feat: SSA parser (#6489)

Co-authored-by: Tom French <[email protected]>

compiler/noirc_evaluator/Cargo.toml

@@ -20,6 +20,7 @@ fxhash.workspace = true
 iter-extended.workspace = true
 thiserror.workspace = true
 num-bigint = "0.4"
+num-traits.workspace = true
 im.workspace = true
 serde.workspace = true
 serde_json.workspace = true
@@ -31,7 +32,8 @@ cfg-if.workspace = true
 
 [dev-dependencies]
 proptest.workspace = true
+similar-asserts.workspace = true
 
 [features]
 bn254 = ["noirc_frontend/bn254"]
-bls12_381= []
+bls12_381 = []

compiler/noirc_evaluator/src/lib.rs

@@ -12,3 +12,21 @@ pub mod ssa;
 pub mod brillig;
 
 pub use ssa::create_program;
+
+/// Trims leading whitespace from each line of the input string, according to
+/// how much leading whitespace there is on the first non-empty line.
+#[cfg(test)]
+pub(crate) fn trim_leading_whitespace_from_lines(src: &str) -> String {
+    let mut lines = src.trim_end().lines();
+    let mut first_line = lines.next().unwrap();
+    while first_line.is_empty() {
+        first_line = lines.next().unwrap();
+    }
+    let indent = first_line.len() - first_line.trim_start().len();
+    let mut result = first_line.trim_start().to_string();
+    for line in lines {
+        result.push('\n');
+        result.push_str(&line[indent..]);
+    }
+    result
+}

compiler/noirc_evaluator/src/ssa.rs

@@ -45,6 +45,7 @@ mod checks;
 pub(super) mod function_builder;
 pub mod ir;
 mod opt;
+mod parser;
 pub mod ssa_gen;
 
 pub struct SsaEvaluatorOptions {

compiler/noirc_evaluator/src/ssa/function_builder/mod.rs

@@ -327,6 +327,16 @@ impl FunctionBuilder {
             .first()
     }
 
+    pub(crate) fn insert_mutable_array_set(
+        &mut self,
+        array: ValueId,
+        index: ValueId,
+        value: ValueId,
+    ) -> ValueId {
+        self.insert_instruction(Instruction::ArraySet { array, index, value, mutable: true }, None)
+            .first()
+    }
+
     /// Insert an instruction to increment an array's reference count. This only has an effect
     /// in unconstrained code where arrays are reference counted and copy on write.
     pub(crate) fn insert_inc_rc(&mut self, value: ValueId) {

compiler/noirc_evaluator/src/ssa/ir/printer.rs

@@ -70,9 +70,16 @@ fn value(function: &Function, id: ValueId) -> String {
         }
         Value::Function(id) => id.to_string(),
         Value::Intrinsic(intrinsic) => intrinsic.to_string(),
-        Value::Array { array, .. } => {
+        Value::Array { array, typ } => {
             let elements = vecmap(array, |element| value(function, *element));
-            format!("[{}]", elements.join(", "))
+            let element_types = &typ.clone().element_types();
+            let element_types_str =
+                element_types.iter().map(|typ| typ.to_string()).collect::<Vec<String>>().join(", ");
+            if element_types.len() == 1 {
+                format!("[{}] of {}", elements.join(", "), element_types_str)
+            } else {
+                format!("[{}] of ({})", elements.join(", "), element_types_str)
+            }
         }
         Value::Param { .. } | Value::Instruction { .. } | Value::ForeignFunction(_) => {
             id.to_string()
@@ -120,7 +127,11 @@ pub(crate) fn display_terminator(
             )
         }
         Some(TerminatorInstruction::Return { return_values, .. }) => {
-            writeln!(f, "    return {}", value_list(function, return_values))
+            if return_values.is_empty() {
+                writeln!(f, "    return")
+            } else {
+                writeln!(f, "    return {}", value_list(function, return_values))
+            }
         }
         None => writeln!(f, "    (no terminator instruction)"),
     }
@@ -140,12 +151,13 @@ pub(crate) fn display_instruction(
         write!(f, "{} = ", value_list(function, results))?;
     }
 
