Summary:
The clang driver option -save-temps was not passed to the LTO config,
so when invoking the ThinLTO backends via clang during distributed
builds there was no way to get LTO to save temp files.
Getting this to work with ThinLTO distributed builds also required
changing the driver to avoid a separate compile step to emit unoptimized
bitcode when the input was already bitcode under -save-temps. Not only is
this unnecessary in general, it is problematic for ThinLTO backends since
the temporary bitcode file to the backend would not match the module path
in the combined index, leading to incorrect ThinLTO backend index-based
optimizations.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, eraman, cfe-commits
Differential Revision: https://reviews.llvm.org/D45217
llvm-svn: 330194
Hopefully fix the remaining bot failure from r254927. Remove
target specification since it shouldn't be needed, and this causes
an error when trying to check the pass execution structure in
test/CodeGen/thinlto_backend.c on non-x86 arches.
llvm-svn: 254940
Summary:
Adds new option -fthinlto-index=<file> to invoke the LTO pipeline
along with function importing via clang using the supplied function
summary index file. This supports invoking the parallel ThinLTO
backend processes in a distributed build environment via clang.
Additionally, this causes the module linker to be invoked on the bitcode
file being compiled to perform any necessary promotion and renaming of
locals that are exported via the function summary index file.
Add a couple tests that confirm we get expected errors when we try to
use the new option on a file that isn't bitcode, or specify an invalid
index file. The tests also confirm that we trigger the expected function
import pass.
Depends on D15024
Reviewers: joker.eph, dexonsmith
Subscribers: joker.eph, davidxl, cfe-commits
Differential Revision: http://reviews.llvm.org/D15025
llvm-svn: 254927
Teresa Johnson