[SampleFDO] Add flag for partial profile.

The common profile usage is to collect profile from a target and then use the profile to guide the optimized build for the same target. There are some cases

[SampleFDO] Add flag for partial profile.

The common profile usage is to collect profile from a target and then use the profile to guide the optimized build for the same target. There are some cases that no profile can be collected for a target. In those cases, although no full profile is available, it is possible to have some partial profile collected from other targets to optimize common libraries and utilities. A flag is needed to tell the partial profile from the full profile apart, so compiler can use different strategy for them.

Differential Revision: https://reviews.llvm.org/D77426

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[SampleFDO] Port MD5 name table support to extbinary format.

Compbinary format uses MD5 to represent strings in name table. That gives smaller profile without the need of compression/decompression w

[SampleFDO] Port MD5 name table support to extbinary format.

Compbinary format uses MD5 to represent strings in name table. That gives smaller profile without the need of compression/decompression when writing/reading the profile. The patch adds the support in extbinary format. It is off by default but user can choose to enable it.

Note the feature of using MD5 in name table can bring very small chance of name conflict leading to profile mismatch. Besides, profile using the feature won't have the profile remapping support.

Differential Revision: https://reviews.llvm.org/D76255

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[Support] On Windows, ensure hardware_concurrency() extends to all CPU sockets and all NUMA groups

The goal of this patch is to maximize CPU utilization on multi-socket or high core count systems, s

[Support] On Windows, ensure hardware_concurrency() extends to all CPU sockets and all NUMA groups

The goal of this patch is to maximize CPU utilization on multi-socket or high core count systems, so that parallel computations such as LLD/ThinLTO can use all hardware threads in the system. Before this patch, on Windows, a maximum of 64 hardware threads could be used at most, in some cases dispatched only on one CPU socket.

== Background ==
Windows doesn't have a flat cpu_set_t like Linux. Instead, it projects hardware CPUs (or NUMA nodes) to applications through a concept of "processor groups". A "processor" is the smallest unit of execution on a CPU, that is, an hyper-thread if SMT is active; a core otherwise. There's a limit of 32-bit processors on older 32-bit versions of Windows, which later was raised to 64-processors with 64-bit versions of Windows. This limit comes from the affinity mask, which historically is represented by the sizeof(void*). Consequently, the concept of "processor groups" was introduced for dealing with systems with more than 64 hyper-threads.

By default, the Windows OS assigns only one "processor group" to each starting application, in a round-robin manner. If the application wants to use more processors, it needs to programmatically enable it, by assigning threads to other "processor groups". This also means that affinity cannot cross "processor group" boundaries; one can only specify a "preferred" group on start-up, but the application is free to allocate more groups if it wants to.

This creates a peculiar situation, where newer CPUs like the AMD EPYC 7702P (64-cores, 128-hyperthreads) are projected by the OS as two (2) "processor groups". This means that by default, an application can only use half of the cores. This situation could only get worse in the years to come, as dies with more cores will appear on the market.

== The problem ==
The heavyweight_hardware_concurrency() API was introduced so that only *one hardware thread per core* was used. Once that API returns, that original intention is lost, only the number of threads is retained. Consider a situation, on Windows, where the system has 2 CPU sockets, 18 cores each, each core having 2 hyper-threads, for a total of 72 hyper-threads. Both heavyweight_hardware_concurrency() and hardware_concurrency() currently return 36, because on Windows they are simply wrappers over std::thread::hardware_concurrency() -- which can only return processors from the current "processor group".

== The changes in this patch ==
To solve this situation, we capture (and retain) the initial intention until the point of usage, through a new ThreadPoolStrategy class. The number of threads to use is deferred as late as possible, until the moment where the std::threads are created (ThreadPool in the case of ThinLTO).

When using hardware_concurrency(), setting ThreadCount to 0 now means to use all the possible hardware CPU (SMT) threads. Providing a ThreadCount above to the maximum number of threads will have no effect, the maximum will be used instead.
The heavyweight_hardware_concurrency() is similar to hardware_concurrency(), except that only one thread per hardware *core* will be used.

When LLVM_ENABLE_THREADS is OFF, the threading APIs will always return 1, to ensure any caller loops will be exercised at least once.

Differential Revision: https://reviews.llvm.org/D71775

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Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly m

Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.

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[llvm-profdata] Fix hint message since argument format has changed

"-sample" option is now changed to "--sample".

