From 0919a84071e55190643eb6e833a51755692b0d29 Mon Sep 17 00:00:00 2001 From: Teresa Johnson Date: Wed, 10 Feb 2016 18:57:54 +0000 Subject: [ThinLTO] Use MD5 hash in function index. Summary: This patch uses the lower 64-bits of the MD5 hash of a function name as a GUID in the function index, instead of storing function names. Any local functions are first given a global name by prepending the original source file name. This is the same naming scheme and GUID used by PGO in the indexed profile format. This change has a couple of benefits. The primary benefit is size reduction in the combined index file, for example 483.xalancbmk's combined index file was reduced by around 70%. It should also result in memory savings for the index file in memory, as the in-memory map is also indexed by the hash instead of the string. Second, this enables integration with indirect call promotion, since the indirect call profile targets are recorded using the same global naming convention and hash. This will enable the function importer to easily locate function summaries for indirect call profile targets to enable their import and subsequent promotion. The original source file name is recorded in the bitcode in a new module-level record for use in the ThinLTO backend pipeline. Reviewers: davidxl, joker.eph Subscribers: llvm-commits, joker.eph Differential Revision: http://reviews.llvm.org/D17028 llvm-svn: 260408 --- llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp | 1 + 1 file changed, 1 insertion(+) (limited to 'llvm/tools') diff --git a/llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp b/llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp index 1a4bc9ef178..1e0209bb79a 100644 --- a/llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp +++ b/llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp @@ -173,6 +173,7 @@ static const char *GetCodeName(unsigned CodeID, unsigned BlockID, STRINGIFY_CODE(MODULE_CODE, GCNAME) STRINGIFY_CODE(MODULE_CODE, VSTOFFSET) STRINGIFY_CODE(MODULE_CODE, METADATA_VALUES) + STRINGIFY_CODE(MODULE_CODE, SOURCE_FILENAME) } case bitc::IDENTIFICATION_BLOCK_ID: switch (CodeID) { -- cgit v1.2.3