[XRay] Make xray_instr_map compatible with Mach-O

[MaskRay]

Summary

The __DATA,xray_instr_map section has label differences like
.quad Lxray_sled_0-Ltmp0 that is represented as a pair of UNSIGNED and SUBTRACTOR relocations.

LLVM integrated assembler attempts to rewrite A-B into A-B'+offset where B' can
be included in the symbol table. B' is called an atom and should be a
non-temporary symbol in the same section. However, since xray_instr_map does
not define a non-temporary symbol, the SUBTRACTO relocation will have no
associated symbol, and its r_extern value will be 0. Therefore, we will see
linker errors like:

error: SUBTRACTOR relocation must be extern at offset 0 of __DATA,xray_instr_map in a.o

To fix this issue, we need to define a non-temporary symbol in the section. We
can accomplish this by renaming Lxray_sleds_start0 to lxray_sleds_start0
("L" to "l").

lxray_sleds_start0 serves as the atom for this dead-strippable subsection.
With the S_ATTR_LIVE_SUPPORT attribute, ld -dead_strip will retain
subsections that reference live functions.

Special thanks to Oleksii Lozovskyi for reporting the issue and providing
initial analysis.

[MaskRay]

rebase
thanks to Oleksii Lozovskyi

[MaskRay]

better description

see also https://maskray.me/blog/2023-06-18-port-llvm-xray-to-apple-systems

[MaskRay]

I'll wait a bit and land this. I have pushed some test cleanup few days ago to make test updates less painful.

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

void AsmPrinter::emitXRayTable() {
   }
 
   auto WordSizeBytes = MAI->getCodePointerSize();
 
   // Now we switch to the instrumentation map section. Because this is done
   // per-function, we are able to create an index entry that will represent the
   // range of sleds associated with a function.
   auto &Ctx = OutContext;
-  MCSymbol *SledsStart = OutContext.createTempSymbol("xray_sleds_start", true);
+  MCSymbol *SledsStart =
+      OutContext.createLinkerPrivateSymbol("xray_sleds_start");
   OutStreamer->switchSection(InstMap);
   OutStreamer->emitLabel(SledsStart);
   for (const auto &Sled : Sleds) {
     MCSymbol *Dot = Ctx.createTempSymbol();
     OutStreamer->emitLabel(Dot);
     OutStreamer->emitValueImpl(
         MCBinaryExpr::createSub(MCSymbolRefExpr::create(Sled.Sled, Ctx),
                                 MCSymbolRefExpr::create(Dot, Ctx), Ctx),

llvm/test/CodeGen/AArch64/xray-attribute-instrumentation.ll

 
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,foo{{$}}
 ; CHECK-LINUX-LABEL: Lxray_sleds_start0:
 ; CHECK-LINUX:         .xword .Lxray_sled_0
 ; CHECK-LINUX:         .xword .Lxray_sled_1
 ; CHECK-LINUX-LABEL: Lxray_sleds_end0:
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS:         .quad Lxray_sled_1
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:
 
 define i32 @bar() nounwind noinline uwtable "function-instrument"="xray-never" "function-instrument"="xray-always" {
 ; CHECK-LABEL: bar:
 ; CHECK-LABEL: Lxray_sled_2:
 ; CHECK-NEXT:  b  #32

 
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,bar{{$}}
 ; CHECK-LINUX-LABEL: Lxray_sleds_start1:
 ; CHECK-LINUX:         .xword .Lxray_sled_2
 ; CHECK-LINUX:         .xword .Lxray_sled_3
 ; CHECK-LINUX-LABEL: Lxray_sleds_end1:
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_2
 ; CHECK-MACOS:         .quad Lxray_sled_3
 ; CHECK-MACOS-LABEL: Lxray_sleds_end1:
 
 define i32 @instrumented() nounwind noinline uwtable "xray-instruction-threshold"="1" {
 ; CHECK-LABEL: instrumented:
 ; CHECK-LABEL: Lxray_sled_4:
 ; CHECK-NEXT:  b  #32