Prune Pass.h include from DataLayout.h. NFCI

Summary:
Reduce include dependencies by no longer including Pass.h from
DataLayout.h. That include seemed irrelevant to DataLayout, as
well as being irre

Prune Pass.h include from DataLayout.h. NFCI

Summary:
Reduce include dependencies by no longer including Pass.h from
DataLayout.h. That include seemed irrelevant to DataLayout, as
well as being irrelevant to several users of DataLayout.

Reviewers: rnk

Reviewed By: rnk

Subscribers: mehdi_amini, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D69261

llvm-svn: 375436

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[SampleFDO] Add compression support for any section in ExtBinary profile format

Previously ExtBinary profile format only supports compression using zlib for
profile symbol list. In this patch, we ex

[SampleFDO] Add compression support for any section in ExtBinary profile format

Previously ExtBinary profile format only supports compression using zlib for
profile symbol list. In this patch, we extend the compression support to any
section. User can select some or all of the sections to compress. In an
experiment, for a 45M profile in ExtBinary format, compressing name table
reduced its size to 24M, and compressing all the sections reduced its size
to 11M.

Differential Revision: https://reviews.llvm.org/D68253

llvm-svn: 373914

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[PGO] Fix typos from r359612. NFC.

llvm-svn: 373369

Recommit [SampleFDO] Expose an interface to return the size of a section
or the size of the profile for profile in ExtBinary format.

Fix a test failure on Mac.

[SampleFDO] Expose an interface to re

Recommit [SampleFDO] Expose an interface to return the size of a section
or the size of the profile for profile in ExtBinary format.

Fix a test failure on Mac.

[SampleFDO] Expose an interface to return the size of a section or the
size of the profile for profile in ExtBinary format.

Sometimes we want to limit the size of the profile by stripping some functions
with low sample count or by stripping some function names with small text size
from profile symbol list. That requires the profile reader to have the
interfaces returning the size of a section or the size of total profile. The
patch add those interfaces.

At the same time, add some dump facility to show the size of each section.

Differential revision: https://reviews.llvm.org/D67726

llvm-svn: 372478

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Revert "[SampleFDO] Expose an interface to return the size of a section or the size"

This reverts commit f118852046a1d255ed8c65c6b5db320e8cea53a0.

Broke the macOS build/greendragon bots.

llvm-svn:

Revert "[SampleFDO] Expose an interface to return the size of a section or the size"

This reverts commit f118852046a1d255ed8c65c6b5db320e8cea53a0.

Broke the macOS build/greendragon bots.

llvm-svn: 372464

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[SampleFDO] Expose an interface to return the size of a section or the size
of the profile for profile in ExtBinary format.

Sometimes we want to limit the size of the profile by stripping some funct

[SampleFDO] Expose an interface to return the size of a section or the size
of the profile for profile in ExtBinary format.

Sometimes we want to limit the size of the profile by stripping some functions
with low sample count or by stripping some function names with small text size
from profile symbol list. That requires the profile reader to have the
interfaces returning the size of a section or the size of total profile. The
patch add those interfaces.

At the same time, add some dump facility to show the size of each section.

llvm-svn: 372439

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[llvm-profdata] Add mode to recover from profile read failures

Add a mode in which profile read errors are not immediately treated as
fatal. In this mode, merging makes forward progress and reports

[llvm-profdata] Add mode to recover from profile read failures

Add a mode in which profile read errors are not immediately treated as
fatal. In this mode, merging makes forward progress and reports failure
only if no inputs can be read.

Differential Revision: https://reviews.llvm.org/D66985

llvm-svn: 370827

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Fix some errors introduced by rL370563 which were not exposed on my local machine.
1. zlib::compress accept &size_t but the param is an uint64_t.
2. Some systems don't have zlib installed. Don't use

Fix some errors introduced by rL370563 which were not exposed on my local machine.
1. zlib::compress accept &size_t but the param is an uint64_t.
2. Some systems don't have zlib installed. Don't use compression by default.

llvm-svn: 370564

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[SampleFDO] Add profile symbol list section to discriminate function being
cold versus function being newly added.

This is the second half of https://reviews.llvm.org/D66374.

Profile symbol list is

[SampleFDO] Add profile symbol list section to discriminate function being
cold versus function being newly added.

This is the second half of https://reviews.llvm.org/D66374.

