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use super::*;
use crate::zkevm_opcode_defs::{FatPointer, Opcode, PtrOpcode};
impl<const N: usize, E: VmEncodingMode<N>> DecodedOpcode<N, E> {
pub fn ptr_opcode_apply<
S: zk_evm_abstractions::vm::Storage,
M: zk_evm_abstractions::vm::Memory,
EV: zk_evm_abstractions::vm::EventSink,
PP: zk_evm_abstractions::vm::PrecompilesProcessor,
DP: zk_evm_abstractions::vm::DecommittmentProcessor,
WT: crate::witness_trace::VmWitnessTracer<N, E>,
>(
&self,
vm_state: &mut VmState<S, M, EV, PP, DP, WT, N, E>,
prestate: PreState<N, E>,
) {
let PreState {
src0,
src1,
dst0_mem_location,
new_pc,
..
} = prestate;
let inner_variant = match self.variant.opcode {
Opcode::Ptr(inner) => inner,
_ => unreachable!(),
};
vm_state.local_state.callstack.get_current_stack_mut().pc = new_pc;
match inner_variant {
a @ PtrOpcode::Add | a @ PtrOpcode::Sub => {
// we check whether src0 is fat pointer
if src0.is_pointer == false {
// src0 is not a pointer
vm_state.set_shorthand_panic();
return;
}
if src1.is_pointer == true {
// can not have ptr + ptr
vm_state.set_shorthand_panic();
return;
}
if src1.value >= zkevm_opcode_defs::ptr::MAX_OFFSET_FOR_ADD_SUB {
// offset is too far to be reasonable, so instead of wrapping behavior we bail out
vm_state.set_shorthand_panic();
return;
}
let PrimitiveValue {
value: src0,
is_pointer: _,
} = src0;
let PrimitiveValue {
value: src1,
is_pointer: _,
} = src1;
let fat_ptr = FatPointer::from_u256(src0);
let offset = src1.low_u32();
let (new_ptr_offset, error) = if a == PtrOpcode::Add {
fat_ptr.offset.overflowing_add(offset)
} else {
fat_ptr.offset.overflowing_sub(offset)
};
if error {
vm_state.set_shorthand_panic();
return;
}
let mut new_ptr = fat_ptr;
new_ptr.offset = new_ptr_offset;
let ptr_as_u256 = new_ptr.to_u256();
// low 128 bits from ptr_as_u256, high 128 - from src0
let result = U256([ptr_as_u256.0[0], ptr_as_u256.0[1], src0.0[2], src0.0[3]]);
let result = PrimitiveValue {
value: result,
is_pointer: true,
};
vm_state.perform_dst0_update(
vm_state.local_state.monotonic_cycle_counter,
result,
dst0_mem_location,
self,
);
}
PtrOpcode::Pack => {
// we check whether src0 is fat pointer
if src0.is_pointer == false {
// src0 is not a pointer
vm_state.set_shorthand_panic();
return;
}
if src1.is_pointer == true {
// can not have ptr + ptr
vm_state.set_shorthand_panic();
return;
}
if src1.value.low_u128() != 0 {
// mask is not a mask indeed
vm_state.set_shorthand_panic();
return;
}
let PrimitiveValue {
value: src0,
is_pointer: _,
} = src0;
let PrimitiveValue {
value: src1,
is_pointer: _,
} = src1;
// low 128 bits from src0, high 128 - from src1
let result = U256([src0.0[0], src0.0[1], src1.0[2], src1.0[3]]);
let result = PrimitiveValue {
value: result,
is_pointer: true,
};
vm_state.perform_dst0_update(
vm_state.local_state.monotonic_cycle_counter,
result,
dst0_mem_location,
self,
);
}
PtrOpcode::Shrink => {
// we check whether src0 is fat pointer
if src0.is_pointer == false {
// src0 is not a pointer
vm_state.set_shorthand_panic();
return;
}
if src1.is_pointer == true {
// can not have ptr + ptr
vm_state.set_shorthand_panic();
return;
}
let PrimitiveValue {
value: src0,
is_pointer: _,
} = src0;
let PrimitiveValue {
value: src1,
is_pointer: _,
} = src1;
let fat_ptr = FatPointer::from_u256(src0);
let offset = src1.low_u32();
let (new_ptr_length, error) = fat_ptr.length.overflowing_sub(offset);
if error {
vm_state.set_shorthand_panic();
return;
}
let mut new_ptr = fat_ptr;
new_ptr.length = new_ptr_length;
let ptr_as_u256 = new_ptr.to_u256();
// low 128 bits from ptr_as_u256, high 128 - from src0
let result = U256([ptr_as_u256.0[0], ptr_as_u256.0[1], src0.0[2], src0.0[3]]);
let result = PrimitiveValue {
value: result,
is_pointer: true,
};
vm_state.perform_dst0_update(
vm_state.local_state.monotonic_cycle_counter,
result,
dst0_mem_location,
self,
);
}
}
}
}