[Bug rtl-optimization/56766] Fails to combine (vec_select (vec_concat ...)) to (vec_merge ...)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56766

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |segher at gcc dot gnu.org

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Segher - I suppose combine doesn't try to match with swapped (but
non-canonical) operand order.  In this case it's unfortunate as targets would
effectively
need to duplicate the patterns containing matching operands but one commutative
and one non-commutative operation...