fix(ssa refactor): allow simplified call inserts & fix const radix ar…

…g handling (#1774)

* fix(ssa refactor): allow simplified call inserts

* fix(ssa refactor): bad radix arg handling

* chore(ssa refactor): cp working test

* Use Cow to avoid clones

* Change _y to a

---------

Co-authored-by: Jake Fecher <jake@aztecprotocol.com>

crates/nargo_cli/tests/test_data_ssa_refactor/to_bytes_integration/Nargo.toml

@@ -0,0 +1,5 @@
+[package]
+authors = [""]
+compiler_version = "0.1"
+
+[dependencies]

crates/nargo_cli/tests/test_data_ssa_refactor/to_bytes_integration/Prover.toml

@@ -0,0 +1,2 @@
+x = "2040124"
+a = "0x2000000000000000000000000000000000000000000000000000000000000000"

crates/nargo_cli/tests/test_data_ssa_refactor/to_bytes_integration/src/main.nr

@@ -0,0 +1,25 @@
+use dep::std;
+
+fn main(x : Field, a: Field)  {
+    let y: Field = 2040124;
+    let be_byte_array = y.to_be_bytes(31);
+    let le_byte_array = x.to_le_bytes(31);
+
+    assert(le_byte_array[0] == 60);
+    assert(le_byte_array[0] == be_byte_array[30]);
+    assert(le_byte_array[1] == be_byte_array[29]);
+    assert(le_byte_array[2] == be_byte_array[28]);
+
+    let z = 0 - 1;
+    let p_bytes = std::field::modulus_le_bytes();
+    let z_bytes = z.to_le_bytes(32);
+    assert(p_bytes[10] == z_bytes[10]);
+    assert(p_bytes[0] == z_bytes[0] as u8 + 1 as u8);
+
+    let p_bits = std::field::modulus_le_bits();
+    let z_bits = z.to_le_bits(std::field::modulus_num_bits() as u32);
+    assert(z_bits[0] == 0);
+    assert(p_bits[100] == z_bits[100]);
+
+    a.to_le_bits(std::field::modulus_num_bits() as u32);
+}

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

@@ -1,4 +1,4 @@
-use std::{collections::HashMap, rc::Rc};
+use std::{borrow::Cow, collections::HashMap, rc::Rc};
 
 use crate::ssa_refactor::ir::instruction::SimplifyResult;
 
@@ -414,14 +414,11 @@ impl<'dfg> InsertInstructionResult<'dfg> {
     }
 
     /// Return all the results contained in the internal results array.
-    /// This is used for instructions returning multiple results that were
-    /// not simplified - like function calls.
-    pub(crate) fn results(&self) -> &'dfg [ValueId] {
+    /// This is used for instructions returning multiple results like function calls.
+    pub(crate) fn results(&self) -> Cow<'dfg, [ValueId]> {
         match self {
-            InsertInstructionResult::Results(results) => results,
-            InsertInstructionResult::SimplifiedTo(_) => {
-                panic!("InsertInstructionResult::results called on a simplified instruction")
-            }
+            InsertInstructionResult::Results(results) => Cow::Borrowed(results),
+            InsertInstructionResult::SimplifiedTo(result) => Cow::Owned(vec![*result]),
             InsertInstructionResult::InstructionRemoved => {
                 panic!("InsertInstructionResult::results called on a removed instruction")
             }

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

@@ -378,7 +378,7 @@ fn simplify_call(func: ValueId, arguments: &[ValueId], dfg: &mut DataFlowGraph)
         Intrinsic::ToRadix(endian) => {
             let field = constant_args[0];
             let radix = constant_args[1].to_u128() as u32;
-            let limb_count = constant_args[1].to_u128() as u32;
+            let limb_count = constant_args[2].to_u128() as u32;
             SimplifiedTo(constant_to_radix(endian, field, radix, limb_count, dfg))
         }
         Intrinsic::BlackBox(_) | Intrinsic::Println | Intrinsic::Sort => None,

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

@@ -1,4 +1,4 @@
-use std::rc::Rc;
+use std::{borrow::Cow, rc::Rc};
 
 use acvm::FieldElement;
 
@@ -236,7 +236,7 @@ impl FunctionBuilder {
         func: ValueId,
         arguments: Vec<ValueId>,
         result_types: Vec<Type>,
-    ) -> &[ValueId] {
+    ) -> Cow<[ValueId]> {
         self.insert_instruction(Instruction::Call { func, arguments }, Some(result_types)).results()
     }
 
@@ -348,3 +348,46 @@ impl std::ops::Index<BasicBlockId> for FunctionBuilder {
         &self.current_function.dfg[id]
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use std::rc::Rc;
+
+    use acvm::FieldElement;
+
+    use crate::ssa_refactor::ir::{
+        function::RuntimeType,
+        instruction::{Endian, Intrinsic},
+        map::Id,
+        types::Type,
+        value::Value,
+    };
+
+    use super::FunctionBuilder;
+
+    #[test]
+    fn insert_constant_call() {
+        // `bits` should be an array of constants [1, 1, 1, 0...]:
+        // let x = 7;
+        // let bits = x.to_le_bits(8);
+        let func_id = Id::test_new(0);
+        let mut builder = FunctionBuilder::new("func".into(), func_id, RuntimeType::Acir);
+        let one = builder.numeric_constant(FieldElement::one(), Type::bool());
+        let zero = builder.numeric_constant(FieldElement::zero(), Type::bool());
+
+        let to_bits_id = builder.import_intrinsic_id(Intrinsic::ToBits(Endian::Little));
+        let input = builder.numeric_constant(FieldElement::from(7_u128), Type::field());
+        let length = builder.numeric_constant(FieldElement::from(8_u128), Type::field());
+        let result_types = vec![Type::Array(Rc::new(vec![Type::bool()]), 8)];
+        let call_result = builder.insert_call(to_bits_id, vec![input, length], result_types)[0];
+
+        let array = match &builder.current_function.dfg[call_result] {
+            Value::Array { array, .. } => array,
+            _ => panic!(),
+        };
+        assert_eq!(array[0], one);
+        assert_eq!(array[1], one);
+        assert_eq!(array[2], one);
+        assert_eq!(array[3], zero);
+    }
+}