Index: lld/ELF/Config.h
===================================================================
--- lld/ELF/Config.h
+++ lld/ELF/Config.h
@@ -40,6 +40,9 @@
 // For --discard-{all,locals,none}.
 enum class DiscardPolicy { Default, All, Locals, None };
 
+// For --icf={none,safe,all}.
+enum class ICFLevel { None, Safe, All };
+
 // For --strip-{all,debug}.
 enum class StripPolicy { None, All, Debug };
 
@@ -137,7 +140,6 @@
   bool GnuUnique;
   bool HasDynamicList = false;
   bool HasDynSymTab;
-  bool ICF;
   bool IgnoreDataAddressEquality;
   bool IgnoreFunctionAddressEquality;
   bool LTODebugPassManager;
@@ -183,6 +185,7 @@
   bool ZRetpolineplt;
   bool ZWxneeded;
   DiscardPolicy Discard;
+  ICFLevel ICF;
   OrphanHandlingPolicy OrphanHandling;
   SortSectionPolicy SortSection;
   StripPolicy Strip;
Index: lld/ELF/Driver.cpp
===================================================================
--- lld/ELF/Driver.cpp
+++ lld/ELF/Driver.cpp
@@ -51,6 +51,7 @@
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compression.h"
+#include "llvm/Support/LEB128.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/TarWriter.h"
 #include "llvm/Support/TargetSelect.h"
@@ -294,7 +295,7 @@
       error("-r and -shared may not be used together");
     if (Config->GcSections)
       error("-r and --gc-sections may not be used together");
-    if (Config->ICF)
+    if (Config->ICF != ICFLevel::None)
       error("-r and --icf may not be used together");
     if (Config->Pie)
       error("-r and -pie may not be used together");
@@ -497,6 +498,15 @@
   return Arg->getValue();
 }
 
+static ICFLevel getICF(opt::InputArgList &Args) {
+  auto *Arg = Args.getLastArg(OPT_icf_none, OPT_icf_safe, OPT_icf_all);
+  if (!Arg || Arg->getOption().getID() == OPT_icf_none)
+    return ICFLevel::None;
+  if (Arg->getOption().getID() == OPT_icf_safe)
+    return ICFLevel::Safe;
+  return ICFLevel::All;
+}
+
 static StripPolicy getStrip(opt::InputArgList &Args) {
   if (Args.hasArg(OPT_relocatable))
     return StripPolicy::None;
@@ -710,7 +720,7 @@
   Config->GcSections = Args.hasFlag(OPT_gc_sections, OPT_no_gc_sections, false);
   Config->GnuUnique = Args.hasFlag(OPT_gnu_unique, OPT_no_gnu_unique, true);
   Config->GdbIndex = Args.hasFlag(OPT_gdb_index, OPT_no_gdb_index, false);
-  Config->ICF = Args.hasFlag(OPT_icf_all, OPT_icf_none, false);
+  Config->ICF = getICF(Args);
   Config->IgnoreDataAddressEquality =
       Args.hasArg(OPT_ignore_data_address_equality);
   Config->IgnoreFunctionAddressEquality =
@@ -1187,14 +1197,51 @@
 
