[Bug testsuite/108190] g++.target/i386/*pr54700*.C testcases fail on x86_64-mingw

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108190

--- Comment #6 from Marc Glisse <glisse at gcc dot gnu.org> ---
Indeed, this looks like a common issue (at least with the x86 backend): the
memory load is combined with the comparison before we try combining the
comparison with the blend, and this last combination is then rejected because
it expects a register, not memory. So either we are too eager in merging loads
with instructions, or we reject instructions too early when we could still fix
the operands with an extra load.