diff --git a/llvm/lib/MC/XCOFFObjectWriter.cpp b/llvm/lib/MC/XCOFFObjectWriter.cpp
--- a/llvm/lib/MC/XCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/XCOFFObjectWriter.cpp
@@ -78,8 +78,8 @@
 struct XCOFFSection {
   const MCSectionXCOFF *const MCSec;
   uint32_t SymbolTableIndex;
-  uint32_t Address;
-  uint32_t Size;
+  uint64_t Address;
+  uint64_t Size;
 
   SmallVector<Symbol, 1> Syms;
   SmallVector<XCOFFRelocation, 1> Relocations;
@@ -101,10 +101,10 @@
   char Name[XCOFF::NameSize];
   // The physical/virtual address of the section. For an object file
   // these values are equivalent.
-  uint32_t Address;
-  uint32_t Size;
-  uint32_t FileOffsetToData;
-  uint32_t FileOffsetToRelocations;
+  uint64_t Address;
+  uint64_t Size;
+  uint64_t FileOffsetToData;
+  uint64_t FileOffsetToRelocations;
   uint32_t RelocationCount;
   int32_t Flags;
 
@@ -190,9 +190,9 @@
 class XCOFFObjectWriter : public MCObjectWriter {
 
   uint32_t SymbolTableEntryCount = 0;
-  uint32_t SymbolTableOffset = 0;
+  uint64_t SymbolTableOffset = 0;
   uint16_t SectionCount = 0;
-  uint32_t RelocationEntryOffset = 0;
+  uint64_t RelocationEntryOffset = 0;
 
   support::endian::Writer W;
   std::unique_ptr<MCXCOFFObjectTargetWriter> TargetObjectWriter;
@@ -295,10 +295,8 @@
   void assignAddressesAndIndices(const MCAsmLayout &);
   void finalizeSectionInfo();
 
-  bool
-  needsAuxiliaryHeader() const { /* TODO aux header support not implemented. */
-    return false;
-  }
+  // TODO aux header support not implemented.
+  bool needsAuxiliaryHeader() const { return false; }
 
   // Returns the size of the auxiliary header to be written to the object file.
   size_t auxiliaryHeaderSize() const {
@@ -310,6 +308,10 @@
 public:
   XCOFFObjectWriter(std::unique_ptr<MCXCOFFObjectTargetWriter> MOTW,
                     raw_pwrite_stream &OS);
+
+  void writeWord(uint64_t Word) {
+    is64Bit() ? W.write<uint64_t>(Word) : W.write<uint32_t>(Word);
+  }
 };
 
 XCOFFObjectWriter::XCOFFObjectWriter(
@@ -413,9 +415,6 @@
 
 void XCOFFObjectWriter::executePostLayoutBinding(MCAssembler &Asm,
                                                  const MCAsmLayout &Layout) {
-  if (is64Bit())
-    report_fatal_error("64-bit XCOFF object files are not supported yet.");
-
   for (const auto &S : Asm) {
     const auto *MCSec = cast<const MCSectionXCOFF>(&S);
     assert(SectionMap.find(MCSec) == SectionMap.end() &&
@@ -624,20 +623,20 @@
   if (Asm.isIncrementalLinkerCompatible())
     report_fatal_error("Incremental linking not supported for XCOFF.");
 
-  if (is64Bit())
-    report_fatal_error("64-bit XCOFF object files are not supported yet.");
-
   finalizeSectionInfo();
   uint64_t StartOffset = W.OS.tell();
 
   writeFileHeader();
   writeSectionHeaderTable();
-  writeSections(Asm, Layout);
-  writeRelocations();
 
-  writeSymbolTable(Layout);
-  // Write the string table.
-  Strings.write(W.OS);
+  if (!is64Bit()) {
+    writeSections(Asm, Layout);
+    writeRelocations();
+
+    writeSymbolTable(Layout);
+    // Write the string table.
+    Strings.write(W.OS);
+  }
 