 // Record sections that define symbols mentioned in --keep-unique <symbol>
 // these sections are inelligible for ICF.
+template <class ELFT>
 static void findKeepUniqueSections(opt::InputArgList &Args) {
+  auto KeepUnique = [](Symbol *S) -> bool {
+    if (auto *D = dyn_cast_or_null<Defined>(S)) {
+      if (D->Section) {
+        D->Section->KeepUnique = true;
+        return true;
+      }
+    }
+    return false;
+  };
+
   for (auto *Arg : Args.filtered(OPT_keep_unique)) {
     StringRef Name = Arg->getValue();
-    if (auto *Sym = dyn_cast_or_null<Defined>(Symtab->find(Name)))
-      Sym->Section->KeepUnique = true;
-    else
+    if (!KeepUnique(Symtab->find(Name)))
       warn("could not find symbol " + Name + " to keep unique");
   }
+
+  if (Config->ICF == ICFLevel::Safe) {
+    for (Symbol *S : Symtab->getSymbols())
+      if (S->includeInDynsym())
+        KeepUnique(S);
+
+    for (InputFile *F : ObjectFiles) {
+      auto *Obj = cast<ObjFile<ELFT>>(F);
+      ArrayRef<Symbol *> Syms = Obj->getSymbols();
+      if (Obj->AddrsigSec) {
+        ArrayRef<uint8_t> Contents =
+            check(Obj->getObj().getSectionContents(Obj->AddrsigSec));
+        const uint8_t *Cur = Contents.begin();
+        while (Cur != Contents.end()) {
+          unsigned Size;
+          const char *Err;
+          uint64_t SymIndex = decodeULEB128(Cur, &Size, Contents.end(), &Err);
+          if (Err)
+            fatal(F->getName() + ": could not decode addrsig section: " + Err);
+          KeepUnique(Syms[SymIndex]);
+          Cur += Size;
+        }
+      } else {
+        for (Symbol *S : Syms)
+          KeepUnique(S);
+      }
+    }
+  }
 }
 
 // Do actual linking. Note that when this function is called,
@@ -1369,8 +1416,8 @@
   markLive<ELFT>();
   demoteSymbols<ELFT>();
   mergeSections();
-  if (Config->ICF) {
-    findKeepUniqueSections(Args);
+  if (Config->ICF != ICFLevel::None) {
+    findKeepUniqueSections<ELFT>(Args);
     doIcf<ELFT>();
   }
 
Index: lld/ELF/ICF.cpp
===================================================================
--- lld/ELF/ICF.cpp
+++ lld/ELF/ICF.cpp
@@ -174,7 +174,8 @@
 
   // Don't merge read only data sections unless
   // --ignore-data-address-equality was passed.
-  if (!(S->Flags & SHF_EXECINSTR) && !Config->IgnoreDataAddressEquality)
+  if (!(S->Flags & SHF_EXECINSTR) &&
+      !(Config->IgnoreDataAddressEquality || Config->ICF == ICFLevel::Safe))
     return false;
 
   // Don't merge synthetic sections as their Data member is not valid and empty.
Index: lld/ELF/InputFiles.h
===================================================================
--- lld/ELF/InputFiles.h
+++ lld/ELF/InputFiles.h
@@ -210,6 +210,9 @@
   // symbol table.
   StringRef SourceFile;
 
+  // Pointer to this input file's .llvm_addrsig section, if it has one.
+  const Elf_Shdr *AddrsigSec = nullptr;
+
 private:
   void
   initializeSections(llvm::DenseSet<llvm::CachedHashStringRef> &ComdatGroups);
Index: lld/ELF/InputFiles.cpp
===================================================================
--- lld/ELF/InputFiles.cpp
+++ lld/ELF/InputFiles.cpp
@@ -428,6 +428,13 @@
     // if -r is given, we'll let the final link discard such sections.
     // This is compatible with GNU.
     if ((Sec.sh_flags & SHF_EXCLUDE) && !Config->Relocatable) {
+      if (Sec.sh_type == SHT_LLVM_ADDRSIG) {
+        if (Sec.sh_link != 0)
+          this->AddrsigSec = &Sec;
+        else if (Config->ICF == ICFLevel::Safe)
+          warn(toString(this) + ": --icf=safe is incompatible with object "
+                                "files created using objcopy or ld -r");
+      }
       this->Sections[I] = &InputSection::Discarded;
       continue;
     }
Index: lld/ELF/Options.td
===================================================================
--- lld/ELF/Options.td
+++ lld/ELF/Options.td
@@ -170,6 +170,8 @@
 
 def icf_all: F<"icf=all">, HelpText<"Enable identical code folding">;
 
+def icf_safe: F<"icf=safe">, HelpText<"Enable safe identical code folding">;
+
 def icf_none: F<"icf=none">, HelpText<"Disable identical code folding (default)">;
 
 def ignore_function_address_equality: F<"ignore-function-address-equality">,