diff options
| -rw-r--r-- | compiler/rustc_abi/src/layout.rs | 76 | ||||
| -rw-r--r-- | compiler/rustc_abi/src/lib.rs | 69 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/ty/instance.rs | 9 | ||||
| -rw-r--r-- | library/core/src/fmt/mod.rs | 6 |
4 files changed, 85 insertions, 75 deletions
diff --git a/compiler/rustc_abi/src/layout.rs b/compiler/rustc_abi/src/layout.rs index 0706dc18f0e..e096ad7e6df 100644 --- a/compiler/rustc_abi/src/layout.rs +++ b/compiler/rustc_abi/src/layout.rs @@ -53,32 +53,32 @@ pub trait LayoutCalculator { kind: StructKind, ) -> Option<LayoutS> { let layout = univariant(self, dl, fields, repr, kind, NicheBias::Start); - // Enums prefer niches close to the beginning or the end of the variants so that other (smaller) - // data-carrying variants can be packed into the space after/before the niche. + // Enums prefer niches close to the beginning or the end of the variants so that other + // (smaller) data-carrying variants can be packed into the space after/before the niche. // If the default field ordering does not give us a niche at the front then we do a second - // run and bias niches to the right and then check which one is closer to one of the struct's - // edges. + // run and bias niches to the right and then check which one is closer to one of the + // struct's edges. if let Some(layout) = &layout { // Don't try to calculate an end-biased layout for unsizable structs, // otherwise we could end up with different layouts for - // Foo<Type> and Foo<dyn Trait> which would break unsizing + // Foo<Type> and Foo<dyn Trait> which would break unsizing. if !matches!(kind, StructKind::MaybeUnsized) { if let Some(niche) = layout.largest_niche { let head_space = niche.offset.bytes(); - let niche_length = niche.value.size(dl).bytes(); - let tail_space = layout.size.bytes() - head_space - niche_length; + let niche_len = niche.value.size(dl).bytes(); + let tail_space = layout.size.bytes() - head_space - niche_len; - // This may end up doing redundant work if the niche is already in the last field - // (e.g. a trailing bool) and there is tail padding. But it's non-trivial to get - // the unpadded size so we try anyway. + // This may end up doing redundant work if the niche is already in the last + // field (e.g. a trailing bool) and there is tail padding. But it's non-trivial + // to get the unpadded size so we try anyway. if fields.len() > 1 && head_space != 0 && tail_space > 0 { let alt_layout = univariant(self, dl, fields, repr, kind, NicheBias::End) .expect("alt layout should always work"); - let niche = alt_layout + let alt_niche = alt_layout .largest_niche .expect("alt layout should have a niche like the regular one"); - let alt_head_space = niche.offset.bytes(); - let alt_niche_len = niche.value.size(dl).bytes(); + let alt_head_space = alt_niche.offset.bytes(); + let alt_niche_len = alt_niche.value.size(dl).bytes(); let alt_tail_space = alt_layout.size.bytes() - alt_head_space - alt_niche_len; @@ -93,7 +93,7 @@ pub trait LayoutCalculator { alt_layout: {}\n", layout.size.bytes(), head_space, - niche_length, + niche_len, tail_space, alt_head_space, alt_niche_len, @@ -684,7 +684,8 @@ pub trait LayoutCalculator { // Also do not overwrite any already existing "clever" ABIs. if variant.fields.count() > 0 && matches!(variant.abi, Abi::Aggregate { .. }) { variant.abi = abi; - // Also need to bump up the size and alignment, so that the entire value fits in here. + // Also need to bump up the size and alignment, so that the entire value fits + // in here. variant.size = cmp::max(variant.size, size); variant.align.abi = cmp::max(variant.align.abi, align.abi); } @@ -868,15 +869,15 @@ fn univariant( // If `-Z randomize-layout` was enabled for the type definition we can shuffle // the field ordering to try and catch some code making assumptions about layouts - // we don't guarantee + // we don't guarantee. if repr.can_randomize_type_layout() && cfg!