Access RTX register information

[eashan gupta via Gcc-help <gcc-help@xxxxxxxxxxx>]

Hi,
Is it possible to access the variable name if we have an RTX which is a reg
that corresponds to a variable declared by the user?

I have found the macro REG_USERVAR_P (RTX) in rtl.h which returns the
boolean "1 if RTX is a reg that corresponds to a variable declared by the
user." But I am unable to get a suitable macro to get the variable name the
reg corresponds to.

On dumping the rtl output using the command:

print_rtl_single(stdout, in_rtx);

I get output:

(reg/v:SI 68 [ c ])

where "c" was the variable name defined by me. How do I access "c" given
the rtx statement, "in_rtx"?

Thank you very much in advance.
Eashan