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

@@ -4,5 +4,6 @@ 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/dfg.rs

@@ -1,6 +1,6 @@
 use super::{
     basic_block::{BasicBlock, BasicBlockId},
-    constant::NumericConstant,
+    constant::{NumericConstant, NumericConstantId},
     function::Signature,
     instruction::{Instruction, InstructionId},
     map::{DenseMap, Id, SecondaryMap, TwoWayMap},
@@ -209,6 +209,34 @@ impl DataFlowGraph {
     }
 }
 
+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)]
 mod tests {
     use super::DataFlowGraph;

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();

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

@@ -15,6 +15,12 @@ pub(crate) type InstructionId = Id<Instruction>;
 /// of this is println.
 pub(crate) struct IntrinsicOpcodes;
 
+impl std::fmt::Display for IntrinsicOpcodes {
+    fn fmt(&self, _f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        todo!("intrinsics have no opcodes yet")
+    }
+}
+
 #[derive(Debug, PartialEq, Eq, Hash, Clone)]
 /// Instructions are used to perform tasks.
 /// The instructions that the IR is able to specify are listed below.
@@ -189,5 +195,18 @@ pub(crate) enum BinaryOp {
     /// Checks whether two types are equal.
     /// Returns true if the types were not equal and
     /// false otherwise.
-    Ne,
+    Neq,
+}
+
+impl std::fmt::Display for BinaryOp {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            BinaryOp::Add => write!(f, "add"),
+            BinaryOp::Sub => write!(f, "sub"),
+            BinaryOp::Mul => write!(f, "mul"),
+            BinaryOp::Div => write!(f, "div"),
+            BinaryOp::Eq => write!(f, "eq"),
+            BinaryOp::Neq => write!(f, "neq"),
+        }
+    }
 }

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

@@ -69,6 +69,12 @@ impl<T> std::fmt::Debug for Id<T> {
     }
 }
 
+impl<T> std::fmt::Display for Id<T> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "${}", self.index)
+    }
+}
+
 /// A DenseMap is a Vec wrapper where each element corresponds
 /// to a unique ID that can be used to access the element. No direct
 /// access to indices is provided. Since IDs must be stable and correspond

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

@@ -0,0 +1,115 @@
+//! This file is for pretty-printing the SSA IR in a human-readable form for debugging.
+use std::fmt::{Formatter, Result};
+
+use iter_extended::vecmap;
+
+use super::{
+    basic_block::BasicBlockId,
+    function::Function,
+    instruction::{Instruction, InstructionId, TerminatorInstruction},
+    value::ValueId,
+};
+
+pub(crate) fn display_function(function: &Function, f: &mut Formatter) -> Result {
+    writeln!(f, "fn {} {{", function.name)?;
+    display_block_with_successors(function, function.entry_block, f)?;
+    write!(f, "}}")
+}
+
+pub(crate) fn display_block_with_successors(
+    function: &Function,
+    block_id: BasicBlockId,
+    f: &mut Formatter,
+) -> Result {
+    display_block(function, block_id, f)?;
+
+    for successor in function.dfg[block_id].successors() {
+        display_block(function, successor, f)?;
+    }
+    Ok(())
+}
+
+pub(crate) fn display_block(
+    function: &Function,
+    block_id: BasicBlockId,
+    f: &mut Formatter,
+) -> Result {
+    let block = &function.dfg[block_id];
+
+    writeln!(f, "{}({}):", block_id, value_list(block.parameters()))?;
+
+    for instruction in block.instructions() {
+        display_instruction(function, *instruction, f)?;
+    }
+
+    display_terminator(block.terminator(), f)
+}
+
+fn value_list(values: &[ValueId]) -> String {
+    vecmap(values, ToString::to_string).join(", ")
+}
+
+pub(crate) fn display_terminator(
+    terminator: Option<&TerminatorInstruction>,
+    f: &mut Formatter,
+) -> Result {
+    match terminator {
+        Some(TerminatorInstruction::Jmp { destination, arguments }) => {
+            writeln!(f, "    jmp {}({})", destination, value_list(arguments))
+        }
+        Some(TerminatorInstruction::JmpIf {
+            condition,
+            arguments,
+            then_destination,
+            else_destination,
+        }) => {
+            let args = value_list(arguments);
+            writeln!(
+                f,
+                "    jmpif {}({}) then: {}, else: {}",
+                condition, args, then_destination, else_destination
+            )
+        }
+        Some(TerminatorInstruction::Return { return_values }) => {
+            writeln!(f, "    return {}", value_list(return_values))
+        }
+        None => writeln!(f, "    (no terminator instruction)"),
+    }
+}
+
+pub(crate) fn display_instruction(
+    function: &Function,
+    instruction: InstructionId,
+    f: &mut Formatter,
+) -> Result {
+    // instructions are always indented within a function
+    write!(f, "    ")?;
+
+    let results = function.dfg.instruction_results(instruction);
+    if !results.is_empty() {
+        write!(f, "{} = ", value_list(results))?;
+    }
+
+    match &function.dfg[instruction] {
+        Instruction::Binary(binary) => {
+            writeln!(f, "{} {}, {}", binary.operator, binary.lhs, binary.rhs)
+        }
+        Instruction::Cast(value, typ) => writeln!(f, "cast {value} as {typ}"),
+        Instruction::Not(value) => writeln!(f, "not {value}"),
+        Instruction::Truncate { value, bit_size, max_bit_size } => {
+            writeln!(f, "truncate {value} to {bit_size} bits, max_bit_size: {max_bit_size}")
+        }
+        Instruction::Constrain(value) => {
+            writeln!(f, "constrain {value}")
+        }
+        Instruction::Call { func, arguments } => {
+            writeln!(f, "call {func}({})", value_list(arguments))
+        }
+        Instruction::Intrinsic { func, arguments } => {
+            writeln!(f, "intrinsic {func}({})", value_list(arguments))
+        }
+        Instruction::Allocate { size } => writeln!(f, "alloc {size} fields"),
+        Instruction::Load { address } => writeln!(f, "load {address}"),
+        Instruction::Store { address, value } => writeln!(f, "store {value} at {address}"),
+    }
+}

