chore(ssa refactor): Handle codegen for literals (#1209)

* Add Context structs and start ssa gen pass

* Fix block arguments

* Fix clippy lint

* Use the correct dfg

* Rename contexts to highlight the inner contexts are shared rather than used directly

* Correctly handle function parameters

* Rename Nested to Tree; add comment

* Add codegen for literals

* PR feedback

* chore(ssa refactor): Add debug printing for the new ssa ir (#1211)

Implement debug printing for the new ssa ir

crates/noirc_evaluator/src/ssa_refactor/ir.rs

@@ -1,7 +1,9 @@
 pub(crate) mod basic_block;
+pub(crate) mod constant;
 pub(crate) mod dfg;
 pub(crate) mod function;
 pub(crate) mod instruction;
 pub(crate) mod map;
+pub(crate) mod printer;
 pub(crate) mod types;
 pub(crate) mod value;

crates/noirc_evaluator/src/ssa_refactor/ir/basic_block.rs

@@ -52,7 +52,29 @@ impl BasicBlock {
         self.instructions.push(instruction);
     }
 
+    pub(crate) fn instructions(&self) -> &[InstructionId] {
+        &self.instructions
+    }
+
     pub(crate) fn set_terminator(&mut self, terminator: TerminatorInstruction) {
         self.terminator = Some(terminator);
     }
+
+    pub(crate) fn terminator(&self) -> Option<&TerminatorInstruction> {
+        self.terminator.as_ref()
+    }
+
+    /// Iterate over all the successors of the currently block, as determined by
+    /// the blocks jumped to in the terminator instruction. If there is no terminator
+    /// instruction yet, this will iterate 0 times.
+    pub(crate) fn successors(&self) -> impl ExactSizeIterator<Item = BasicBlockId> {
+        match &self.terminator {
+            Some(TerminatorInstruction::Jmp { destination, .. }) => vec![*destination].into_iter(),
+            Some(TerminatorInstruction::JmpIf { then_destination, else_destination, .. }) => {
+                vec![*then_destination, *else_destination].into_iter()
+            }
+            Some(TerminatorInstruction::Return { .. }) => vec![].into_iter(),
+            None => vec![].into_iter(),
+        }
+    }
 }

crates/noirc_evaluator/src/ssa_refactor/ir/constant.rs

@@ -0,0 +1,56 @@
+use acvm::FieldElement;
+
+use super::map::Id;
+
+/// Represents a numeric constant in Ssa. Constants themselves are
+/// uniqued in the DataFlowGraph and immutable.
+///
+/// This is just a thin wrapper around FieldElement so that
+/// we can use Id<NumericConstant> without it getting confused
+/// with a possible future use of Id<FieldElement>.
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
+pub(crate) struct NumericConstant(FieldElement);
+
+impl NumericConstant {
+    pub(crate) fn new(value: FieldElement) -> Self {
+        Self(value)
+    }
+
+    pub(crate) fn value(&self) -> &FieldElement {
+        &self.0
+    }
+}
+
+pub(crate) type NumericConstantId = Id<NumericConstant>;
+
+impl std::ops::Add for NumericConstant {
+    type Output = NumericConstant;
+
+    fn add(self, rhs: Self) -> Self::Output {
+        Self::new(self.0 + rhs.0)
+    }
+}
+
+impl std::ops::Sub for NumericConstant {
+    type Output = NumericConstant;
+
+    fn sub(self, rhs: Self) -> Self::Output {
+        Self::new(self.0 - rhs.0)
+    }
+}
+
+impl std::ops::Mul for NumericConstant {
+    type Output = NumericConstant;
+
+    fn mul(self, rhs: Self) -> Self::Output {
+        Self::new(self.0 * rhs.0)
+    }
+}
+
+impl std::ops::Div for NumericConstant {
+    type Output = NumericConstant;
+
+    fn div(self, rhs: Self) -> Self::Output {
+        Self::new(self.0 / rhs.0)
+    }
+}

crates/noirc_evaluator/src/ssa_refactor/ir/dfg.rs

@@ -1,12 +1,14 @@
 use super::{
     basic_block::{BasicBlock, BasicBlockId},
+    constant::{NumericConstant, NumericConstantId},
     function::Signature,
     instruction::{Instruction, InstructionId},
-    map::{DenseMap, Id, SecondaryMap},
+    map::{DenseMap, Id, SecondaryMap, TwoWayMap},
     types::Type,
     value::{Value, ValueId},
 };
 
+use acvm::FieldElement;
 use iter_extended::vecmap;
 
 #[derive(Debug, Default)]
@@ -20,6 +22,7 @@ impl ValueList {
         self.0.push(value);
         self.len() - 1
     }
+
     /// Returns the number of values in the list.
     fn len(&self) -> usize {
         self.0.len()
@@ -29,6 +32,7 @@ impl ValueList {
     fn clear(&mut self) {
         self.0.clear();
     }
+
     /// Returns the ValueId's as a slice.
     pub(crate) fn as_slice(&self) -> &[ValueId] {
         &self.0
@@ -55,6 +59,11 @@ pub(crate) struct DataFlowGraph {
     /// function.
     values: DenseMap<Value>,
 
+    /// Storage for all constants used within a function.
+    /// Each constant is unique, attempting to insert the same constant
+    /// twice will return the same ConstantId.
+    constants: TwoWayMap<NumericConstant>,
+
     /// Function signatures of external methods
     signatures: DenseMap<Signature>,
 
