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
@@ -1,60 +1,79 @@
 # REQUIRES: x86
 # RUN: rm -rf %t; split-file %s %t
 
+## Check that we fold identical function bodies correctly. Note: This test
+## has many different functions; each group of similarly-named functions aim
+## to test one aspect of ICF's logic. To prevent accidental folding across
+## groups, we use `mov` instructions with a variety of immediates, with
+## different immediate values for each group.
+
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin19.0.0 %t/main.s -o %t/main.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin19.0.0 %t/abs.s -o %t/abs.o
 # RUN: %lld -lSystem --icf=all -o %t/main %t/main.o %t/abs.o
 # RUN: llvm-objdump -d --syms %t/main | FileCheck %s
 
 # CHECK-LABEL: SYMBOL TABLE:
-# CHECK:       [[#%x,MAIN:]] g   F __TEXT,__text _main
-# CHECK:       [[#%x,A:]]    g   F __TEXT,__text _a1
-# CHECK:       [[#%x,H:]]    g   F __TEXT,__text _h
-# CHECK:       [[#%x,A]]     g   F __TEXT,__text _a2
-# CHECK:       [[#%x,A]]     g   F __TEXT,__text _a3
-# CHECK:       [[#%x,B:]]    g   F __TEXT,__text _b
-# CHECK:       [[#%x,B2:]]   g   F __TEXT,__text _b2
-# CHECK:       [[#%x,C:]]    g   F __TEXT,__text _c
-# CHECK:       [[#%x,D:]]    g   F __TEXT,__text _d
-# CHECK:       [[#%x,E:]]    g   F __TEXT,__text _e
-# CHECK:       [[#%x,F:]]    g   F __TEXT,__text _f
-# CHECK:       [[#%x,G:]]    g   F __TEXT,__text _g
-# CHECK:       [[#%x,I:]]    g   F __TEXT,__text _i
-# CHECK:       [[#%x,J:]]    g   F __TEXT,__text _j
-# CHECK:       [[#%x,SR:]]   g   F __TEXT,__text _sr1
-# CHECK:       [[#%x,SR]]    g   F __TEXT,__text _sr2
-# CHECK:       [[#%x,MR:]]   g   F __TEXT,__text _mr1
-# CHECK:       [[#%x,MR]]    g   F __TEXT,__text _mr2
-# CHECK:       [[#%x,K1:]]   g   O __TEXT,__foo  _k1
-# CHECK:       [[#%x,A:]]    g   F __TEXT,__text _k2
+# CHECK: [[#%x,ABS1B_REF:]]                 l     F __TEXT,__text _abs1a_ref
+# CHECK: [[#%x,ABS1B_REF:]]                 l     F __TEXT,__text _abs1b_ref
+# CHECK: [[#%x,ABS1B_REF_WITH_ADDEND:]]     l     F __TEXT,__text _abs1a_ref_with_addend
+# CHECK: [[#%x,ABS1B_REF_WITH_ADDEND:]]     l     F __TEXT,__text _abs1b_ref_with_addend
+# CHECK: [[#%x,ABS2_REF:]]                  l     F __TEXT,__text _abs2_ref
+# CHECK: [[#%x,NOT_ABS_REF:]]               l     F __TEXT,__text _not_abs_ref
+# CHECK: [[#%x,DYLIB_REF_2:]]               l     F __TEXT,__text _dylib_ref_1
+# CHECK: [[#%x,DYLIB_REF_2:]]               l     F __TEXT,__text _dylib_ref_2
+# CHECK: [[#%x,DYLIB_REF_3:]]               l     F __TEXT,__text _dylib_ref_3
+# CHECK: [[#%x,ALT:]]                       l     F __TEXT,__text _alt
+# CHECK: [[#%x,WITH_ALT_ENTRY:]]            l     F __TEXT,__text _with_alt_entry
+# CHECK: [[#%x,WITH_ALT_ENTRY:]]            l     F __TEXT,__text _no_alt_entry
+# CHECK: [[#%x,DEFINED_REF_WITH_ADDEND_2:]] l     F __TEXT,__text _defined_ref_with_addend_1
+# CHECK: [[#%x,DEFINED_REF_WITH_ADDEND_2:]] l     F __TEXT,__text _defined_ref_with_addend_2
+# CHECK: [[#%x,RECURSIVE:]]                 l     F __TEXT,__text _recursive
+# CHECK: [[#%x,CALL_RECURSIVE_2:]]          l     F __TEXT,__text _call_recursive_1
+# 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_2
+# 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
+# CHECK: [[#%x,INIT_2:]]                    l     F __TEXT,__text _init_2
+# CHECK: [[#%x,INIT_3:]]                    l     O __TEXT,__foo  _init_3
 ### FIXME: Mutually-recursive functions with identical bodies (see below)
-# COM:         [[#%x,XR:]]   g   F __TEXT,__text _xr1
-# COM:         [[#%x,XR]]    g   F __TEXT,__text _xr2
+# COM:   [[#%x,ASYMMETRIC_RECURSIVE_2:]]    l   F __TEXT,__text _asymmetric_recursive_1
+# COM:   [[#%x,ASYMMETRIC_RECURSIVE_2]]     l   F __TEXT,__text _asymmetric_recursive_2
 
