llvm-project/llvm/tools/lto
Duncan P. N. Exon Smith 5a490d0026 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.)

llvm-svn: 235943
2015-04-27 23:38:54 +00:00
..
CMakeLists.txt Unbreak cmake build with shared libraries enabled. 2014-12-20 01:51:02 +00:00
LTODisassembler.cpp
Makefile Remove definition of LLVM_VERSION_INFO; this macro is not used by any of the 2014-09-26 21:53:12 +00:00
lto.cpp LTO: Add API to choose whether to embed uselists 2015-04-27 23:38:54 +00:00
lto.exports [LTO API] add lto_codegen_set_should_internalize. 2015-04-17 17:10:09 +00:00