-    display_instruction_inner(function, &function.dfg[instruction], f)
+    display_instruction_inner(function, &function.dfg[instruction], results, f)
 }
 
 fn display_instruction_inner(
     function: &Function,
     instruction: &Instruction,
+    results: &[ValueId],
     f: &mut Formatter,
 ) -> Result {
     let show = |id| value(function, id);
@@ -169,18 +181,29 @@ fn display_instruction_inner(
             }
         }
         Instruction::Call { func, arguments } => {
-            writeln!(f, "call {}({})", show(*func), value_list(function, arguments))
+            let arguments = value_list(function, arguments);
+            writeln!(f, "call {}({}){}", show(*func), arguments, result_types(function, results))
+        }
+        Instruction::Allocate => {
+            writeln!(f, "allocate{}", result_types(function, results))
+        }
+        Instruction::Load { address } => {
+            writeln!(f, "load {}{}", show(*address), result_types(function, results))
         }
-        Instruction::Allocate => writeln!(f, "allocate"),
-        Instruction::Load { address } => writeln!(f, "load {}", show(*address)),
         Instruction::Store { address, value } => {
             writeln!(f, "store {} at {}", show(*value), show(*address))
         }
         Instruction::EnableSideEffectsIf { condition } => {
             writeln!(f, "enable_side_effects {}", show(*condition))
         }
         Instruction::ArrayGet { array, index } => {
-            writeln!(f, "array_get {}, index {}", show(*array), show(*index))
+            writeln!(
+                f,
+                "array_get {}, index {}{}",
+                show(*array),
+                show(*index),
+                result_types(function, results)
+            )
         }
         Instruction::ArraySet { array, index, value, mutable } => {
             let array = show(*array);
@@ -211,6 +234,17 @@ fn display_instruction_inner(
     }
 }
 
+fn result_types(function: &Function, results: &[ValueId]) -> String {
+    let types = vecmap(results, |result| function.dfg.type_of_value(*result).to_string());
+    if types.is_empty() {
+        String::new()
+    } else if types.len() == 1 {
+        format!(" -> {}", types[0])
+    } else {
+        format!(" -> ({})", types.join(", "))
+    }
+}
+
 /// Tries to extract a constant string from an error payload.
 pub(crate) fn try_to_extract_string_from_error_payload(
     error_selector: ErrorSelector,

compiler/noirc_evaluator/src/ssa/ir/types.rs

@@ -229,7 +229,11 @@ impl std::fmt::Display for Type {
             Type::Reference(element) => write!(f, "&mut {element}"),
             Type::Array(element, length) => {
                 let elements = vecmap(element.iter(), |element| element.to_string());
-                write!(f, "[{}; {length}]", elements.join(", "))
+                if elements.len() == 1 {
+                    write!(f, "[{}; {length}]", elements.join(", "))
+                } else {
+                    write!(f, "[({}); {length}]", elements.join(", "))
+                }
             }
             Type::Slice(element) => {
                 let elements = vecmap(element.iter(), |element| element.to_string());

compiler/noirc_evaluator/src/ssa/opt/array_set.rs

@@ -206,135 +206,47 @@ fn make_mutable(
 
 #[cfg(test)]
 mod tests {
-    use std::sync::Arc;
-
-    use im::vector;
-    use noirc_frontend::monomorphization::ast::InlineType;
-
-    use crate::ssa::{
-        function_builder::FunctionBuilder,
-        ir::{
-            function::RuntimeType,
-            instruction::{BinaryOp, Instruction},
-            map::Id,
-            types::Type,
-        },
-    };
+    use crate::ssa::{opt::assert_normalized_ssa_equals, Ssa};
 
