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[Bug target/32661] __builtin_ia32_vec_ext suboptimal for pointer/ref args



------- Comment #6 from scovich at gmail dot com  2007-07-11 20:27 -------
(In reply to comment #5)
> SImode moves will be a bit harder, because shufps insn pattern is involved in
> the vector expansion.

IIRC, shufps takes 3 cycles on Core2
(http://www.agner.org/optimize/instruction_tables.pdf), even without the
operand type mismatch (does that still exist?). That's >=4 cycles.

Storing the vector to stack and load the desired entry would take <=4 cycles,
even without Intel's store-load optimizations, and I imagine the optimizer
would be able to deal with it better.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32661


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