RTL definition

[Ben Elliston]

> I thought that RTL represented something close to the target machine,
> but not machine-dependent. I firstly thought that the output of the
> middle-end was an RTL machine-independent representation, to which is
> applied a few low-optimization machine-independent passes, and after
> that is translated to a RTL machine-dependent to be applied other
> optimization passes.

There are certain details that you will discover in the RTL that makes
it highly machine-dependent.  For example, the register number where
functions place their values is defined by the ABI and implemented by
the backend.  RTL is by no means machine neutral.

Cheers, Ben

-- 
Ben Elliston <bje@au.ibm.com>
Australia Development Lab, IBM