Index: lld/ELF/Driver.cpp
===================================================================
--- lld/ELF/Driver.cpp
+++ lld/ELF/Driver.cpp
@@ -608,9 +608,6 @@
 }
 
 static DiscardPolicy getDiscard(opt::InputArgList &args) {
-  if (args.hasArg(OPT_relocatable))
-    return DiscardPolicy::None;
-
   auto *arg =
       args.getLastArg(OPT_discard_all, OPT_discard_locals, OPT_discard_none);
   if (!arg)
Index: lld/ELF/Symbols.h
===================================================================
--- lld/ELF/Symbols.h
+++ lld/ELF/Symbols.h
@@ -238,8 +238,8 @@
         exportDynamic(isExportDynamic(k, visibility)), inDynamicList(false),
         canInline(false), referenced(false), traced(false), needsPltAddr(false),
         isInIplt(false), gotInIgot(false), isPreemptible(false),
-        used(!config->gcSections), needsTocRestore(false),
-        scriptDefined(false) {}
+        used(!config->gcSections && binding != llvm::ELF::STB_LOCAL),
+        needsTocRestore(false), scriptDefined(false) {}
 
 public:
   // True the symbol should point to its PLT entry.
@@ -258,6 +258,7 @@
   uint8_t isPreemptible : 1;
 
   // True if an undefined or shared symbol is used from a live section.
+  // True if a local symbol is referenced by a relocation.
   uint8_t used : 1;
 
   // True if a call to this symbol needs to be followed by a restore of the
Index: lld/ELF/Writer.cpp
===================================================================
--- lld/ELF/Writer.cpp
+++ lld/ELF/Writer.cpp
@@ -560,8 +560,7 @@
 
 // The main function of the writer.
 template <class ELFT> void Writer<ELFT>::run() {
-  if (config->discard != DiscardPolicy::All)
-    copyLocalSymbols();
+  copyLocalSymbols();
 
   if (config->copyRelocs)
     addSectionSymbols();
@@ -638,6 +637,31 @@
     error("failed to write to the output file: " + toString(std::move(e)));
 }
 
+template <class ELFT, class RelTy>
+static void markUsedLocalSymbolsImpl(ObjFile<ELFT> *file,
+                                     llvm::ArrayRef<RelTy> rels) {
+  for (const RelTy &rel : rels) {
+    Symbol &sym = file->getRelocTargetSym(rel);
+    if (sym.isLocal())
+      sym.used = true;
+  }
+}
+
+template <class ELFT> static void markUsedLocalSymbols() {
+  for (InputFile *file : objectFiles) {
+    ObjFile<ELFT> *f = cast<ObjFile<ELFT>>(file);
+    for (InputSectionBase *s : f->getSections()) {
+      InputSection *isec = dyn_cast_or_null<InputSection>(s);
+      if (!isec)
+        continue;
+      if (isec->type == SHT_REL)
+        markUsedLocalSymbolsImpl(f, isec->getDataAs<typename ELFT::Rel>());
+      else if (isec->type == SHT_RELA)
+        markUsedLocalSymbolsImpl(f, isec->getDataAs<typename ELFT::Rela>());
+    }
+  }
+}
+
 static bool shouldKeepInSymtab(const Defined &sym) {
   if (sym.isSection())
     return false;
@@ -645,11 +669,13 @@
   if (config->discard == DiscardPolicy::None)
     return true;
 
-  // If -emit-reloc is given, all symbols including local ones need to be
-  // copied because they may be referenced by relocations.
-  if (config->emitRelocs)
+  // If --emit-reloc or -r is given, preserve symbols referenced by relocations.
+  if (config->copyRelocs && sym.used)
     return true;
 
+  if (config->discard == DiscardPolicy::All)
+    return false;
+
   // In ELF assembly .L symbols are normally discarded by the assembler.
   // If the assembler fails to do so, the linker discards them if
   // * --discard-locals is used.
@@ -695,6 +721,8 @@
 template <class ELFT> void Writer<ELFT>::copyLocalSymbols() {
   if (!in.symTab)
     return;
+  if (config->copyRelocs && config->discard != DiscardPolicy::None)
+    markUsedLocalSymbols<ELFT>();
   for (InputFile *file : objectFiles) {
     ObjFile<ELFT> *f = cast<ObjFile<ELFT>>(file);
     for (Symbol *b : f->getLocalSymbols()) {
Index: lld/test/ELF/discard-locals-preserve-used.s
===================================================================
--- /dev/null
+++ lld/test/ELF/discard-locals-preserve-used.s
@@ -0,0 +1,48 @@
+# REQUIRES: x86
+
+## This test checks that --discard-all and --discard-locals, when used with -r
+## or --emit-relocs, preserve local symbols which are used in relocations and
+## remove only unreferenced ones.
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64 -save-temp-labels %s -o %t
+
+# RUN: ld.lld --discard-none -shared --emit-relocs %t -o - | \
+# RUN:   llvm-nm - | FileCheck %s --check-prefix=DISCARD-NONE
+
+# RUN: ld.lld --discard-locals -shared --emit-relocs %t -o - | \
+# RUN:   llvm-nm - | FileCheck %s --check-prefix=DISCARD-LOCALS
+
+# RUN: ld.lld --discard-all -shared --emit-relocs %t -o - | \
+# RUN:   llvm-nm - | FileCheck %s --check-prefix=DISCARD-ALL
+
+# RUN: ld.lld --discard-none -r %t -o - | \
+# RUN:   llvm-nm - | FileCheck %s --check-prefix=DISCARD-NONE
+
+# RUN: ld.lld --discard-locals -r %t -o - | \
+# RUN:   llvm-nm - | FileCheck %s --check-prefix=DISCARD-LOCALS
+
+# RUN: ld.lld --discard-all -r %t -o - | \
+# RUN:   llvm-nm - | FileCheck %s --check-prefix=DISCARD-ALL
+
+# DISCARD-NONE:      .LUnused
+# DISCARD-NONE-NEXT: .LUsed
+# DISCARD-NONE-NEXT: Unused
+# DISCARD-NONE-NEXT: Used
+
+# DISCARD-LOCALS-NOT:  .LUnused
+# DISCARD-LOCALS:      .LUsed
+# DISCARD-LOCALS-NEXT: Unused
+# DISCARD-LOCALS-NEXT: Used
+
+# DISCARD-ALL-NOT:  .LUnused
+# DISCARD-ALL:      .LUsed
+# DISCARD-ALL-NOT:  Unused
+# DISCARD-ALL-NEXT: Used
+
+.text
+    jmp .LUsed@PLT
+    call Used@PLT
+.LUnused:
+Unused:
+.LUsed:
+Used: