From f3f7f4bc540065abea6b2677564384783545de3d Mon Sep 17 00:00:00 2001 From: Rafael Espindola Date: Fri, 14 Oct 2016 17:01:39 +0000 Subject: [PATCH] Move alignTo computation inside the if. This is an improvement when compiling with llvm. llvm doesn't inline the call to insert, so the align is always executed and shows up in the profile. With gcc the call to insert is inlined and the align computation moved and done only if needed. With this patch we explicitly only compute it if it is needed. In the two tests with debug info, the speedup was scylla master 3.008959365 patch 2.932080942 1.02621974786x faster firefox master 6.709823604 patch 6.592387227 1.01781393795x faster In all others the difference was in the noise. llvm-svn: 284249 --- lib/MC/StringTableBuilder.cpp | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/lib/MC/StringTableBuilder.cpp b/lib/MC/StringTableBuilder.cpp index 42292d42fb7..e5d2a4ae58a 100644 --- a/lib/MC/StringTableBuilder.cpp +++ b/lib/MC/StringTableBuilder.cpp @@ -195,9 +195,11 @@ size_t StringTableBuilder::add(CachedHashString S) { assert(S.size() > COFF::NameSize && "Short string in COFF string table!"); assert(!isFinalized()); - size_t Start = alignTo(Size, Alignment); - auto P = StringIndexMap.insert(std::make_pair(S, Start)); - if (P.second) + auto P = StringIndexMap.insert(std::make_pair(S, 0)); + if (P.second) { + size_t Start = alignTo(Size, Alignment); + P.first->second = Start; Size = Start + S.size() + (K != RAW); + } return P.first->second; }