Hi Denis,
|
VectorizedArray<Number>r0 =op.do_vectorized(index);
VectorizedArray<Number>r1 =op.do_vectorized(index+nvecs);
VectorizedArray<Number>r2 =op.do_vectorized(index+2*nvecs);
VectorizedArray<Number>r3 =op.do_vectorized(index+3*nvecs);
|
where
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constunsignedintnvecs =VectorizedArray<Number>::n_array_elements;
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I wonder should not declarations be moved to the class variable as
/mutable/?
I don't know internals of VectorizedArray, but i would assume that
currently it allocates memory for the two variables on each call to
do_vectorized(),
which would not be the case otherwise.
Do you mean r0 through r3? There is no memory allocation involved as
VectorizedArray<double> is a small array of at most 512 bit (64 bytes).
It is kept on the stack or just as a temporary variable in the registers
of the machine code. From the outside, it is the same as a double
variable and creating/copying it is just as cheap or expensive as
copying a double variable, at least as long as load/stores go to L1 cache.
So it is actually cheaper to not have the variables in the class. The
compiler would need to write back the value of memory variable to memory
once it leaves the function, whereas it can simply ignore them for
temporary variables.
Best,
Martin
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