   return W.OS.tell() - StartOffset;
 }
@@ -734,18 +733,24 @@
 }
 
 void XCOFFObjectWriter::writeFileHeader() {
-  assert(!is64Bit() && "Writing 64-bit file header is not yet supported.");
-  W.write<uint16_t>(XCOFF::XCOFF32);
+  W.write<uint16_t>(is64Bit() ? XCOFF::XCOFF64 : XCOFF::XCOFF32);
   W.write<uint16_t>(SectionCount);
   W.write<int32_t>(0); // TimeStamp
-  W.write<uint32_t>(SymbolTableOffset);
-  W.write<int32_t>(SymbolTableEntryCount);
-  W.write<uint16_t>(0); // AuxHeaderSize
-  W.write<uint16_t>(0); // Flags
+  writeWord(SymbolTableOffset);
+  if (is64Bit()) {
+    W.write<uint16_t>(0); // AuxHeaderSize. No optional header for an object
+                          // file that is not to be loaded.
+    W.write<uint16_t>(0); // Flags
+    W.write<int32_t>(0);  // SymbolTableEntryCount. Not supported yet.
+  } else {
+    W.write<int32_t>(SymbolTableEntryCount);
+    W.write<uint16_t>(0); // AuxHeaderSize. No optional header for an object
+                          // file that is not to be loaded.
+    W.write<uint16_t>(0); // Flags
+  }
 }
 
 void XCOFFObjectWriter::writeSectionHeaderTable() {
-  assert(!is64Bit() && "Writing 64-bit section headers is not yet supported.");
   auto writeSectionHeader = [&](const SectionEntry *Sec, bool IsDwarf) {
     // Nothing to write for this Section.
     if (Sec->Index == SectionEntry::UninitializedIndex)
@@ -758,17 +763,24 @@
     // Write the Physical Address and Virtual Address. In an object file these
     // are the same.
     // We use 0 for DWARF sections' Physical and Virtual Addresses.
-    W.write<uint32_t>(IsDwarf ? 0 : Sec->Address);
-    W.write<uint32_t>(IsDwarf ? 0 : Sec->Address);
-
-    W.write<uint32_t>(Sec->Size);
-    W.write<uint32_t>(Sec->FileOffsetToData);
-    W.write<uint32_t>(Sec->FileOffsetToRelocations);
-    W.write<uint32_t>(0); // FileOffsetToLineNumberInfo. Not supported yet.
-
-    W.write<uint16_t>(Sec->RelocationCount);
-    W.write<uint16_t>(0); // NumberOfLineNumbers. Not supported yet.
-    W.write<int32_t>(Sec->Flags);
+    writeWord(IsDwarf ? 0 : Sec->Address);
+    writeWord(IsDwarf ? 0 : Sec->Address);
+
+    writeWord(Sec->Size);
+    writeWord(Sec->FileOffsetToData);
+    writeWord(Sec->FileOffsetToRelocations);
+    writeWord(0); // FileOffsetToLineNumberInfo. Not supported yet.
+
+    if (is64Bit()) {
+      W.write<uint32_t>(0); // NumberOfRelocations. Not yet supported in 64-bit.
+      W.write<uint32_t>(0); // NumberOfLineNumbers. Not supported yet.
+      W.write<int32_t>(Sec->Flags);
+      W.OS.write_zeros(4);
+    } else {
+      W.write<uint16_t>(Sec->RelocationCount);
+      W.write<uint16_t>(0); // NumberOfLineNumbers. Not supported yet.
+      W.write<int32_t>(Sec->Flags);
+    }
 
     return true;
   };
@@ -1031,8 +1043,13 @@
   SymbolTableEntryCount = SymbolTableIndex;
 
   // Calculate the RawPointer value for each section.
-  uint64_t RawPointer = XCOFF::FileHeaderSize32 + auxiliaryHeaderSize() +
-                        SectionCount * XCOFF::SectionHeaderSize32;
+  uint64_t RawPointer =
+      (is64Bit() ? (XCOFF::FileHeaderSize64 +
+                    SectionCount * XCOFF::SectionHeaderSize64)
+                 : (XCOFF::FileHeaderSize32 +
+                    SectionCount * XCOFF::SectionHeaderSize32)) +
+      auxiliaryHeaderSize();
+
   for (auto *Sec : Sections) {
     if (Sec->Index == SectionEntry::UninitializedIndex || Sec->IsVirtual)
       continue;
diff --git a/llvm/test/CodeGen/PowerPC/aix-available-externally-linkage.ll b/llvm/test/CodeGen/PowerPC/aix-available-externally-linkage.ll
--- a/llvm/test/CodeGen/PowerPC/aix-available-externally-linkage.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-available-externally-linkage.ll
@@ -11,10 +11,7 @@
 ; RUN: llvm-readobj --symbols %t.o | \
 ; RUN:   FileCheck --check-prefix=XCOFF32 %s
 
-; RUN: not --crash llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff \
-; RUN:     -mcpu=pwr4 -mattr=-altivec -filetype=obj -o %t.o 2>&1 < %s | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @_ZN3Foo1aE = available_externally constant i32 -1
 
diff --git a/llvm/test/CodeGen/PowerPC/aix-extern-weak.ll b/llvm/test/CodeGen/PowerPC/aix-extern-weak.ll
--- a/llvm/test/CodeGen/PowerPC/aix-extern-weak.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-extern-weak.ll
@@ -8,11 +8,7 @@
 ; RUN: -mattr=-altivec -data-sections=false -xcoff-traceback-table=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --symbols %t.o | FileCheck --check-prefix=CHECKSYM %s
 
-; RUN: not --crash llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc64-ibm-aix-xcoff \
-; RUN: -mattr=-altivec -data-sections=false -xcoff-traceback-table=false -filetype=obj -o %t.o 2>&1 < %s | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
-
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @foo_ext_weak_p = global void (...)* bitcast (void ()* @foo_ext_weak_ref to void (...)*)
 @b_w = extern_weak global i32
diff --git a/llvm/test/CodeGen/PowerPC/aix-extern.ll b/llvm/test/CodeGen/PowerPC/aix-extern.ll
--- a/llvm/test/CodeGen/PowerPC/aix-extern.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-extern.ll
@@ -8,9 +8,7 @@
 ; RUN: -mattr=-altivec -data-sections=false -xcoff-traceback-table=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --symbols %t.o | FileCheck --check-prefix=CHECKSYM %s
 
-; RUN: not --crash llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc64-ibm-aix-xcoff \
-; RUN: -mattr=-altivec -data-sections=false -xcoff-traceback-table=false -filetype=obj -o %t.o 2>&1 < %s | FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @bar_p = global i32 (...)* @bar_ref, align 4
 @b_e = external global i32, align 4
diff --git a/llvm/test/CodeGen/PowerPC/aix-func-align.ll b/llvm/test/CodeGen/PowerPC/aix-func-align.ll
--- a/llvm/test/CodeGen/PowerPC/aix-func-align.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-func-align.ll
@@ -9,9 +9,7 @@
 ; RUN:     -xcoff-traceback-table=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=SYMS %s
 
-; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -filetype=obj < %s 2>&1 | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 define i32 @foo()  align 32 {
 entry:
diff --git a/llvm/test/CodeGen/PowerPC/aix-internal.ll b/llvm/test/CodeGen/PowerPC/aix-internal.ll
--- a/llvm/test/CodeGen/PowerPC/aix-internal.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-internal.ll
@@ -1,8 +1,8 @@
 ; RUN: llc -mtriple powerpc-ibm-aix -verify-machineinstrs -mcpu=pwr4 -mattr=-altivec \
 ; RUN: -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --syms %t.o | FileCheck %s
-; RUN: not --crash llc -mtriple powerpc64-ibm-aix -verify-machineinstrs -mcpu=pwr4 -mattr=-altivec \
-; RUN: -filetype=obj -o %t.o < %s 2>&1 | FileCheck --check-prefix=64-CHECK %s
+
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 define internal i32 @foo() {
   ret i32 1
@@ -34,5 +34,3 @@
 
 ; Make sure no label is emitted.
 ; CHECK-NOT: Name: foo
-
-;64-CHECK: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
diff --git a/llvm/test/CodeGen/PowerPC/aix-llvm-intrinsic.ll b/llvm/test/CodeGen/PowerPC/aix-llvm-intrinsic.ll
--- a/llvm/test/CodeGen/PowerPC/aix-llvm-intrinsic.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-llvm-intrinsic.ll
@@ -9,10 +9,7 @@
 ; RUN: llvm-readobj --symbols %t.o | FileCheck --check-prefix=CHECKSYM %s
 ; RUN: llvm-objdump -r -d --symbol-description %t.o | FileCheck --check-prefix=CHECKRELOC %s
 