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

@@ -42,3 +42,24 @@ impl Type {
         Type::Numeric(NumericType::NativeField)
     }
 }
+
+impl std::fmt::Display for Type {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Type::Numeric(numeric) => numeric.fmt(f),
+            Type::Reference => write!(f, "reference"),
+            Type::Function => write!(f, "function"),
+            Type::Unit => write!(f, "unit"),
+        }
+    }
+}
+
+impl std::fmt::Display for NumericType {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            NumericType::Signed { bit_size } => write!(f, "i{bit_size}"),
+            NumericType::Unsigned { bit_size } => write!(f, "u{bit_size}"),
+            NumericType::NativeField => write!(f, "Field"),
+        }
+    }
+}

crates/noirc_evaluator/src/ssa_refactor/ssa_builder/function_builder.rs

@@ -29,8 +29,8 @@ pub(crate) struct FunctionBuilder<'ssa> {
 }
 
 impl<'ssa> FunctionBuilder<'ssa> {
-    pub(crate) fn new(context: &'ssa SharedBuilderContext) -> Self {
-        let new_function = Function::new();
+    pub(crate) fn new(function_name: String, context: &'ssa SharedBuilderContext) -> Self {
+        let new_function = Function::new(function_name);
         let current_block = new_function.entry_block();
 
         Self {
@@ -43,8 +43,8 @@ impl<'ssa> FunctionBuilder<'ssa> {
     }
 
     /// Finish the current function and create a new function
-    pub(crate) fn new_function(&mut self) {
-        let new_function = Function::new();
+    pub(crate) fn new_function(&mut self, name: String) {
+        let new_function = Function::new(name);
         let old_function = std::mem::replace(&mut self.current_function, new_function);
 
         self.finished_functions.push((self.current_function_id, old_function));

crates/noirc_evaluator/src/ssa_refactor/ssa_gen/context.rs

@@ -32,22 +32,23 @@ pub(super) struct SharedContext {
 
 impl<'a> FunctionContext<'a> {
     pub(super) fn new(
+        function_name: String,
         parameters: &Parameters,
         shared_context: &'a SharedContext,
         shared_builder_context: &'a SharedBuilderContext,
     ) -> Self {
         let mut this = Self {
             definitions: HashMap::new(),
-            builder: FunctionBuilder::new(shared_builder_context),
+            builder: FunctionBuilder::new(function_name, shared_builder_context),
             shared_context,
         };
         this.add_parameters_to_scope(parameters);
         this
     }
 
-    pub(super) fn new_function(&mut self, parameters: &Parameters) {
+    pub(super) fn new_function(&mut self, name: String, parameters: &Parameters) {
         self.definitions.clear();
-        self.builder.new_function();
+        self.builder.new_function(name);
         self.add_parameters_to_scope(parameters);
     }
 

crates/noirc_evaluator/src/ssa_refactor/ssa_gen/mod.rs

@@ -19,14 +19,15 @@ pub(crate) fn generate_ssa(program: Program) {
     let builder_context = SharedBuilderContext::default();
 
     let main = context.program.main();
+    let mut function_context =
+        FunctionContext::new(main.name.clone(), &main.parameters, &context, &builder_context);
 
-    let mut function_context = FunctionContext::new(&main.parameters, &context, &builder_context);
     function_context.codegen_expression(&main.body);
 
     while let Some((src_function_id, _new_id)) = context.pop_next_function_in_queue() {
         let function = &context.program[src_function_id];
         // TODO: Need to ensure/assert the new function's id == new_id
-        function_context.new_function(&function.parameters);
+        function_context.new_function(function.name.clone(), &function.parameters);
         function_context.codegen_expression(&function.body);
     }
 }