Add clippy suggestions

cranelift/codegen/meta/src/cdsl/instructions.rs

@@ -228,8 +228,8 @@ impl InstructionBuilder {
     }
 
     fn build(self) -> Instruction {
-        let operands_in = self.operands_in.unwrap_or_else(Vec::new);
-        let operands_out = self.operands_out.unwrap_or_else(Vec::new);
+        let operands_in = self.operands_in.unwrap_or_default();
+        let operands_out = self.operands_out.unwrap_or_default();
 
         let mut value_opnums = Vec::new();
         let mut imm_opnums = Vec::new();
@@ -375,7 +375,7 @@ fn verify_polymorphic(
             if (free_typevar.is_some() && tv == &free_typevar.unwrap())
                 || tv.singleton_type().is_some()
             {
-                match is_ctrl_typevar_candidate(tv, &operands_in, &operands_out) {
+                match is_ctrl_typevar_candidate(tv, operands_in, operands_out) {
                     Ok(_other_typevars) => {
                         return Some(PolymorphicInfo {
                             use_typevar_operand: true,
@@ -410,7 +410,7 @@ fn verify_polymorphic(
 
     // At this point, if the next unwrap() fails, it means the output type couldn't be used as a
     // controlling type variable either; panicking is the right behavior.
-    is_ctrl_typevar_candidate(tv, &operands_in, &operands_out).unwrap();
+    is_ctrl_typevar_candidate(tv, operands_in, operands_out).unwrap();
 
     Some(PolymorphicInfo {
         use_typevar_operand: false,

cranelift/codegen/meta/src/cdsl/operands.rs

@@ -50,10 +50,7 @@ impl Operand {
     }
 
     pub fn is_value(&self) -> bool {
-        match self.kind.fields {
-            OperandKindFields::TypeVar(_) => true,
-            _ => false,
-        }
+        matches!(self.kind.fields, OperandKindFields::TypeVar(_))
     }
 
     pub fn type_var(&self) -> Option<&TypeVar> {
@@ -64,28 +61,25 @@ impl Operand {
     }
 
     pub fn is_varargs(&self) -> bool {
-        match self.kind.fields {
-            OperandKindFields::VariableArgs => true,
-            _ => false,
-        }
+        matches!(self.kind.fields, OperandKindFields::VariableArgs)
     }
 
     /// Returns true if the operand has an immediate kind or is an EntityRef.
     pub fn is_immediate_or_entityref(&self) -> bool {
-        match self.kind.fields {
+        matches!(
+            self.kind.fields,
             OperandKindFields::ImmEnum(_)
-            | OperandKindFields::ImmValue
-            | OperandKindFields::EntityRef => true,
-            _ => false,
-        }
+                | OperandKindFields::ImmValue
+                | OperandKindFields::EntityRef
+        )
     }
 
     /// Returns true if the operand has an immediate kind.
     pub fn is_immediate(&self) -> bool {
-        match self.kind.fields {
-            OperandKindFields::ImmEnum(_) | OperandKindFields::ImmValue => true,
-            _ => false,
-        }
+        matches!(
+            self.kind.fields,
+            OperandKindFields::ImmEnum(_) | OperandKindFields::ImmValue
+        )
     }
 }
 
@@ -158,18 +152,18 @@ impl OperandKind {
     }
 }
 
-impl Into<OperandKind> for &TypeVar {
-    fn into(self) -> OperandKind {
+impl From<&TypeVar> for OperandKind {
+    fn from(type_var: &TypeVar) -> Self {
         OperandKind {
             rust_field_name: "value",
             rust_type: "ir::Value",
-            fields: OperandKindFields::TypeVar(self.into()),
+            fields: OperandKindFields::TypeVar(type_var.into()),
             doc: None,
         }
     }
 }
-impl Into<OperandKind> for &OperandKind {
-    fn into(self) -> OperandKind {
-        self.clone()
+impl From<&OperandKind> for OperandKind {
+    fn from(kind: &OperandKind) -> Self {
+        kind.clone()
     }
 }

cranelift/codegen/meta/src/cdsl/settings.rs

@@ -75,14 +75,14 @@ pub(crate) enum PresetType {
     OtherPreset(PresetIndex),
 }
 
