replace_rtx

[Rajkishore Barik]

Hi,

I am doing some modification to gcc's RTL code. I am trying to split a 
pseudo (old) into two pseudos (old and new)
and rewriting some part of the code to replace the "old" pseudo by the 
"new" pseudo. I am using the "replace_rtx" function
to perform the replacement. However I get "fatal error: internal 
consistency failure" when I try to execute any program.

The specific call that I make is:

replace_rtx (insn, old_rtx, new_rtx);

I notice that "replace_rtx" actually performs the replacement when I try 
to print the "insn" before and after the call. However, later on I get the 
error
"internal consistency failure".

I would like to know what are the cases in which this error is thrown. Is 
there any document which I can refer to?

regards,
Raj