diff --git a/lld/MachO/ICF.cpp b/lld/MachO/ICF.cpp
--- a/lld/MachO/ICF.cpp
+++ b/lld/MachO/ICF.cpp
@@ -176,8 +176,31 @@
     }
     return isecA->icfEqClass[icfPass % 2] == isecB->icfEqClass[icfPass % 2];
   };
-  return std::equal(ia->relocs.begin(), ia->relocs.end(), ib->relocs.begin(),
-                    f);
+  if (!std::equal(ia->relocs.begin(), ia->relocs.end(), ib->relocs.begin(), f))
+    return false;
+
+  // If there are symbols with associated unwind info, check that the unwind
+  // info matches. For simplicity, we only handle the case where there are only
+  // symbols at offset zero within the section (which is typically the case with
+  // .subsections_via_symbols.)
+  auto hasCU = [](Defined *d) { return d->compactUnwind; };
+  auto itA = std::find_if(ia->symbols.begin(), ia->symbols.end(), hasCU);
+  auto itB = std::find_if(ib->symbols.begin(), ib->symbols.end(), hasCU);
+  if (itA == ia->symbols.end())
+    return itB == ib->symbols.end();
+  if (itB == ib->symbols.end())
+    return false;
+  const Defined *da = *itA;
+  const Defined *db = *itB;
+  if (da->compactUnwind->icfEqClass[icfPass % 2] !=
+          db->compactUnwind->icfEqClass[icfPass % 2] ||
+      da->value != 0 || db->value != 0)
+    return false;
+  auto isZero = [](Defined *d) { return d->value == 0; };
+  return std::find_if_not(std::next(itA), ia->symbols.end(), isZero) ==
+             ia->symbols.end() &&
+         std::find_if_not(std::next(itB), ib->symbols.end(), isZero) ==
+             ib->symbols.end();
 }
 
 // Find the first InputSection after BEGIN whose equivalence class differs
@@ -334,18 +357,14 @@
     bool isHashable = (isCodeSection(isec) || isCfStringSection(isec)) &&
                       !isec->shouldOmitFromOutput() &&
                       isec->isHashableForICF();
-    // ICF can't fold functions with unwind info
-    if (isHashable)
-      for (Defined *d : isec->symbols)
-        if (d->compactUnwind) {
-          isHashable = false;
-          break;
-        }
-
-    if (isHashable)
+    if (isHashable) {
       hashable.push_back(isec);
-    else
+      for (Defined *d : isec->symbols)
+        if (d->compactUnwind)
+          hashable.push_back(d->compactUnwind);
+    } else {
       isec->icfEqClass[0] = ++icfUniqueID;
+    }
   }
   parallelForEach(hashable,
                   [](ConcatInputSection *isec) { isec->hashForICF(); });
diff --git a/lld/MachO/InputFiles.cpp b/lld/MachO/InputFiles.cpp
--- a/lld/MachO/InputFiles.cpp
+++ b/lld/MachO/InputFiles.cpp
@@ -892,10 +892,23 @@
 
