https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99881
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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Target| |x86_64-*-*
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
But 2 element construction _should_ be cheap. What is missing is the move
cost from GPR to XMM regs (but we do not have a good idea whether the sources
are memory, so it's not as clear-cut here either).
IMHO a better approach might be to up unaligned vector store/load costs?
For the testcase at hand why does a throughput of 1 pose a problem? There's
only one punpckldq instruction around?
Note that for the case of non-loop vectorization of 'double' the two element
vector CTORs are common and important to handle cheaply. See also all the
discussion in PR98856