 
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,instrumented{{$}}
 ; CHECK-LINUX-LABEL: Lxray_sleds_start2:
 ; CHECK-LINUX:         .xword .Lxray_sled_4
 ; CHECK-LINUX:         .xword .Lxray_sled_5
 ; CHECK-LINUX-LABEL: Lxray_sleds_end2:
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start2:
+; CHECK-MACOS-LABEL: lxray_sleds_start2:
 ; CHECK-MACOS:         .quad Lxray_sled_4
 ; CHECK-MACOS:         .quad Lxray_sled_5
 ; CHECK-MACOS-LABEL: Lxray_sleds_end2:
 
 define i32 @not_instrumented() nounwind noinline uwtable "xray-instruction-threshold"="1" "function-instrument"="xray-never" {
 ; CHECK-LABEL: not_instrumented
 ; CHECK-NOT: Lxray_sled_6
   ret i32 0
 ; CHECK:  ret
 }

llvm/test/CodeGen/AArch64/xray-omit-function-index.ll

 }
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,foo{{$}}
 ; CHECK-LINUX-LABEL: Lxray_sleds_start0:
 ; CHECK-LINUX:         .xword .Lxray_sled_0
 ; CHECK-LINUX:         .xword .Lxray_sled_1
 ; CHECK-LINUX-LABEL: Lxray_sleds_end0:
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS:         .quad Lxray_sled_1
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:
 
 ; CHECK-NOT: xray_fn_idx

llvm/test/CodeGen/AArch64/xray-partial-instrumentation-skip-entry.ll

 }
 
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,foo{{$}}
 ; CHECK-LINUX-LABEL: Lxray_sleds_start0:
 ; CHECK-LINUX:         .xword .Lxray_sled_0
 ; CHECK-LINUX-LABEL: Lxray_sleds_end0:
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:

llvm/test/CodeGen/AArch64/xray-partial-instrumentation-skip-exit.ll

 }
 
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,foo{{$}}
 ; CHECK-LINUX-LABEL: Lxray_sleds_start0:
 ; CHECK-LINUX:         .xword .Lxray_sled_0
 ; CHECK-LINUX-LABEL: Lxray_sleds_end0:
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:

llvm/test/CodeGen/AArch64/xray-tail-call-sled.ll

 ; CHECK-LINUX:       [[TMP:.Ltmp[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .xword .Lxray_sled_1-[[TMP]]
 ; CHECK-LINUX-LABEL: Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,callee{{$}}
 ; CHECK-LINUX:         .xword .Lxray_sleds_start0
 ; CHECK-LINUX-NEXT:    .xword 2
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS-NEXT:  [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS:         .quad Lxray_sled_0-[[TMP]]
 ; CHECK-MACOS:       [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_1-[[TMP]]
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start0-[[IDX]]
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_start0-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad 2
 
 define i32 @caller() nounwind noinline uwtable "function-instrument"="xray-always" {
 ; CHECK:       .p2align 2
 ; CHECK-LABEL: Lxray_sled_2:
 ; CHECK-NEXT:  b  #32
 ; CHECK-COUNT-7:  nop
 ; CHECK-NEXT:  Ltmp[[#]]:

 ; CHECK-LINUX:         .xword .Lxray_sled_3
 ; CHECK-LINUX-LABEL: Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,caller{{$}}
 ; CHECK-LINUX:       [[IDX:\.Lxray_fn_idx[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .xword .Lxray_sleds_start1-[[IDX]]
 ; CHECK-LINUX-NEXT:    .xword 2
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_2
 ; CHECK-MACOS:         .quad Lxray_sled_3
 ; CHECK-MACOS-LABEL: Lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start1-[[IDX]]
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_start1-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad 2

llvm/test/CodeGen/ARM/xray-armv6-attribute-instrumentation.ll

 ; CHECK-LINUX:         .long .Lxray_sled_0
 ; CHECK-LINUX:         .long .Lxray_sled_1
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",%progbits,foo{{$}}
 ; CHECK-LINUX:         .long .Lxray_sleds_start0-.Lxray_fn_idx0
 ; CHECK-LINUX-NEXT:    .long 2
 
 ; CHECK-IOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-IOS-LABEL: Lxray_sleds_start0:
+; CHECK-IOS-LABEL: lxray_sleds_start0:
 ; CHECK-IOS:         .long Lxray_sled_0
 ; CHECK-IOS:         .long Lxray_sled_1
 ; CHECK-IOS-LABEL: Lxray_sleds_end0:
 ; CHECK-IOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
-; CHECK-IOS:         .long Lxray_sleds_start0-lxray_fn_idx0
+; CHECK-IOS:         .long lxray_sleds_start0-lxray_fn_idx0
 ; CHECK-IOS-NEXT:    .long 2

llvm/test/CodeGen/ARM/xray-armv7-attribute-instrumentation.ll

 ; CHECK-LINUX:         .long .Lxray_sled_1
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",%progbits,foo{{$}}
 ; CHECK-LINUX:       .Lxray_fn_idx0:
 ; CHECK-LINUX-NEXT:    .long .Lxray_sleds_start0-.Lxray_fn_idx0
 ; CHECK-LINUX-NEXT:    .long 2
 
