llvm-profdata: Indirect infrequently used fields to reduce memory usage

Examining a large profile example, it seems relatively few records have
non-empty IndirectCall and MemOP data, so indirecting these through a
unique_ptr (non-null only when they are non-empty) Reduces memory usage
on this particular example from 14GB to 10GB according to valgrind's
massif.

I suspect it'd still be worth moving InstrProfWriter to its own data
structure that had Counts and the indirected IndirectCall+MemOP, and did
not include the Name, Hash, or Error fields. This would reduce the size
of this dominant data structure by half of this new, lower amount.
(Name(2), Hash(1), Error(1) ~= Counts(vector, 3), ValueProfData
(unique_ptr, 1))
-> From code review feedback, might actually refactor InstrProfRecord
itself to have a sub-struct with all the counts, and use that from
InstrProfWriter, rather than InstrProfWriter owning its own data
structure for this.

Reviewers: davidxl

Differential Revision: https://reviews.llvm.org/D34694

llvm-svn: 306631

0 files changed, 0 insertions, 0 deletions