From 40bcbe48e8ecefc6f873acef10f3265401008655 Mon Sep 17 00:00:00 2001
From: Jez Ng <jezng@fb.com>
Date: Sat, 11 Dec 2021 01:01:13 -0500
Subject: [PATCH] [lld-macho][nfc] InputSections don't need to track their
 total # of callsites

... only whether they have more than zero. This simplifies the code slightly.

I've also moved the field into the ConcatInputSection subclass since it doesn't
actually get used by the other InputSections.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D115539
---
 lld/MachO/ConcatOutputSection.cpp | 11 +++++------
 lld/MachO/InputSection.h          |  9 ++++-----
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/lld/MachO/ConcatOutputSection.cpp b/lld/MachO/ConcatOutputSection.cpp
index 46cd15a..9f71e81 100644
--- a/lld/MachO/ConcatOutputSection.cpp
+++ b/lld/MachO/ConcatOutputSection.cpp
@@ -124,13 +124,13 @@ bool ConcatOutputSection::needsThunks() const {
   if (!target->usesThunks())
     return false;
   uint64_t isecAddr = addr;
-  for (InputSection *isec : inputs)
+  for (ConcatInputSection *isec : inputs)
     isecAddr = alignTo(isecAddr, isec->align) + isec->getSize();
   if (isecAddr - addr + in.stubs->getSize() <=
       std::min(target->backwardBranchRange, target->forwardBranchRange))
     return false;
   // Yes, this program is large enough to need thunks.
-  for (InputSection *isec : inputs) {
+  for (ConcatInputSection *isec : inputs) {
     for (Reloc &r : isec->relocs) {
       if (!target->hasAttr(r.type, RelocAttrBits::BRANCH))
         continue;
@@ -143,9 +143,8 @@ bool ConcatOutputSection::needsThunks() const {
       // might need to create more for this referent at the time we are
       // estimating distance to __stubs in estimateStubsInRangeVA().
       ++thunkInfo.callSiteCount;
-      // Knowing InputSection call site count will help us avoid work on those
-      // that have no BRANCH relocs.
-      ++isec->callSiteCount;
+      // We can avoid work on InputSections that have no BRANCH relocs.
+      isec->hasCallSites = true;
     }
   }
   return true;
@@ -250,7 +249,7 @@ void ConcatOutputSection::finalize() {
                                     isecVA + forwardBranchRange - slop)
       finalizeOne(inputs[finalIdx++]);
 
-    if (isec->callSiteCount == 0)
+    if (!isec->hasCallSites)
       continue;
 
     if (finalIdx == endIdx && stubsInRangeVA == TargetInfo::outOfRangeVA) {
diff --git a/lld/MachO/InputSection.h b/lld/MachO/InputSection.h
index 1183e32..fa13722 100644
--- a/lld/MachO/InputSection.h
+++ b/lld/MachO/InputSection.h
@@ -57,9 +57,8 @@ public:
   OutputSection *parent = nullptr;
 
   uint32_t align = 1;
-  uint32_t callSiteCount : 31;
   // is address assigned?
-  uint32_t isFinal : 1;
+  bool isFinal = false;
 
   ArrayRef<uint8_t> data;
   std::vector<Reloc> relocs;
@@ -86,12 +85,11 @@ protected:
 
   InputSection(Kind kind, StringRef segname, StringRef name, InputFile *file,
                ArrayRef<uint8_t> data, uint32_t align, uint32_t flags)
-      : align(align), callSiteCount(0), isFinal(false), data(data),
+      : align(align), data(data),
         shared(make<Shared>(file, name, segname, flags, kind)) {}
 
   InputSection(const InputSection &rhs)
-      : align(rhs.align), callSiteCount(0), isFinal(false), data(rhs.data),
-        shared(rhs.shared) {}
+      : align(rhs.align), data(rhs.data), shared(rhs.shared) {}
 
   const Shared *const shared;
 };
@@ -143,6 +141,7 @@ public:
   // first and not copied to the output.
   bool wasCoalesced = false;
   bool live = !config->deadStrip;
+  bool hasCallSites = false;
   // This variable has two usages. Initially, it represents the input order.
   // After assignAddresses is called, it represents the offset from the
   // beginning of the output section this section was assigned to.
-- 
2.7.4