From d5033a4576f8dabf3a4c35d0534aa83dde744098 Mon Sep 17 00:00:00 2001 From: Teresa Johnson Date: Mon, 14 Nov 2016 16:40:19 +0000 Subject: [ThinLTO] Make inline assembly handling more efficient in summary Summary: The change in r285513 to prevent exporting of locals used in inline asm added all locals in the llvm.used set to the reference set of functions containing inline asm. Since these locals were marked NoRename, this automatically prevented importing of the function. Unfortunately, this caused an explosion in the summary reference lists in some cases. In my particular example, it happened for a large protocol buffer generated C++ file, where many of the generated functions contained an inline asm call. It was exacerbated when doing a ThinLTO PGO instrumentation build, where the PGO instrumentation included thousands of private __profd_* values that were added to llvm.used. We really only need to include a single llvm.used local (NoRename) value in the reference list of a function containing inline asm to block it being imported. However, it seems cleaner to add a flag to the summary that explicitly describes this situation, which is what this patch does. Reviewers: mehdi_amini Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D26402 llvm-svn: 286840 --- llvm/lib/Bitcode/Reader/BitcodeReader.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'llvm/lib/Bitcode/Reader/BitcodeReader.cpp') diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp index bf1f6a5..94a3bcf 100644 --- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp +++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp @@ -946,7 +946,10 @@ static GlobalValueSummary::GVFlags getDecodedGVSummaryFlags(uint64_t RawFlags, RawFlags = RawFlags >> 4; bool NoRename = RawFlags & 0x1; bool IsNotViableToInline = RawFlags & 0x2; - return GlobalValueSummary::GVFlags(Linkage, NoRename, IsNotViableToInline); + bool HasInlineAsmMaybeReferencingInternal = RawFlags & 0x4; + return GlobalValueSummary::GVFlags(Linkage, NoRename, + HasInlineAsmMaybeReferencingInternal, + IsNotViableToInline); } static GlobalValue::VisibilityTypes getDecodedVisibility(unsigned Val) { -- cgit v1.1