@@ -91,41 +100,50 @@ impl DataFlowGraph {
     }
 
     /// Inserts a new instruction into the DFG.
+    /// This does not add the instruction to the block or populate the instruction's result list
     pub(crate) fn make_instruction(&mut self, instruction_data: Instruction) -> InstructionId {
         let id = self.instructions.insert(instruction_data);
-
         // Create a new vector to store the potential results for the instruction.
         self.results.insert(id, Default::default());
         id
     }
 
+    /// Insert a value into the dfg's storage and return an id to reference it.
+    /// Until the value is used in an instruction it is unreachable.
     pub(crate) fn make_value(&mut self, value: Value) -> ValueId {
         self.values.insert(value)
     }
 
-    /// Attaches results to the instruction.
+    /// Creates a new constant value, or returns the Id to an existing one if
+    /// one already exists.
+    pub(crate) fn make_constant(&mut self, value: FieldElement, typ: Type) -> ValueId {
+        let constant = self.constants.insert(NumericConstant::new(value));
+        self.values.insert(Value::NumericConstant { constant, typ })
+    }
+
+    /// Attaches results to the instruction, clearing any previous results.
     ///
-    /// Returns the number of results that this instruction
-    /// produces.
+    /// Returns the results of the instruction
     pub(crate) fn make_instruction_results(
         &mut self,
         instruction_id: InstructionId,
         ctrl_typevar: Type,
-    ) -> usize {
+    ) -> &[ValueId] {
         // Clear all of the results instructions associated with this
         // instruction.
         self.results.get_mut(&instruction_id).expect("all instructions should have a `result` allocation when instruction was added to the DFG").clear();
 
         // Get all of the types that this instruction produces
         // and append them as results.
         let typs = self.instruction_result_types(instruction_id, ctrl_typevar);
-        let num_typs = typs.len();
 
         for typ in typs {
             self.append_result(instruction_id, typ);
         }
 
-        num_typs
+        self.results.get_mut(&instruction_id)
+            .expect("all instructions should have a `result` allocation when instruction was added to the DFG")
+            .as_slice()
     }
 
     /// Return the result types of this instruction.
@@ -181,6 +199,42 @@ impl DataFlowGraph {
         block.add_parameter(parameter);
         parameter
     }
+
+    pub(crate) fn insert_instruction_in_block(
+        &mut self,
+        block: BasicBlockId,
+        instruction: InstructionId,
+    ) {
+        self.blocks[block].insert_instruction(instruction);
+    }
+}
+
+impl std::ops::Index<InstructionId> for DataFlowGraph {
+    type Output = Instruction;
+    fn index(&self, id: InstructionId) -> &Self::Output {
+        &self.instructions[id]
+    }
+}
+
+impl std::ops::Index<ValueId> for DataFlowGraph {
+    type Output = Value;
+    fn index(&self, id: ValueId) -> &Self::Output {
+        &self.values[id]
+    }
+}
+
+impl std::ops::Index<NumericConstantId> for DataFlowGraph {
+    type Output = NumericConstant;
+    fn index(&self, id: NumericConstantId) -> &Self::Output {
+        &self.constants[id]
+    }
+}
+
+impl std::ops::Index<BasicBlockId> for DataFlowGraph {
+    type Output = BasicBlock;
+    fn index(&self, id: BasicBlockId) -> &Self::Output {
+        &self.blocks[id]
+    }
 }
 
 #[cfg(test)]
@@ -190,19 +244,17 @@ mod tests {
         instruction::Instruction,
         types::{NumericType, Type},
     };
-    use acvm::FieldElement;
 
     #[test]
     fn make_instruction() {
         let mut dfg = DataFlowGraph::default();
-        let ins = Instruction::Immediate { value: FieldElement::from(0u128) };
+        let ins = Instruction::Allocate { size: 20 };
         let ins_id = dfg.make_instruction(ins);
 
         let num_results =
-            dfg.make_instruction_results(ins_id, Type::Numeric(NumericType::NativeField));
+            dfg.make_instruction_results(ins_id, Type::Numeric(NumericType::NativeField)).len();
 
         let results = dfg.instruction_results(ins_id);
-
         assert_eq!(results.len(), num_results);
     }
 }

crates/noirc_evaluator/src/ssa_refactor/ir/function.rs

@@ -18,7 +18,10 @@ pub(crate) struct Function {
     source_locations: SecondaryMap<Instruction, Location>,
 
     /// The first basic block in the function
-    entry_block: BasicBlockId,
+    pub(super) entry_block: BasicBlockId,
+
+    /// Name of the function for debugging only
+    pub(super) name: String,
 
     pub(crate) dfg: DataFlowGraph,
 }
@@ -27,10 +30,10 @@ impl Function {
     /// Creates a new function with an automatically inserted entry block.
     ///
     /// Note that any parameters to the function must be manually added later.
-    pub(crate) fn new() -> Self {
+    pub(crate) fn new(name: String) -> Self {
         let mut dfg = DataFlowGraph::default();
         let entry_block = dfg.new_block();
-        Self { source_locations: SecondaryMap::new(), entry_block, dfg }
+        Self { name, source_locations: SecondaryMap::new(), entry_block, dfg }
     }
 
     pub(crate) fn entry_block(&self) -> BasicBlockId {
@@ -47,6 +50,12 @@ pub(crate) struct Signature {
     pub(crate) returns: Vec<Type>,
 }
 
+impl std::fmt::Display for Function {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        super::printer::display_function(self, f)
+    }
+}
+
 #[test]
 fn sign_smoke() {
     let mut signature = Signature::default();