 # CHECK-LABEL: Disassembly of section __TEXT,__text:
-# CHECK:       [[#%x,MAIN]] <_main>:
-# CHECK-NEXT:  callq 0x[[#%x,A]]  <_k2>
-# CHECK-NEXT:  callq 0x[[#%x,A]]  <_k2>
-# CHECK-NEXT:  callq 0x[[#%x,A]]  <_k2>
-# CHECK-NEXT:  callq 0x[[#%x,B]]  <_b>
-# CHECK-NEXT:  callq 0x[[#%x,B2]] <_b2>
-# CHECK-NEXT:  callq 0x[[#%x,C]]  <_c>
-# CHECK-NEXT:  callq 0x[[#%x,D]]  <_d>
-# CHECK-NEXT:  callq 0x[[#%x,E]]  <_e>
-# CHECK-NEXT:  callq 0x[[#%x,F]]  <_f>
-# CHECK-NEXT:  callq 0x[[#%x,G]]  <_g>
-# CHECK-NEXT:  callq 0x[[#%x,H]]  <_h>
-# CHECK-NEXT:  callq 0x[[#%x,I]]  <_i>
-# CHECK-NEXT:  callq 0x[[#%x,J]]  <_j>
-# CHECK-NEXT:  callq 0x[[#%x,K1]] <_k1>
-# CHECK-NEXT:  callq 0x[[#%x,A]]  <_k2>
-# CHECK-NEXT:  callq 0x[[#%x,SR]] <_sr2>
-# CHECK-NEXT:  callq 0x[[#%x,SR]] <_sr2>
-# CHECK-NEXT:  callq 0x[[#%x,MR]] <_mr2>
-# CHECK-NEXT:  callq 0x[[#%x,MR]] <_mr2>
-### FIXME: Mutually-recursive functions with identical bodies (see below)
-# COM-NEXT:    callq 0x[[#%x,XR]] <_xr2>
-# COM-NEXT:    callq 0x[[#%x,XR]] <_xr2>
+# CHECK:        <_main>:
+# CHECK: callq 0x[[#%x,ABS1B_REF:]]                 <_abs1b_ref>
+# CHECK: callq 0x[[#%x,ABS1B_REF:]]                 <_abs1b_ref>
+# CHECK: callq 0x[[#%x,ABS1B_REF_WITH_ADDEND:]]     <_abs1b_ref_with_addend>
+# CHECK: callq 0x[[#%x,ABS1B_REF_WITH_ADDEND:]]     <_abs1b_ref_with_addend>
+# CHECK: callq 0x[[#%x,ABS2_REF:]]                  <_abs2_ref>
+# CHECK: callq 0x[[#%x,NOT_ABS_REF:]]               <_not_abs_ref>
+# CHECK: callq 0x[[#%x,DYLIB_REF_2:]]               <_dylib_ref_2>
+# CHECK: callq 0x[[#%x,DYLIB_REF_2:]]               <_dylib_ref_2>
+# CHECK: callq 0x[[#%x,DYLIB_REF_3:]]               <_dylib_ref_3>
+# CHECK: callq 0x[[#%x,ALT:]]                       <_alt>
+# CHECK: callq 0x[[#%x,WITH_ALT_ENTRY:]]            <_with_alt_entry>
+# CHECK: callq 0x[[#%x,WITH_ALT_ENTRY:]]            <_with_alt_entry>
+# CHECK: callq 0x[[#%x,DEFINED_REF_WITH_ADDEND_2:]] <_defined_ref_with_addend_2>
+# CHECK: callq 0x[[#%x,DEFINED_REF_WITH_ADDEND_2:]] <_defined_ref_with_addend_2>
+# CHECK: callq 0x[[#%x,RECURSIVE:]]                 <_recursive>
+# CHECK: callq 0x[[#%x,CALL_RECURSIVE_2:]]          <_call_recursive_2>
+# 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,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)
+# COM:   callq 0x[[#%x,ASYMMETRIC_RECURSIVE_2]]     <_asymmetric_recursive_2>
+# COM:   callq 0x[[#%x,ASYMMETRIC_RECURSIVE_2]]     <_asymmetric_recursive_2>
+# CHECK: callq 0x[[#%x,INIT_2:]]                    <_init_2>
+# CHECK: callq 0x[[#%x,INIT_2:]]                    <_init_2>
+# CHECK: callq 0x[[#%x,INIT_3:]]                    <_init_3>
 
