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| author | Daniel Podder <dapodd@microsoft.com> | 2017-03-29 19:01:55 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2017-03-29 19:01:55 -0700 |
| commit | 926d104068fffb7e7cf867ab4c92082aab968692 (patch) | |
| tree | a41b9d30e6b8fee46739f8e539f8fe5fd6f552cb /configure.cmake | |
| parent | f990ce64c49d268bcaef5a87d5838f5008ff0a30 (diff) | |
| download | coreclr-926d104068fffb7e7cf867ab4c92082aab968692.tar.gz coreclr-926d104068fffb7e7cf867ab4c92082aab968692.tar.bz2 coreclr-926d104068fffb7e7cf867ab4c92082aab968692.zip | |
Add PGO support for Clang/LLVM on Unix (#10533)
Extend PGO support from VC++ on WIN32 to Clang/LLVM on UNIX as well.
* Just like on Windows: if profile data is missing, skip enabling PGO
(allows non-PGO builds in branches where we don't publish PGO data).
* PGO with LTO requires additional dependencies (namely a discoverable
`ld.gold` and `LLVMgold.so`). To protect against broken support and
keep the build flexible across a wider array of distros, attempt to
detect whether PGO compilation would work (using cmake's
`try_compile()`), and fall back to a non-PGO/non-LTO build if the test
fails.
Diffstat (limited to 'configure.cmake')
| -rw-r--r-- | configure.cmake | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/configure.cmake b/configure.cmake new file mode 100644 index 0000000000..97b4bc6599 --- /dev/null +++ b/configure.cmake @@ -0,0 +1,12 @@ +include(CheckCXXSourceCompiles) + +# VC++ guarantees support for LTCG (LTO's equivalent) +if(NOT WIN32) + # Function required to give CMAKE_REQUIRED_* local scope + function(check_have_lto) + set(CMAKE_REQUIRED_FLAGS -flto) + set(CMAKE_REQUIRED_LIBRARIES -flto -fuse-ld=gold) + check_cxx_source_compiles("int main() { return 0; }" HAVE_LTO) + endfunction(check_have_lto) + check_have_lto() +endif(NOT WIN32) |