alpha: Missing canonical insn aliases

[rth7680]

It would be nice to have some of the canonical alises:

bis     $r31,$r31,$r31  -> nop
ldq_u   $31,0(X)        -> unop

bis     $r31,S,D        -> mov S,D
bis     $r31,#u8,D      -> mov #u8,D
lda     D,s16($r31)     -> mov #s16,D

cpys    $f31,$f31,$f31  -> fnop
cpys    S,S,D           -> fmov S,D
cpys    $f31,S,D        -> fabs S,D
cpysn   S,S,D           -> fneg S,D

There's a list in the Alpha Architecture Handbook section A.4.4 Stylized Code Forms.

Perhaps some of this will come naturally when the Alpha LLVM backend is upstreamed...

[Rot127]

Perhaps some of this will come naturally when the Alpha LLVM backend is upstreamed...

Which one? I am not aware there is any modern one.
This Alpha module is based on the one which was removed from LLVM-3.

[rth7680]

https://github.com/alphalinux-org/llvm-project/tree/alpha-triple

I only noticed because of patches sent to the linux-alpha mailing list to enable building with clang.

PS: I've checked the source there, and all of the aliases above are present. :-)