     #[test]
     fn array_set_in_loop_with_conditional_clone() {
         // We want to make sure that we do not mark a single array set mutable which is loaded
         // from and cloned in a loop. If the array is inadvertently marked mutable, and is cloned in a previous iteration
         // of the loop, its clone will also be altered.
-        //
-        // brillig fn main f0 {
-        //     b0():
-        //       v3 = allocate
-        //       store [[Field 0, Field 0, Field 0, Field 0, Field 0], [Field 0, Field 0, Field 0, Field 0, Field 0]] at v3
-        //       v4 = allocate
-        //       store [[Field 0, Field 0, Field 0, Field 0, Field 0], [Field 0, Field 0, Field 0, Field 0, Field 0]] at v4
-        //       jmp b1(u32 0)
-        //     b1(v6: u32):
-        //       v8 = lt v6, u32 5
-        //       jmpif v8 then: b3, else: b2
-        //     b3():
-        //       v9 = eq v6, u32 5
-        //       jmpif v9 then: b4, else: b5
-        //     b4():
-        //       v10 = load v3
-        //       store v10 at v4
-        //       jmp b5()
-        //     b5():
-        //       v11 = load v3
-        //       v13 = array_get v11, index Field 0
-        //       v14 = array_set v13, index v6, value Field 20
-        //       v15 = array_set v11, index v6, value v14
-        //       store v15 at v3
-        //       v17 = add v6, u32 1
-        //       jmp b1(v17)
-        //     b2():
-        //       return
-        //   }
-        let main_id = Id::test_new(0);
-        let mut builder = FunctionBuilder::new("main".into(), main_id);
-        builder.set_runtime(RuntimeType::Brillig(InlineType::default()));
-
-        let array_type = Type::Array(Arc::new(vec![Type::field()]), 5);
-        let zero = builder.field_constant(0u128);
-        let array_constant =
-            builder.array_constant(vector![zero, zero, zero, zero, zero], array_type.clone());
-        let nested_array_type = Type::Array(Arc::new(vec![array_type.clone()]), 2);
-        let nested_array_constant = builder
-            .array_constant(vector![array_constant, array_constant], nested_array_type.clone());
-
-        let v3 = builder.insert_allocate(array_type.clone());
-
-        builder.insert_store(v3, nested_array_constant);
-
-        let v4 = builder.insert_allocate(array_type.clone());
-        builder.insert_store(v4, nested_array_constant);
-
-        let b1 = builder.insert_block();
-        let zero_u32 = builder.numeric_constant(0u128, Type::unsigned(32));
-        builder.terminate_with_jmp(b1, vec![zero_u32]);
-
-        // Loop header
-        builder.switch_to_block(b1);
-        let v5 = builder.add_block_parameter(b1, Type::unsigned(32));
-        let five = builder.numeric_constant(5u128, Type::unsigned(32));
-        let v8 = builder.insert_binary(v5, BinaryOp::Lt, five);
-
-        let b2 = builder.insert_block();
-        let b3 = builder.insert_block();
-        let b4 = builder.insert_block();
-        let b5 = builder.insert_block();
-        builder.terminate_with_jmpif(v8, b3, b2);
-
-        // Loop body
-        // b3 is the if statement conditional
-        builder.switch_to_block(b3);
-        let two = builder.numeric_constant(5u128, Type::unsigned(32));
-        let v9 = builder.insert_binary(v5, BinaryOp::Eq, two);
-        builder.terminate_with_jmpif(v9, b4, b5);
-
-        // b4 is the rest of the loop after the if statement
-        builder.switch_to_block(b4);
-        let v10 = builder.insert_load(v3, nested_array_type.clone());
-        builder.insert_store(v4, v10);
-        builder.terminate_with_jmp(b5, vec![]);
-
-        builder.switch_to_block(b5);
-        let v11 = builder.insert_load(v3, nested_array_type.clone());
-        let twenty = builder.field_constant(20u128);
-        let v13 = builder.insert_array_get(v11, zero, array_type.clone());
-        let v14 = builder.insert_array_set(v13, v5, twenty);
-        let v15 = builder.insert_array_set(v11, v5, v14);
-
-        builder.insert_store(v3, v15);
-        let one = builder.numeric_constant(1u128, Type::unsigned(32));
-        let v17 = builder.insert_binary(v5, BinaryOp::Add, one);
-        builder.terminate_with_jmp(b1, vec![v17]);
-
-        builder.switch_to_block(b2);
-        builder.terminate_with_return(vec![]);
+        let src = "
+            brillig(inline) fn main f0 {
+              b0():
+                v1 = allocate -> &mut [Field; 5]
+                store [[Field 0, Field 0, Field 0, Field 0, Field 0] of Field, [Field 0, Field 0, Field 0, Field 0, Field 0] of Field] of [Field; 5] at v1
+                v6 = allocate -> &mut [Field; 5]
+                store [[Field 0, Field 0, Field 0, Field 0, Field 0] of Field, [Field 0, Field 0, Field 0, Field 0, Field 0] of Field] of [Field; 5] at v6
+                jmp b1(u32 0)
+              b1(v0: u32):
+                v12 = lt v0, u32 5
+                jmpif v12 then: b3, else: b2
+              b3():
+                v13 = eq v0, u32 5
+                jmpif v13 then: b4, else: b5
+              b4():
+                v14 = load v1 -> [[Field; 5]; 2]
+                store v14 at v6
+                jmp b5()
+              b5():
+                v15 = load v1 -> [[Field; 5]; 2]
+                v16 = array_get v15, index Field 0 -> [Field; 5]
+                v18 = array_set v16, index v0, value Field 20
+                v19 = array_set v15, index v0, value v18
+                store v19 at v1
+                v21 = add v0, u32 1
+                jmp b1(v21)
+              b2():
+                return
+            }
+            ";
+        let ssa = Ssa::from_str(src).unwrap();
 
-        let ssa = builder.finish();
         // We expect the same result as above
         let ssa = ssa.array_set_optimization();
-
-        let main = ssa.main();
-        assert_eq!(main.reachable_blocks().len(), 6);
-
-        let array_set_instructions = main.dfg[b5]
-            .instructions()
-            .iter()
-            .filter(|instruction| matches!(&main.dfg[**instruction], Instruction::ArraySet { .. }))
-            .collect::<Vec<_>>();
-
-        assert_eq!(array_set_instructions.len(), 2);
-        if let Instruction::ArraySet { mutable, .. } = &main.dfg[*array_set_instructions[0]] {
-            // The single array set should not be marked mutable
-            assert!(!mutable);
-        }
+        assert_normalized_ssa_equals(ssa, src);
     }
 }