(feature = "randomize") { #[cfg(feature = "randomize")] { - // `ReprOptions.layout_seed` is a deterministic seed that we can use to - // randomize field ordering with + // `ReprOptions.layout_seed` is a deterministic seed we can use to randomize field + // ordering. let mut rng = Xoshiro128StarStar::seed_from_u64(repr.field_shuffle_seed.as_u64()); - // Shuffle the ordering of the fields + // Shuffle the ordering of the fields. optimizing.shuffle(&mut rng); } // Otherwise we just leave things alone and actually optimize the type's fields @@ -892,27 +893,26 @@ fn univariant( .max() .unwrap_or(0); - // Calculates a sort key to group fields by their alignment or possibly some size-derived - // pseudo-alignment. + // Calculates a sort key to group fields by their alignment or possibly some + // size-derived pseudo-alignment. let alignment_group_key = |layout: Layout<'_>| { if let Some(pack) = pack { - // return the packed alignment in bytes + // Return the packed alignment in bytes. layout.align().abi.min(pack).bytes() } else { - // returns log2(effective-align). - // This is ok since `pack` applies to all fields equally. - // The calculation assumes that size is an integer multiple of align, except for ZSTs. - // + // Returns `log2(effective-align)`. This is ok since `pack` applies to all + // fields equally. The calculation assumes that size is an integer multiple of + // align, except for ZSTs. let align = layout.align().abi.bytes(); let size = layout.size().bytes(); let niche_size = layout.largest_niche().map(|n| n.available(dl)).unwrap_or(0); - // group [u8; 4] with align-4 or [u8; 6] with align-2 fields + // Group [u8; 4] with align-4 or [u8; 6] with align-2 fields. let size_as_align = align.max(size).trailing_zeros(); let size_as_align = if largest_niche_size > 0 { match niche_bias { - // Given `A(u8, [u8; 16])` and `B(bool, [u8; 16])` we want to bump the array - // to the front in the first case (for aligned loads) but keep the bool in front - // in the second case for its niches. + // Given `A(u8, [u8; 16])` and `B(bool, [u8; 16])` we want to bump the + // array to the front in the first case (for aligned loads) but keep + // the bool in front in the second case for its niches. NicheBias::Start => max_field_align.trailing_zeros().min(size_as_align), // When moving niches towards the end of the struct then for // A((u8, u8, u8, bool), (u8, bool, u8)) we want to keep the first tuple @@ -931,14 +931,14 @@ fn univariant( match kind { StructKind::AlwaysSized | StructKind::MaybeUnsized => { - // Currently `LayoutS` only exposes a single niche so sorting is usually sufficient - // to get one niche into the preferred position. If it ever supported multiple niches - // then a more advanced pick-and-pack approach could provide better results. - // But even for the single-niche cache it's not optimal. E.g. for - // A(u32, (bool, u8), u16) it would be possible to move the bool to the front - // but it would require packing the tuple together with the u16 to build a 4-byte - // group so that the u32 can be placed after it without padding. This kind - // of packing can't be achieved by sorting. + // Currently `LayoutS` only exposes a single niche so sorting is usually + // sufficient to get one niche into the preferred position. If it ever + // supported multiple niches then a more advanced pick-and-pack approach could + // provide better results. But even for the single-niche cache it's not + // optimal. E.g. for A(u32, (bool, u8), u16) it would be possible to move the + // bool to the front but it would require packing the tuple together with the + // u16 to build a 4-byte group so that the u32 can be placed after it without + // padding. This kind of packing can't be achieved by sorting. optimizing.sort_by_key(|&x| { let f = fields[x]; let field_size = f.size().bytes(); diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs index b30ff058a30..31566c221cc 100644 --- a/compiler/rustc_abi/src/lib.rs +++ b/compiler/rustc_abi/src/lib.rs @@ -53,10 +53,11 @@ bitflags! { #[derive(Copy, Clone, Debug, Eq, PartialEq)] #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))] pub enum IntegerType { - /// Pointer sized integer type, i.e. isize and usize. The field shows signedness, that - /// is, `Pointer(true)` is isize. + /// Pointer-sized integer type, i.e. `isize` and `usize`. The field shows signedness, e.g. + /// `Pointer(true)` means `isize`. Pointer(bool), - /// Fix sized integer type, e.g. i8, u32, i128 The bool field shows signedness, `Fixed(I8, false)` means `u8` + /// Fixed-sized integer type, e.g. `i8`, `u32`, `i128`. The bool field shows signedness, e.g. + /// `Fixed(I8, false)` means `u8`. Fixed(Integer, bool), } @@ -69,7 +70,7 @@ impl IntegerType { } } -/// Represents the repr options provided by the user, +/// Represents the