[AsmPrinter] Use linker-private symbols in xray_instr_map

[MaskRay]

Summary

When compiling with -fxray-instrument for Apple platforms, XRay pass
generates relocation entries that offend Mach-O linker on x86_64.

All emitted entries in xray_instr_map use local labels, so the entire
section ends up filled with local (r_extern=0) relocations, which is
not allowed on x86_64 in Mach-O.

The linker is able to figure it out as long as there is at least one
external relocation in the section, making all local relocations
piggyback on the external one before them. Indulge the linker with
some "private" symbols, which are considered external for relocation
purposes, but are otherwise local to object files (i.e., "static",
do not get globally exported and are generally removed after linking).

Depends on D145291

[ilammy]

• Rebased on top of updated dependent revisions

[MaskRay]

xray_fn_idx entries should use PC-relative relocations as well, but I never get around to fix it. I wonder whether the change may make this patch unneeded or we are going to find other Mach-O relocation related issues.

---

All emitted entries in xray_instr_map use local labels, so the entire section ends up filled with local (r_extern=0) relocations, which is not allowed on x86_64 in Mach-O.

I wondered why clang --target=arm64-apple-darwin -fxray-instrument -fxray-instruction-threshold=1 a.c works while -S then -c a.o reported an assembler report.
The issue seems to be related to an ancient ld64 workaround done in 2015: d6223a24718df3c30b67422c2eb6d0e93af9c4e8

[MaskRay]

In D145850#4412388, @MaskRay wrote:

xray_fn_idx entries should use PC-relative relocations as well, but I never get around to fix it. I wonder whether the change may make this patch unneeded or we are going to find other Mach-O relocation related issues.

Created D152661. I wonder whether it bypasses some ld64 limitations.

[MaskRay]

I think codegen works not but cmake still needs work:)

llvm/include/llvm/MC/MCContext.h

public:
   /// \name McInst Management
 
   /// Create and return a new MC instruction.
   MCInst *createMCInst();
 
   /// \name Symbol Management
   /// @{
 
-  /// Create and return a new linker temporary symbol with a unique but
-  /// unspecified name.
+  /// Create and return a new linker temporary symbol with a unique name.
+  /// The overload without Name uses and unspecified name.
   MCSymbol *createLinkerPrivateTempSymbol();
+  MCSymbol *createLinkerPrivateTempSymbol(const Twine &Name);
 
   /// Create a temporary symbol with a unique name. The name will be omitted
   /// in the symbol table if UseNamesOnTempLabels is false (default except
   /// MCAsmStreamer). The overload without Name uses an unspecified name.
   MCSymbol *createTempSymbol();
   MCSymbol *createTempSymbol(const Twine &Name, bool AlwaysAddSuffix = true);
 
   /// Create a temporary symbol with a unique name whose name cannot be

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.createLinkerPrivateTempSymbol("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),
         WordSizeBytes);
     OutStreamer->emitValueImpl(
         MCBinaryExpr::createSub(
             MCSymbolRefExpr::create(CurrentFnBegin, Ctx),
             MCBinaryExpr::createAdd(MCSymbolRefExpr::create(Dot, Ctx),
                                     MCConstantExpr::create(WordSizeBytes, Ctx),
                                     Ctx),
             Ctx),
         WordSizeBytes);
     Sled.emit(WordSizeBytes, OutStreamer.get());
   }
-  MCSymbol *SledsEnd = OutContext.createTempSymbol("xray_sleds_end", true);
+  MCSymbol *SledsEnd =
+      OutContext.createLinkerPrivateTempSymbol("xray_sleds_end");
   OutStreamer->emitLabel(SledsEnd);
 
   // We then emit a single entry in the index per function. We use the symbols
   // that bound the instrumentation map as the range for a specific function.
   // Each entry here will be 2 * word size aligned, as we're writing down two
   // pointers. This should work for both 32-bit and 64-bit platforms.
   if (FnSledIndex) {
     OutStreamer->switchSection(FnSledIndex);

llvm/lib/MC/MCContext.cpp

 
 MCSymbol *MCContext::createNamedTempSymbol(const Twine &Name) {
   SmallString<128> NameSV;
   raw_svector_ostream(NameSV) << MAI->getPrivateGlobalPrefix() << Name;
   return createSymbol(NameSV, true, false);
 }
 
