Split merge sections early.

Now that getSectionPiece is fast (uses a hash) it is probably OK to
split merge sections early.

The reason I want to do this is to split eh_frame sections in the same
place.

This does mean that we have to decompress early. Given that the only
compressed sections are debug info, I don't think we are missing much.

It is a small improvement: 0.5% on the geometric mean.

1 files changed, 1 insertions, 1 deletions

diff --git a/lld/ELF/MarkLive.cpp b/lld/ELF/MarkLive.cpp
index 6b80e8e77aa..d7cc74e48c1 100644
--- a/lld/ELF/MarkLive.cpp
+++ b/lld/ELF/MarkLive.cpp
@@ -207,7 +207,7 @@ template <class ELFT> static void doGcSections() {
     // (splittable) sections, each piece of data has independent liveness bit.
     // So we explicitly tell it which offset is in use.
     if (auto *MS = dyn_cast<MergeInputSection>(Sec))
-      MS->markLiveAt(Offset);
+      MS->getSectionPiece(Offset)->Live = true;
 
     if (Sec->Live)
       return;