-impl Into<PresetType> for BoolSettingIndex {
-    fn into(self) -> PresetType {
-        PresetType::BoolSetting(self)
+impl From<BoolSettingIndex> for PresetType {
+    fn from(bool_setting_index: BoolSettingIndex) -> Self {
+        PresetType::BoolSetting(bool_setting_index)
     }
 }
-impl Into<PresetType> for PresetIndex {
-    fn into(self) -> PresetType {
-        PresetType::OtherPreset(self)
+impl From<PresetIndex> for PresetType {
+    fn from(value: PresetIndex) -> Self {
+        PresetType::OtherPreset(value)
     }
 }
 
@@ -134,13 +134,7 @@ impl SettingGroup {
     fn num_bool_settings(&self) -> u8 {
         self.settings
             .iter()
-            .filter(|s| {
-                if let SpecificSetting::Bool(_) = s.specific {
-                    true
-                } else {
-                    false
-                }
-            })
+            .filter(|s| matches!(s.specific, SpecificSetting::Bool(_)))
             .count() as u8
     }
 
@@ -184,14 +178,15 @@ pub(crate) enum PredicateNode {
     And(Box<PredicateNode>, Box<PredicateNode>),
 }
 
-impl Into<PredicateNode> for BoolSettingIndex {
-    fn into(self) -> PredicateNode {
-        PredicateNode::OwnedBool(self)
+impl From<BoolSettingIndex> for PredicateNode {
+    fn from(bool_setting_index: BoolSettingIndex) -> Self {
+        PredicateNode::OwnedBool(bool_setting_index)
     }
 }
-impl<'a> Into<PredicateNode> for (BoolSettingIndex, &'a SettingGroup) {
-    fn into(self) -> PredicateNode {
-        let (index, group) = (self.0, self.1);
+
+impl<'a> From<(BoolSettingIndex, &'a SettingGroup)> for PredicateNode {
+    fn from(val: (BoolSettingIndex, &'a SettingGroup)) -> Self {
+        let (index, group) = (val.0, val.1);
         let setting = &group.settings[index.0];
         PredicateNode::SharedBool(group.name, setting.name)
     }

cranelift/codegen/meta/src/cdsl/types.rs

@@ -267,12 +267,9 @@ impl Iterator for LaneTypeIterator {
     type Item = LaneType;
     fn next(&mut self) -> Option<Self::Item> {
         if let Some(i) = self.int_iter.next() {
-            Some(LaneType::from(i))
-        } else if let Some(f) = self.float_iter.next() {
-            Some(LaneType::from(f))
-        } else {
-            None
+            return Some(LaneType::from(i));
         }
+        self.float_iter.next().map(LaneType::from)
     }
 }
 
@@ -491,10 +488,6 @@ impl ReferenceTypeIterator {
 impl Iterator for ReferenceTypeIterator {
     type Item = ReferenceType;
     fn next(&mut self) -> Option<Self::Item> {
-        if let Some(r) = self.reference_iter.next() {
-            Some(ReferenceType::from(r))
-        } else {
-            None
-        }
+        self.reference_iter.next().map(ReferenceType::from)
     }
 }

cranelift/codegen/meta/src/cdsl/typevar.rs

@@ -279,14 +279,14 @@ impl TypeVar {
     }
 }
 
-impl Into<TypeVar> for &TypeVar {
-    fn into(self) -> TypeVar {
-        self.clone()
+impl From<&TypeVar> for TypeVar {
+    fn from(type_var: &TypeVar) -> Self {
+        type_var.clone()
     }
 }
-impl Into<TypeVar> for ValueType {
-    fn into(self) -> TypeVar {
-        TypeVar::new_singleton(self)
+impl From<ValueType> for TypeVar {
+    fn from(value_type: ValueType) -> Self {
+        TypeVar::new_singleton(value_type)
     }
 }
 