 MCSymbol *MCContext::createLinkerPrivateTempSymbol() {
+  return createLinkerPrivateTempSymbol("tmp");
+}
+
+MCSymbol *MCContext::createLinkerPrivateTempSymbol(const Twine &Name) {
   SmallString<128> NameSV;
-  raw_svector_ostream(NameSV) << MAI->getLinkerPrivateGlobalPrefix() << "tmp";
+  raw_svector_ostream(NameSV) << MAI->getLinkerPrivateGlobalPrefix() << Name;
   return createSymbol(NameSV, true, false);
 }
 
 MCSymbol *MCContext::createTempSymbol() { return createTempSymbol("tmp"); }
 
 MCSymbol *MCContext::createNamedTempSymbol() {
   return createNamedTempSymbol("tmp");
 }

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{{$}}
-; 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: 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-NEXT:  nop
 ; CHECK-NEXT:  nop
 ; CHECK-NEXT:  nop

 
 ; 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{{$}}
-; 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: 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-NEXT:  nop
 ; CHECK-NEXT:  nop
 ; CHECK-NEXT:  nop

 
 ; 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{{$}}
-; 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:
+; 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{{$}}
-; 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: 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{{$}}
-; 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: 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{{$}}
-; 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: lxray_sleds_end0:

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

 ; CHECK-LINUX:       .Ltmp3:
 ; CHECK-LINUX-NEXT:    .xword .Lxray_sled_1-.Ltmp3
 ; CHECK-LINUX-LABEL: Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,callee{{$}}
 ; CHECK-LINUX:         .xword .Lxray_sleds_start0
 ; CHECK-LINUX-NEXT:    .xword .Lxray_sleds_end0
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS-NEXT:  Ltmp2:
 ; CHECK-MACOS:         .quad Lxray_sled_0-Ltmp2
 ; CHECK-MACOS:       Ltmp3:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_1-Ltmp3
-; CHECK-MACOS-LABEL: Lxray_sleds_end0:
+; CHECK-MACOS-LABEL: lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start0
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end0
+; CHECK-MACOS:         .quad lxray_sleds_start0
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_end0
 
 define i32 @caller() nounwind noinline uwtable "function-instrument"="xray-always" {
 ; CHECK:       .p2align 2
 ; CHECK-LABEL: Lxray_sled_2:
 ; CHECK-NEXT:  b  #32
 ; CHECK-NEXT:  nop
 ; CHECK-NEXT:  nop
 ; CHECK-NEXT:  nop

 ; CHECK-LINUX:         .xword .Lxray_sled_2
 ; CHECK-LINUX:         .xword .Lxray_sled_3
 ; CHECK-LINUX-LABEL: Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,caller{{$}}
 ; CHECK-LINUX:         .xword .Lxray_sleds_start1
 ; CHECK-LINUX-NEXT:    .xword .Lxray_sleds_end1
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_2
 ; CHECK-MACOS:         .quad Lxray_sled_3
-; CHECK-MACOS-LABEL: Lxray_sleds_end1:
+; CHECK-MACOS-LABEL: lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start1
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end1
+; CHECK-MACOS:         .quad lxray_sleds_start1
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_end1

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,"awo",%progbits,foo{{$}}
 ; CHECK-LINUX:         .long .Lxray_sleds_start0
 ; CHECK-LINUX-NEXT:    .long .Lxray_sleds_end0
 
 ; CHECK-IOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-IOS-LABEL: Lxray_sleds_start0:
+; CHECK-IOS-LABEL: lxray_sleds_start0:
 ; CHECK-IOS:         .long Lxray_sled_0
 ; CHECK-IOS:         .long Lxray_sled_1
-; CHECK-IOS-LABEL: Lxray_sleds_end0:
+; CHECK-IOS-LABEL: lxray_sleds_end0:
 ; CHECK-IOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-IOS:         .long Lxray_sleds_start0
-; CHECK-IOS-NEXT:    .long Lxray_sleds_end0
+; CHECK-IOS:         .long lxray_sleds_start0
+; CHECK-IOS-NEXT:    .long lxray_sleds_end0

llvm/test/CodeGen/ARM/xray-armv7-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,"awo",%progbits,foo{{$}}
 ; CHECK-LINUX:         .long .Lxray_sleds_start0
 ; CHECK-LINUX-NEXT:    .long .Lxray_sleds_end0
 
