diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -182,9 +182,7 @@
   StackAlignment = getPlatformStackAlignment();
 
   // Determine endianness.
-  // FIXME: Part of the TargetMachine.
-  IsLittleEndian = (TargetTriple.getArch() == Triple::ppc64le ||
-                    TargetTriple.getArch() == Triple::ppcle);
+  IsLittleEndian = TM.isLittleEndian();
 }
 
 bool PPCSubtarget::enableMachineScheduler() const { return true; }
diff --git a/llvm/lib/Target/PowerPC/PPCTargetMachine.h b/llvm/lib/Target/PowerPC/PPCTargetMachine.h
--- a/llvm/lib/Target/PowerPC/PPCTargetMachine.h
+++ b/llvm/lib/Target/PowerPC/PPCTargetMachine.h
@@ -25,9 +25,12 @@
 class PPCTargetMachine final : public LLVMTargetMachine {
 public:
   enum PPCABI { PPC_ABI_UNKNOWN, PPC_ABI_ELFv1, PPC_ABI_ELFv2 };
+  enum Endian { NOT_DETECTED, LITTLE, BIG };
+
 private:
   std::unique_ptr<TargetLoweringObjectFile> TLOF;
   PPCABI TargetABI;
+  Endian Endianness = Endian::NOT_DETECTED;
 
   mutable StringMap<std::unique_ptr<PPCSubtarget>> SubtargetMap;
 
@@ -63,6 +66,8 @@
     // Addrspacecasts are always noops.
     return true;
   }
+
+  bool isLittleEndian() const;
 };
 } // end namespace llvm
 
diff --git a/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp b/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
--- a/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -126,13 +126,17 @@
   initializeGlobalISel(PR);
 }
 
+static bool isLittleEndianTriple(const Triple &T) {
+  return T.getArch() == Triple::ppc64le || T.getArch() == Triple::ppcle;
+}
+
 /// Return the datalayout string of a subtarget.
 static std::string getDataLayoutString(const Triple &T) {
   bool is64Bit = T.getArch() == Triple::ppc64 || T.getArch() == Triple::ppc64le;
   std::string Ret;
 
   // Most PPC* platforms are big endian, PPC(64)LE is little endian.
-  if (T.getArch() == Triple::ppc64le || T.getArch() == Triple::ppcle)
+  if (isLittleEndianTriple(T))
     Ret = "e";
   else
     Ret = "E";
@@ -317,7 +321,8 @@
                         getEffectiveRelocModel(TT, RM),
                         getEffectivePPCCodeModel(TT, CM, JIT), OL),
       TLOF(createTLOF(getTargetTriple())),
-      TargetABI(computeTargetABI(TT, Options)) {
+      TargetABI(computeTargetABI(TT, Options)),
+      Endianness(isLittleEndianTriple(TT) ? Endian::LITTLE : Endian::BIG) {
   initAsmInfo();
 }
 
@@ -540,6 +545,12 @@
   return TargetTransformInfo(PPCTTIImpl(this, F));
 }
 
+bool PPCTargetMachine::isLittleEndian() const {
+  assert(Endianness != Endian::NOT_DETECTED &&
+         "Unable to determine endianness");
+  return Endianness == Endian::LITTLE;
+}
+
 static MachineSchedRegistry
 PPCPreRASchedRegistry("ppc-prera",
                       "Run PowerPC PreRA specific scheduler",