From eb37330ac77774a9fe030aaa3c5759afa3377db5 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Tue, 21 Dec 2021 20:19:51 -0800
Subject: [PATCH] [ELF] Change mipsGotIndex to uint32_t

This does not decrease sizeof(InputSection) (important for memory usage) on
ELF64 by itself but allows we to add another uint32_t.
---
 lld/ELF/InputFiles.h          |  2 +-
 lld/ELF/SyntheticSections.cpp | 17 ++++++++---------
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/lld/ELF/InputFiles.h b/lld/ELF/InputFiles.h
index 1075029..e15f879 100644
--- a/lld/ELF/InputFiles.h
+++ b/lld/ELF/InputFiles.h
@@ -111,7 +111,7 @@ public:
   SmallVector<Symbol *, 0> symbols;
 
   // Index of MIPS GOT built for this file.
-  llvm::Optional<uint32_t> mipsGotIndex;
+  uint32_t mipsGotIndex = -1;
 
   // outSecOff of .got2 in the current file. This is used by PPC32 -fPIC/-fPIE
   // to compute offsets in PLT call stubs.
diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index a901c89..e25401b 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -763,18 +763,18 @@ size_t MipsGotSection::FileGot::getIndexedEntriesNum() const {
 }
 
 MipsGotSection::FileGot &MipsGotSection::getGot(InputFile &f) {
-  if (!f.mipsGotIndex.hasValue()) {
+  if (f.mipsGotIndex == uint32_t(-1)) {
     gots.emplace_back();
     gots.back().file = &f;
     f.mipsGotIndex = gots.size() - 1;
   }
-  return gots[*f.mipsGotIndex];
+  return gots[f.mipsGotIndex];
 }
 
 uint64_t MipsGotSection::getPageEntryOffset(const InputFile *f,
                                             const Symbol &sym,
                                             int64_t addend) const {
-  const FileGot &g = gots[*f->mipsGotIndex];
+  const FileGot &g = gots[f->mipsGotIndex];
   uint64_t index = 0;
   if (const OutputSection *outSec = sym.getOutputSection()) {
     uint64_t secAddr = getMipsPageAddr(outSec->addr);
@@ -788,7 +788,7 @@ uint64_t MipsGotSection::getPageEntryOffset(const InputFile *f,
 
 uint64_t MipsGotSection::getSymEntryOffset(const InputFile *f, const Symbol &s,
                                            int64_t addend) const {
-  const FileGot &g = gots[*f->mipsGotIndex];
+  const FileGot &g = gots[f->mipsGotIndex];
   Symbol *sym = const_cast<Symbol *>(&s);
   if (sym->isTls())
     return g.tls.lookup(sym) * config->wordsize;
@@ -798,13 +798,13 @@ uint64_t MipsGotSection::getSymEntryOffset(const InputFile *f, const Symbol &s,
 }
 
 uint64_t MipsGotSection::getTlsIndexOffset(const InputFile *f) const {
-  const FileGot &g = gots[*f->mipsGotIndex];
+  const FileGot &g = gots[f->mipsGotIndex];
   return g.dynTlsSymbols.lookup(nullptr) * config->wordsize;
 }
 
 uint64_t MipsGotSection::getGlobalDynOffset(const InputFile *f,
                                             const Symbol &s) const {
-  const FileGot &g = gots[*f->mipsGotIndex];
+  const FileGot &g = gots[f->mipsGotIndex];
   Symbol *sym = const_cast<Symbol *>(&s);
   return g.dynTlsSymbols.lookup(sym) * config->wordsize;
 }
@@ -1061,10 +1061,9 @@ uint64_t MipsGotSection::getGp(const InputFile *f) const {
   // For files without related GOT or files refer a primary GOT
   // returns "common" _gp value. For secondary GOTs calculate
   // individual _gp values.
-  if (!f || !f->mipsGotIndex.hasValue() || *f->mipsGotIndex == 0)
+  if (!f || f->mipsGotIndex == uint32_t(-1) || f->mipsGotIndex == 0)
     return ElfSym::mipsGp->getVA(0);
-  return getVA() + gots[*f->mipsGotIndex].startIndex * config->wordsize +
-         0x7ff0;
+  return getVA() + gots[f->mipsGotIndex].startIndex * config->wordsize + 0x7ff0;
 }
 
 void MipsGotSection::writeTo(uint8_t *buf) {
-- 
2.7.4