-; RUN: not --crash llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc64-ibm-aix-xcoff \
-; RUN:                 -mattr=-altivec -filetype=obj -o %t.o 2>&1 < %s | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 %struct.S = type { i32, i32 }
 
diff --git a/llvm/test/CodeGen/PowerPC/aix-overflow-toc.py b/llvm/test/CodeGen/PowerPC/aix-overflow-toc.py
--- a/llvm/test/CodeGen/PowerPC/aix-overflow-toc.py
+++ b/llvm/test/CodeGen/PowerPC/aix-overflow-toc.py
@@ -11,10 +11,7 @@
 # RUN:     -filetype=obj -o %t.o < %t.ll
 # RUN: llvm-objdump -D -r --symbol-description %t.o | FileCheck --check-prefix=DIS32 %s
 
-# RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -data-sections=false \
-# RUN:     -mcpu=pwr4 -mattr=-altivec -filetype=obj -o %t.o 2>&1 < %t.ll | \
-# RUN:   FileCheck --check-prefix=XCOFF64 %s
-# XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+## FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 numentries = 12290
 for x in range(0, numentries):
diff --git a/llvm/test/CodeGen/PowerPC/aix-return55.ll b/llvm/test/CodeGen/PowerPC/aix-return55.ll
--- a/llvm/test/CodeGen/PowerPC/aix-return55.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-return55.ll
@@ -5,9 +5,7 @@
 ; RUN: llvm-objdump -D %t.o | FileCheck --check-prefix=CHECKOBJ %s
 ; RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=CHECKSECT %s
 
-; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -filetype=obj < %s 2>&1 | \
-; RUN: FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @a = global i64 320255973571806, align 8
 @d = global double 5.000000e+00, align 8
diff --git a/llvm/test/CodeGen/PowerPC/aix-tls-xcoff-variables.ll b/llvm/test/CodeGen/PowerPC/aix-tls-xcoff-variables.ll
--- a/llvm/test/CodeGen/PowerPC/aix-tls-xcoff-variables.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-tls-xcoff-variables.ll
@@ -10,8 +10,7 @@
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefixes=SYMS,SYMS-NODATASECT %s
 ; RUN: llvm-objdump -D --symbol-description %t.o | FileCheck --check-prefixes=OBJDUMP-NODATASECT %s
 
-; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -filetype=obj < %s 2>&1 | FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 ; SECTION:      File: {{.*}}aix-tls-xcoff-variables.ll.tmp.o
 ; SECTION-NEXT: Format: aixcoff-rs6000
diff --git a/llvm/test/CodeGen/PowerPC/aix-user-defined-memcpy.ll b/llvm/test/CodeGen/PowerPC/aix-user-defined-memcpy.ll
--- a/llvm/test/CodeGen/PowerPC/aix-user-defined-memcpy.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-user-defined-memcpy.ll
@@ -1,20 +1,17 @@
 ; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff -mcpu=pwr4 \
-; RUN: -mattr=-altivec -filetype=obj -xcoff-traceback-table=false -o %t.o < %s
+; RUN:   -mattr=-altivec -filetype=obj -xcoff-traceback-table=false -o %t.o < %s
 
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=32-SYM %s
 
 ; RUN: llvm-readobj --relocs --expand-relocs %t.o | FileCheck \
-; RUN: --check-prefix=32-REL %s
+; RUN:   --check-prefix=32-REL %s
 
 ; RUN: llvm-objdump -D %t.o | FileCheck --check-prefix=32-DIS %s
 
 ; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff \
-; RUN:     -mcpu=pwr4 -mattr=-altivec < %s | \
-; RUN:   FileCheck %s
+; RUN:   -mcpu=pwr4 -mattr=-altivec < %s | FileCheck %s
 
-; RUN: not --crash llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff \
-; RUN: -mcpu=pwr4 -mattr=-altivec -filetype=obj < %s 2>&1 | FileCheck \
-; RUN: --check-prefix=64-CHECK %s
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 ; Test verifies:
 ; If there exists a user-defined function whose name is the same as the
@@ -117,5 +114,3 @@
 ; 32-DIS-NEXT:       28: 80 01 00 08                   lwz 0, 8(1)
 ; 32-DIS-NEXT:       2c: 7c 08 03 a6                   mtlr 0
 ; 32-DIS-NEXT:       30: 4e 80 00 20                   blr
-
-; 64-CHECK: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
diff --git a/llvm/test/CodeGen/PowerPC/aix-weak.ll b/llvm/test/CodeGen/PowerPC/aix-weak.ll
--- a/llvm/test/CodeGen/PowerPC/aix-weak.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-weak.ll
@@ -1,17 +1,14 @@
 ; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff -xcoff-traceback-table=false -mcpu=pwr4 \
-; RUN: -mattr=-altivec -data-sections=false < %s | FileCheck --check-prefixes=COMMON,BIT32 %s
+; RUN:   -mattr=-altivec -data-sections=false < %s | FileCheck --check-prefixes=COMMON,BIT32 %s
 
