How could I cast the return type of a function created by gimple_build_call?

[Feng LI]

Hi,

I'm building a function with
fread = build_decl (LOCATION, FUNCTION_DECL, get_identifier (name), type);

and then use it in gimple with
gimple gfread = gimple_build_call (fread, 1, offset);
gimple_call_set_lhs (fread, lhs);

But I need a cast here, since the lhs has a different type than the return value
of the function fread. So I suppose that I need a cast here to cast from the
return type of fread -> type_of (lhs). But I've no idea how could I
achieve this?
Any suggestions?

Thanks,
Feng