Speed up AddSectionToTheEnd. It was walking all fragments in all sections.
This is really slow with we have 1000s of sections each with a corresponding
relocation section. Also, it is only used by the ELF writer to add
basic data, so there is no need to force a new layout pass.
Should fix PR8563.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118377 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 9dc67644..8e87d5b 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -590,24 +590,14 @@
void MCAssembler::AddSectionToTheEnd(const MCObjectWriter &Writer,
MCSectionData &SD, MCAsmLayout &Layout) {
// Create dummy fragments and assign section ordinals.
- unsigned SectionIndex = 0;
- for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it)
- SectionIndex++;
-
+ unsigned SectionIndex = size();
SD.setOrdinal(SectionIndex);
// Assign layout order indices to sections and fragments.
- unsigned FragmentIndex = 0;
- unsigned i = 0;
- for (unsigned e = Layout.getSectionOrder().size(); i != e; ++i) {
- MCSectionData *SD = Layout.getSectionOrder()[i];
+ const MCFragment &Last = *Layout.getSectionOrder().back()->rbegin();
+ unsigned FragmentIndex = Last.getLayoutOrder() + 1;
- for (MCSectionData::iterator it2 = SD->begin(),
- ie2 = SD->end(); it2 != ie2; ++it2)
- FragmentIndex++;
- }
-
- SD.setLayoutOrder(i);
+ SD.setLayoutOrder(Layout.getSectionOrder().size());
for (MCSectionData::iterator it2 = SD.begin(),
ie2 = SD.end(); it2 != ie2; ++it2) {
it2->setLayoutOrder(FragmentIndex++);
@@ -615,11 +605,6 @@
Layout.getSectionOrder().push_back(&SD);
Layout.LayoutSection(&SD);
-
- // Layout until everything fits.
- while (LayoutOnce(Writer, Layout))
- continue;
-
}
void MCAssembler::Finish(MCObjectWriter *Writer) {