 ### TODO:
 ### * Fold: funcs only differ in alignment
@@ -77,291 +96,167 @@
 #--- main.s
 .subsections_via_symbols
 .text
-.globl _h
-.alt_entry _h
-
-### Fold: _a1 & _a2 have identical bodies, flags, relocs
 
-.globl _a1
-.p2align 2
-_a1:
-  callq _d
-### No fold: _h is an alt entry past _a1
-_h:
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
+_abs1a_ref:
   movabs $_abs1a, %rdx
-  movl $0, %eax
-  ret
-
-.globl _a2
-.p2align 2
-_a2:
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $0, %eax
-  ret
 
-### Fold: reference to absolute symbol with different name but identical value
-
-.globl _a3
-.p2align 2
-_a3:
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
+_abs1b_ref:
   movabs $_abs1b, %rdx
-  movl $0, %eax
-  ret
 
-### No fold: the absolute symbol value differs
+_abs1a_ref_with_addend:
+  movabs $_abs1a + 3, %rdx
 
-.globl _b
-.p2align 2
-_b:
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
+_abs1b_ref_with_addend:
+  movabs $_abs1b + 3, %rdx
+
+## No fold: the absolute symbol value differs
+_abs2_ref:
   movabs $_abs2, %rdx
-  movl $0, %eax
-  ret
 
-### No fold: _not_abs has the same value as _abs1{a,b}, but is not absolute.
+## No fold: _not_abs has the same value as _abs1{a,b}, but is not absolute.
+_not_abs_ref:
+  movabs $_not_abs, %rdx
 
-.globl _b2
-.p2align 2
-_b2:
-  callq _d
+_dylib_ref_1:
   mov ___nan@GOTPCREL(%rip), %rax
   callq ___isnan
-  movabs $_not_abs, %rdx
-  movl $0, %eax
-  ret
-
-### No fold: _c has slightly different body from _a1 & _a2
 
-.globl _c
-.p2align 2
-_c:
-  callq _d
+_dylib_ref_2:
   mov ___nan@GOTPCREL(%rip), %rax
   callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $1, %eax
-  ret
 