 ; CHECK-IOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-IOS-LABEL: Lxray_sleds_start0:
+; CHECK-IOS-LABEL: lxray_sleds_start0:
 ; CHECK-IOS:         .long Lxray_sled_0
 ; CHECK-IOS:         .long Lxray_sled_1
-; CHECK-IOS-LABEL: Lxray_sleds_end0:
+; CHECK-IOS-LABEL: lxray_sleds_end0:
 ; CHECK-IOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-IOS:         .long Lxray_sleds_start0
-; CHECK-IOS-NEXT:    .long Lxray_sleds_end0
+; CHECK-IOS:         .long lxray_sleds_start0
+; CHECK-IOS-NEXT:    .long lxray_sleds_end0

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

 ; CHECK-LINUX:         .quad .Lxray_sled_0
 ; CHECK-LINUX:         .quad .Lxray_sled_1
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,foo{{$}}
 ; CHECK-LINUX:         .quad .Lxray_sleds_start0
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_end0
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS:         .quad Lxray_sled_1
-; CHECK-MACOS-LABEL: Lxray_sleds_end0:
+; CHECK-MACOS-LABEL: lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start0
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end0
+; CHECK-MACOS:         .quad lxray_sleds_start0
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_end0
 
 
 ; 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:       .ascii "\353\t"

 ; CHECK-LINUX:       .Ltmp4:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sled_4-.Ltmp4
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,bar{{$}}
 ; CHECK-LINUX:         .quad .Lxray_sleds_start1
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_end1
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:       Ltmp2:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_2-Ltmp2
 ; CHECK-MACOS:       Ltmp3:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_3-Ltmp3
 ; CHECK-MACOS:       Ltmp4:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_4-Ltmp4
-; CHECK-MACOS-LABEL: Lxray_sleds_end1:
+; CHECK-MACOS-LABEL: lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start1
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end1
+; CHECK-MACOS:         .quad lxray_sleds_start1
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_end1

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

define i32 @customevent() nounwind "function-instrument"="xray-always" !dbg !1 {
     ; PIC-NEXT:  movq %rcx, %rdi
     ; PIC-NEXT:  movq %rax, %rsi
     ; PIC-NEXT:  callq __xray_CustomEvent@PLT
     ; PIC-NEXT:  popq %rsi
     ; PIC-NEXT:  popq %rdi
     ret i32 0
 }
 ; CHECK-LABEL: xray_instr_map
-; CHECK-LABEL: Lxray_sleds_start0:
+; CHECK-LABEL: xray_sleds_start0:
 ; CHECK:       .quad {{.*}}xray_event_sled_0
 
 define i32 @typedevent() nounwind "function-instrument"="xray-always" !dbg !2 {
     %eventptr = alloca i8
     %eventsize = alloca i32
     %eventtype = alloca i16
     store i16 6, ptr %eventtype
     %type = load i16, ptr %eventtype
define i32 @typedevent() nounwind "function-instrument"="xray-always" !dbg !2 {
     ; PIC-NEXT:  movq %rax, %rdx
     ; PIC-NEXT:  callq __xray_TypedEvent@PLT
     ; PIC-NEXT:  popq %rdx
     ; PIC-NEXT:  popq %rsi
     ; PIC-NEXT:  popq %rdi
     ret i32 0
 }
 ; CHECK-LABEL: xray_instr_map
-; CHECK-LABEL: Lxray_sleds_start1:
+; CHECK-LABEL: xray_sleds_start1:
 ; CHECK:       .quad {{.*}}xray_typed_event_sled_0
 
 declare void @llvm.xray.customevent(ptr, i32)
 declare void @llvm.xray.typedevent(i16, ptr, i32)
 
 ;; Construct call site entries for PATCHABLE_EVENT_CALL.
 ; DBG:     DW_TAG_subprogram
 ; DBG:       DW_TAG_call_site

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

 ; CHECK-LINUX:       .Ltmp1:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sled_1-.Ltmp1
 ; CHECK-LINUX-NEXT:    .quad .Lfunc_begin0-(.Ltmp1+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:  Ltmp0:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_0-Ltmp0
 ; CHECK-MACOS-NEXT:    .quad Lfunc_begin0-(Ltmp0+8)
 ; CHECK-MACOS-NEXT:    .byte 0x03
 ; CHECK-MACOS-NEXT:    .byte 0x01
 ; CHECK-MACOS-NEXT:    .byte 0x02
 ; CHECK-MACOS:         .space 13
 ; CHECK-MACOS:       Ltmp1:

 ; CHECK-LINUX:       .Ltmp4:
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sled_3-.Ltmp4
 ; CHECK-LINUX-NEXT:    .quad .Lfunc_begin1-(.Ltmp4+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:  Ltmp3:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_2-Ltmp3
 ; CHECK-MACOS-NEXT:    .quad Lfunc_begin1-(Ltmp3+8)
 ; CHECK-MACOS-NEXT:    .byte 0x03
 ; CHECK-MACOS-NEXT:    .byte 0x01
 ; CHECK-MACOS-NEXT:    .byte 0x02
 ; CHECK-MACOS:         .space 13
 ; CHECK-MACOS:       Ltmp4:
 ; CHECK-MACOS-NEXT:    .quad Lxray_sled_3-Ltmp4
 ; CHECK-MACOS-NEXT:    .quad Lfunc_begin1-(Ltmp4+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-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-NEXT:    .quad .Lxray_sleds_end0
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
-; CHECK-MACOS-LABEL: Lxray_sleds_end0:
+; CHECK-MACOS-LABEL: lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start0
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end0
+; CHECK-MACOS:         .quad lxray_sleds_start0
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_end0
 
 
 ; 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:
   %cond = icmp eq i32 %i, 0

 ; CHECK-LINUX:         .quad .Lxray_sled_1
 ; CHECK-LINUX:         .quad .Lxray_sled_2
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,bar{{$}}
 ; CHECK-LINUX:         .quad .Lxray_sleds_start1
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_end1
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_1
 ; CHECK-MACOS:         .quad Lxray_sled_2
-; CHECK-MACOS-LABEL: Lxray_sleds_end1:
+; CHECK-MACOS-LABEL: lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start1
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end1
+; CHECK-MACOS:         .quad lxray_sleds_start1
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_end1

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

 ; 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-NEXT:    .quad .Lxray_sleds_end0
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
-; CHECK-MACOS-LABEL: Lxray_sleds_end0:
+; CHECK-MACOS-LABEL: lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start0
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end0
+; CHECK-MACOS:         .quad lxray_sleds_start0
+; 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:       .ascii "\353\t"

 ; 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:         .quad .Lxray_sleds_start1
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_end1
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_1
-; CHECK-MACOS-LABEL: Lxray_sleds_end1:
+; CHECK-MACOS-LABEL: lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start1
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end1
+; CHECK-MACOS:         .quad lxray_sleds_start1
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_end1

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

 ; CHECK-LINUX:         .quad .Lxray_sled_0
 ; CHECK-LINUX:         .quad .Lxray_sled_1
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end0:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,callee{{$}}
 ; CHECK-LINUX:         .quad .Lxray_sleds_start0
 ; CHECK-LINUX-NEXT:    .quad .Lxray_sleds_end0
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start0:
+; CHECK-MACOS-LABEL: lxray_sleds_start0:
 ; CHECK-MACOS:         .quad Lxray_sled_0
 ; CHECK-MACOS:         .quad Lxray_sled_1
-; CHECK-MACOS-LABEL: Lxray_sleds_end0:
+; CHECK-MACOS-LABEL: lxray_sleds_end0:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start0
-; CHECK-MACOS-NEXT:    .quad Lxray_sleds_end0
+; CHECK-MACOS:         .quad lxray_sleds_start0
+; CHECK-MACOS-NEXT:    .quad lxray_sleds_end0
 
 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-LABEL: Lxray_sled_3:

 ; CHECK-LINUX:         .quad .Lxray_sled_2
 ; CHECK-LINUX:         .quad .Lxray_sled_3
 ; CHECK-LINUX-LABEL: .Lxray_sleds_end1:
 ; CHECK-LINUX-LABEL: .section xray_fn_idx,"awo",@progbits,caller{{$}}
 ; CHECK-LINUX:         .quad .Lxray_sleds_start1
 ; CHECK-LINUX:         .quad .Lxray_sleds_end1
 
 ; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map{{$}}
-; CHECK-MACOS-LABEL: Lxray_sleds_start1:
+; CHECK-MACOS-LABEL: lxray_sleds_start1:
 ; CHECK-MACOS:         .quad Lxray_sled_2
 ; CHECK-MACOS:         .quad Lxray_sled_3
-; CHECK-MACOS-LABEL: Lxray_sleds_end1:
+; CHECK-MACOS-LABEL: lxray_sleds_end1:
 ; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx{{$}}
-; CHECK-MACOS:         .quad Lxray_sleds_start1
-; CHECK-MACOS:         .quad Lxray_sleds_end1
+; CHECK-MACOS:         .quad lxray_sleds_start1
+; CHECK-MACOS:         .quad lxray_sleds_end1