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Fixing mem_gas_cost calcualtion by jumping to U512

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This commit is contained in:
Tomusdrw 2016-01-17 13:59:30 +01:00
parent 83ac4bce06
commit aca68dcfe7
1 changed files with 3 additions and 2 deletions
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5
src/evm/interpreter.rs
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@ -490,8 +490,9 @@ impl Interpreter {
let s = mem_size >> 5; let s = mem_size >> 5;
// s * memory_gas + s * s / quad_coeff_div // s * memory_gas + s * s / quad_coeff_div
let a = overflowing!(s.overflowing_mul(U256::from(schedule.memory_gas))); let a = overflowing!(s.overflowing_mul(U256::from(schedule.memory_gas)));
let b = overflowing!(s.overflowing_mul(s / U256::from(schedule.quad_coeff_div))); // We need to go to U512 to calculate s*s/quad_coeff_div
Ok(a + b) let b = U256::from(U512::from(s) * U512::from(s) / U512::from(schedule.quad_coeff_div));
Ok(overflowing!(a.overflowing_add(b)))
}; };
let current_mem_size = U256::from(current_mem_size); let current_mem_size = U256::from(current_mem_size);
let req_mem_size_rounded = (overflowing!(mem_size.overflowing_add(U256::from(31))) >> 5) << 5; let req_mem_size_rounded = (overflowing!(mem_size.overflowing_add(U256::from(31))) >> 5) << 5;