wip: variables

Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>

crates/llvm-context/src/polkavm/context/function/mod.rs

@@ -7,7 +7,7 @@ pub mod r#return;
 pub mod runtime;
 pub mod yul_data;
 
-use std::collections::HashMap;
+use std::collections::{BTreeMap, HashMap};
 
 use inkwell::debug_info::AsDIScope;
 
@@ -29,6 +29,10 @@ pub struct Function<'ctx> {
     declaration: Declaration<'ctx>,
     /// The stack representation.
     stack: HashMap<String, Pointer<'ctx>>,
+    /// The stack variables buffer.
+    stack_variables: inkwell::values::GlobalValue<'ctx>,
+    /// The stack variable names to slot mapping.
+    stack_slots: BTreeMap<String, usize>,
     /// The return value entity.
     r#return: Return<'ctx>,
 
@@ -53,6 +57,7 @@ impl<'ctx> Function<'ctx> {
         name: String,
         declaration: Declaration<'ctx>,
         r#return: Return<'ctx>,
+        stack_variables: inkwell::values::GlobalValue<'ctx>,
 
         entry_block: inkwell::basic_block::BasicBlock<'ctx>,
         return_block: inkwell::basic_block::BasicBlock<'ctx>,
@@ -61,6 +66,8 @@ impl<'ctx> Function<'ctx> {
             name,
             declaration,
             stack: HashMap::with_capacity(Self::STACK_HASHMAP_INITIAL_CAPACITY),
+            stack_variables,
+            stack_slots: BTreeMap::new(),
             r#return,
 
             entry_block,
@@ -279,4 +286,40 @@ impl<'ctx> Function<'ctx> {
             .as_mut()
             .expect("The Yul data must have been initialized")
     }
+
+    /// Returns the stack variables global value.
+    pub fn stack_variables(&self) -> inkwell::values::GlobalValue<'ctx> {
+        self.stack_variables
+    }
+
+    /// Returns the slot for the given variable name.
+    pub fn stack_variable_slot(&mut self, name: String) -> usize {
+        let len = self.stack_slots.len();
+        *self.stack_slots.entry(name).or_insert_with(|| len)
+    }
+
+    pub fn stack_variable_pointer<D: crate::PolkaVMDependency + Clone>(
+        &mut self,
+        name: String,
+        context: &mut super::Context<'ctx, D>,
+    ) -> Pointer<'ctx> {
+        let pointer_name = format!("var_{}", &name);
+        let slot = self.stack_variable_slot(name);
+        Pointer::new(
+            context.word_type(),
+            Default::default(),
+            unsafe {
+                context.builder().build_gep(
+                    context.word_type(),
+                    self.stack_variables().as_pointer_value(),
+                    &[
+                        context.xlen_type().const_zero(),
+                        context.xlen_type().const_int(slot as u64, false),
+                    ],
+                    &pointer_name,
+                )
+            }
+            .unwrap(),
+        )
+    }
 }

crates/llvm-context/src/polkavm/context/mod.rs

@@ -503,10 +503,17 @@ where
             }
         };
 
+        let stack_variables = format!("__vars_{name}");
+        self.declare_global(
+            &stack_variables,
+            self.word_type().array_type(0),
+            Default::default(),
+        );
         let function = Function::new(
             name.to_owned(),
             FunctionDeclaration::new(r#type, value),
             r#return,
+            self.get_global(&stack_variables).unwrap().value,
             entry_block,
             return_block,
         );

crates/llvm-context/src/polkavm/context/pointer/mod.rs

@@ -8,6 +8,7 @@ use crate::polkavm::context::Context;
 use crate::polkavm::Dependency;
 
 pub mod heap;
+//pub mod stack;
 pub mod storage;
 
 /// The LLVM pointer.