Profile symbol list is the collection of function symbols showing up in
the binary which generates the current profile. It is used to discriminate
function being cold versus function being newly added. Profile symbol list
is only added for profile with ExtBinary format.

During profile use compilation, when profile-sample-accurate is enabled,
a function without profile will be regarded as cold only when it is
contained in that list.

Differential Revision: https://reviews.llvm.org/D66766

llvm-svn: 370563

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[SampleFDO] Add ExtBinary format to support extension of binary profile.

This is a patch split from https://reviews.llvm.org/D66374. It tries to add
a new format of profile called ExtBinary. The for

[SampleFDO] Add ExtBinary format to support extension of binary profile.

This is a patch split from https://reviews.llvm.org/D66374. It tries to add
a new format of profile called ExtBinary. The format adds a section header
table to the profile and organize the profile in sections, so the future
extension like adding a new section or extending an existing section will be
easier while keeping backward compatiblity feasible.

Differential Revision: https://reviews.llvm.org/D66513

llvm-svn: 369798

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[llvm] Migrate llvm::make_unique to std::make_unique

Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of

[llvm] Migrate llvm::make_unique to std::make_unique

Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013

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Rename F_{None,Text,Append} to OF_{None,Text,Append}. NFC

F_{None,Text,Append} are kept for compatibility since r334221.

llvm-svn: 367800

llvm-profdata] Handle the cases of overlapping input file and output file

Currently llvm-profdata does not expect the same file name for the input profile
and the output profile.
>llvm-profdata merg

llvm-profdata] Handle the cases of overlapping input file and output file

Currently llvm-profdata does not expect the same file name for the input profile
and the output profile.
>llvm-profdata merge A.profraw B.profraw -o B.profraw
The above command runs successfully but the resulted B.profraw is not correct.
This patch fixes the issue by moving the initialization of writer after loading
the profile.

For the show command, the following will report a confusing error of
"Empty raw profile file":
>llvm-profdata show B.profraw -o B.profraw
It's harder to fix as we need to output something before loading the input profile.
I don't think that a fix for this is worth the effort. I just make the error explicit for
the show command.

Differential Revision: https://reviews.llvm.org/D64360

llvm-svn: 365386

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[llvm-profdata] Add overlap command to compute similarity b/w two profile files

Add overlap functionality to llvm-profdata tool to compute the similarity
between two profile files.

Differential Rev

[llvm-profdata] Add overlap command to compute similarity b/w two profile files

Add overlap functionality to llvm-profdata tool to compute the similarity
between two profile files.

Differential Revision: https://reviews.llvm.org/D60977

llvm-svn: 359612

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[llvm-profdata] Deleted unused Cutoffs added by D16005

llvm-svn: 356248

[PGO] Context sensitive PGO (part 2)

Part 2 of CSPGO changes (mostly related to ProfileSummary).
Note that I use a default parameter in setProfileSummary() and getSummary().
This is to break the dep

[PGO] Context sensitive PGO (part 2)

Part 2 of CSPGO changes (mostly related to ProfileSummary).
Note that I use a default parameter in setProfileSummary() and getSummary().
This is to break the dependency in clang. I will make the parameter explicit
after changing clang in a separated patch.

Differential Revision: https://reviews.llvm.org/D54175

llvm-svn: 355131

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Fix some include order and file headers issues. NFC

llvm-svn: 354550

[PGO] Fix the type of the formated variable

Change the format type of Value to PRIu64 since it is a uint64_t.
The problem was detected on mips boards building 32-bit binaries,
where it was printing

[PGO] Fix the type of the formated variable

Change the format type of Value to PRIu64 since it is a uint64_t.
The problem was detected on mips boards building 32-bit binaries,
where it was printing junk values and causing test failure.

Patch by Milos Stojanovic.

Differential Revision: https://reviews.llvm.org/D57583

llvm-svn: 353194

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Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

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[llvm-profdata] add value-cutoff functionality in show command

This patch improves llvm-profdata show command:
(1) add -value-cutoff=<N> option: Show only those functions whose max count
values

[llvm-profdata] add value-cutoff functionality in show command

This patch improves llvm-profdata show command:
(1) add -value-cutoff=<N> option: Show only those functions whose max count
values are greater or equal to N.
(2) add -list-below-cutoff option: Only output names of functions whose max
count value are below the cutoff.
(3) formats value-profile counts and prints out percentage.

Differential Revision: https://reviews.llvm.org/D56342

llvm-svn: 350673

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