llvm/lib/LTO
Duncan P. N. Exon Smith 0b29dea9f1 LTO: Add API to choose whether to embed uselists
Reverse libLTO's default behaviour for preserving use-list order in
bitcode, and add API for controlling it.  The default setting is now
`false` (don't preserve them), which is consistent with `clang`'s
default behaviour.

Users of libLTO should call `lto_codegen_should_embed_uselists(CG,true)`
prior to calling `lto_codegen_write_merged_modules()` whenever the
output file isn't part of the production workflow in order to reproduce
results with subsequent calls to `llc`.

(I haven't added tests since `llvm-lto` (the test tool for LTO) doesn't
support bitcode output, and even if it did: there isn't actually a good
way to test whether a tool has passed the flag.  If the order is already
"natural" (if the order will already round-trip) then no use-list
directives are emitted at all.  At some point I'll circle back to add
tests to `llvm-as` (etc.) that they actually respect the flag, at which
point I can somehow add a test here as well.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235943 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-27 23:38:54 +00:00
..
CMakeLists.txt Use ADDITIONAL_HEADER_DIRS in all LLVM CMake projects. 2015-02-11 03:28:02 +00:00
LLVMBuild.txt Update libdeps since TLI was moved from Target to Analysis in r226078. 2015-01-15 05:21:00 +00:00
LTOCodeGenerator.cpp LTO: Add API to choose whether to embed uselists 2015-04-27 23:38:54 +00:00
LTOModule.cpp Remove more superfluous .str() and replace std::string concatenation with Twine. 2015-03-30 15:42:36 +00:00
Makefile Test commit. Fixed a copy-paste error in the Makefile for lib/LTO. 2013-10-03 18:05:12 +00:00