From 5a490d00261aaf3def5d71240b174b1ff6cdbb9f Mon Sep 17 00:00:00 2001 From: "Duncan P. N. Exon Smith" Date: Mon, 27 Apr 2015 23:38:54 +0000 Subject: 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 --- llvm/include/llvm-c/lto.h | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'llvm/include/llvm-c/lto.h') diff --git a/llvm/include/llvm-c/lto.h b/llvm/include/llvm-c/lto.h index 9d0d7263a58..1db077822ae 100644 --- a/llvm/include/llvm-c/lto.h +++ b/llvm/include/llvm-c/lto.h @@ -40,7 +40,7 @@ typedef bool lto_bool_t; * @{ */ -#define LTO_API_VERSION 14 +#define LTO_API_VERSION 15 /** * \since prior to LTO_API_VERSION=3 @@ -558,6 +558,18 @@ extern void lto_codegen_set_should_internalize(lto_code_gen_t cg, lto_bool_t ShouldInternalize); +/** + * \brief Set whether to embed uselists in bitcode. + * + * Sets whether \a lto_codegen_write_merged_modules() should embed uselists in + * output bitcode. This should be turned on for all -save-temps output. + * + * \since LTO_API_VERSION=15 + */ +extern void +lto_codegen_set_should_embed_uselists(lto_code_gen_t cg, + lto_bool_t ShouldEmbedUselists); + #ifdef __cplusplus } #endif -- cgit v1.2.3