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tload/tstore in evm
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@cdump
cdump committed Oct 11, 2024
1 parent 1825787 commit 58b1f4e
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Showing 3 changed files with 128 additions and 17 deletions.
4 changes: 2 additions & 2 deletions src/arguments/calldata.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -12,7 +12,7 @@ impl CallData<Label> for CallDataImpl {
let mut data = [0; 32];
if offset < VAL_4 {
let off = usize::try_from(offset).expect("len checked");
data[..4 - off].copy_from_slice(&self.selector()[off..]);
data[..4 - off].copy_from_slice(&self.selector[off..]);
}
Element {
data,
Expand All @@ -33,7 +33,7 @@ impl CallData<Label> for CallDataImpl {
if offset < VAL_4 {
let off = usize::try_from(offset).expect("len checked");
let nlen = std::cmp::min(data.len(), 4 - off);
data[..nlen].copy_from_slice(&self.selector()[off..off + nlen]);
data[..nlen].copy_from_slice(&self.selector[off..off + nlen]);
}
Ok((data, Some(Label::CallData)))
}
Expand Down
2 changes: 1 addition & 1 deletion src/evm/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@ pub mod op;
pub mod stack;
pub mod vm;

pub use alloy_primitives::U256;
pub use alloy_primitives::{I256, U256};

pub const VAL_0_B: [u8; 32] = U256::ZERO.to_be_bytes();

Expand Down
139 changes: 125 additions & 14 deletions src/evm/vm.rs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
use super::{calldata::CallData, element::Element, memory::Memory, op, stack::Stack, U256};
use super::{calldata::CallData, element::Element, memory::Memory, op, stack::Stack, I256, U256};
use super::{VAL_0_B, VAL_1, VAL_1024_B, VAL_1M_B, VAL_1_B, VAL_256, VAL_32};
use std::{error, fmt};

Expand Down Expand Up @@ -193,10 +193,32 @@ where
(5, if s1.is_zero() { U256::ZERO } else { s0 / s1 })
}),

op::SDIV => self.bop(op, |_, s0, _, s1| {
(
5,
if s1.is_zero() {
U256::ZERO
} else {
(I256::from_raw(s0) / I256::from_raw(s1)).into_raw()
},
)
}),

op::MOD => self.bop(op, |_, s0, _, s1| {
(5, if s1.is_zero() { U256::ZERO } else { s0 % s1 })
}),

op::SMOD => self.bop(op, |_, s0, _, s1| {
(
5,
if s1.is_zero() {
U256::ZERO
} else {
(I256::from_raw(s0) % I256::from_raw(s1)).into_raw()
},
)
}),

op::EXP => self.bop(op, |_, s0, _, s1| {
(
50 * (1 + s1.bit_len() / 8) as u32, /*approx*/
Expand Down Expand Up @@ -231,16 +253,16 @@ where

op::SLT => self.bop(op, |_, s0, _, s1| {
(3, {
let sign0 = s0.bit(255);
let sign1 = s1.bit(255);
let sign0 = s0.bit(U256::BITS - 1);
let sign1 = s1.bit(U256::BITS - 1);
U256::from(if sign0 == sign1 { s0 < s1 } else { sign0 })
})
}),

op::SGT => self.bop(op, |_, s0, _, s1| {
(3, {
let sign0 = s0.bit(255);
let sign1 = s1.bit(255);
let sign0 = s0.bit(U256::BITS - 1);
let sign1 = s1.bit(U256::BITS - 1);
U256::from(if sign0 == sign1 { s0 > s1 } else { !sign0 })
})
}),
Expand Down Expand Up @@ -271,9 +293,12 @@ where
op::XOR => self.bop(op, |_, s0, _, s1| (3, s0 ^ s1)),

op::NOT => {
let v = self.stack.pop_uint()?;
let raws0 = self.stack.pop()?;
let v: U256 = (&raws0).into();
self.stack.push_uint(!v);
Ok(StepResult::new(op, 3))
let mut ret = StepResult::new(op, 3);
ret.fa = Some(raws0);
Ok(ret)
}