   for (SubsectionEntry &entry : *cuSubsecMap) {
     ConcatInputSection *isec = cast<ConcatInputSection>(entry.isec);
+    // Hack!! Since each CUE contains a different function address, if ICF
+    // operated naively and compared the entire contents of each CUE, entries
+    // with identical unwind info but belonging to different functions would
+    // never be considered equivalent. To work around this problem, we slice
+    // away the function address here. (Note that we do not adjust the offsets
+    // of the corresponding relocations.) We rely on `relocateCompactUnwind()`
+    // to correctly handle these truncated input sections.
+    isec->data = isec->data.slice(target->wordSize);
+
     ConcatInputSection *referentIsec;
-    for (const Reloc &r : isec->relocs) {
-      if (r.offset != 0)
+    for (auto it = isec->relocs.begin(); it != isec->relocs.end();) {
+      Reloc &r = *it;
+      // We only wish to handle the relocation for CUE::functionAddress.
+      if (r.offset != 0) {
+        ++it;
         continue;
+      }
       uint64_t add = r.addend;
       if (auto *sym = cast_or_null<Defined>(r.referent.dyn_cast<Symbol *>())) {
         add += sym->value;
@@ -904,19 +917,29 @@
         referentIsec =
             cast<ConcatInputSection>(r.referent.dyn_cast<InputSection *>());
       }
+      if (referentIsec->getSegName() != segment_names::text)
+        error("compact unwind references address in " + toString(referentIsec) +
+              " which is not in segment __TEXT");
       // The functionAddress relocations are typically section relocations.
       // However, unwind info operates on a per-symbol basis, so we search for
       // the function symbol here.
-      auto it = llvm::lower_bound(
+      auto symIt = llvm::lower_bound(
           referentIsec->symbols, add,
           [](Defined *d, uint64_t add) { return d->value < add; });
       // The relocation should point at the exact address of a symbol (with no
       // addend).
-      if (it == referentIsec->symbols.end() || (*it)->value != add) {
+      if (symIt == referentIsec->symbols.end() || (*symIt)->value != add) {
         assert(referentIsec->wasCoalesced);
+        ++it;
         continue;
       }
-      (*it)->compactUnwind = isec;
+      (*symIt)->compactUnwind = isec;
+      // Since we've sliced away the functionAddress, we should remove the
+      // corresponding relocation too. Given that clang emits relocations in
+      // reverse order of address, this relocation should be at the end of the
+      // vector for most of our input object files, so this is typically an O(1)
+      // operation.
+      it = isec->relocs.erase(it);
     }
   }
 }
diff --git a/lld/MachO/UnwindInfoSection.cpp b/lld/MachO/UnwindInfoSection.cpp
--- a/lld/MachO/UnwindInfoSection.cpp
+++ b/lld/MachO/UnwindInfoSection.cpp
@@ -274,7 +274,8 @@
       return;
 
     // Write the rest of the CUE.
-    memcpy(buf, d->compactUnwind->data.data(), d->compactUnwind->data.size());
+    memcpy(buf + sizeof(Ptr), d->compactUnwind->data.data(),
+           d->compactUnwind->data.size());
     for (const Reloc &r : d->compactUnwind->relocs) {
       uint64_t referentVA = 0;
       if (auto *referentSym = r.referent.dyn_cast<Symbol *>()) {
diff --git a/lld/test/MachO/icf.s b/lld/test/MachO/icf.s
--- a/lld/test/MachO/icf.s
+++ b/lld/test/MachO/icf.s
@@ -32,8 +32,9 @@
 # CHECK: [[#%x,CALL_RECURSIVE_2:]]          l     F __TEXT,__text _call_recursive_2
 # CHECK: [[#%x,CHECK_LENGTH_1:]]            l     F __TEXT,__text _check_length_1
 # CHECK: [[#%x,CHECK_LENGTH_2:]]            l     F __TEXT,__text _check_length_2
-# CHECK: [[#%x,HAS_UNWIND_1:]]              l     F __TEXT,__text _has_unwind_1
+# CHECK: [[#%x,HAS_UNWIND_2:]]              l     F __TEXT,__text _has_unwind_1
 # CHECK: [[#%x,HAS_UNWIND_2:]]              l     F __TEXT,__text _has_unwind_2
+# CHECK: [[#%x,HAS_UNWIND_3:]]              l     F __TEXT,__text _has_unwind_3
 # CHECK: [[#%x,MUTALLY_RECURSIVE_2:]]       l     F __TEXT,__text _mutually_recursive_1
 # CHECK: [[#%x,MUTALLY_RECURSIVE_2:]]       l     F __TEXT,__text _mutually_recursive_2
 # CHECK: [[#%x,INIT_2:]]                    l     F __TEXT,__text _init_1
@@ -64,8 +65,9 @@
 # CHECK: callq 0x[[#%x,CALL_RECURSIVE_2:]]          <_call_recursive_2>
 # CHECK: callq 0x[[#%x,CHECK_LENGTH_1:]]            <_check_length_1>
 # CHECK: callq 0x[[#%x,CHECK_LENGTH_2:]]            <_check_length_2>
-# CHECK: callq 0x[[#%x,HAS_UNWIND_1:]]              <_has_unwind_1>
 # CHECK: callq 0x[[#%x,HAS_UNWIND_2:]]              <_has_unwind_2>
+# CHECK: callq 0x[[#%x,HAS_UNWIND_2:]]              <_has_unwind_2>
+# CHECK: callq 0x[[#%x,HAS_UNWIND_3:]]              <_has_unwind_3>
 # CHECK: callq 0x[[#%x,MUTALLY_RECURSIVE_2:]]       <_mutually_recursive_2>
 # CHECK: callq 0x[[#%x,MUTALLY_RECURSIVE_2:]]       <_mutually_recursive_2>
 ## FIXME: Mutually-recursive functions with identical bodies (see below)
@@ -170,8 +172,7 @@
 _my_personality:
   mov $1345, %rax
 
