sway_ir/
value.rs

1//! The base descriptor for various values within the IR.
2//!
3//! [`Value`]s can be function arguments, constants and instructions. [`Instruction`]s generally
4//! refer to each other and to constants via the [`Value`] wrapper.
5//!
6//! Like most IR data structures they are `Copy` and cheap to pass around by value. They are
7//! therefore also easy to replace, a common practice for optimization passes.
8
9use rustc_hash::FxHashMap;
10
11use crate::{
12    block::BlockArgument,
13    context::Context,
14    instruction::InstOp,
15    irtype::Type,
16    metadata::{combine, MetadataIndex},
17    pretty::DebugWithContext,
18    Block, Constant, Instruction,
19};
20
21/// A wrapper around an [ECS](https://github.com/orlp/slotmap) handle into the
22/// [`Context`].
23#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, DebugWithContext)]
24pub struct Value(#[in_context(values)] pub slotmap::DefaultKey);
25
26#[doc(hidden)]
27#[derive(Debug, Clone, DebugWithContext)]
28pub struct ValueContent {
29    pub value: ValueDatum,
30    pub metadata: Option<MetadataIndex>,
31}
32
33#[doc(hidden)]
34#[derive(Debug, Clone, DebugWithContext)]
35pub enum ValueDatum {
36    Argument(BlockArgument),
37    Constant(Constant),
38    Instruction(Instruction),
39}
40
41impl Value {
42    /// Return a new argument [`Value`].
43    pub fn new_argument(context: &mut Context, arg: BlockArgument) -> Value {
44        let content = ValueContent {
45            value: ValueDatum::Argument(arg),
46            metadata: None,
47        };
48        Value(context.values.insert(content))
49    }
50
51    /// Return a new constant [`Value`].
52    pub fn new_constant(context: &mut Context, constant: Constant) -> Value {
53        let content = ValueContent {
54            value: ValueDatum::Constant(constant),
55            metadata: None,
56        };
57        Value(context.values.insert(content))
58    }
59
60    /// Return a new `u64` constant [`Value`] set to `value`.
61    pub fn new_u64_constant(context: &mut Context, value: u64) -> Value {
62        let constant = crate::ConstantContent::new_uint(context, 64, value);
63        let constant = Constant::unique(context, constant);
64        Self::new_constant(context, constant)
65    }
66
67    /// Return a new instruction [`Value`].
68    pub fn new_instruction(context: &mut Context, block: Block, instruction: InstOp) -> Value {
69        let content = ValueContent {
70            value: ValueDatum::Instruction(Instruction {
71                op: instruction,
72                parent: block,
73            }),
74            metadata: None,
75        };
76        Value(context.values.insert(content))
77    }
78
79    /// Add some metadata to this value.
80    ///
81    /// As a convenience the `md_idx` argument is an `Option`, in which case this function is a
82    /// no-op.
83    ///
84    /// If there is no existing metadata then the new metadata are added alone. Otherwise the new
85    /// metadatum are added to the list of metadata.
86    pub fn add_metadatum(self, context: &mut Context, md_idx: Option<MetadataIndex>) -> Self {
87        if md_idx.is_some() {
88            let orig_md = context.values[self.0].metadata;
89            let new_md = combine(context, &orig_md, &md_idx);
90            context.values[self.0].metadata = new_md;
91        }
92        self
93    }
94
95    /// Return this value's metadata.
96    pub fn get_metadata(&self, context: &Context) -> Option<MetadataIndex> {
97        context.values[self.0].metadata
98    }
99
100    /// Return whether this is a constant value.
101    pub fn is_constant(&self, context: &Context) -> bool {
102        matches!(context.values[self.0].value, ValueDatum::Constant(_))
103    }
104
105    /// Return whether this value is an instruction, and specifically a 'terminator'.
106    ///
107    /// A terminator is always the last instruction in a block (and may not appear anywhere else)
108    /// and is either a branch or return.
109    pub fn is_terminator(&self, context: &Context) -> bool {
110        match &context.values[self.0].value {
111            ValueDatum::Instruction(Instruction { op, .. }) => op.is_terminator(),
112            ValueDatum::Argument(..) | ValueDatum::Constant(..) => false,
113        }
114    }
115
116    /// If this value is an instruction and if any of its parameters is `old_val` then replace them
117    /// with `new_val`.
118    pub fn replace_instruction_value(&self, context: &mut Context, old_val: Value, new_val: Value) {
119        self.replace_instruction_values(context, &FxHashMap::from_iter([(old_val, new_val)]))
120    }
121
122    /// If this value is an instruction and if any of its parameters is in `replace_map` as
123    /// a key, replace it with the mapped value.
124    pub fn replace_instruction_values(
125        &self,
126        context: &mut Context,
127        replace_map: &FxHashMap<Value, Value>,
128    ) {
129        if let ValueDatum::Instruction(instruction) =
130            &mut context.values.get_mut(self.0).unwrap().value
131        {
132            instruction.op.replace_values(replace_map);
133        }
134    }
135
136    /// Replace this value with another one, in-place.
137    pub fn replace(&self, context: &mut Context, other: ValueDatum) {
138        context.values[self.0].value = other;
139    }
140
141    /// Get a reference to this value as an instruction, iff it is one.
142    pub fn get_instruction<'a>(&self, context: &'a Context) -> Option<&'a Instruction> {
143        if let ValueDatum::Instruction(instruction) = &context.values[self.0].value {
144            Some(instruction)
145        } else {
146            None
147        }
148    }
149
150    /// Get a mutable reference to this value as an instruction, iff it is one.
151    pub fn get_instruction_mut<'a>(&self, context: &'a mut Context) -> Option<&'a mut Instruction> {
152        if let ValueDatum::Instruction(instruction) =
153            &mut context.values.get_mut(self.0).unwrap().value
154        {
155            Some(instruction)
156        } else {
157            None
158        }
159    }
160
161    /// Get a reference to this value as a constant, iff it is one.
162    pub fn get_constant<'a>(&self, context: &'a Context) -> Option<&'a Constant> {
163        if let ValueDatum::Constant(cn) = &context.values[self.0].value {
164            Some(cn)
165        } else {
166            None
167        }
168    }
169
170    /// Get a reference to this value as an argument, iff it is one.
171    pub fn get_argument<'a>(&self, context: &'a Context) -> Option<&'a BlockArgument> {
172        if let ValueDatum::Argument(arg) = &context.values[self.0].value {
173            Some(arg)
174        } else {
175            None
176        }
177    }
178
179    /// Get a mutable reference to this value as an argument, iff it is one.
180    pub fn get_argument_mut<'a>(&self, context: &'a mut Context) -> Option<&'a mut BlockArgument> {
181        if let ValueDatum::Argument(arg) = &mut context.values[self.0].value {
182            Some(arg)
183        } else {
184            None
185        }
186    }
187
188    /// Get the type for this value, if found.
189    ///
190    /// Arguments and constants always have a type, but only some instructions do.
191    pub fn get_type(&self, context: &Context) -> Option<Type> {
192        match &context.values[self.0].value {
193            ValueDatum::Argument(BlockArgument { ty, .. }) => Some(*ty),
194            ValueDatum::Constant(c) => Some(c.get_content(context).ty),
195            ValueDatum::Instruction(ins) => ins.get_type(context),
196        }
197    }
198
199    /// Get the pointer inner type for this value, iff it is a pointer.
200    pub fn match_ptr_type(&self, context: &Context) -> Option<Type> {
201        self.get_type(context)
202            .and_then(|ty| ty.get_pointee_type(context))
203    }
204}
sway_ir/value.rs

sway_ir/
value.rs