op::BYTE => self.bop(op, |_, s0, raws1, _| {
Expand All @@ -300,7 +325,7 @@ where
3,
if s0 < VAL_256 {
s1 >> s0
} else if s1.bit(255) {
} else if s1.bit(U256::BITS - 1) {
U256::MAX
} else {
U256::ZERO
Expand All @@ -323,9 +348,15 @@ where
}

op::KECCAK256 => {
let mut ret = StepResult::new(op, 30);
ret.fa = Some(self.stack.pop()?); // offset
ret.sa = Some(self.stack.pop()?); // size
let offset = self.stack.pop()?;
let size = self.stack.pop()?;
let gas_used: u32 = 30
+ 6 * (U256::from_be_bytes(size.data)
.try_into()
.unwrap_or(5_000_000));
let mut ret = StepResult::new(op, gas_used);
ret.fa = Some(offset);
ret.sa = Some(size);
self.stack.push_data(VAL_1_B);
Ok(ret)
}
Expand Down Expand Up @@ -448,6 +479,12 @@ where
Ok(StepResult::new(op, 20))
}

op::BLOBHASH => {
self.stack.pop()?;
self.stack.push_data(VAL_1_B);
Ok(StepResult::new(op, 3))
}

op::SELFBALANCE => {
self.stack.push_data(VAL_0_B);
Ok(StepResult::new(op, 5))
Expand Down Expand Up @@ -489,14 +526,14 @@ where
Ok(StepResult::new(op, 2))
}

op::SLOAD => {
op::SLOAD | op::TLOAD => {
let mut ret = StepResult::new(op, 100);
ret.fa = Some(self.stack.pop()?); // slot
self.stack.push_data(VAL_0_B);
Ok(ret)
}

op::SSTORE => {
op::SSTORE | op::TSTORE => {
let mut ret = StepResult::new(op, 100);
ret.fa = Some(self.stack.pop()?); // slot
ret.sa = Some(self.stack.pop()?); // value
Expand Down Expand Up @@ -564,7 +601,7 @@ where
Ok(ret)
}

op::STOP | op::SELFDESTRUCT => {
op::STOP | op::SELFDESTRUCT | op::INVALID => {
// skip stack pop()s
self.stopped = true;
Ok(StepResult::new(op, 5))
Expand All @@ -573,3 +610,77 @@ where
}
}
}

#[cfg(test)]
mod tests {
use super::*;

#[derive(Clone)]
struct DummyCallData {}

impl CallData<u8> for DummyCallData {
fn load32(&self, _: U256) -> Element<u8> {
Element {
data: [0; 32],
label: None,
}
}

fn load(&self, _: U256, _: U256) -> Result<(Vec<u8>, Option<u8>), Box<dyn error::Error>> {
Err("unsupported".into())
}

fn selector(&self) -> [u8; 4] {
[0; 4]
}

fn len(&self) -> U256 {
U256::ZERO
}
}

#[test]
fn test_arithmetic() {
let mut vm = Vm::new(&[], DummyCallData {});
let cases = [
(
I256::unchecked_from(-1).into_raw(),
op::ADD,
U256::from(3),
U256::from(2),
),
(
I256::unchecked_from(-1).into_raw(),
op::LT,
U256::from(3),
U256::from(0),
),
(
I256::unchecked_from(-1).into_raw(),
op::SLT,
U256::from(3),
U256::from(1),
),
(
I256::unchecked_from(-4).into_raw(),
op::SDIV,
U256::from(2),
I256::unchecked_from(-2).into_raw(),
),
(
I256::unchecked_from(-4).into_raw(),
op::SDIV,
I256::unchecked_from(-2).into_raw(),
U256::from(2),
),
];

for (lhs, op, rhs, expected) in cases.into_iter() {
vm.stack.push_uint(rhs);
vm.stack.push_uint(lhs);
assert!(vm.exec_opcode(op).is_ok());
let r = vm.stack.pop_uint().unwrap();
assert_eq!(r, expected);
}
}
}

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