From b11ef0897cd7c67740d309e28d228c03f4dcba88 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka Date: Sat, 14 Nov 2015 06:35:56 +0000 Subject: Reduce the size of MCRelaxableFragment. MCRelaxableFragment previously kept a copy of MCSubtargetInfo and MCInst to enable re-encoding the MCInst later during relaxation. A copy of MCSubtargetInfo (instead of a reference or pointer) was needed because the feature bits could be modified by the parser. This commit replaces the MCSubtargetInfo copy in MCRelaxableFragment with a constant reference to MCSubtargetInfo. The copies of MCSubtargetInfo are kept in MCContext, and the target parsers are now responsible for asking MCContext to provide a copy whenever the feature bits of MCSubtargetInfo have to be toggled. With this patch, I saw a 4% reduction in peak memory usage when I compiled verify-uselistorder.lto.bc using llc. rdar://problem/21736951 Differential Revision: http://reviews.llvm.org/D14346 llvm-svn: 253127 --- llvm/lib/MC/MCContext.cpp | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'llvm/lib/MC/MCContext.cpp') diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp index 2160b4e..93c7aaf 100644 --- a/llvm/lib/MC/MCContext.cpp +++ b/llvm/lib/MC/MCContext.cpp @@ -78,6 +78,7 @@ void MCContext::reset() { ELFAllocator.DestroyAll(); MachOAllocator.DestroyAll(); + MCSubtargetAllocator.DestroyAll(); UsedNames.clear(); Symbols.clear(); SectionSymbols.clear(); @@ -439,6 +440,10 @@ MCSectionCOFF *MCContext::getAssociativeCOFFSection(MCSectionCOFF *Sec, COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE); } +MCSubtargetInfo &MCContext::getSubtargetCopy(const MCSubtargetInfo &STI) { + return *new (MCSubtargetAllocator.Allocate()) MCSubtargetInfo(STI); +} + //===----------------------------------------------------------------------===// // Dwarf Management //===----------------------------------------------------------------------===// -- cgit v1.1