@@ -507,7 +507,7 @@ impl TypeSet {
             self.dynamic_lanes
                 .iter()
                 .filter(|&&x| x < MAX_LANES)
-                .map(|&x| x),
+                .copied(),
         );
         copy.dynamic_lanes = NumSet::new();
         copy
@@ -660,13 +660,7 @@ pub(crate) enum Interval {
 impl Interval {
     fn to_range(&self, full_range: Range, default: Option<RangeBound>) -> Option<Range> {
         match self {
-            Interval::None => {
-                if let Some(default_val) = default {
-                    Some(default_val..default_val)
-                } else {
-                    None
-                }
-            }
+            Interval::None => default.map(|default_val| default_val..default_val),
 
             Interval::All => Some(full_range),
 
@@ -683,9 +677,9 @@ impl Interval {
     }
 }
 
-impl Into<Interval> for Range {
-    fn into(self) -> Interval {
-        Interval::Range(self)
+impl From<Range> for Interval {
+    fn from(range: Range) -> Self {
+        Interval::Range(range)
     }
 }
 

cranelift/codegen/meta/src/constant_hash.rs

@@ -30,7 +30,7 @@ pub fn generate_table<'cont, T, I: iter::Iterator<Item = &'cont T>, H: Fn(&T) ->
     let mut table = vec![None; size];
 
     for i in items {
-        let mut h = hash_function(&i) % size;
+        let mut h = hash_function(i) % size;
         let mut s = 0;
         while table[h].is_some() {
             s += 1;

cranelift/codegen/meta/src/gen_inst.rs

@@ -700,7 +700,7 @@ fn get_constraint<'entries, 'table>(
     if let Some(free_typevar) = type_var.free_typevar() {
         if ctrl_typevar.is_some() && free_typevar != *ctrl_typevar.unwrap() {
             assert!(type_var.base.is_none());
-            return format!("Free({})", type_sets.add(&type_var.get_raw_typeset()));
+            return format!("Free({})", type_sets.add(type_var.get_raw_typeset()));
         }
     }
 
@@ -809,7 +809,7 @@ fn gen_type_constraints(all_inst: &AllInstructions, fmt: &mut Formatter) {
     fmt.indent(|fmt| {
         for inst in all_inst.iter() {
             let (ctrl_typevar, ctrl_typeset) = if let Some(poly) = &inst.polymorphic_info {
-                let index = type_sets.add(&*poly.ctrl_typevar.get_raw_typeset());
+                let index = type_sets.add(poly.ctrl_typevar.get_raw_typeset());
                 (Some(&poly.ctrl_typevar), index)
             } else {
                 (None, TYPESET_LIMIT)
@@ -857,7 +857,7 @@ fn gen_type_constraints(all_inst: &AllInstructions, fmt: &mut Formatter) {
                 .collect::<Vec<_>>()
                 .join(", ")));
             if let Some(poly) = &inst.polymorphic_info {
-                fmt.comment(format!("Polymorphic over {}", typeset_to_string(&poly.ctrl_typevar.get_raw_typeset())));
+                fmt.comment(format!("Polymorphic over {}", typeset_to_string(poly.ctrl_typevar.get_raw_typeset())));
             }
 
             // Compute the bit field encoding, c.f. instructions.rs.
@@ -1730,7 +1730,7 @@ fn gen_builder(
     fmt.line("pub trait InstBuilder<'f>: InstBuilderBase<'f> {");
     fmt.indent(|fmt| {
         for inst in instructions.iter() {
-            gen_inst_builder(inst, &*inst.format, fmt);
+            gen_inst_builder(inst, &inst.format, fmt);
             fmt.empty_line();
         }
         for (i, format) in formats.iter().enumerate() {

cranelift/codegen/meta/src/gen_settings.rs

@@ -267,10 +267,10 @@ fn gen_getters(group: &SettingGroup, fmt: &mut Formatter) {
         }
 
         for setting in &group.settings {
-            gen_getter(&setting, fmt);
+            gen_getter(setting, fmt);
         }
         for predicate in &group.predicates {
-            gen_pred_getter(&predicate, &group, fmt);
+            gen_pred_getter(predicate, group, fmt);
         }
     });
     fmtln!(fmt, "}");
@@ -364,8 +364,8 @@ fn gen_descriptors(group: &SettingGroup, fmt: &mut Formatter) {
 