repr options provided by the user. #[derive(Copy, Clone, Debug, Eq, PartialEq, Default)] #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))] pub struct ReprOptions { @@ -139,7 +140,7 @@ impl ReprOptions { } /// Returns `true` if this type is valid for reordering and `-Z randomize-layout` - /// was enabled for its declaration crate + /// was enabled for its declaration crate. pub fn can_randomize_type_layout(&self) -> bool { !self.inhibit_struct_field_reordering_opt() && self.flags.contains(ReprFlags::RANDOMIZE_LAYOUT) @@ -217,7 +218,8 @@ pub enum TargetDataLayoutErrors<'a> { } impl TargetDataLayout { - /// Parse data layout from an [llvm data layout string](https://llvm.org/docs/LangRef.html#data-layout) + /// Parse data layout from an + /// [llvm data layout string](https://llvm.org/docs/LangRef.html#data-layout) /// /// This function doesn't fill `c_enum_min_size` and it will always be `I32` since it can not be /// determined from llvm string. @@ -242,10 +244,11 @@ impl TargetDataLayout { }; // Parse a size string. - let size = |s: &'a str, cause: &'a str| parse_bits(s, "size", cause).map(Size::from_bits); + let parse_size = + |s: &'a str, cause: &'a str| parse_bits(s, "size", cause).map(Size::from_bits); // Parse an alignment string. - let align = |s: &[&'a str], cause: &'a str| { + let parse_align = |s: &[&'a str], cause: &'a str| { if s.is_empty() { return Err(TargetDataLayoutErrors::MissingAlignment { cause }); } @@ -269,22 +272,22 @@ impl TargetDataLayout { [p] if p.starts_with('P') => { dl.instruction_address_space = parse_address_space(&p[1..], "P")? } - ["a", ref a @ ..] => dl.aggregate_align = align(a, "a")?, - ["f32", ref a @ ..] => dl.f32_align = align(a, "f32")?, - ["f64", ref a @ ..] => dl.f64_align = align(a, "f64")?, + ["a", ref a @ ..] => dl.aggregate_align = parse_align(a, "a")?, + ["f32", ref a @ ..] => dl.f32_align = parse_align(a, "f32")?, + ["f64", ref a @ ..] => dl.f64_align = parse_align(a, "f64")?, // FIXME(erikdesjardins): we should be parsing nonzero address spaces // this will require replacing TargetDataLayout::{pointer_size,pointer_align} // with e.g. `fn pointer_size_in(AddressSpace)` [p @ "p", s, ref a @ ..] | [p @ "p0", s, ref a @ ..] => { - dl.pointer_size = size(s, p)?; - dl.pointer_align = align(a, p)?; + dl.pointer_size = parse_size(s, p)?; + dl.pointer_align = parse_align(a, p)?; } [s, ref a @ ..] if s.starts_with('i') => { let Ok(bits) = s[1..].parse::<u64>() else { - size(&s[1..], "i")?; // For the user error. + parse_size(&s[1..], "i")?; // For the user error. continue; }; - let a = align(a, s)?; + let a = parse_align(a, s)?; match bits { 1 => dl.i1_align = a, 8 => dl.i8_align = a, @@ -301,8 +304,8 @@ impl TargetDataLayout { } } [s, ref a @ ..] if s.starts_with('v') => { - let v_size = size(&s[1..], "v")?; - let a = align(a, s)?; + let v_size = parse_size(&s[1..], "v")?; + let a = parse_align(a, s)?; if let Some(v) = dl.vector_align.iter_mut().find(|v| v.0 == v_size) { v.1 = a; continue; @@ -747,7 +750,6 @@ impl Align { /// A pair of alignments, ABI-mandated and preferred. #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)] #[cfg_attr(feature = "nightly", derive(HashStable_Generic))] - pub struct AbiAndPrefAlign { pub abi: Align, pub pref: Align, @@ -773,7 +775,6 @@ impl AbiAndPrefAlign { /// Integers, also used for enum discriminants. #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)] #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))] - pub enum Integer { I8, I16, @@ -937,8 +938,7 @@ impl Primitive { } /// Inclusive wrap-around range of valid values, that is, if -/// start > end, it represents `start..=MAX`, -/// followed by `0..=end`. +/// start > end, it represents `start..=MAX`, followed by `0..=end`. /// /// That is, for an i8 primitive, a range of `254..=2` means following /// sequence: @@ -970,21 +970,21 @@ impl WrappingRange { /// Returns `self` with replaced `start` #[inline(always)] - pub fn with_start(mut self, start: u128) -> Self { + fn with_start(mut self, start: u128) -> Self { self.start = start; self } /// Returns `self` with replaced `end` #[inline(always)] - pub fn with_end(mut self, end: u128) -> Self { + fn with_end(mut self, end: u128) -> Self { self.end = end; self } /// Returns `true` if `size` completely fills the range. #[inline] - pub fn is_full_for(&self, size: Size) -> bool { + fn is_full_for(&self, size: Size) -> bool { let max_value = size.unsigned_int_max(); debug_assert!