Question about an rtx expression.

[Paolo Bonzini]

Leehod Baruch wrote:

>Hello,
>
>Is it true that in a SET, a search for a _use_ of a register
>in the LHS should be done only inside a memory address?
>
Also within the second and third arguments of a ZERO_EXTRACT.  And its 
first argument may be a MEM, in which case you should look into it.  
Look at df_uses_record in df.c for more information.

But you can simply use the data flow info you compute, and just avoid 
uses that have the DF_REF_READ_WRITE flag set (because they occur in the 
LHS, or within an autoincrement/autodecrement)?

Paolo