     // Generate hash table.
     let mut hash_entries: Vec<SettingOrPreset> = Vec::new();
-    hash_entries.extend(group.settings.iter().map(|x| SettingOrPreset::Setting(x)));
-    hash_entries.extend(group.presets.iter().map(|x| SettingOrPreset::Preset(x)));
+    hash_entries.extend(group.settings.iter().map(SettingOrPreset::Setting));
+    hash_entries.extend(group.presets.iter().map(SettingOrPreset::Preset));
 
     let hash_table = generate_table(hash_entries.iter(), hash_entries.len(), |entry| {
         simple_hash(entry.name())
@@ -399,9 +399,9 @@ fn gen_descriptors(group: &SettingGroup, fmt: &mut Formatter) {
             fmt.comment(format!(
                 "{}: {}",
                 preset.name,
-                preset.setting_names(&group).collect::<Vec<_>>().join(", ")
+                preset.setting_names(group).collect::<Vec<_>>().join(", ")
             ));
-            for (mask, value) in preset.layout(&group) {
+            for (mask, value) in preset.layout(group) {
                 fmtln!(fmt, "(0b{:08b}, 0b{:08b}),", mask, value);
             }
         }
@@ -502,7 +502,7 @@ pub(crate) fn generate(
     out_dir: &str,
 ) -> Result<(), error::Error> {
     let mut fmt = Formatter::new();
-    gen_group(&settings, parent_group, &mut fmt);
+    gen_group(settings, parent_group, &mut fmt);
     fmt.update_file(filename, out_dir)?;
     Ok(())
 }

cranelift/codegen/meta/src/lib.rs

@@ -31,9 +31,9 @@ pub fn generate(isas: &[isa::Isa], out_dir: &str, isle_dir: &str) -> Result<(),
         &shared_defs.settings,
         gen_settings::ParentGroup::None,
         "settings.rs",
-        &out_dir,
+        out_dir,
     )?;
-    gen_types::generate("types.rs", &out_dir)?;
+    gen_types::generate("types.rs", out_dir)?;
 
     // - per ISA definitions.
     let target_isas = isa::define(isas, &mut shared_defs);
@@ -49,7 +49,7 @@ pub fn generate(isas: &[isa::Isa], out_dir: &str, isle_dir: &str) -> Result<(),
         "inst_builder.rs",
         "clif_opt.isle",
         "clif_lower.isle",
-        &out_dir,
+        out_dir,
         isle_dir,
     )?;
 
@@ -58,7 +58,7 @@ pub fn generate(isas: &[isa::Isa], out_dir: &str, isle_dir: &str) -> Result<(),
             &isa.settings,
             gen_settings::ParentGroup::Shared,
             &format!("settings-{}.rs", isa.name),
-            &out_dir,
+            out_dir,
         )?;
     }
 

cranelift/codegen/meta/src/shared/mod.rs

@@ -58,7 +58,7 @@ impl Definitions {
             // Check name.
             if let Some(existing_format) = format_names.get(&inst.format.name) {
                 assert!(
-                    Rc::ptr_eq(&existing_format, &inst.format),
+                    Rc::ptr_eq(existing_format, &inst.format),
                     "formats must uniquely named; there's a\
                      conflict on the name '{}', please make sure it is used only once.",
                     existing_format.name
@@ -80,7 +80,7 @@ impl Definitions {
             }
         }
 
-        let mut result = Vec::from_iter(format_structures.into_iter().map(|(_, v)| v));
+        let mut result = Vec::from_iter(format_structures.into_values());
         result.sort_by_key(|format| format.name);
         result
     }