[Bug tree-optimization/119718] __attribute__((musttail)) affects whether -foptimize-tail-calls will in fact optimize a tail call

[lucier at math dot purdue.edu via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119718

--- Comment #3 from lucier at math dot purdue.edu ---
Originally I understood musttail to be "It's crucial that this call be
optimized, fail and tell me why if you can't do it", without changing whether a
call is optimized.  (This is always assuming the presence of
-foptimize-sibling-calls.)

It seems that having musttail change which tail calls are optimized is (a) a
recent change (it didn't seem to happen a month ago) and (b) makes it hard to
debug problems without looking at stack backtraces in gdb.

So the position I'm trying to take is that this is not a good thing.