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author | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2015-04-27 23:38:54 +0000 |
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committer | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2015-04-27 23:38:54 +0000 |
commit | 0b29dea9f171fa7cbcd7df2cff8f8e596b083895 (patch) | |
tree | 8f521ab2567324bb7447f0ff3b521befd6e0b1fc /tools/lto | |
parent | b176a4f2e41751bb52bd791979749c16d22bef18 (diff) |
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
Diffstat (limited to 'tools/lto')
-rw-r--r-- | tools/lto/lto.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/lto/lto.cpp b/tools/lto/lto.cpp index e66a7786a14..d6ceebed728 100644 --- a/tools/lto/lto.cpp +++ b/tools/lto/lto.cpp @@ -338,3 +338,8 @@ void lto_codegen_set_should_internalize(lto_code_gen_t cg, bool ShouldInternalize) { unwrap(cg)->setShouldInternalize(ShouldInternalize); } + +void lto_codegen_set_should_embed_uselists(lto_code_gen_t cg, + lto_bool_t ShouldEmbedUselists) { + unwrap(cg)->setShouldEmbedUselists(ShouldEmbedUselists); +} |