[BOLT] Add function layout class

This patch adds a dedicated class to keep track of each function's
layout. It also lays the groundwork for splitting functions into
multiple fragments (as opposed to

[BOLT] Add function layout class

This patch adds a dedicated class to keep track of each function's
layout. It also lays the groundwork for splitting functions into
multiple fragments (as opposed to a strict hot/cold split).

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D129518

show more ...

[BOLT] Do not merge cold and hot chains of basic blocks

There is a post-processing in ext-tsp block reordering that merges some blocks
into chains. This allows to maintain the original block order i

[BOLT] Do not merge cold and hot chains of basic blocks

There is a post-processing in ext-tsp block reordering that merges some blocks
into chains. This allows to maintain the original block order in the absense of
profile data and can be beneficial for code size (when fallthroughs are merged).
In the earlier version we could merge hot and cold (with zero execution count)
chains, that later were split by SplitFunction.cpp (when split-all-cold=1). The
diff eliminates the redundant merging.

It is unlikely the change will affect the performance of a binary in a
measurable way, as it is mostly operates with cold basic blocks. However, after
the diff the impact of split-all-cold is almost negligible and we can avoid the
extra function splitting.

Measuring on the clang binary (negative is good, positive is a regression):
**clang12**
benchmark1: `0.0253`
benchmark2: `-0.1843`
benchmark3: `0.3234`
benchmark4: `0.0333`

**clang10**
benchmark1 `-0.2517`
benchmark2 `-0.3703`
benchmark3 `-0.1186`
benchmark4 `-0.3822`

**clang7**
benchmark1 `0.2526`
benchmark2 `0.0500`
benchmark3 `0.3024`
benchmark4 `-0.0489`

**Overall**: `-0.0671 ± 0.1172` (insignificant)

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D129397

show more ...

[BOLT][NFC] Use range-based STL wrappers

Replace `std::` algorithms taking begin/end iterators with `llvm::` counterparts
accepting ranges.

Reviewed By: rafauler

Differential Revision: https://rev

[BOLT][NFC] Use range-based STL wrappers

Replace `std::` algorithms taking begin/end iterators with `llvm::` counterparts
accepting ranges.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D128154

show more ...

[bolt] Remove unneeded cl::ZeroOrMore for cl::opt options

[BOLT][NFC] Fix braces usage in Passes

Summary:
Refactor bolt/*/Passes to follow the braces rule for if/else/loop from
[LLVM Coding Standards](https://llvm.org/docs/CodingStandards.html).

(cherry p

[BOLT][NFC] Fix braces usage in Passes

Summary:
Refactor bolt/*/Passes to follow the braces rule for if/else/loop from
[LLVM Coding Standards](https://llvm.org/docs/CodingStandards.html).

(cherry picked from FBD33344642)

show more ...

[BOLT][NFC] Fix file-description comments

Summary: Fix comments at the start of source files.

(cherry picked from FBD33274597)

[BOLT][NFC] Reformat with clang-format

Summary: Selectively apply clang-format to BOLT code base.

(cherry picked from FBD33119052)

[BOLT] Use more ADT data structures for BinaryFunction

Summary:
Switched members of BinaryFunction to ADT where it was possible and
made sense. As a result, the size of BinaryFunction on x86-64 Linu

[BOLT] Use more ADT data structures for BinaryFunction

Summary:
Switched members of BinaryFunction to ADT where it was possible and
made sense. As a result, the size of BinaryFunction on x86-64 Linux
reduced from 1624 bytes to 1448.

(cherry picked from FBD32981555)

show more ...

Rebase: [NFC] Refactor sources to be buildable in shared mode

Summary:
Moves source files into separate components, and make explicit
component dependency on each other, so LLVM build system knows h

Rebase: [NFC] Refactor sources to be buildable in shared mode

Summary:
Moves source files into separate components, and make explicit
component dependency on each other, so LLVM build system knows how to
build BOLT in BUILD_SHARED_LIBS=ON.

Please use the -c merge.renamelimit=230 git option when rebasing your
work on top of this change.

To achieve this, we create a new library to hold core IR files (most
classes beginning with Binary in their names), a new library to hold
Utils, some command line options shared across both RewriteInstance
and core IR files, a new library called Rewrite to hold most classes
concerned with running top-level functions coordinating the binary
rewriting process, and a new library called Profile to hold classes
dealing with profile reading and writing.

To remove the dependency from BinaryContext into X86-specific classes,
we do some refactoring on the BinaryContext constructor to receive a
reference to the specific backend directly from RewriteInstance. Then,
the dependency on X86 or AArch64-specific classes is transfered to the
Rewrite library. We can't have the Core library depend on targets
because targets depend on Core (which would create a cycle).

Files implementing the entry point of a tool are transferred to the
tools/ folder. All header files are transferred to the include/
folder. The src/ folder was renamed to lib/.

(cherry picked from FBD32746834)

show more ...