-### No fold: _d has the same body as _a1 & _a2, but _d is recursive!
+## No fold: referent dylib symbol differs
+_dylib_ref_3:
+  mov ___inf@GOTPCREL(%rip), %rax
+  callq ___inf
+
+## We can merge two sections even if one of them has an alt entry. Just make
+## sure we don't merge the alt entry symbol with a regular symbol.
+.alt_entry _alt
+_with_alt_entry:
+  movq $3132, %rax
+_alt:
+  ret
 
-.globl _d
-.p2align 2
-_d:
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $0, %eax
+_no_alt_entry:
+  movq $3132, %rax
   ret
 
-### No fold: the function body is longer
+_defined_ref_with_addend_1:
+  callq _with_alt_entry + 4
 
-.globl _e
-.p2align 2
-_e:
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $0, %eax
-  ret
-  nop
+_defined_ref_with_addend_2:
+  callq _with_alt_entry + 4
 
-### No fold: GOT referent dylib symbol differs
+## _recursive has the same body as its next two callers, but cannot be folded
+## with them.
+_recursive:
+  callq _recursive
 
-.globl _f
-.p2align 2
-_f:
-  callq _d
-  mov ___inf@GOTPCREL(%rip), %rax
-  callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $0, %eax
-  ret
+_call_recursive_1:
+  callq _recursive
 
-### No fold: call referent dylib symbol differs
+_call_recursive_2:
+  callq _recursive
 
-.globl _g
-.p2align 2
-_g:
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isinf
-  movabs $_abs1a, %rdx
-  movl $0, %eax
-  ret
+## Functions of different lengths should not be folded
+_check_length_1:
+  movq $97, %rax
+
+_check_length_2:
+  movq $97, %rax
+  .space 1
 
-### No fold: functions have personality and/or LSDA
-### Mere presence of personality and/or LSDA isolates a function into its own
-### equivalence class. We don't care if two functions happen to have identical
-### personality & LSDA.
+_my_personality:
+  mov $1345, %rax
 
-.globl _i
-.p2align 2
-_i:
+## No fold: functions have unwind info.
+## FIXME: Fold functions with identical unwind info.
+_has_unwind_1:
   .cfi_startproc
-  .cfi_personality 155, _my_personality0
-  .cfi_lsda 16, _exception0
+  .cfi_personality 155, _my_personality
   .cfi_def_cfa_offset 16
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $0, %eax
   ret
   .cfi_endproc
 
-.globl _j
-.p2align 2
-_j:
+_has_unwind_2:
   .cfi_startproc
-  .cfi_personality 155, _my_personality0
-  .cfi_lsda 16, _exception0
+  .cfi_personality 155, _my_personality
   .cfi_def_cfa_offset 16
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $0, %eax
   ret
   .cfi_endproc
 
