feat: add (x | 1) optimization for booleans (#6795)

noir-lang · Dec 12, 2024 · feec2a1 · feec2a1
1 parent 919149d
commit feec2a1
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Showing 3 changed files with 16 additions and 11 deletions.
diff --git a/compiler/noirc_evaluator/src/ssa/ir/instruction/binary.rs b/compiler/noirc_evaluator/src/ssa/ir/instruction/binary.rs
@@ -256,6 +256,10 @@ impl Binary {
                 if rhs_is_zero {
                     return SimplifyResult::SimplifiedTo(self.lhs);
                 }
+                if operand_type == NumericType::bool() && (lhs_is_one || rhs_is_one) {
+                    let one = dfg.make_constant(FieldElement::one(), operand_type);
+                    return SimplifyResult::SimplifiedTo(one);
+                }
                 if dfg.resolve(self.lhs) == dfg.resolve(self.rhs) {
                     return SimplifyResult::SimplifiedTo(self.lhs);
                 }

diff --git a/compiler/noirc_evaluator/src/ssa/ir/instruction/call.rs b/compiler/noirc_evaluator/src/ssa/ir/instruction/call.rs
@@ -480,20 +480,14 @@ fn simplify_slice_push_back(
 }
 
 fn simplify_slice_pop_back(
-    element_type: Type,
+    slice_type: Type,
     arguments: &[ValueId],
     dfg: &mut DataFlowGraph,
     block: BasicBlockId,
     call_stack: CallStack,
 ) -> SimplifyResult {
-    let element_types = match element_type.clone() {
-        Type::Slice(element_types) | Type::Array(element_types, _) => element_types,
-        _ => {
-            unreachable!("ICE: Expected slice or array, but got {element_type}");
-        }
-    };
-
-    let element_count = element_type.element_size();
+    let element_types = slice_type.element_types();
+    let element_count = element_types.len();
     let mut results = VecDeque::with_capacity(element_count + 1);
 
     let new_slice_length = update_slice_length(arguments[0], dfg, BinaryOp::Sub, block);
@@ -507,14 +501,17 @@ fn simplify_slice_pop_back(
     flattened_len = update_slice_length(flattened_len, dfg, BinaryOp::Sub, block);
 
     // We must pop multiple elements in the case of a slice of tuples
-    for _ in 0..element_count {
+    // Iterating through element types in reverse here since we're popping from the end
+    for element_type in element_types.iter().rev() {
         let get_last_elem_instr =
             Instruction::ArrayGet { array: arguments[1], index: flattened_len };
+
+        let element_type = Some(vec![element_type.clone()]);
         let get_last_elem = dfg
             .insert_instruction_and_results(
                 get_last_elem_instr,
                 block,
-                Some(element_types.to_vec()),
+                element_type,
                 call_stack.clone(),
             )
             .first();

diff --git a/compiler/noirc_evaluator/src/ssa/ir/instruction/call/blackbox.rs b/compiler/noirc_evaluator/src/ssa/ir/instruction/call/blackbox.rs
@@ -173,7 +173,11 @@ pub(super) fn simplify_msm(
                 var_scalars.push(zero);
                 let result_x = dfg.make_constant(result_x, NumericType::NativeField);
                 let result_y = dfg.make_constant(result_y, NumericType::NativeField);
+
+                // Pushing a bool here is intentional, multi_scalar_mul takes two arguments:
+                // `points: [(Field, Field, bool); N]` and `scalars: [(Field, Field); N]`.
                 let result_is_infinity = dfg.make_constant(result_is_infinity, NumericType::bool());
+
                 var_points.push(result_x);
                 var_points.push(result_y);
                 var_points.push(result_is_infinity);