From 202d7692bc70eefa26c0ee5d01a8ad279073e8ac Mon Sep 17 00:00:00 2001
From: VegOwOtenks <vegowotenks@jossco.de>
Date: Wed, 11 Sep 2024 00:36:55 +0200
Subject: [PATCH] Implement ConvertIntToChar

---
 src/bytecode.rs | 2 ++
 src/jvm.rs      | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/src/bytecode.rs b/src/bytecode.rs
index 21185ff..38247c2 100644
--- a/src/bytecode.rs
+++ b/src/bytecode.rs
@@ -88,6 +88,7 @@ impl Bytecode {
             0x82 => (Instruction::XorInt(), 1),
             0x84 => (Instruction::IncrementLocalInt(self.bytes[offset+1], i8::from_be_bytes([self.bytes[offset+2]])), 3),
 
+            0x92 => (Instruction::ConvertIntToChar(), 1),
             0x95 => (Instruction::CompareFloatL(), 1),
             0x96 => (Instruction::CompareFloatG(), 1),
             0x99 => {
@@ -334,6 +335,7 @@ pub enum Instruction {
     XorInt()                                = 0x82, // value, value => xor
     IncrementLocalInt(u8, i8)               = 0x84, // increment local variable by constant i8
 
+    ConvertIntToChar()                      = 0x92, // truncate int to 16 bits
     CompareFloatL()                         = 0x95, // compare float, push -1 if one is NaN
     CompareFloatG()                         = 0x96, // compare float, push  1 if one is NaN
     BranchZero(i16)                         = 0x99, // branch if value == 0
diff --git a/src/jvm.rs b/src/jvm.rs
index 108a53a..731cb5f 100644
--- a/src/jvm.rs
+++ b/src/jvm.rs
@@ -914,6 +914,13 @@ impl JVM {
                     wrap_stackframe_error(class, method, frame.operand_stack.push(StackValue::Int(comparison_result)))?;
                 }
 
+                Instruction::ConvertIntToChar() => {
+                    let int_value  = wrap_stackframe_error(class, method, frame.operand_stack.pop_int(0))?;
+                    let char_value = int_value & 0x0000FFFF;
+
+                    frame.operand_stack.push(StackValue::Int(char_value)).unwrap();
+                }
+
                 Instruction::DivideInt() => {
                     // TODO: Obey all the rules
                     let quotient = wrap_stackframe_error(class, method, frame.operand_stack.pop_int(0))?;