This change added a new inline advisor that takes optimization remarks from previous inlining as input, and provides the decision as advice so current inlining can replay inline decisions of a different compilation. Dwarf inline stack with line and discriminator is used as anchor for call sites including call context. The change can be useful for Inliner tuning as it provides a channel to allow external input for tweaking inline decisions. Existing alternatives like alwaysinline attribute is per-function, not per-callsite. Per-callsite inline intrinsic can be another solution (not yet existing), but it's intrusive to implement and also does not differentiate call context.
A switch -sample-profile-inline-replay=<inline_remarks_file> is added to hook up the new inline advisor with SampleProfileLoader's inline decision for replay. Since SampleProfileLoader does top-down inlining, inline decision can be specialized for each call context, hence we should be able to replay inlining accurately. However with a bottom-up inliner like CGSCC inlining, the replay can be limited due to lack of specialization for different call context. Apart from that limitation, the new inline advisor can still be used by regular CGSCC inliner later if needed for tuning purpose.
This is a resubmit of https://reviews.llvm.org/D83743
Summary:
This is the InlineAdvisor used in 'development' mode. It enables two
scenarios:
- loading models via a command-line parameter, thus allowing for rapid
training iteration, where models can be used for the next exploration
phase without requiring recompiling the compiler. This trades off some
compilation speed for the added flexibility.
- collecting training logs, in the form of tensorflow.SequenceExample
protobufs. We generate these as textual protobufs, which simplifies
generation and testing. The protobufs may then be readily consumed by a
tensorflow-based training algorithm.
To speed up training, training logs may also be collected from the
'default' training policy. In that case, this InlineAdvisor does not
use a model.
RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140763.html
Reviewers: jdoerfert, davidxl
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83733
Summary:
This change added a new inline advisor that takes optimization remarks from previous inlining as input, and provides the decision as advice so current inlining can replay inline decisions of a different compilation. Dwarf inline stack with line and discriminator is used as anchor for call sites including call context. The change can be useful for Inliner tuning as it provides a channel to allow external input for tweaking inline decisions. Existing alternatives like alwaysinline attribute is per-function, not per-callsite. Per-callsite inline intrinsic can be another solution (not yet existing), but it's intrusive to implement and also does not differentiate call context.
A switch -sample-profile-inline-replay=<inline_remarks_file> is added to hook up the new inline advisor with SampleProfileLoader's inline decision for replay. Since SampleProfileLoader does top-down inlining, inline decision can be specialized for each call context, hence we should be able to replay inlining accurately. However with a bottom-up inliner like CGSCC inlining, the replay can be limited due to lack of specialization for different call context. Apart from that limitation, the new inline advisor can still be used by regular CGSCC inliner later if needed for tuning purpose.
Subscribers: mgorny, aprantl, hiraditya, llvm-commits
Tags: #llvm
Resubmit for https://reviews.llvm.org/D84086
as it is failing the inline-replay.ll test as well as sanitizers/Werror
from returning a stack local variable.
This reverts commit 029946b112684c27b27f7c2d7554f22b33ae1e0b.
Summary:
This change added a new inline advisor that takes optimization remarks for previous inlining as input, and provide the decision as advice so current inlining can replay inline decision of a different compilation. Dwarf inline stack with line and discriminator is used as anchor for call sites. The change can be useful for Inliner tuning.
A switch -sample-profile-inline-replay=<inline_remarks_file> is added to hook up the new inliner advisor with SampleProfileLoader's inline decision for replay. The new inline advisor can also be used by regular CGSCC inliner later if needed.
Reviewers: davidxl, mtrofin, wmi, hoy
Subscribers: aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83743
This is in preparation for the 'development' mode advisor. We currently
want to track what the default policy's decision would have been, this
refactoring makes it easier to do that.
Summary:
Add call site location info into inline remarks so we can differentiate inline sites.
This can be useful for inliner tuning. We can also reconstruct full hierarchical inline
tree from parsing such remarks. The messege of inline remark is also tweaked so we can
differentiate SampleProfileLoader inline from CGSCC inline.
Reviewers: wmi, davidxl, hoy
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D82213
Summary:
Other derivations will all want to emit optimization remarks and, as
part of that, use debug info.
Additionally, drive-by const-ing.
Reviewers: davidxl, dblaikie
Subscribers: aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81507
Summary:
Experiments show that inline deferral past pre-inlining slightly
pessimizes the performance.
This patch introduces an option to control inline deferral during PGO.
The option defaults to true for now (that is, NFC).
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: eraman, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80776
Summary:
This simplifies the interface by storing the function analysis manager
with the InlineAdvisor, and, thus, not requiring it be passed each time
we inquire for an advice.
Reviewers: davidxl, asbirlea
Subscribers: eraman, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80405
Summary:
This patch sets inline-deferral-scale to 2.
Both internal and SPEC benchmarking show that 2 is the best number
among -1, 2, 3, and 4.
inline-deferral-scale SPECint2006
------------------------------------------------------------
-1 38.0 (the default without this patch)
2 38.5
3 38.1
4 38.1
With the new default number, shouldBeDeferred returns true if:
TotalCost < IC.getCost() * 2
where
TotalCost is TotalSecondaryCost + IC.getCost() * NumCallerUsers.
If TotalCost >= 0 and NumCallerUsers >= 2, then
TotalCost >= IC.getCost() * 2, so shouldBeDeferred returns true only
when NumCallerUsers is 1.
Now, if TotalSecondaryCost < 0, which can happen if
InlineConstants::LastCallToStaticBonus, a huge number, has been
subtracted from TotalSecondaryCost, then TotalCost may be negative.
In this case, shouldBeDeferred may return true even when
NumCallerUsers >= 2.
Reviewers: davidxl, nikic
Reviewed By: davidxl
Subscribers: xbolva00, hiraditya, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80229
This reverts commit 454de99a6fec705e76ed7743bf538f7a77296f59.
The problem was that one of the ctor arguments of CallAnalyzer was left
to be const std::function<>&. A function_ref was passed for it, and then
the ctor stored the value in a function_ref field. So a std::function<>
would be created as a temporary, and not survive past the ctor
invocation, while the field would.
Tested locally by following https://github.com/google/sanitizers/wiki/SanitizerBotReproduceBuild
Original Differential Revision: https://reviews.llvm.org/D79917
Summary:
Replacing uses of std::function pointers or refs, or Optional, to
function_ref, since the usage pattern allows that. If the function is
optional, using a default parameter value (nullptr). This led to a few
parameter reshufles, to push all optionals to the end of the parameter
list.
Reviewers: davidxl, dblaikie
Subscribers: arsenm, jvesely, nhaehnle, eraman, hiraditya, haicheng, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79917
Summary:
This change introduces InliningAdvisor (and related APIs), the interface
that abstracts decision making away from the inlining pass. We will use
this interface to delegate decision making to a trained ML model,
subsequently (see referenced RFC).
RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140763.html
Reviewers: davidxl, eraman, dblaikie
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79042
Summary:
This patch makes shouldBeDeferred static because it is called only
from shouldInline in the same .cpp file.
Reviewers: davidxl, mtrofin
Reviewed By: mtrofin
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79750
