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Kito Cheng 7a5cb15ea6 [RISCV] Lazily add RVV C intrinsics.
Leverage the method OpenCL uses that adds C intrinsics when the lookup
failed. There is no need to define C intrinsics in the header file any
more. It could help to avoid the large header file to speed up the
compilation of RVV source code. Besides that, only the C intrinsics used
by the users will be added into the declaration table.

This patch is based on https://reviews.llvm.org/D103228 and inspired by
OpenCL implementation.

### Experimental Results

#### TL;DR:

- Binary size of clang increase ~200k, which is +0.07%  for debug build and +0.13% for release build.
- Single file compilation speed up ~33x for debug build and ~8.5x for release build
- Regression time reduce ~10% (`ninja check-all`, enable all targets)

#### Header size change
```
       |      size |     LoC |
------------------------------
Before | 4,434,725 |  69,749 |
After  |     6,140 |     162 |
```

#### Single File Compilation Time
Testcase:
```
#include <riscv_vector.h>

vint32m1_t test_vadd_vv_vfloat32m1_t(vint32m1_t op1, vint32m1_t op2, size_t vl) {
  return vadd(op1, op2, vl);
}
```
##### Debug build:
Before:
```
real    0m19.352s
user    0m19.252s
sys     0m0.092s
```

After:
```
real    0m0.576s
user    0m0.552s
sys     0m0.024s
```

~33x speed up for debug build

##### Release build:
Before:
```
real    0m0.773s
user    0m0.741s
sys     0m0.032s
```

After:
```
real    0m0.092s
user    0m0.080s
sys     0m0.012s
```

~8.5x speed up for release build

#### Regression time
Note: the failed case is `tools/llvm-debuginfod-find/debuginfod.test` which is unrelated to this patch.

##### Debug build
Before:
```
Testing Time: 1358.38s
  Skipped          :    11
  Unsupported      :   446
  Passed           : 75767
  Expectedly Failed:   190
  Failed           :     1
```
After
```
Testing Time: 1220.29s
  Skipped          :    11
  Unsupported      :   446
  Passed           : 75767
  Expectedly Failed:   190
  Failed           :     1
```
##### Release build
Before:
```
Testing Time: 381.98s
  Skipped          :    12
  Unsupported      :  1407
  Passed           : 74765
  Expectedly Failed:   176
  Failed           :     1
```
After:
```
Testing Time: 346.25s
  Skipped          :    12
  Unsupported      :  1407
  Passed           : 74765
  Expectedly Failed:   176
  Failed           :     1
```

#### Binary size of clang

##### Debug build
Before
```
   text    data     bss     dec     hex filename
335261851       12726004         552812 348540667       14c64efb        bin/clang
```
After
```
   text    data     bss     dec     hex filename
335442803       12798708         552940 348794451       14ca2e53        bin/clang
```
+253K, +0.07% code size

##### Release build
Before
```
   text    data     bss     dec     hex filename
144123975       8374648  483140 152981763       91e5103 bin/clang
```
After
```
   text    data     bss     dec     hex filename
144255762       8447296  483268 153186326       9217016 bin/clang
```
+204K, +0.13%

Authored-by: Kito Cheng <kito.cheng@sifive.com>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Reviewed By: khchen, aaron.ballman

Differential Revision: https://reviews.llvm.org/D111617
2022-07-26 15:47:47 +08:00
.github [github] format and refactor GitHub workflows 2022-06-11 11:31:21 +04:30
bolt [BOLT] Support files with no symbols 2022-07-26 00:07:59 -07:00
clang [RISCV] Lazily add RVV C intrinsics. 2022-07-26 15:47:47 +08:00
clang-tools-extra Remove redundaunt virtual specifiers (NFC) 2022-07-25 23:00:59 -07:00
cmake [cmake] Fix missing paren in `FindPrefixFromConfig` 2022-07-26 07:35:12 +00:00
compiler-rt [Clang] Fix how we set the NumPositiveBits on an EnumDecl to cover the case of single enumerator with value zero or an empty enum 2022-07-25 16:01:01 -07:00
cross-project-tests Pretty printer test fixes 2022-07-12 19:29:38 +00:00
flang [flang] Rename variables in test. NFCI 2022-07-26 07:33:24 +00:00
libc [libc][Obvious] Use the correct StringView constructor in dirent_test. 2022-07-25 20:47:17 +00:00
libclc Remove references to old mailing lists that have moved to discourse. Replace with links to discourse. 2022-07-22 09:59:03 -07:00
libcxx [libc++] Fix algorithms which use reverse_iterator 2022-07-25 18:35:20 +02:00
libcxxabi Remove references to old mailing lists that have moved to discourse. Replace with links to discourse. 2022-07-22 09:59:03 -07:00
libunwind [libunwind][SystemZ] Use process_vm_readv to avoid potential segfaults 2022-07-18 16:54:48 +02:00
lld [lld-macho] Implement -hidden-l 2022-07-26 01:41:51 +02:00
lldb [lldb][AArch64] Add support for memory tags in core files 2022-07-26 08:46:36 +01:00
llvm [lldb][AArch64] Add support for memory tags in core files 2022-07-26 08:46:36 +01:00
llvm-libgcc [llvm-libgcc] initial commit 2022-02-16 17:06:45 +00:00
mlir Use isa instead of dyn_cast (NFC) 2022-07-25 23:00:58 -07:00
openmp [Libomptarget] Add checks for AMDGPU TargetID using new image info 2022-07-26 02:44:31 -05:00
polly Remove redundaunt virtual specifiers (NFC) 2022-07-25 23:00:59 -07:00
pstl [libc++] Use _LIBCPP_ASSERT by default for _PSTL_ASSERTions 2022-05-20 16:58:21 +02:00
runtimes [runtimes] Add pstl to the list of default runtimes to fix the build 2022-07-22 22:57:37 +02:00
third-party Ensure newlines at the end of files (NFC) 2021-12-26 08:51:06 -08:00
utils [bazel] Add new rule for c60b897d22 2022-07-25 20:29:01 -07:00
.arcconfig
.arclint
.clang-format
.clang-tidy [clangd] Cleanup of readability-identifier-naming 2022-02-01 13:31:52 +00:00
.git-blame-ignore-revs Add __config formatting to .git-blame-ignore-revs 2022-06-14 09:52:49 -04:00
.gitignore [llvm] Ignore .rej files in .gitignore 2022-04-28 08:44:51 -07:00
.mailmap .mailmap: remove stray space in comment 2022-02-24 18:50:08 -05:00
CONTRIBUTING.md docs: update some bug tracker references (NFC) 2022-01-10 15:59:08 -08:00
README.md Fix grammar and punctuation across several docs; NFC 2022-04-07 07:11:11 -04:00
SECURITY.md [docs] Describe reporting security issues on the chromium tracker. 2021-05-19 15:21:50 -07:00