 ; CHECK-IOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-IOS-LABEL: Lxray_sleds_start0:
+; CHECK-IOS-LABEL: lxray_sleds_start0:
 ; CHECK-IOS:         .long Lxray_sled_0
 ; CHECK-IOS:         .long Lxray_sled_1
 ; CHECK-IOS-LABEL: Lxray_sleds_end0:
 ; CHECK-IOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-IOS:       lxray_fn_idx0:
-; CHECK-IOS:         .long Lxray_sleds_start0-lxray_fn_idx0
+; CHECK-IOS:         .long lxray_sleds_start0-lxray_fn_idx0
 ; CHECK-IOS-NEXT:    .long 2

llvm/test/CodeGen/X86/xray-attribute-instrumentation.ll

 ; CHECK-LINUX:         .quad .Lxray_sled_1
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,foo{{$}}
 ; CHECK-LINUX:       [[IDX:\.Lxray_fn_idx[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_start0-[[IDX]]
 ; CHECK-LINUX-NEXT:    .quad 2
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS:         .quad Lxray_sled_1
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start0-[[IDX]]
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_start0-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad 2
 
 
 ; We test multiple returns in a single function to make sure we're getting all
 ; of them with XRay instrumentation.
 define i32 @bar(i32 %i) nounwind noinline uwtable "function-instrument"="xray-always" {
 ; CHECK:       .p2align 1, 0x90
 ; CHECK-LABEL: Lxray_sled_2:

 ; CHECK-LINUX-NEXT:    .quad .Lxray_sled_4-[[TMP]]
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,bar{{$}}
 ; CHECK-LINUX:       [[IDX:\.Lxray_fn_idx[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_start1-[[IDX]]
 ; CHECK-LINUX-NEXT:    .quad 3
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:       [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_2-[[TMP]]
 ; CHECK-MACOS:       [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_3-[[TMP]]
 ; CHECK-MACOS:       [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_4-[[TMP]]
 ; CHECK-MACOS-LABEL: Lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start1-[[IDX]]
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_start1-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad 3

llvm/test/CodeGen/X86/xray-log-args.ll

 ; CHECK-LINUX:       [[TMP:.Ltmp[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sled_1-[[TMP]]
 ; CHECK-LINUX-NEXT:    .quad .Lfunc_begin0-([[TMP]]+8)
 ; CHECK-LINUX-NEXT:    .byte 0x01
 ; CHECK-LINUX-NEXT:    .byte 0x01
 ; CHECK-LINUX-NEXT:    .byte 0x02
 ; CHECK-LINUX:         .zero 13
 
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS-NEXT:  [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_0-[[TMP]]
 ; CHECK-MACOS-NEXT:    .quad Lfunc_begin0-([[TMP]]+8)
 ; CHECK-MACOS-NEXT:    .byte 0x03
 ; CHECK-MACOS-NEXT:    .byte 0x01
 ; CHECK-MACOS-NEXT:    .byte 0x02
 ; CHECK-MACOS:         .space 13
 ; CHECK-MACOS:       [[TMP:Ltmp[0-9]+]]:

 ; CHECK-LINUX:       [[TMP:.Ltmp[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sled_3-[[TMP]]
 ; CHECK-LINUX-NEXT:    .quad .Lfunc_begin1-([[TMP]]+8)
 ; CHECK-LINUX-NEXT:    .byte 0x02
 ; CHECK-LINUX-NEXT:    .byte 0x01
 ; CHECK-LINUX-NEXT:    .byte 0x02
 ; CHECK-LINUX:         .zero 13
 
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS-NEXT:  [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_2-[[TMP]]
 ; CHECK-MACOS-NEXT:    .quad Lfunc_begin1-([[TMP]]+8)
 ; CHECK-MACOS-NEXT:    .byte 0x03
 ; CHECK-MACOS-NEXT:    .byte 0x01
 ; CHECK-MACOS-NEXT:    .byte 0x02
 ; CHECK-MACOS:         .space 13
 ; CHECK-MACOS:       [[TMP:Ltmp[0-9]+]]:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_3-[[TMP]]
 ; CHECK-MACOS-NEXT:    .quad Lfunc_begin1-([[TMP]]+8)
 ; CHECK-MACOS-NEXT:    .byte 0x02
 ; CHECK-MACOS-NEXT:    .byte 0x01
 ; CHECK-MACOS-NEXT:    .byte 0x02
 ; CHECK-MACOS:         .space 13

llvm/test/CodeGen/X86/xray-partial-instrumentation-skip-entry.ll

 ; CHECK-LINUX:         .quad .Lxray_sled_0
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,foo{{$}}
 ; CHECK-LINUX:       [[IDX:\.Lxray_fn_idx[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_start0-[[IDX]]
 ; CHECK-LINUX-NEXT:    .quad 1
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start0-[[IDX]]
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_start0-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad 1
 