 ; RUN: llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff -xcoff-traceback-table=false -mcpu=pwr4 \
-; RUN: -mattr=-altivec -data-sections=false < %s | FileCheck --check-prefixes=COMMON,BIT64 %s
+; RUN:   -mattr=-altivec -data-sections=false < %s | FileCheck --check-prefixes=COMMON,BIT64 %s
 
 ; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff -xcoff-traceback-table=false -mcpu=pwr4 \
-; RUN: -mattr=-altivec -data-sections=false -filetype=obj -o %t.o < %s
+; RUN:   -mattr=-altivec -data-sections=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --symbols %t.o | FileCheck --check-prefix=CHECKSYM %s
 
-; RUN: not --crash llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc64-ibm-aix-xcoff \
-; RUN: -mattr=-altivec -data-sections=false -filetype=obj -o %t.o 2>&1 < %s | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @foo_weak_p = global void (...)* bitcast (void ()* @foo_ref_weak to void (...)*), align 4
 @b = weak global i32 0, align 4
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-data-only-notoc.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-data-only-notoc.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-data-only-notoc.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-data-only-notoc.ll
@@ -4,9 +4,7 @@
 ; RUN: llc -mtriple powerpc-ibm-aix-xcoff -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=SYMS %s
 
-; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -filetype=obj < %s 2>&1 | \
-; RUN: FileCheck --check-prefix=OBJ64 %s
-; OBJ64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @a = external global i32, align 4
 @b = external global i64, align 8
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-data.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-data.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-data.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-data.ll
@@ -6,12 +6,13 @@
 
 ; RUN: llc -mtriple powerpc-ibm-aix-xcoff -data-sections=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --section-headers --file-header %t.o | \
-; RUN: FileCheck --check-prefix=OBJ %s
+; RUN:   FileCheck --check-prefix=OBJ %s
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=SYMS %s
 
-; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -data-sections=false -filetype=obj < %s 2>&1 | \
-; RUN: FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
+; RUN: llc -mtriple powerpc64-ibm-aix-xcoff -data-sections=false -filetype=obj -o %t64.o < %s
+; RUN: llvm-readobj --section-headers --file-header %t64.o | \
+; RUN:   FileCheck --check-prefix=OBJ64 %s
 