README.md

The LLVM Compiler Infrastructure

This directory and its sub-directories contain the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

The README briefly describes how to get started with building LLVM. For more information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting Started with the LLVM System

Taken from here.

Overview

Welcome to the LLVM project!

The LLVM project has multiple components. The core of the project is itself called "LLVM". This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer. It also contains basic regression tests.

C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

The LLVM Getting Started documentation may be out of date. The Clang Getting Started page might have more accurate information.

This is an example work-flow and configuration to get and build the LLVM source:

  1. Checkout LLVM (including related sub-projects like Clang):

    • git clone https://github.com/llvm/llvm-project.git

    • Or, on windows, git clone --config core.autocrlf=false https://github.com/llvm/llvm-project.git

  2. Configure and build LLVM and Clang:

    • cd llvm-project

    • cmake -S llvm -B build -G <generator> [options]

      Some common build system generators are:

      • Ninja --- for generating Ninja build files. Most llvm developers use Ninja.
      • Unix Makefiles --- for generating make-compatible parallel makefiles.
      • Visual Studio --- for generating Visual Studio projects and solutions.
      • Xcode --- for generating Xcode projects.

      Some common options:

      • -DLLVM_ENABLE_PROJECTS='...' and -DLLVM_ENABLE_RUNTIMES='...' --- semicolon-separated list of the LLVM sub-projects and runtimes you'd like to additionally build. LLVM_ENABLE_PROJECTS can include any of: clang, clang-tools-extra, cross-project-tests, flang, libc, libclc, lld, lldb, mlir, openmp, polly, or pstl. LLVM_ENABLE_RUNTIMES can include any of libcxx, libcxxabi, libunwind, compiler-rt, libc or openmp. Some runtime projects can be specified either in LLVM_ENABLE_PROJECTS or in LLVM_ENABLE_RUNTIMES.

        For example, to build LLVM, Clang, libcxx, and libcxxabi, use -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi".

      • -DCMAKE_INSTALL_PREFIX=directory --- Specify for directory the full path name of where you want the LLVM tools and libraries to be installed (default /usr/local). Be careful if you install runtime libraries: if your system uses those provided by LLVM (like libc++ or libc++abi), you must not overwrite your system's copy of those libraries, since that could render your system unusable. In general, using something like /usr is not advised, but /usr/local is fine.

      • -DCMAKE_BUILD_TYPE=type --- Valid options for type are Debug, Release, RelWithDebInfo, and MinSizeRel. Default is Debug.

      • -DLLVM_ENABLE_ASSERTIONS=On --- Compile with assertion checks enabled (default is Yes for Debug builds, No for all other build types).

    • cmake --build build [-- [options] <target>] or your build system specified above directly.

      • The default target (i.e. ninja or make) will build all of LLVM.

      • The check-all target (i.e. ninja check-all) will run the regression tests to ensure everything is in working order.

      • CMake will generate targets for each tool and library, and most LLVM sub-projects generate their own check-<project> target.

      • Running a serial build will be slow. To improve speed, try running a parallel build. That's done by default in Ninja; for make, use the option -j NNN, where NNN is the number of parallel jobs to run. In most cases, you get the best performance if you specify the number of CPU threads you have. On some Unix systems, you can specify this with -j$(nproc).

    • For more information see CMake.

Consult the Getting Started with LLVM page for detailed information on configuring and compiling LLVM. You can visit Directory Layout to learn about the layout of the source code tree.

Getting in touch

Join LLVM Discourse forums, discord chat or #llvm IRC channel on OFTC.

The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.