 
 ; We test multiple returns in a single function to make sure we're getting all
 ; of them with XRay instrumentation.
 define i32 @bar(i32 %i) nounwind noinline uwtable "function-instrument"="xray-always" "xray-skip-entry" {
 ; CHECK-NOT: Lxray_sled_1:
 Test:

 ; CHECK-LINUX:         .quad .Lxray_sled_2
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,bar{{$}}
 ; CHECK-LINUX:       [[IDX:\.Lxray_fn_idx[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_start1-[[IDX]]
 ; CHECK-LINUX-NEXT:    .quad 2
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_1
 ; CHECK-MACOS:         .quad Lxray_sled_2
 ; CHECK-MACOS-LABEL: Lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start1-[[IDX]]
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_start1-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad 2

llvm/test/CodeGen/X86/xray-partial-instrumentation-skip-exit.ll

 ; CHECK:       retq
 }
 
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,foo{{$}}
 ; CHECK-LINUX-LABEL: .Lxray_sleds_start0:
 ; CHECK-LINUX:         .quad .Lxray_sled_0
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,foo{{$}}
-; CHECK-LINUX:         .quad .Lxray_sleds_start0
+; CHECK-LINUX:       [[IDX:.lxray_fn_idx[0-9]+]]:
+; CHECK-LINUX:         .quad .Lxray_sleds_start0-[[IDX]]
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_end0
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start0
+; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
+; CHECK-MACOS:         .quad lxray_sleds_start0-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end0
 
 
 ; We test multiple returns in a single function to make sure we're skipping all
 ; of them with XRay instrumentation.
 define i32 @bar(i32 %i) nounwind noinline uwtable "function-instrument"="xray-always" "xray-skip-exit" {
 ; CHECK:       .p2align 1, 0x90
 ; CHECK-LABEL: Lxray_sled_1:

 
 ; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,bar{{$}}
 ; CHECK-LINUX-LABEL: .Lxray_sleds_start1:
 ; CHECK-LINUX:         .quad .Lxray_sled_1
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,bar{[$}}
 ; CHECK-LINUX:       .Lxray_fn_idx0:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_start1-.Lxray_fn_idx0
-; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_end1
+; CHECK-LINUX-NEXT:    .quad 2
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_1
 ; CHECK-MACOS-LABEL: Lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       Lxray_fn_idx0:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start1-Lxray_fn_idx0
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end1
+; CHECK-MACOS-NEXT:    .quad 2

llvm/test/CodeGen/X86/xray-tail-call-sled.ll

 ; CHECK-LINUX:         .quad .Lxray_sled_1
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,callee{{$}}
 ; CHECK-LINUX:       [[IDX:\.Lxray_fn_idx[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_start0-[[IDX]]
 ; CHECK-LINUX-NEXT:    .quad 2
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS:         .quad Lxray_sled_1
 ; CHECK-MACOS-LABEL: Lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start0-[[IDX]]
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_start0-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad 2
 
 define dso_local i32 @caller() nounwind noinline uwtable "function-instrument"="xray-always" {
 ; CHECK:       .p2align 1, 0x90
 ; CHECK-LABEL: Lxray_sled_2:
 ; CHECK:       .ascii "\353\t"
 ; CHECK-NEXT:  nopw 512(%rax,%rax)
 ; CHECK:       .p2align 1, 0x90

 ; CHECK-LINUX:         .quad .Lxray_sled_3
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,caller{{$}}
 ; CHECK-LINUX:       [[IDX:\.Lxray_fn_idx[0-9]+]]:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_start1-[[IDX]]
 ; CHECK-LINUX-NEXT:    .quad 2
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_2
 ; CHECK-MACOS:         .quad Lxray_sled_3
 ; CHECK-MACOS-LABEL: Lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
 ; CHECK-MACOS:       [[IDX:lxray_fn_idx[0-9]+]]:
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_start1-[[IDX]]
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_start1-[[IDX]]
 ; CHECK-MACOS-NEXT:    .quad 2