 = &raw mut (*_2); + let _f = &raw mut *mut_ref; +} + +// EMIT_MIR ref_of_deref.pointers.InstSimplify.diff +// CHECK-LABEL: pointers +pub unsafe fn pointers(const_ptr: *const [i32], mut_ptr: *mut i32) { + // CHECK: _3 = &(*_1); + let _a = &*const_ptr; + // CHECK: _4 = &(*_2); + let _b = &*mut_ptr; + // CHECK: _5 = &mut (*_2); + let _c = &mut *mut_ptr; + // CHECK: _6 = _1; + let _d = &raw const *const_ptr; + // CHECK: _7 = &raw const (*_2); + let _e = &raw const *mut_ptr; + // CHECK: _8 = _2; + let _f = &raw mut *mut_ptr; +}