
I am now going to ask for two C compilers, and their associated flags.
The first such set (CC & CCFLAGS) are used in compiling the non-generated
ATLAS code.  This code is written in normal C, and responds well to high
levels of optimization.  Typically, this is set to your default compiler,
and your highest levels of optimization.

The second set of C compilers (MCC & MMFLAGS) is used to compile the generated
ATLAS code.  Generated codes are written at a very low-level (think of C used
as a kind of portable assembler).  On many platforms, high levels of
optimization are detrimental, as the compiler tries to pipeline a perfectly
pipelined code, and succeeds in reducing performance substantially (this
occurs on DEC ALPHAs & Sun UltraSparcs, for instance).  If the default does
not work for you, try a midrange optimization such as -O.  The generated code
does not alias any output arguments, so aliasing optimizations should be OK.

