That exactly is the problem. You can't have a CONST_INT inside a
ZERO_EXTEND. That is not valid.
You'll need a separate pattern to recognize the CONST_INT without a
ZERO_EXTEND around it. Unfortunately, this will not give reload
the freedom it should have.
You mean I should remove the const_int (by predicator) in umulhisi3 pattern?
I mean if I remove it, how to deal with the "reg = const_int * reg"
in umulhisi3 pattern.
You follow these steps:
1) rename the existing pattern to something else than umulhisi3, and
make it only accept register_operands
2) create another insn that matches (mult (zero_extend (match_operand
"register_operand") (const_int))
3) create a define_expand that checks for a CONST_INT and does not wrap
it (but wraps REGs and SUBREGs and if applicable MEMs).
This is in general how you deal with too-forgiving predicates during
expansion.
Paolo
