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Re: Reload questions
- To: Toshiyasu Morita <tm at netcom dot com>
- Subject: Re: Reload questions
- From: Geoff Keating <geoffk at cygnus dot com>
- Date: 21 Jan 2000 19:06:04 -0800
- CC: gcc-bugs at gcc dot gnu dot org
- References: <200001220055.QAA14785@netcom.com>
Toshiyasu Morita <tm@netcom.com> writes:
> I'm trying to figure out the difference between an input reload and an
> output reload. I'm assuming from the name that an "input reload" is a
> restore (from stack) for the input operands of an insn, and an "output
> reload" is a spill (to the stack) for the output operands of an insns.
>
> Are my assumptions correct?
These are typical examples of input and output reloads. Generally, an
input reload is a reload for the input operands of an insn, and
similarly for an output reload :-).
Reloads can also do things like:
- copy from the wrong kind of register to the right kind
- turn the wrong kind (non-offsettable) of MEM into the right kind,
usually by getting its address in a register
- substitute an immediate value for a register
--
- Geoffrey Keating <geoffk@cygnus.com>