obviating ZDOT_RETURN

[jeffhammond]

Because all BLAS1 routines are bandwidth limited, there is essentially no value to using them over straightforward implementations by qualified programmers.

ZDOT_RETURN is a workaround for flaws in BLAS1 implementations. I think it would be prudent to just implement dot products in BAGEL directly.

[shiozaki]

Sounds like a great idea (as long as the code is competitive with MKL; "qualified" is the key). The code should be used only when, e.g., MKL is not present.

[jeffhammond]

It's much easier than you think :-) Intel compiler with naive C or Fortran loops should beat MKL for BLAS1 because autovectorization will be sufficient and user code is easier to inline and/or fuse. I'll perform some experiments and share full details. Note also that C++ loops trivially avoids any incompatibility between std::complex and Fortran complex double, should any exist (I can't remember what ISO says about this).