[Bug rtl-optimization/78120] [6/7 Regression] If conversion no longer performed

[bernds at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78120

--- Comment #7 from Bernd Schmidt <bernds at gcc dot gnu.org> ---
Sorry James, I think these two got mixed up in my memory.

I've attached a candidate patch I'm testing. This tries to make a better effort
to calculate before/after costs for the speed case so we don't rely entirely on
max_seq_cost. I'd be interested in whether it produces good results on ARM (or
even on x86) if someone is set up to run benchmarks.