Index: lib/Driver/ToolChains/Clang.cpp
===================================================================
--- lib/Driver/ToolChains/Clang.cpp
+++ lib/Driver/ToolChains/Clang.cpp
@@ -35,6 +35,7 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"
+#include "llvm/Support/TargetParser.h"
 #include "llvm/Support/YAMLParser.h"
 
 #ifdef LLVM_ON_UNIX
@@ -1278,43 +1279,13 @@
   // FIXME: Support -meabi.
   // FIXME: Parts of this are duplicated in the backend, unify this somehow.
   const char *ABIName = nullptr;
-  if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ)) {
+  if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ))
     ABIName = A->getValue();
-  } else if (Triple.isOSBinFormatMachO()) {
-    if (arm::useAAPCSForMachO(Triple)) {
-      ABIName = "aapcs";
-    } else if (Triple.isWatchABI()) {
-      ABIName = "aapcs16";
-    } else {
-      ABIName = "apcs-gnu";
-    }
-  } else if (Triple.isOSWindows()) {
-    // FIXME: this is invalid for WindowsCE
-    ABIName = "aapcs";
-  } else {
-    // Select the default based on the platform.
-    switch (Triple.getEnvironment()) {
-    case llvm::Triple::Android:
-    case llvm::Triple::GNUEABI:
-    case llvm::Triple::GNUEABIHF:
-    case llvm::Triple::MuslEABI:
-    case llvm::Triple::MuslEABIHF:
-      ABIName = "aapcs-linux";
-      break;
-    case llvm::Triple::EABIHF:
-    case llvm::Triple::EABI:
-      ABIName = "aapcs";
-      break;
-    default:
-      if (Triple.getOS() == llvm::Triple::NetBSD)
-        ABIName = "apcs-gnu";
-      else if (Triple.getOS() == llvm::Triple::OpenBSD)
-        ABIName = "aapcs-linux";
-      else
-        ABIName = "aapcs";
-      break;
-    }
+  else {
+    StringRef CPU = getCPUName(Args, Triple, /*FromAs*/ false);
+    ABIName = llvm::ARM::computeDefaultTargetABI(Triple, CPU).data();
   }
+
   CmdArgs.push_back("-target-abi");
   CmdArgs.push_back(ABIName);
 
Index: test/CodeGen/arm-v8.1a-neon-intrinsics.c
===================================================================
--- test/CodeGen/arm-v8.1a-neon-intrinsics.c
+++ test/CodeGen/arm-v8.1a-neon-intrinsics.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple armv8.1a-linux-gnu -target-feature +neon \
+// RUN: %clang_cc1 -triple armv8.1a-linux-gnu -target-abi apcs-gnu -target-feature +neon \
 // RUN:  -S -emit-llvm -o - %s \
 // RUN:  | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-ARM
 
Index: test/CodeGen/named_reg_global.c
===================================================================
--- test/CodeGen/named_reg_global.c
+++ test/CodeGen/named_reg_global.c
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -triple x86_64-linux-gnu -S -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-X86-64
 // RUN: %clang_cc1 -triple arm64-linux-gnu -S -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-ARM
-// RUN: %clang_cc1 -triple armv7-linux-gnu -S -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-ARM
+// RUN: %clang_cc1 -triple armv7-linux-gnu -target-abi apcs-gnu -S -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-ARM
 
 // CHECK-NOT: @sp = common global
 
Index: test/CodeGen/neon-immediate-ubsan.c
===================================================================
--- test/CodeGen/neon-immediate-ubsan.c
+++ test/CodeGen/neon-immediate-ubsan.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple armv7s-linux-gnu -emit-llvm -o - %s \
+// RUN: %clang_cc1 -triple armv7s-linux-gnu -target-abi apcs-gnu -emit-llvm -o - %s \
 // RUN:     -target-feature +neon -target-cpu cortex-a8 \
 // RUN:     -fsanitize=signed-integer-overflow \
 // RUN:   | FileCheck %s --check-prefix=CHECK --check-prefix=ARMV7
Index: test/CodeGen/xray-attributes-supported.cpp
===================================================================
--- test/CodeGen/xray-attributes-supported.cpp
+++ test/CodeGen/xray-attributes-supported.cpp
@@ -1,5 +1,5 @@
 // RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple x86_64-unknown-linux-gnu | FileCheck %s
-// RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple arm-unknown-linux-gnu | FileCheck %s
+// RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple arm-unknown-linux-gnu -target-abi apcs-gnu | FileCheck %s
 // RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips-unknown-linux-gnu | FileCheck %s
 // RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mipsel-unknown-linux-gnu | FileCheck %s
 // RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips64-unknown-linux-gnu | FileCheck %s