🔄 From Solidity to Bytecode: How Code Runs
Understand compilation, opcodes, and how the EVM executes instructions
Your Progress
0 / 5 completed←
Previous
Introduction
⚙️ How EVM Works
EVM executes smart contracts step-by-step using bytecode instructions (opcodes). Let's watch a simple contract add two numbers and save the result!
🎮 Interactive: EVM Execution Simulator
Step through a simple smart contract that adds 5 + 3 and stores the result
Step 1 of 7
Gas Remaining: 21,000
START
Smart contract execution begins
STACK (LIFO)
Empty
MEMORY (Temporary)
Empty
STORAGE (Permanent)
Empty
📚 The Execution Process
1️⃣
Solidity → Bytecode
Your Solidity code is compiled to bytecode (hex):
60056003016000552️⃣
Deploy to Blockchain
Bytecode is stored at a contract address. Every node has a copy of this code.
3️⃣
Call Contract Function
User sends transaction → EVM loads bytecode → executes opcodes one by one.
4️⃣
State Changes
Storage updates are written to blockchain. All nodes update their state identically.
5️⃣
Consensus
Miners/validators verify execution matches. If all agree, changes are permanent.
🔤 Common EVM Opcodes
PUSH / POP
Add/remove values from stack. PUSH1 0x05 pushes 5.
ADD / SUB / MUL / DIV
Arithmetic operations. Pop two values, push result.
SLOAD / SSTORE
Load from or store to permanent blockchain storage.
CALL / DELEGATECALL
Call another contract's function. DELEGATECALL uses caller's context.
JUMPI
Conditional jump (if statement). Jump to bytecode position.
REVERT
Undo all changes and return error. Used in require() statements.
🧠 Why Stack-Based?
✅ Simple & Efficient
Stack operations are fast. Push, pop, operate—minimal overhead. Perfect for deterministic execution.
✅ Easy to Verify
Every node can execute the same stack operations and get identical results. Critical for consensus.
✅ Compact Bytecode
Stack instructions are small. Less data to store on blockchain = lower costs.
💡 Real Example: Token Transfer
// Solidity
balances[to] += amount;
balances[from] -= amount;
balances[from] -= amount;
// EVM Bytecode Operations
1. SLOAD balances[from] → load sender balance
2. PUSH amount → push transfer amount
3. SUB → subtract amount from balance
4. SSTORE balances[from] → save new balance
5. SLOAD balances[to] → load receiver balance
6. PUSH amount → push transfer amount
7. ADD → add amount to balance
8. SSTORE balances[to] → save new balance