first 4 bytes in an input data/calldata is function name and the input that we are providinig that' how it remix knows to call which function it's called the signature (cast sig "updateNumberOfHorses(uint256)" gives -- > 0x67d41eca)
callData(it is input data in remix) --> Function dispatch (this is 0x67d41eca function dispatch) --> function is called
EVM is stack stores data --> this is cheapest place to store data on Evm
three places to store data on EVM stack, memory, storage
when we call calldata opcode then it pops off the 0x00 opcode and replaces that with itself starting from 0 index calldata == function name and input it is taking so the evm knows which function to call (example -- updateNumberOfHorses(uint256) will give 0x67d41eca)
Anytime we need to do a operation we need to stick to the stack in evm
cast --to-base 0xF102 dec == 61698
CALLDATALOAD can only take place 32 bytes of calldata onto the stack
0x01(hex) = 1 byte = 1 bits 0x0102 = 2 bytes = 0b 1 00000010 ==> 1 -- 0x01(cast --to-base 0x01 bin) and 00000010 -- 0x02
1 byte = 8 bits
Main data structure we are wokring in ethereum is stack,
For running particular file in below case it's huff and debug a particular function forge test --match-path ./test/testV1/HorseStoreHuff.t.sol --debug testUpdateHorses
Why do we need free memory pointers during deployment when we get opcodes like
"0x80 0x40 MSTORE"
because stack itself has less slots for storing data (0x40 in special space in solidity in memory space as it points to the next empty free memory slot)
