add basic instruction encoder

Author: Robbepop

crates/wasmi/src/engine/translator/translator2/instrs.rs

@@ -0,0 +1,50 @@
+use super::{Instr, Reset};
+use crate::ir::Instruction;
+use alloc::vec::Vec;
+
+/// Creates and encodes the list of [`Instruction`]s for a function.
+#[derive(Debug, Default)]
+pub struct InstrEncoder {
+    /// The list of constructed instructions and their parameters.
+    instrs: Vec<Instruction>,
+}
+
+impl Reset for InstrEncoder {
+    fn reset(&mut self) {
+        self.instrs.clear();
+    }
+}
+
+impl InstrEncoder {
+    /// Returns the next [`Instr`].
+    #[must_use]
+    fn next_instr(&self) -> Instr {
+        Instr::from_usize(self.instrs.len())
+    }
+
+    /// Pushes an [`Instruction`] to the [`InstrEncoder`].
+    ///
+    /// Returns an [`Instr`] that refers to the pushed [`Instruction`].
+    #[must_use]
+    pub fn push_instr(&mut self, instruction: Instruction) -> Instr {
+        let instr = self.next_instr();
+        self.instrs.push(instruction);
+        instr
+    }
+
+    /// Pushes an [`Instruction`] parameter to the [`InstrEncoder`].
+    ///
+    /// The parameter is associated to the last pushed [`Instruction`].
+    pub fn push_param(&mut self, instruction: Instruction) {
+        self.instrs.push(instruction);
+    }
+
+    /// Returns a shared reference to the [`Instruction`] associated to [`Instr`].
+    ///
+    /// # Panics
+    ///
+    /// If `instr` is out of bounds for `self`.
+    pub fn get(&self, instr: Instr) -> &Instruction {
+        &self.instrs[instr.into_usize()]
+    }
+}

crates/wasmi/src/engine/translator/translator2/mod.rs

@@ -1,5 +1,6 @@
 #![expect(dead_code, unused_imports, unused_variables)]
 
+mod instrs;
 mod layout;
 #[cfg(feature = "simd")]
 mod simd;
@@ -8,14 +9,15 @@ mod utils;
 mod visit;
 
 use self::{
+    instrs::InstrEncoder,
     layout::{StackLayout, StackSpace},
     stack::{LocalIdx, Operand, OperandIdx, Stack},
     utils::Reset,
 };
 use crate::{
     core::FuelCostsProvider,
     engine::{
-        translator::{LabelRegistry, WasmTranslator},
+        translator::{Instr, LabelRegistry, WasmTranslator},
         CompiledFuncEntity,
     },
     module::{FuncIdx, ModuleHeader, WasmiValueType},
@@ -59,6 +61,8 @@ pub struct FuncTranslator {
     layout: StackLayout,
     /// Registers and pins labels and tracks their users.
     labels: LabelRegistry,
+    /// Constructs and encodes function instructions.
+    instrs: InstrEncoder,
 }
 
 /// Heap allocated data structured used by the [`FuncTranslator`].
@@ -70,6 +74,8 @@ pub struct FuncTranslatorAllocations {
     layout: StackLayout,
     /// Registers and pins labels and tracks their users.
     labels: LabelRegistry,
+    /// Constructs and encodes function instructions.
+    instrs: InstrEncoder,
 }
 
 impl WasmTranslator<'_> for FuncTranslator {
@@ -141,6 +147,7 @@ impl FuncTranslator {
             stack,
             layout,
             labels,
+            instrs,
         })
     }
 
@@ -150,6 +157,7 @@ impl FuncTranslator {
             stack: self.stack,
             layout: self.layout,
             labels: self.labels,
+            instrs: self.instrs,
         }
     }