From 47bfa846f37cf053471656b572a35d2bfca16715 Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Sun, 27 Jul 2025 13:21:06 -0700 Subject: [PATCH] Allow more MIR SROA --- compiler/rustc_mir_transform/src/sroa.rs | 36 +++++-------------- ...y.run2-{closure#0}.Inline.panic-abort.diff | 36 +++++++++---------- ....run2-{closure#0}.Inline.panic-unwind.diff | 36 +++++++++---------- 3 files changed, 40 insertions(+), 68 deletions(-) diff --git a/compiler/rustc_mir_transform/src/sroa.rs b/compiler/rustc_mir_transform/src/sroa.rs index 7c6ccc89c4f30..80c4b58a57444 100644 --- a/compiler/rustc_mir_transform/src/sroa.rs +++ b/compiler/rustc_mir_transform/src/sroa.rs @@ -1,4 +1,4 @@ -use rustc_abi::{FIRST_VARIANT, FieldIdx}; +use rustc_abi::FieldIdx; use rustc_data_structures::flat_map_in_place::FlatMapInPlace; use rustc_hir::LangItem; use rustc_index::IndexVec; @@ -32,7 +32,7 @@ impl<'tcx> crate::MirPass<'tcx> for ScalarReplacementOfAggregates { let typing_env = body.typing_env(tcx); loop { debug!(?excluded); - let escaping = escaping_locals(tcx, typing_env, &excluded, body); + let escaping = escaping_locals(tcx, &excluded, body); debug!(?escaping); let replacements = compute_flattening(tcx, typing_env, body, escaping); debug!(?replacements); @@ -64,7 +64,6 @@ impl<'tcx> crate::MirPass<'tcx> for ScalarReplacementOfAggregates { /// client code. fn escaping_locals<'tcx>( tcx: TyCtxt<'tcx>, - typing_env: ty::TypingEnv<'tcx>, excluded: &DenseBitSet, body: &Body<'tcx>, ) -> DenseBitSet { @@ -72,31 +71,12 @@ fn escaping_locals<'tcx>( if ty.is_union() || ty.is_enum() { return true; } - if let ty::Adt(def, _args) = ty.kind() { - if def.repr().simd() { - // Exclude #[repr(simd)] types so that they are not de-optimized into an array - return true; - } - if tcx.is_lang_item(def.did(), LangItem::DynMetadata) { - // codegen wants to see the `DynMetadata`, - // not the inner reference-to-opaque-type. - return true; - } - // We already excluded unions and enums, so this ADT must have one variant - let variant = def.variant(FIRST_VARIANT); - if variant.fields.len() > 1 { - // If this has more than one field, it cannot be a wrapper that only provides a - // niche, so we do not want to automatically exclude it. - return false; - } - let Ok(layout) = tcx.layout_of(typing_env.as_query_input(ty)) else { - // We can't get the layout - return true; - }; - if layout.layout.largest_niche().is_some() { - // This type has a niche - return true; - } + if let ty::Adt(def, _args) = ty.kind() + && tcx.is_lang_item(def.did(), LangItem::DynMetadata) + { + // codegen wants to see the `DynMetadata`, + // not the inner reference-to-opaque-type. + return true; } // Default for non-ADTs false diff --git a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff index 169a6768448fc..22e6ea722ddaf 100644 --- a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff +++ b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff @@ -64,9 +64,8 @@ + let mut _45: &mut std::future::Ready<()>; + let mut _46: &mut std::pin::Pin<&mut std::future::Ready<()>>; + scope 14 (inlined > as DerefMut>::deref_mut) { -+ let mut _47: std::pin::Pin<&mut std::future::Ready<()>>; + scope 15 (inlined Pin::<&mut std::future::Ready<()>>::as_mut) { -+ let mut _48: &mut &mut std::future::Ready<()>; ++ let mut _47: &mut &mut std::future::Ready<()>; + scope 16 (inlined Pin::<&mut std::future::Ready<()>>::new_unchecked) { + } + scope 18 (inlined <&mut std::future::Ready<()> as DerefMut>::deref_mut) { @@ -76,15 +75,15 @@ + } + } + scope 19 (inlined Option::<()>::take) { -+ let mut _49: std::option::Option<()>; ++ let mut _48: std::option::Option<()>; + scope 20 (inlined std::mem::replace::>) { + scope 21 { + } + } + } + scope 22 (inlined #[track_caller] Option::<()>::expect) { -+ let mut _50: isize; -+ let mut _51: !; ++ let mut _49: isize; ++ let mut _50: !; + scope 23 { + } + } @@ -229,28 +228,25 @@ + StorageDead(_24); + StorageLive(_45); + StorageLive(_46); -+ StorageLive(_51); ++ StorageLive(_50); + StorageLive(_42); + StorageLive(_43); + StorageLive(_44); + _46 = &mut _19; + StorageLive(_47); -+ StorageLive(_48); -+ _48 = &mut (_19.0: &mut std::future::Ready<()>); ++ _47 = &mut (_19.0: &mut std::future::Ready<()>); + _45 = copy (_19.0: &mut std::future::Ready<()>); -+ StorageDead(_48); -+ _47 = Pin::<&mut std::future::Ready<()>> { pointer: copy _45 }; + StorageDead(_47); + _44 = &mut ((*_45).0: std::option::Option<()>); -+ StorageLive(_49); -+ _49 = Option::<()>::None; ++ StorageLive(_48); ++ _48 = Option::<()>::None; + _43 = copy ((*_45).0: std::option::Option<()>); -+ ((*_45).0: std::option::Option<()>) = copy _49; -+ StorageDead(_49); ++ ((*_45).0: std::option::Option<()>) = copy _48; ++ StorageDead(_48); + StorageDead(_44); -+ StorageLive(_50); -+ _50 = discriminant(_43); -+ switchInt(move _50) -> [0: bb11, 1: bb12, otherwise: bb5]; ++ StorageLive(_49); ++ _49 = discriminant(_43); ++ switchInt(move _49) -> [0: bb11, 1: bb12, otherwise: bb5]; } + + bb5: { @@ -313,16 +309,16 @@ + } + + bb11: { -+ _51 = option::expect_failed(const "`Ready` polled after completion") -> unwind unreachable; ++ _50 = option::expect_failed(const "`Ready` polled after completion") -> unwind unreachable; + } + + bb12: { + _42 = move ((_43 as Some).0: ()); -+ StorageDead(_50); ++ StorageDead(_49); + StorageDead(_43); + _18 = Poll::<()>::Ready(move _42); + StorageDead(_42); -+ StorageDead(_51); ++ StorageDead(_50); + StorageDead(_46); + StorageDead(_45); + StorageDead(_22); diff --git a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff index 14ba3311d2dc1..8b027e988b8e8 100644 --- a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff +++ b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff @@ -66,9 +66,8 @@ + let mut _47: &mut std::future::Ready<()>; + let mut _48: &mut std::pin::Pin<&mut std::future::Ready<()>>; + scope 14 (inlined > as DerefMut>::deref_mut) { -+ let mut _49: std::pin::Pin<&mut std::future::Ready<()>>; + scope 15 (inlined Pin::<&mut std::future::Ready<()>>::as_mut) { -+ let mut _50: &mut &mut std::future::Ready<()>; ++ let mut _49: &mut &mut std::future::Ready<()>; + scope 16 (inlined Pin::<&mut std::future::Ready<()>>::new_unchecked) { + } + scope 18 (inlined <&mut std::future::Ready<()> as DerefMut>::deref_mut) { @@ -78,15 +77,15 @@ + } + } + scope 19 (inlined Option::<()>::take) { -+ let mut _51: std::option::Option<()>; ++ let mut _50: std::option::Option<()>; + scope 20 (inlined std::mem::replace::>) { + scope 21 { + } + } + } + scope 22 (inlined #[track_caller] Option::<()>::expect) { -+ let mut _52: isize; -+ let mut _53: !; ++ let mut _51: isize; ++ let mut _52: !; + scope 23 { + } + } @@ -246,28 +245,25 @@ + StorageDead(_24); + StorageLive(_47); + StorageLive(_48); -+ StorageLive(_53); ++ StorageLive(_52); + StorageLive(_44); + StorageLive(_45); + StorageLive(_46); + _48 = &mut _19; + StorageLive(_49); -+ StorageLive(_50); -+ _50 = &mut (_19.0: &mut std::future::Ready<()>); ++ _49 = &mut (_19.0: &mut std::future::Ready<()>); + _47 = copy (_19.0: &mut std::future::Ready<()>); -+ StorageDead(_50); -+ _49 = Pin::<&mut std::future::Ready<()>> { pointer: copy _47 }; + StorageDead(_49); + _46 = &mut ((*_47).0: std::option::Option<()>); -+ StorageLive(_51); -+ _51 = Option::<()>::None; ++ StorageLive(_50); ++ _50 = Option::<()>::None; + _45 = copy ((*_47).0: std::option::Option<()>); -+ ((*_47).0: std::option::Option<()>) = copy _51; -+ StorageDead(_51); ++ ((*_47).0: std::option::Option<()>) = copy _50; ++ StorageDead(_50); + StorageDead(_46); -+ StorageLive(_52); -+ _52 = discriminant(_45); -+ switchInt(move _52) -> [0: bb16, 1: bb17, otherwise: bb7]; ++ StorageLive(_51); ++ _51 = discriminant(_45); ++ switchInt(move _51) -> [0: bb16, 1: bb17, otherwise: bb7]; } - bb6 (cleanup): { @@ -354,16 +350,16 @@ + } + + bb16: { -+ _53 = option::expect_failed(const "`Ready` polled after completion") -> bb11; ++ _52 = option::expect_failed(const "`Ready` polled after completion") -> bb11; + } + + bb17: { + _44 = move ((_45 as Some).0: ()); -+ StorageDead(_52); ++ StorageDead(_51); + StorageDead(_45); + _18 = Poll::<()>::Ready(move _44); + StorageDead(_44); -+ StorageDead(_53); ++ StorageDead(_52); + StorageDead(_48); + StorageDead(_47); + StorageDead(_22);