fix: emit all allocas in the init block instead of the current block

src/compiler.rs

@@ -538,6 +538,7 @@ fn compile_func(
                         context,
                         registry,
                         module,
+                        &pre_entry_block,
                         block,
                         location,
                         metadata,
@@ -724,6 +725,7 @@ fn compile_func(
                             context,
                             registry,
                             module,
+                            &pre_entry_block,
                             block,
                             location,
                             metadata,

src/libfuncs/felt252_dict.rs

@@ -109,9 +109,14 @@ pub fn build_squash<'ctx, 'this>(
         .to_native_assert_error("runtime library should be available")?;
 
     let range_check_ptr =
-        entry.alloca1(context, location, IntegerType::new(context, 64).into(), 0)?;
+        helper
+            .init_block()
+            .alloca1(context, location, IntegerType::new(context, 64).into(), 0)?;
     entry.store(context, location, range_check_ptr, range_check)?;
-    let gas_ptr = entry.alloca1(context, location, IntegerType::new(context, 64).into(), 0)?;
+    let gas_ptr =
+        helper
+            .init_block()
+            .alloca1(context, location, IntegerType::new(context, 64).into(), 0)?;
     entry.store(context, location, gas_ptr, gas)?;
 
     runtime_bindings.dict_squash(

src/libfuncs/qm31.rs

@@ -433,8 +433,14 @@ pub fn build_binary_op<'ctx, 'this>(
     let lhs = entry.arg(0)?;
     let rhs = entry.arg(1)?;
 
-    let lhs_ptr = entry.alloca1(context, location, qm31_ty, get_integer_layout(31).align())?;
-    let rhs_ptr = entry.alloca1(context, location, qm31_ty, get_integer_layout(31).align())?;
+    let lhs_ptr =
+        helper
+            .init_block()
+            .alloca1(context, location, qm31_ty, get_integer_layout(31).align())?;
+    let rhs_ptr =
+        helper
+            .init_block()
+            .alloca1(context, location, qm31_ty, get_integer_layout(31).align())?;
 
     entry.store(context, location, lhs_ptr, lhs)?;
     entry.store(context, location, rhs_ptr, rhs)?;

src/libfuncs/squashed_dict.rs

@@ -78,7 +78,10 @@ pub fn build_into_entries<'ctx, 'this>(
         &info.branch_signatures()[0].vars[0].ty,
     )?;
     // Alloc the necessary memory
-    let array_ptr = entry.alloca1(context, location, array_ty, array_layout.align())?;
+    let array_ptr =
+        helper
+            .init_block()
+            .alloca1(context, location, array_ty, array_layout.align())?;
 
     // Runtime function that creates the array with its content
     metadata

src/metadata/runtime_bindings.rs

@@ -730,7 +730,7 @@ impl RuntimeBindingsMeta {
     pub fn libfunc_qm31_bin_op<'c, 'a>(
         &mut self,
         context: &'c Context,
-        module: &Module,
+        helper: &LibfuncHelper<'c, 'a>,
         block: &'a Block<'c>,
         lhs_ptr: Value<'c, '_>,
         rhs_ptr: Value<'c, '_>,
@@ -741,20 +741,25 @@ impl RuntimeBindingsMeta {
         'c: 'a,
     {
         let qm31_ty = llvm::r#type::array(IntegerType::new(context, 31).into(), 4);
-        let res_ptr = block.alloca1(context, location, qm31_ty, get_integer_layout(31).align())?;
+        let res_ptr = helper.init_block().alloca1(
+            context,
+            location,
+            qm31_ty,
+            get_integer_layout(31).align(),
+        )?;
 
         let function = match op {
             QM31BinaryOperator::Add => {
-                self.build_function(context, module, block, location, RuntimeBinding::QM31Add)?
+                self.build_function(context, helper, block, location, RuntimeBinding::QM31Add)?
             }
             QM31BinaryOperator::Sub => {
-                self.build_function(context, module, block, location, RuntimeBinding::QM31Sub)?
+                self.build_function(context, helper, block, location, RuntimeBinding::QM31Sub)?
             }
             QM31BinaryOperator::Mul => {
-                self.build_function(context, module, block, location, RuntimeBinding::QM31Mul)?
+                self.build_function(context, helper, block, location, RuntimeBinding::QM31Mul)?
             }
             QM31BinaryOperator::Div => {
-                self.build_function(context, module, block, location, RuntimeBinding::QM31Div)?
+                self.build_function(context, helper, block, location, RuntimeBinding::QM31Div)?
             }
         };
 

src/utils/trace_dump.rs

@@ -74,7 +74,7 @@ use cairo_lang_sierra::{
 use cairo_lang_utils::ordered_hash_map::OrderedHashMap;
 use melior::{
     helpers::LlvmBlockExt,
-    ir::{BlockRef, Location, Module, Value, ValueLike},
+    ir::{Block, BlockRef, Location, Module, Value, ValueLike},
     Context,
 };
 
@@ -88,6 +88,7 @@ pub fn build_state_snapshot(
     context: &Context,
     registry: &ProgramRegistry<CoreType, CoreLibfunc>,
     module: &Module,
+    init_block: &Block,
     block: &BlockRef,
     location: Location,
     metadata: &mut MetadataStorage,
@@ -103,7 +104,9 @@ pub fn build_state_snapshot(
 
         let layout = value_type.layout(registry).unwrap();
 
-        let value_ptr = block
+        // Allocas must live in the init block so that they are not executed on every loop
+        // iteration, which would grow the stack unboundedly.
+        let value_ptr = init_block
             .alloca1(context, location, value.r#type(), layout.align())
             .unwrap();
         block.store(context, location, value_ptr, *value).unwrap();