Q: regmove.c:gen_add3_insn

[Thomas Sailer]

gen_add3_insn tries to create an add insn
that adds a register and a constant. If 
the target does not support word_mode
adds with constants, then gen_add3_insn
returns NULL_RTX (rightly so), but then
discover_flags_reg crashes.

Could if (!tmp) return NULL_RTX; be added
to discover_flags_reg just after the
gen_add3_insn invocation, or would bad
things happen if this is done?

Tom