-## No fold: functions have unwind info.
-## FIXME: Fold functions with identical unwind info.
+## Functions with identical unwind info should be folded.
 _has_unwind_1:
   .cfi_startproc
   .cfi_personality 155, _my_personality
@@ -186,6 +187,15 @@
   ret
   .cfi_endproc
 
+## This function has different unwind info from the preceding two, and therefore
+## should not be folded.
+_has_unwind_3:
+  .cfi_startproc
+  .cfi_personality 155, _my_personality
+  .cfi_def_cfa_offset 8
+  ret
+  .cfi_endproc
+
 ## Fold: Mutually-recursive functions with symmetric bodies
 _mutually_recursive_1:
   callq _mutually_recursive_1 # call myself
@@ -253,6 +263,7 @@
   callq _check_length_2
   callq _has_unwind_1
   callq _has_unwind_2
+  callq _has_unwind_3
   callq _mutually_recursive_1
   callq _mutually_recursive_2
   callq _asymmetric_recursive_1
diff --git a/lld/test/MachO/invalid/compact-unwind-bad-reloc.s b/lld/test/MachO/invalid/compact-unwind-bad-reloc.s
--- a/lld/test/MachO/invalid/compact-unwind-bad-reloc.s
+++ b/lld/test/MachO/invalid/compact-unwind-bad-reloc.s
@@ -1,13 +1,12 @@
 # REQUIRES: x86
-# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin19.0.0 %s -o %t.o
-# RUN: not %lld -pie -lSystem -lc++ %t.o -o %t 2>&1 | FileCheck %s -DFILE=%t.o
+# RUN: rm -rf %t; split-file %s %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin19.0.0 %t/bad-function.s -o %t/bad-function.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin19.0.0 %t/bad-personality.s -o %t/bad-personality.o
+# RUN: not %lld -pie -lSystem -lc++ %t/bad-function.o -o %t 2>&1 | FileCheck %s -DFILE=%t/bad-function.o
+# RUN: not %lld -pie -lSystem -lc++ %t/bad-personality.o -o %t 2>&1 | FileCheck %s -DFILE=%t/bad-personality.o
 # CHECK: error: compact unwind references address in [[FILE]]:(__data) which is not in segment __TEXT
 
-.globl _main, _not_a_function
-.text
-_main:
-  retq
-
+#--- bad-function.s
 .data
 _not_a_function:
   .cfi_startproc
@@ -15,3 +14,17 @@
   .cfi_def_cfa_offset 16
   retq
   .cfi_endproc
+
+#--- bad-personality.s
+.globl _main, _not_a_function
+.text
+_main:
+  .cfi_startproc
+  .cfi_personality 155, _my_personality
+  .cfi_def_cfa_offset 16
+  retq
+  .cfi_endproc
+
+.data
+.globl _my_personality
+_my_personality: