+def poly64_common(u, v, presfn, dispwd = 32, mulwd = 64,
+ redcwd = 32, klimit = 256):
+ w = 8*len(u)
+ presfn(TAG_INPUT_U, w, C.GF.loadb(u), w, dispwd, 'u')
+ presfn(TAG_INPUT_V, w, C.GF.loadb(v), w, dispwd, 'v')
+ y = poly64_mul(u, v, presfn, dispwd, mulwd, klimit, "u", "v")
+ y = (C.GF.loadb(y) << 1).storeb(w/4)
+ z = poly64_redc(y, presfn, dispwd, redcwd)
+ return z
+