plonky2/evm/src/cpu/kernel/asm/moddiv.asm
2022-07-28 10:35:53 +02:00

40 lines
867 B
NASM

/// Division modulo 0x30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47, the BN254 base field order
/// To replace with more efficient method using non-determinism later.
// Returns y * (x^-1) where the inverse is taken modulo N
%macro moddiv
// stack: x, y
%inverse
// stack: x^-1, y
%mulmodn
%endmacro
%macro mulmodn
// stack: x, y
%bn_base
// stack: N, x, y
SWAP2
// stack: y, x, N
MULMOD
%endmacro
%macro squaremodn
// stack: x
DUP1
// stack: x, x
%mulmodn
%endmacro
// Non-deterministically provide the inverse modulo N.
%macro inverse
// stack: x
PROVER_INPUT(ff::bn254_base::inverse)
// stack: x^-1, x
%stack (inv, x) -> (inv, x, @BN_BASE, inv)
// stack: x^-1, x, N, x^-1
MULMOD
// stack: x^-1 * x, x^-1
%assert_eq_const(1)
// stack: x^-1
%endmacro