sipa, is it possible to see these talks live ?
or even a recording i guess
kanzure: at RWC we ran into Neven, who sounded very excited that someone may actually use his scheme :)
jojeyh: there will be a recording later
sipa: has he reviewed the paper yet?
gmaxwell, morcos some not completely thought out discussion on fee bumping/transaction replacement #12271 . I haven't really seen a good central location for discussion, so I continue re-inventing the wheel
:o "Two new instructions (addex and vmsumudm) introduced to accelerate arbitrary-precision integer arithmetic, and specifically to accelerate Blockchain’s implementation of elliptical curve encryption signature algorithm. The OV bit is employed to provide an additional, independent carry status bit, allowing software to parallelize carry propagation."
luke-jr: whoa, interesting
luke-jr: what is that for?
powerpc 9 ISA apparently
"Add Extended using alternate carry bit Z23-form" and "Vector Multiply-Sum Unsigned Doubleword Modulo VA-form"
"The unsigned integer value in doubleword element 0 of VR[VRA] is multiplied by the unsigned integer value in doubleword element 0 of VR[VRB] to produce a 128-bit product. The unsigned integer value in doubleword element 1 of VR[VRA] is multiplied by the unsigned integer value in doubleword element 1 of VR[VRB] to produce a 128-bit product. The two 128-bit unsigned integer products and the 128-bit unsigned integer in VR[VRC] are summed.
vmsumudm seems SIMD 2x 64*64 -> 128 bit multiplication, where the two results are added to a third 128 bit value
The low-order 128 bits of the sum are placed into VR[VRT]. Any carry out or overflow status is discarded."
hopefully this is compatible with libsecp256k1's existing optimisations
that seems quite useful for the kind off mult-sum operations in secp256k1 secp256k1_fe_mul_inner and such