 @ivar = local_unnamed_addr global i32 35, align 4
 @llvar = local_unnamed_addr global i64 36, align 8
@@ -681,3 +682,58 @@
 ; SYMS-NEXT:     }
 ; SYMS-NEXT:   }
 ; SYMS:      ]
+
+; OBJ64:      Format: aix5coff64-rs6000
+; OBJ64-NEXT: Arch: powerpc64
+; OBJ64-NEXT: AddressSize: 64bit
+; OBJ64-NEXT: FileHeader {
+; OBJ64-NEXT:   Magic: 0x1F7
+; OBJ64-NEXT:   NumberOfSections: 3
+; OBJ64-NEXT:   TimeStamp: None (0x0)
+; OBJ64-NEXT:   SymbolTableOffset: 0x170
+; OBJ64-NEXT:   SymbolTableEntries: 0
+; OBJ64-NEXT:   OptionalHeaderSize: 0x0
+; OBJ64-NEXT:   Flags: 0x0
+; OBJ64-NEXT: }
+
+; OBJ64:      Sections [
+; OBJ64-NEXT:   Section {
+; OBJ64-NEXT:     Index: [[#OBJ64_INDX:]]
+; OBJ64-NEXT:     Name: .text
+; OBJ64-NEXT:     PhysicalAddress: 0x0
+; OBJ64-NEXT:     VirtualAddress: 0x0
+; OBJ64-NEXT:     Size: 0x0
+; OBJ64-NEXT:     RawDataOffset: 0xF0
+; OBJ64-NEXT:     RelocationPointer: 0x0
+; OBJ64-NEXT:     LineNumberPointer: 0x0
+; OBJ64-NEXT:     NumberOfRelocations: 0
+; OBJ64-NEXT:     NumberOfLineNumbers: 0
+; OBJ64-NEXT:     Type: STYP_TEXT (0x20)
+; OBJ64-NEXT:   }
+; OBJ64-NEXT:   Section {
+; OBJ64-NEXT:     Index: [[#OBJ64_INDX+1]]
+; OBJ64-NEXT:     Name: .data
+; OBJ64-NEXT:     PhysicalAddress: 0x0
+; OBJ64-NEXT:     VirtualAddress: 0x0
+; OBJ64-NEXT:     Size: 0x80
+; OBJ64-NEXT:     RawDataOffset: 0xF0
+; OBJ64-NEXT:     RelocationPointer: 0x0
+; OBJ64-NEXT:     LineNumberPointer: 0x0
+; OBJ64-NEXT:     NumberOfRelocations: 0
+; OBJ64-NEXT:     NumberOfLineNumbers: 0
+; OBJ64-NEXT:     Type: STYP_DATA (0x40)
+; OBJ64-NEXT:   }
+; OBJ64-NEXT:   Section {
+; OBJ64-NEXT:     Index: [[#OBJ64_INDX+2]]
+; OBJ64-NEXT:     Name: .bss
+; OBJ64-NEXT:     PhysicalAddress: 0x80
+; OBJ64-NEXT:     VirtualAddress: 0x80
+; OBJ64-NEXT:     Size: 0x6C
+; OBJ64-NEXT:     RawDataOffset: 0x0
+; OBJ64-NEXT:     RelocationPointer: 0x0
+; OBJ64-NEXT:     LineNumberPointer: 0x0
+; OBJ64-NEXT:     NumberOfRelocations: 0
+; OBJ64-NEXT:     NumberOfLineNumbers: 0
+; OBJ64-NEXT:     Type: STYP_BSS (0x80)
+; OBJ64-NEXT:   }
+; OBJ64-NEXT: ]
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-externL.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-externL.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-externL.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-externL.ll
@@ -8,10 +8,7 @@
 ; RUN: llvm-readobj --symbols %t.o | \
 ; RUN:   FileCheck --check-prefix=XCOFF32 %s
 
-; RUN: not --crash llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff \
-; RUN:     -mcpu=pwr4 -mattr=-altivec -filetype=obj -o %t.o 2>&1 < %s | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @La = external global i32, align 4
 
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-huge-relocs.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-huge-relocs.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-huge-relocs.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-huge-relocs.ll
@@ -20,13 +20,7 @@
 ; RUN:     -mcpu=pwr4 -mattr=-altivec -filetype=obj -o %t.o %t.ll
 ; RUN: llvm-readobj --section-headers %t.o | FileCheck --check-prefix=XCOFF32 %s
 
-; RUN: not --crash llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff \
-; RUN:                 -mcpu=pwr4 -mattr=-altivec -filetype=obj -o %t.o %t.overflow.ll 2>&1 | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; RUN: not --crash llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff \
-; RUN:                 -mcpu=pwr4 -mattr=-altivec -filetype=obj -o %t.o %t.ll 2>&1 | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @c = external global i8, align 1
 @arr = global [SIZE x i8*] [MACRO], align 8
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-lcomm.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-lcomm.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-lcomm.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-lcomm.ll
@@ -3,12 +3,10 @@
 
 ; RUN: llc -mtriple powerpc-ibm-aix-xcoff -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --section-headers --file-header %t.o | \
-; RUN: FileCheck --check-prefix=OBJ %s
+; RUN:   FileCheck --check-prefix=OBJ %s
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=SYMS %s
 
-; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -filetype=obj < %s 2>&1 | \
-; RUN: FileCheck --check-prefix=OBJ64 %s
-; OBJ64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @a = internal global i32 0, align 4
 @b = internal global i64 0, align 8
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-lower-comm.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-lower-comm.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-lower-comm.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-lower-comm.ll
@@ -6,10 +6,7 @@
 ; RUN: llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc-ibm-aix-xcoff -data-sections=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj -r --expand-relocs --syms %t.o | FileCheck --check-prefixes=RELOC,SYM %s
 
