Summary:
Currently type test assume sequences inserted for devirtualization are
removed during WPD. This patch delays their removal until later in the
optimization pipeline. This is an enabler for upcoming enhancements to
indirect call promotion, for example streamlined promotion guard
sequences that compare against vtable address instead of the target
function, when there are small number of possible vtables (either
determined via WPD or by in-progress type profiling). We need the type
tests to correlate the callsites with the address point offset needed in
the compare sequence, and optionally to associated type summary info
computed during WPD.
This depends on work in D71913 to enable invocation of LowerTypeTests to
drop type test assume sequences, which will now be invoked following ICP
in the ThinLTO post-LTO link pipelines, and also after the existing
export phase LowerTypeTests invocation in regular LTO (which is already
after ICP). We cannot simply move the existing import phase
LowerTypeTests pass later in the ThinLTO post link pipelines, as the
comment in PassBuilder.cpp notes (it must run early because when
performing CFI other passes may disturb the sequences it looks for).
This necessitated adding a new type test resolution "Unknown" that we
can use on the type test assume sequences previously removed by WPD,
that we now want LTT to ignore.
Depends on D71913.
Reviewers: pcc, evgeny777
Subscribers: mehdi_amini, Prazek, hiraditya, steven_wu, dexonsmith, arphaman, davidxl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73242
This restores 2af97be802 (reverted at
6288f86e87), with all the fixes I had
applied at the time, along with a new fix for non-determinism in the
ordering of a couple of passes due to being accessed as parameters on
the same call.
I've also added --dump-input=fail to the new tests so I can more
thoroughly fix any additional failures.
This reverts commit 2af97be802.
After attempting to fix bot failures from matching issues (mostly due to
inconsistent printing of "llvm::" prefixes on objects, and
AnalysisManager objects being printed differntly, I am now seeing some
differences I don't understand (real differences in the passes being
printed). Giving up at this point to allow the bots to recover. Will
revisit later.
Hopefully final bot fix for last few failures from
2af97be802.
Looks like sometimes the "llvm::" preceeding objects get printed in the
debug pass manager output and sometimes they don't. Replace with
wildcard matching.
Additional fixes for bot failures from 2af97be802.
Remove more exact matching on AnalyisManagers, as they can vary.
Also allow different orders between LoopAnalysis and
BranchProbabilityAnalysis as that can vary due to both being accessed in
the parameter list of a call.
Should fix most of the buildbot failures from
2af97be802, by loosening up the matching
on the AnalysisProxy output.
Added in --dump-input=fail on the one test that appears to be something
different, so I can hopefully debug it better.
Summary:
I've added some more extensive ThinLTO pipeline testing with the new PM,
motivated by the bug fixed in D72386.
I beefed up llvm/test/Other/new-pm-pgo.ll a little so that it tests
ThinLTO pre and post link with PGO, similar to the testing for the
default pipelines with PGO.
Added new pre and post link PGO tests for both instrumentation and
sample PGO that exhaustively test the pipelines at different
optimization levels via opt.
Added a clang test to exhaustively test the post link pipeline invoked for
distributed builds. I am currently only testing O2 and O3 since these
are the most important for performance.
It would be nice to add similar exhaustive testing for full LTO, and for
the old PM, but I don't have the bandwidth now and this is a start to
cover some of the situations that are not currently default and were
under tested.
Reviewers: wmi
Subscribers: mehdi_amini, inglorion, hiraditya, steven_wu, dexonsmith, jfb, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D72538
Teresa Johnson