[PATCH] D32596: [InstCombine] Transform fmul X, +2.0 --> fadd X, X.

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

I would guess we should prefer fmul as the canonical form, for the same reason we prefer "shl %x, 1" over "add %x, %x": we optimize instructions where hasOneUse() is true more aggressively.  I guess it doesn't make a big difference either way, though.

Either way, please add a testcase for "fadd %x, %x", to confirm that we canonicalize both fadd and fmul to the same form.


https://reviews.llvm.org/D32596