http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771
Aldy Hernandez <aldyh at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2012-06-01
Ever Confirmed|0 |1
--- Comment #5 from Aldy Hernandez <aldyh at gcc dot gnu.org> 2012-06-01
16:39:12 UTC ---
This is a mental note for whenever we decide to pick this up again...
The current approach with the returns-twice patch is a bit heavy handed, as the
register allocator will more-or-less give up across returns-twice. With the
appropriate abnormal edges, the allocator will get more exact info. Whether or
not it's able to do anything extra with this info is a different story...
That's why, we should drop this to ultra low priority-- the returns-twice
approach is good enough.
However, when someone gets bored, the way to debug this is with any trivial
testcase:
int glob;
foo()
{
__transaction_atomic { glob=666; }
}
If one reverts the returns-twice patch referenced in this PR, one sees the
abnormal edges all the way up to *.c.*t.optimized. The edges get corrupted
somewhere in the RTL passes.
