Avoid issuing inc & dec_rc outside of unconstrained code

noir-lang · Jan 3, 2025 · a34c46b · a34c46b
1 parent 54ca620
commit a34c46b
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Showing 2 changed files with 30 additions and 21 deletions.
diff --git a/compiler/noirc_evaluator/src/ssa/function_builder/mod.rs b/compiler/noirc_evaluator/src/ssa/function_builder/mod.rs
@@ -467,29 +467,33 @@ impl FunctionBuilder {
     ///
     /// Returns whether a reference count instruction was issued.
     fn update_array_reference_count(&mut self, value: ValueId, increment: bool) -> bool {
-        match self.type_of_value(value) {
-            Type::Numeric(_) => false,
-            Type::Function => false,
-            Type::Reference(element) => {
-                if element.contains_an_array() {
-                    let reference = value;
-                    let value = self.insert_load(reference, element.as_ref().clone());
-                    self.update_array_reference_count(value, increment);
-                    true
-                } else {
-                    false
+        if self.current_function.runtime().is_brillig() {
+            match self.type_of_value(value) {
+                Type::Numeric(_) => false,
+                Type::Function => false,
+                Type::Reference(element) => {
+                    if element.contains_an_array() {
+                        let reference = value;
+                        let value = self.insert_load(reference, element.as_ref().clone());
+                        self.update_array_reference_count(value, increment);
+                        true
+                    } else {
+                        false
+                    }
                 }
-            }
-            Type::Array(..) | Type::Slice(..) => {
-                // If there are nested arrays or slices, we wait until ArrayGet
-                // is issued to increment the count of that array.
-                if increment {
-                    self.insert_inc_rc(value);
-                } else {
-                    self.insert_dec_rc(value);
+                Type::Array(..) | Type::Slice(..) => {
+                    // If there are nested arrays or slices, we wait until ArrayGet
+                    // is issued to increment the count of that array.
+                    if increment {
+                        self.insert_inc_rc(value);
+                    } else {
+                        self.insert_dec_rc(value);
+                    }
+                    true
                 }
-                true
             }
+        } else {
+            false
         }
     }
 

diff --git a/compiler/noirc_evaluator/src/ssa/opt/remove_unreachable.rs b/compiler/noirc_evaluator/src/ssa/opt/remove_unreachable.rs
@@ -5,6 +5,7 @@ use fxhash::FxHashSet as HashSet;
 use crate::ssa::{
     ir::{
         function::{Function, FunctionId},
+        instruction::Instruction,
         value::Value,
     },
     ssa_gen::Ssa,
@@ -60,7 +61,11 @@ fn used_functions(func: &Function) -> BTreeSet<FunctionId> {
         let block = &func.dfg[block_id];
 
         for instruction_id in block.instructions() {
-            func.dfg[*instruction_id].for_each_value(&mut find_functions);
+            let instruction = &func.dfg[*instruction_id];
+
+            if matches!(instruction, Instruction::Store { .. } | Instruction::Call { .. }) {
+                instruction.for_each_value(&mut find_functions);
+            }
         }
 
         block.unwrap_terminator().for_each_value(&mut find_functions);