This commit generalizes NRVO to cover C structs (both trivial and
non-trivial structs).
rdar://problem/33599681
Differential Revision: https://reviews.llvm.org/D44968
llvm-svn: 328809
In C, we'll wait until the end of the scope to clean up aggregate
temporaries used for returns from calls. This means in cases like:
{
// Assuming that `Bar` is large enough to warrant indirect returns
struct Bar b = {};
b = foo(&b);
b = foo(&b);
b = foo(&b);
b = foo(&b);
}
...We'll allocate space for 5 Bars on the stack (`b`, and 4
temporaries). This becomes painful in things like large switch
statements.
If cleaning up sooner is trivial, we should do it.
llvm-svn: 327229
Akira Hatanaka