feat(brillig): loops (#1610)

* make ranges be polymorphic integers

* feat: brillig loop support

* fix: fixed brillig returns and stop

* fix: do not apply constants folding to brillig fns

* chore: update acvm pointer, cleanup

* style: newline on cargo toml

* make behavior consistent

* remove closure

* change index_type

* Update crates/noirc_frontend/src/hir/type_check/expr.rs

* better debug information for unsupported instruction

* remove edge case for optimizations

* clippy fix

* patch infinite loop

---------

Co-authored-by: kevaundray <kevtheappdev@gmail.com>
Co-authored-by: jfecher <jake@aztecprotocol.com>

Cargo.toml

@@ -24,7 +24,7 @@ edition = "2021"
 rust-version = "1.66"
 
 [workspace.dependencies]
-acvm = "=0.14.1"
+acvm = "=0.14.2"
 arena = { path = "crates/arena" }
 fm = { path = "crates/fm" }
 iter-extended = { path = "crates/iter-extended" }

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

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

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

@@ -0,0 +1 @@
+sum = "6"

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

@@ -0,0 +1,14 @@
+// Tests a very simple program.
+// 
+// The features being tested is basic looping on brillig
+fn main(sum: u32){
+    assert(loop(4) == sum);
+}
+
+unconstrained fn loop(x: u32) -> u32 {
+    let mut sum = 0;
+    for i in 0..x {
+        sum = sum + i;
+    }
+    sum
+}

crates/noirc_evaluator/src/brillig/binary.rs

@@ -0,0 +1,106 @@
+use crate::ssa_refactor::ir::{
+    instruction::BinaryOp,
+    types::{NumericType, Type},
+};
+use acvm::acir::brillig_vm::{BinaryFieldOp, BinaryIntOp};
+
+/// Type to encapsulate the binary operation types in Brillig
+pub(crate) enum BrilligBinaryOp {
+    Field { op: BinaryFieldOp },
+    Integer { op: BinaryIntOp, bit_size: u32 },
+}
+
+impl BrilligBinaryOp {
+    /// Convert an SSA binary operation into:
+    /// - Brillig Binary Integer Op, if it is a integer type
+    /// - Brillig Binary Field Op, if it is a field type
+    pub(crate) fn convert_ssa_binary_op_to_brillig_binary_op(
+        ssa_op: BinaryOp,
+        typ: Type,
+    ) -> BrilligBinaryOp {
+        // First get the bit size and whether its a signed integer, if it is a numeric type
+        // if it is not,then we return None, indicating that
+        // it is a Field.
+        let bit_size_signedness = match typ {
+          Type::Numeric(numeric_type) => match numeric_type {
+              NumericType::Signed { bit_size } => Some((bit_size, true)),
+              NumericType::Unsigned { bit_size } => Some((bit_size, false)),
+              NumericType::NativeField => None,
+          },
+          _ => unreachable!("only numeric types are allowed in binary operations. References are handled separately"),
+      };
+
+        fn binary_op_to_field_op(op: BinaryOp) -> BinaryFieldOp {
+            match op {
+                BinaryOp::Add => BinaryFieldOp::Add,
+                BinaryOp::Sub => BinaryFieldOp::Sub,
+                BinaryOp::Mul => BinaryFieldOp::Mul,
+                BinaryOp::Div => BinaryFieldOp::Div,
+                BinaryOp::Eq => BinaryFieldOp::Equals,
+                _ => unreachable!(
+              "Field type cannot be used with {op}. This should have been caught by the frontend"
+          ),
+            }
+        }
+        fn binary_op_to_int_op(op: BinaryOp, is_signed: bool) -> BinaryIntOp {
+            match op {
+              BinaryOp::Add => BinaryIntOp::Add,
+              BinaryOp::Sub => BinaryIntOp::Sub,
+              BinaryOp::Mul => BinaryIntOp::Mul,
+              BinaryOp::Div => {
+                  if is_signed {
+                      BinaryIntOp::SignedDiv
+                  } else {
+                      BinaryIntOp::UnsignedDiv
+                  }
+              },
+              BinaryOp::Mod => todo!("This is not supported by Brillig. It should either be added into Brillig or legalized by the SSA IR"),
+              BinaryOp::Eq => BinaryIntOp::Equals,
+              BinaryOp::Lt => BinaryIntOp::LessThan,
+              BinaryOp::And => BinaryIntOp::And,
+              BinaryOp::Or => BinaryIntOp::Or,
+              BinaryOp::Xor => BinaryIntOp::Xor,
+              BinaryOp::Shl => BinaryIntOp::Shl,
+              BinaryOp::Shr => BinaryIntOp::Shr,
+          }
+        }
+        // If bit size is available then it is a binary integer operation
+        match bit_size_signedness {
+            Some((bit_size, is_signed)) => {
+                let binary_int_op = binary_op_to_int_op(ssa_op, is_signed);
+                BrilligBinaryOp::Integer { op: binary_int_op, bit_size }
+            }
+            None => {
+                let binary_field_op = binary_op_to_field_op(ssa_op);
+                BrilligBinaryOp::Field { op: binary_field_op }
+            }
+        }
+    }
+}
+
+/// Returns the type of the operation considering the types of the operands
+/// TODO: SSA issues binary operations between fields and integers.
+/// This probably should be explicitely casted in SSA to avoid having to coerce at this level.
+pub(crate) fn type_of_binary_operation(lhs_type: Type, rhs_type: Type) -> Type {
+    match (lhs_type, rhs_type) {
+        // If either side is a Field constant then, we coerce into the type
+        // of the other operand
+        (Type::Numeric(NumericType::NativeField), typ)
+        | (typ, Type::Numeric(NumericType::NativeField)) => typ,
+        // If both sides are numeric type, then we expect their types to be
+        // the same.
+        (Type::Numeric(lhs_type), Type::Numeric(rhs_type)) => {
+            assert_eq!(
+                lhs_type, rhs_type,
+                "lhs and rhs types in a binary operation are always the same"
+            );
+            Type::Numeric(lhs_type)
+        }
+        _ => {
+            unreachable!(
+                "ICE: Binary operation between types {:?} and {:?} is not allowed",
+                lhs_type, rhs_type
+            )
+        }
+    }
+}