crates/llvm-context/src/polkavm/context/pointer/stack.rs

@@ -0,0 +1,111 @@
+//! The revive simulated EVM stack variable functions.
+
+use inkwell::values::BasicValueEnum;
+
+use crate::polkavm::context::runtime::RuntimeFunction;
+use crate::polkavm::context::Context;
+use crate::polkavm::Dependency;
+use crate::polkavm::WriteLLVM;
+
+/// Load a word size value from a heap pointer.
+pub struct DeclareVariable;
+
+impl<D> RuntimeFunction<D> for DeclareVariable
+where
+    D: Dependency + Clone,
+{
+    const NAME: &'static str = "__revive_declare_variable";
+
+    fn r#type<'ctx>(context: &Context<'ctx, D>) -> inkwell::types::FunctionType<'ctx> {
+        context
+            .llvm
+            .ptr_type(Default::default())
+            .fn_type(&[context.xlen_type().into()], false)
+    }
+
+    fn emit_body<'ctx>(
+        &self,
+        context: &mut Context<'ctx, D>,
+    ) -> anyhow::Result<Option<BasicValueEnum<'ctx>>> {
+        let offset = Self::paramater(context, 0).into_int_value();
+        let length = context
+            .xlen_type()
+            .const_int(revive_common::BYTE_LENGTH_WORD as u64, false);
+        let pointer = context.build_heap_gep(offset, length)?;
+        let value = context
+            .builder()
+            .build_load(context.word_type(), pointer.value, "value")?;
+        context
+            .basic_block()
+            .get_last_instruction()
+            .expect("Always exists")
+            .set_alignment(revive_common::BYTE_LENGTH_BYTE as u32)
+            .expect("Alignment is valid");
+
+        let swapped_value = context.build_byte_swap(value)?;
+        Ok(Some(swapped_value))
+    }
+}
+
+impl<D> WriteLLVM<D> for LoadWord
+where
+    D: Dependency + Clone,
+{
+    fn declare(&mut self, context: &mut Context<D>) -> anyhow::Result<()> {
+        <Self as RuntimeFunction<_>>::declare(self, context)
+    }
+
+    fn into_llvm(self, context: &mut Context<D>) -> anyhow::Result<()> {
+        <Self as RuntimeFunction<_>>::emit(&self, context)
+    }
+}
+
+/// Store a word size value through a heap pointer.
+pub struct StoreWord;
+
+impl<D> RuntimeFunction<D> for StoreWord
+where
+    D: Dependency + Clone,
+{
+    const NAME: &'static str = "__revive_store_heap_word";
+
+    fn r#type<'ctx>(context: &Context<'ctx, D>) -> inkwell::types::FunctionType<'ctx> {
+        context.void_type().fn_type(
+            &[context.xlen_type().into(), context.word_type().into()],
+            false,
+        )
+    }
+
+    fn emit_body<'ctx>(
+        &self,
+        context: &mut Context<'ctx, D>,
+    ) -> anyhow::Result<Option<BasicValueEnum<'ctx>>> {
+        let offset = Self::paramater(context, 0).into_int_value();
+        let length = context
+            .xlen_type()
+            .const_int(revive_common::BYTE_LENGTH_WORD as u64, false);
+        let pointer = context.build_heap_gep(offset, length)?;
+
+        let value = context.build_byte_swap(Self::paramater(context, 1))?;
+
+        context
+            .builder()
+            .build_store(pointer.value, value)?
+            .set_alignment(revive_common::BYTE_LENGTH_BYTE as u32)
+            .expect("Alignment is valid");
+        Ok(None)
+    }
+}
+
+impl<D> WriteLLVM<D> for StoreWord
+where
+    D: Dependency + Clone,
+{
+    fn declare(&mut self, context: &mut Context<D>) -> anyhow::Result<()> {
+        <Self as RuntimeFunction<_>>::declare(self, context)
+    }
+
+    fn into_llvm(self, context: &mut Context<D>) -> anyhow::Result<()> {
+        <Self as RuntimeFunction<_>>::emit(&self, context)
+    }
+}