Machine Dependent Reorganization Pass
Jim Wilson
wilson@specifixinc.com
Thu Apr 29 12:02:00 GMT 2004
kernel_learner wrote:
> The other one is using the rtx of each instruction to
> see whether it's destination matches with any of the
> sources for the very next instruction.
There can be multiple destinations and sources. You can find the
destinations by using note_stores. You can check to see if an insn uses
a dest by calling reg_mentioned_p.
I was going to point you at an example that shows how to use note_stores
in rtlanal.c, and then I noticed a function called insn_dependent_p that
does this already.
You might need to change it a bit for your purposes, in case your
targets idea of dependence does not match exactly what insn_dependent_p
does. For instance, there might be a disagreement on whether two loads
to different addresses are dependent. They are in you only have one
load port, but they are not in the strict sense that insn_dependent_p uses.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com
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