Quoting Lev Yudalevich <lyuda...@gmail.com>:
First, thank you very very much for your reply! Next, would you be so kind to give me a hint where can I find any info about what you called "required conversions patterns from / to PSImode" please?
doc/rtl.texi, section Standard Pattern Names For Generation, most notably the trunc*, extend* and zero_extend* patterns. Note that the requirements for some patterns depend on macros like TRULY_NOOP_TRUNCATION, POINTER_SIZE and POINTERS_EXTEND_UNSIGNED, as described in doc/tm.texi.