-### No fold: _k1 is in a different section from _a1
-.section __TEXT,__foo
-.globl _k1
-.p2align 2
-_k1:
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $0, %eax
-  ret
-  nopl (%rax)
-
-### Fold: _k2 is in a section that gets renamed and output as __text
-.section __TEXT,__StaticInit
-.globl _k2
-.p2align 2
-_k2:
-  callq _d
-  mov ___nan@GOTPCREL(%rip), %rax
-  callq ___isnan
-  movabs $_abs1a, %rdx
-  movl $0, %eax
-  ret
-## For some reason, llvm-mc generates different nop encodings when adding
-## padding for __StaticInit vs __text functions. So we explicitly specify the
-## nop here to make sure this function can be folded with _a1.
-  nopl (%rax)
-
-### Fold: Simple recursion
-
-.text
-.globl _sr1
-.p2align 2
-_sr1:
-  callq _sr1
-  movl $0, %eax
-  ret
-
-.globl _sr2
-.p2align 2
-_sr2:
-  callq _sr2
-  movl $0, %eax
-  ret
-
-### Fold: Mutually-recursive functions with symmetric bodies
-
-.globl _mr1
-.p2align 2
-_mr1:
-  callq _mr1 # call myself
-  callq _mr2 # call my twin
-  movl $0, %eax
-  ret
-
-.globl _mr2
-.p2align 2
-_mr2:
-  callq _mr2 # call myself
-  callq _mr1 # call my twin
-  movl $0, %eax
-  ret
-
-### Fold: Mutually-recursive functions with identical bodies
-###
-### FIXME: This test is currently broken. Recursive call sites have no relocs
-### and the non-zero displacement field is already written to the section
-### data, while non-recursive call sites use symbol relocs and section data
-### contains zeros in the displacement field. Thus, ICF's equalsConstant()
-### finds that the section data doesn't match.
-###
-### ELF folds this case properly because it emits symbol relocs for all calls,
-### even recursive ones.
-
-.globl _xr1
-.p2align 2
-_xr1:
-  callq _xr1 # call myself
-  callq _xr2 # call my twin
+## Fold: Mutually-recursive functions with symmetric bodies
+_mutually_recursive_1:
+  callq _mutually_recursive_1 # call myself
+  callq _mutually_recursive_2 # call my twin
+
+_mutually_recursive_2:
+  callq _mutually_recursive_2 # call myself
+  callq _mutually_recursive_1 # call my twin
+
+## Fold: Mutually-recursive functions with identical bodies
+##
+## FIXME: This test is currently broken. Recursive call sites have no relocs
+## and the non-zero displacement field is already written to the section
+## data, while non-recursive call sites use symbol relocs and section data
+## contains zeros in the displacement field. Thus, ICF's equalsConstant()
+## finds that the section data doesn't match.
+##
+## ELF folds this case properly because it emits symbol relocs for all calls,
+## even recursive ones.
+
+_asymmetric_recursive_1:
+  callq _asymmetric_recursive_1 # call myself
+  callq _asymmetric_recursive_2 # call my twin
   movl $3, %eax
-  ret
 
-.globl _xr2
-.p2align 2
-_xr2:
-  callq _xr1 # call my twin
-  callq _xr2 # call myself
+_asymmetric_recursive_2:
+  callq _asymmetric_recursive_1 # call my twin
+  callq _asymmetric_recursive_2 # call myself
   movl $3, %eax
-  ret
 
-###
+_init_1:
+  movq $12938, %rax
 
-.globl _main
-.p2align 2
-_main:
-  callq _a1
-  callq _a2
-  callq _a3
-  callq _b
-  callq _b2
-  callq _c
-  callq _d
-  callq _e
-  callq _f
-  callq _g
-  callq _h
-  callq _i
-  callq _j
-  callq _k1
-  callq _k2
-  callq _sr1
-  callq _sr2
-  callq _mr1
-  callq _mr2
-  callq _xr1
-  callq _xr2
-  ret
+## Fold: _init_2 is in a section that gets renamed and output as __text
+.section __TEXT,__StaticInit
+_init_2:
+  movq $12938, %rax
 
-.globl _my_personality0
-.p2align 2
-_my_personality0:
-  movl $0, %eax
-  ret
+## No fold: _init_3 is in a different output section from _init_{1,2}
+.section __TEXT,__foo
+_init_3:
+  movq $12938, %rax
 
-.section __TEXT,__gcc_except_tab
-.globl _exception0
-_exception0:
-  .space 1
+.text
+.globl _main
+_main:
+  callq _abs1a_ref
+  callq _abs1b_ref
+  callq _abs1a_ref_with_addend
+  callq _abs1b_ref_with_addend
+  callq _abs2_ref
+  callq _not_abs_ref
+  callq _dylib_ref_1
+  callq _dylib_ref_2
+  callq _dylib_ref_3
+  callq _alt
+  callq _with_alt_entry
+  callq _no_alt_entry
+  callq _defined_ref_with_addend_1
+  callq _defined_ref_with_addend_2
+  callq _recursive
+  callq _call_recursive_1
+  callq _call_recursive_2
+  callq _check_length_1
+  callq _check_length_2
+  callq _has_unwind_1
+  callq _has_unwind_2
+  callq _mutually_recursive_1
+  callq _mutually_recursive_2
+  callq _asymmetric_recursive_1
+  callq _asymmetric_recursive_2
+  callq _init_1
+  callq _init_2
+  callq _init_3