Which register allocator is used for each -O level?

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#1

I notice this from the “Getting Started with LLVM Core Libraries” book:

“The default allocator is mapped to one of the four options and is selected
depending on the current optimization level (the -O option).”

(the four options being pbqp, greedy, basic, fast)

Which -O option maps to which of these four options?

Phil

#2

Hi Phil,

O0 should be the fast allocator and anything else should be greedy allocator.
Though IIRC, the target can override this behavior.

Cheers,
-Quentin