Hi, Couple of remarks inline.
+# [1] https://www.openssl.org/~appro/cryptogams/
https://github.com/dot-asm/cryptogams/ is arguably better reference.
+SYM_FUNC_START(x25519_fe51_mul) +.align 5
The goal is to align the label, not the first instruction after the directive. It's not a problem in this spot, in the beginning of the module that is, but further below it's likely to inject redundant nops between the label and meaningful code. But since the directive in question is not position-sensitive one can resolve this by changing the order of the directive and the SYM_FUNC_START macro.
Cheers.