(self.start <= max_value && self.end <= max_value); self.start == (self.end.wrapping_add(1) & max_value) @@ -1066,7 +1066,8 @@ impl Scalar { } #[inline] - /// Allows the caller to mutate the valid range. This operation will panic if attempted on a union. + /// Allows the caller to mutate the valid range. This operation will panic if attempted on a + /// union. pub fn valid_range_mut(&mut self) -> &mut WrappingRange { match self { Scalar::Initialized { valid_range, .. } => valid_range, @@ -1074,7 +1075,8 @@ impl Scalar { } } - /// Returns `true` if all possible numbers are valid, i.e `valid_range` covers the whole layout + /// Returns `true` if all possible numbers are valid, i.e `valid_range` covers the whole + /// layout. #[inline] pub fn is_always_valid<C: HasDataLayout>(&self, cx: &C) -> bool { match *self { @@ -1252,7 +1254,6 @@ impl AddressSpace { /// in terms of categories of C types there are ABI rules for. #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)] #[cfg_attr(feature = "nightly", derive(HashStable_Generic))] - pub enum Abi { Uninhabited, Scalar(Scalar), @@ -1457,17 +1458,19 @@ impl Niche { return None; } - // Extend the range of valid values being reserved by moving either `v.start` or `v.end` bound. - // Given an eventual `Option<T>`, we try to maximize the chance for `None` to occupy the niche of zero. - // This is accomplished by preferring enums with 2 variants(`count==1`) and always taking the shortest path to niche zero. - // Having `None` in niche zero can enable some special optimizations. + // Extend the range of valid values being reserved by moving either `v.start` or `v.end` + // bound. Given an eventual `Option<T>`, we try to maximize the chance for `None` to occupy + // the niche of zero. This is accomplished by preferring enums with 2 variants(`count==1`) + // and always taking the shortest path to niche zero. Having `None` in niche zero can + // enable some special optimizations. // // Bound selection criteria: // 1. Select closest to zero given wrapping semantics. // 2. Avoid moving past zero if possible. // - // In practice this means that enums with `count > 1` are unlikely to claim niche zero, since they have to fit perfectly. - // If niche zero is already reserved, the selection of bounds are of little interest. + // In practice this means that enums with `count > 1` are unlikely to claim niche zero, + // since they have to fit perfectly. If niche zero is already reserved, the selection of + // bounds are of little interest. let move_start = |v: WrappingRange| { let start = v.start.wrapping_sub(count) & max_value; Some((start, Scalar::Initialized { value, valid_range: v.with_start(start) })) diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs index 0b0a708e42b..0a425be52ff 100644 --- a/compiler/rustc_middle/src/ty/instance.rs +++ b/compiler/rustc_middle/src/ty/instance.rs @@ -617,12 +617,17 @@ impl<'tcx> Instance<'tcx> { v: EarlyBinder<T>, ) -> Result<T, NormalizationError<'tcx>> where - T: TypeFoldable<TyCtxt<'tcx>> + Clone, + T: TypeFoldable<TyCtxt<'tcx>>, { if let Some(args) = self.args_for_mir_body() { tcx.try_instantiate_and_normalize_erasing_regions(args, param_env, v) } else { - tcx.try_normalize_erasing_regions(param_env, v.skip_binder()) + // We're using `instantiate_identity` as e.g. + // `FnPtrShim` is separately generated for every + // instantiation of the `FnDef`, so the MIR body + // is already instantiated. Any generic parameters it + // contains are generic parameters from the caller. + tcx.try_normalize_erasing_regions(param_env, v.instantiate_identity()) } } diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs index fc91d1afc43..f7d3cda2fe9 100644 --- a/library/core/src/fmt/mod.rs +++ b/library/core/src/fmt/mod.rs @@ -791,8 +791,10 @@ pub trait Octal { /// assert_eq!(format!("l as binary is: {l:b}"), "l as binary is: 1101011"); /// /// assert_eq!( -/// format!("l as binary is: {l:#032b}"), -/// "l as binary is: 0b000000000000000000000001101011" +/// // Note that the `0b` prefix added by `#` is included in the total width, so we +/// // need to add two to correctly display all 32 bits. +/// format!("l as binary is: {l:#034b}"), +/// "l as binary is: 0b00000000000000000000000001101011" /// ); /// ``` #[stable(feature = "rust1", since = "1.0.0")] |