-; RUN: not --crash llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc64-ibm-aix-xcoff \
-; RUN: -data-sections=false -filetype=obj < %s 2>&1 | \
-; RUN:   FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @common = common global i32 0, align 4
 @pointer = global i32* @common, align 4
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-reloc.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-reloc.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-reloc.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-reloc.ll
@@ -1,15 +1,13 @@
 ; RUN: llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc-ibm-aix-xcoff -mattr=-altivec \
 ; RUN:     -xcoff-traceback-table=false -data-sections=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --section-headers --file-header %t.o | \
-; RUN: FileCheck --check-prefix=OBJ %s
+; RUN:   FileCheck --check-prefix=OBJ %s
 ; RUN: llvm-readobj --relocs --expand-relocs %t.o | FileCheck --check-prefix=RELOC %s
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=SYM %s
 ; RUN: llvm-objdump -D %t.o | FileCheck --check-prefix=DIS %s
 ; RUN: llvm-objdump -r %t.o | FileCheck --check-prefix=DIS_REL %s
 
-; RUN: not --crash llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc64-ibm-aix-xcoff -mattr=-altivec -data-sections=false -filetype=obj < %s 2>&1 | \
-; RUN: FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @globalA = global i32 1, align 4
 @globalB = global i32 2, align 4
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll
@@ -5,13 +5,11 @@
 
 ; RUN: llc -verify-machineinstrs -mcpu=pwr7 -mtriple powerpc-ibm-aix-xcoff -data-sections=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --section-headers --file-header %t.o | \
-; RUN: FileCheck --check-prefix=OBJ %s
+; RUN:   FileCheck --check-prefix=OBJ %s
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=SYMS %s
 ; RUN: llvm-objdump -D %t.o | FileCheck --check-prefix=DIS %s
 
-; RUN: not --crash llc -verify-machineinstrs -mcpu=pwr7 -mtriple powerpc64-ibm-aix-xcoff -data-sections=false -filetype=obj < %s 2>&1 | \
-; RUN: FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @const_ivar = constant i32 35, align 4
 @const_llvar = constant i64 36, align 8
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-toc.ll
@@ -9,9 +9,7 @@
 ; RUN:     --xcoff-traceback-table=false -filetype=obj -o %t.o < %s
 ; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=SYM %s
 
-; RUN: not --crash llc -verify-machineinstrs -mcpu=pwr4 -mattr=-altivec -mtriple powerpc64-ibm-aix-xcoff -filetype=obj -o %t.o 2>&1 \
-; RUN: < %s | FileCheck --check-prefix=XCOFF64 %s
-; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @a = external global i32, align 4
 @b = external global i64, align 8
diff --git a/llvm/test/CodeGen/PowerPC/basic-toc-data-extern.ll b/llvm/test/CodeGen/PowerPC/basic-toc-data-extern.ll
--- a/llvm/test/CodeGen/PowerPC/basic-toc-data-extern.ll
+++ b/llvm/test/CodeGen/PowerPC/basic-toc-data-extern.ll
@@ -2,10 +2,8 @@
 ; RUN: not --crash llc -filetype=obj -mtriple powerpc-ibm-aix-xcoff  \
 ; RUN:                 -verify-machineinstrs < %s 2>&1 | \
 ; RUN:   FileCheck %s --check-prefix=OBJ32
-; RUN: llc -mtriple powerpc64-ibm-aix-xcoff -verify-machineinstrs < %s | FileCheck %s
-; RUN: not --crash llc -filetype=obj -mtriple powerpc64-ibm-aix-xcoff  \
-; RUN:                 -verify-machineinstrs < %s 2>&1 | \
-; RUN:   FileCheck %s --check-prefix=OBJ64
+
+;; FIXME: currently only fileHeader and sectionHeaders are supported in XCOFF64.
 
 @i = external global i32, align 4  #0
 
@@ -20,6 +18,5 @@
 ; CHECK-NEXT:   .extern i[TD]
 
 ; OBJ32: LLVM ERROR:  toc-data not yet supported when writing object files.
-; OBJ64: LLVM ERROR:  64-bit XCOFF object files are not supported yet.
 
 attributes #0 = { "toc-data" }