2 files changed, 46 insertions, 50 deletions
diff --git a/llvm/lib/Support/TargetParser.cpp b/llvm/lib/Support/TargetParser.cpp
index b16351906a4..13bb6f23bc8 100644
--- a/llvm/lib/Support/TargetParser.cpp
+++ b/llvm/lib/Support/TargetParser.cpp
@@ -784,6 +784,42 @@ unsigned llvm::ARM::parseArchVersion(StringRef Arch) {
   return 0;
 }
 
+StringRef llvm::ARM::computeDefaultTargetABI(const Triple &TT, StringRef CPU) {
+  StringRef ArchName =
+      CPU.empty() ? TT.getArchName() : ARM::getArchName(ARM::parseCPUArch(CPU));
+
+  if (TT.isOSBinFormatMachO()) {
+    if (TT.getEnvironment() == Triple::EABI ||
+        TT.getOS() == Triple::UnknownOS ||
+        llvm::ARM::parseArchProfile(ArchName) == ARM::PK_M)
+      return "aapcs";
+    if (TT.isWatchABI())
+      return "aapcs16";
+    return "apcs-gnu";
+  } else if (TT.isOSWindows())
+    // FIXME: this is invalid for WindowsCE.
+    return "aapcs";
+
+  // Select the default based on the platform.
+  switch (TT.getEnvironment()) {
+  case Triple::Android:
+  case Triple::GNUEABI:
+  case Triple::GNUEABIHF:
+  case Triple::MuslEABI:
+  case Triple::MuslEABIHF:
+    return "aapcs-linux";
+  case Triple::EABIHF:
+  case Triple::EABI:
+    return "aapcs";
+  default:
+    if (TT.isOSNetBSD())
+      return "apcs-gnu";
+    if (TT.isOSOpenBSD())
+      return "aapcs-linux";
+    return "aapcs";
+  }
+}
+
 StringRef llvm::AArch64::getCanonicalArchName(StringRef Arch) {
   return ARM::getCanonicalArchName(Arch);
 }
diff --git a/llvm/lib/Target/ARM/ARMTargetMachine.cpp b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
index eb71e557ec9..4eb244a13c1 100644
--- a/llvm/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
@@ -110,60 +110,20 @@ static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
 static ARMBaseTargetMachine::ARMABI
 computeTargetABI(const Triple &TT, StringRef CPU,
                  const TargetOptions &Options) {
-  if (Options.MCOptions.getABIName() == "aapcs16")
+  StringRef ABIName = Options.MCOptions.getABIName();
+
+  if (ABIName.empty())
+    ABIName = ARM::computeDefaultTargetABI(TT, CPU);
+
+  if (ABIName == "aapcs16")
     return ARMBaseTargetMachine::ARM_ABI_AAPCS16;
-  else if (Options.MCOptions.getABIName().startswith("aapcs"))
+  else if (ABIName.startswith("aapcs"))
     return ARMBaseTargetMachine::ARM_ABI_AAPCS;
-  else if (Options.MCOptions.getABIName().startswith("apcs"))
+  else if (ABIName.startswith("apcs"))
     return ARMBaseTargetMachine::ARM_ABI_APCS;
 
-  assert(Options.MCOptions.getABIName().empty() &&
-         "Unknown target-abi option!");
-
-  ARMBaseTargetMachine::ARMABI TargetABI =
-      ARMBaseTargetMachine::ARM_ABI_UNKNOWN;
-
-  unsigned ArchKind = ARM::parseCPUArch(CPU);
-  StringRef ArchName = ARM::getArchName(ArchKind);
-  // FIXME: This is duplicated code from the front end and should be unified.
-  if (TT.isOSBinFormatMachO()) {
-    if (TT.getEnvironment() == Triple::EABI ||
-        (TT.getOS() == Triple::UnknownOS && TT.isOSBinFormatMachO()) ||
-        ARM::parseArchProfile(ArchName) == ARM::PK_M) {
-      TargetABI = ARMBaseTargetMachine::ARM_ABI_AAPCS;
-    } else if (TT.isWatchABI()) {
-      TargetABI = ARMBaseTargetMachine::ARM_ABI_AAPCS16;
-    } else {
-      TargetABI = ARMBaseTargetMachine::ARM_ABI_APCS;
-    }
-  } else if (TT.isOSWindows()) {
-    // FIXME: this is invalid for WindowsCE
-    TargetABI = ARMBaseTargetMachine::ARM_ABI_AAPCS;
-  } else {
-    // Select the default based on the platform.
-    switch (TT.getEnvironment()) {
-    case Triple::Android:
-    case Triple::GNUEABI:
-    case Triple::GNUEABIHF:
-    case Triple::MuslEABI:
-    case Triple::MuslEABIHF:
-    case Triple::EABIHF:
-    case Triple::EABI:
-      TargetABI = ARMBaseTargetMachine::ARM_ABI_AAPCS;
-      break;
-    case Triple::GNU:
-      TargetABI = ARMBaseTargetMachine::ARM_ABI_APCS;
-      break;
-    default:
-      if (TT.isOSNetBSD())
-        TargetABI = ARMBaseTargetMachine::ARM_ABI_APCS;
-      else
-        TargetABI = ARMBaseTargetMachine::ARM_ABI_AAPCS;
-      break;
-    }
-  }
-
-  return TargetABI;
+  llvm_unreachable("Unhandled/unknown ABI Name!");
+  return ARMBaseTargetMachine::ARM_ABI_UNKNOWN;
 }
 
 static std::string computeDataLayout(const Triple &TT, StringRef CPU,