Index: clang/docs/ClangCommandLineReference.rst
===================================================================
--- clang/docs/ClangCommandLineReference.rst
+++ clang/docs/ClangCommandLineReference.rst
@@ -1307,6 +1307,10 @@
 
 .. option:: -fcommon, -fno-common
 
+Place definitions of variables with no storage class and no initializer
+(tentative definitions) in a common block, or generate individual
+zero-initialized definitions (default -fno-common).
+
 .. option:: -fcompile-resource=<arg>, --resource <arg>, --resource=<arg>
 
 .. option:: -fconstant-cfstrings, -fno-constant-cfstrings
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -84,6 +84,7 @@
 Modified Compiler Flags
 -----------------------
 
+- -fno-common has been enabled as the default for all targets.
 
 New Pragmas in Clang
 --------------------
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -848,7 +848,8 @@
   Group<f_clang_Group>;
 def : Flag<["-"], "frecord-gcc-switches">, Alias<frecord_command_line>;
 def : Flag<["-"], "fno-record-gcc-switches">, Alias<fno_record_command_line>;
-def fcommon : Flag<["-"], "fcommon">, Group<f_Group>;
+def fcommon : Flag<["-"], "fcommon">, Group<f_Group>,
+  Flags<[CoreOption, CC1Option]>, HelpText<"Place uninitialized global variables in a common block">;
 def fcompile_resource_EQ : Joined<["-"], "fcompile-resource=">, Group<f_Group>;
 def fcomplete_member_pointers : Flag<["-"], "fcomplete-member-pointers">, Group<f_clang_Group>,
    Flags<[CoreOption, CC1Option]>,
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -1408,20 +1408,6 @@
   }
 }
 
-static bool isNoCommonDefault(const llvm::Triple &Triple) {
-  switch (Triple.getArch()) {
-  default:
-    if (Triple.isOSFuchsia())
-      return true;
-    return false;
-
-  case llvm::Triple::xcore:
-  case llvm::Triple::wasm32:
-  case llvm::Triple::wasm64:
-    return true;
-  }
-}
-
 static bool hasMultipleInvocations(const llvm::Triple &Triple,
                                    const ArgList &Args) {
   // Supported only on Darwin where we invoke the compiler multiple times
@@ -5661,11 +5647,9 @@
   if (!Args.hasFlag(options::OPT_Qy, options::OPT_Qn, true))
     CmdArgs.push_back("-Qn");
 
-  // -fcommon is the default unless compiling kernel code or the target says so
-  bool NoCommonDefault = KernelOrKext || isNoCommonDefault(RawTriple);
-  if (!Args.hasFlag(options::OPT_fcommon, options::OPT_fno_common,
-                    !NoCommonDefault))
-    CmdArgs.push_back("-fno-common");
+  // -fno-common is the default, set -fcommon only when that flag is set.
+  if (Args.hasFlag(options::OPT_fcommon, options::OPT_fno_common, false))
+    CmdArgs.push_back("-fcommon");
 
   // -fsigned-bitfields is default, and clang doesn't yet support
   // -funsigned-bitfields.
Index: clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- clang/lib/Frontend/CompilerInvocation.cpp
+++ clang/lib/Frontend/CompilerInvocation.cpp
@@ -809,7 +809,7 @@
   Opts.RecordCommandLine =
       std::string(Args.getLastArgValue(OPT_record_command_line));
   Opts.MergeAllConstants = Args.hasArg(OPT_fmerge_all_constants);
-  Opts.NoCommon = Args.hasArg(OPT_fno_common);
+  Opts.NoCommon = !Args.hasArg(OPT_fcommon);
   Opts.NoInlineLineTables = Args.hasArg(OPT_gno_inline_line_tables);
   Opts.NoImplicitFloat = Args.hasArg(OPT_no_implicit_float);
   Opts.OptimizeSize = getOptimizationLevelSize(Args);
Index: clang/test/CodeGen/2008-07-21-mixed-var-fn-decl.c
===================================================================
--- clang/test/CodeGen/2008-07-21-mixed-var-fn-decl.c
+++ clang/test/CodeGen/2008-07-21-mixed-var-fn-decl.c
@@ -3,6 +3,6 @@
 int g0, f0();
 int f1(), g1;
 
-// CHECK: @g0 = common {{(dso_local )?}}global i32 0, align 4
-// CHECK: @g1 = common {{(dso_local )?}}global i32 0, align 4
+// CHECK: @g0 = {{(dso_local )?}}global i32 0, align 4
+// CHECK: @g1 = {{(dso_local )?}}global i32 0, align 4
 
Index: clang/test/CodeGen/2009-10-20-GlobalDebug.c
===================================================================
--- clang/test/CodeGen/2009-10-20-GlobalDebug.c
+++ clang/test/CodeGen/2009-10-20-GlobalDebug.c
@@ -2,10 +2,10 @@
 // RUN: %clang -target i386-apple-darwin10 -flto -S -g %s -o - | FileCheck %s
 
 // CHECK: @main.localstatic = internal global i32 0, align 4, !dbg [[L:![0-9]+]]
-// CHECK: @global = common global i32 0, align 4, !dbg [[G:![0-9]+]]
+// CHECK: @global = global i32 0, align 4, !dbg [[G:![0-9]+]]
 
 int global;
-int main() { 
+int main() {
   static int localstatic;
   return 0;
 }
Index: clang/test/CodeGen/aarch64-sve.c
===================================================================
--- clang/test/CodeGen/aarch64-sve.c
+++ clang/test/CodeGen/aarch64-sve.c
@@ -16,7 +16,7 @@
 // CHECK-DEBUG: cannot yet generate debug info for SVE type '__SVFloat64_t'
 // CHECK-DEBUG: cannot yet generate debug info for SVE type '__SVBool_t'
 
-// CHECK: @ptr = common global <vscale x 16 x i8>* null, align 8
+// CHECK: @ptr = global <vscale x 16 x i8>* null, align 8
 // CHECK: %s8 = alloca <vscale x 16 x i8>, align 16
 // CHECK: %s16 = alloca <vscale x 8 x i16>, align 16
 // CHECK: %s32 = alloca <vscale x 4 x i32>, align 16
Index: clang/test/CodeGen/address-space.c
===================================================================
--- clang/test/CodeGen/address-space.c
+++ clang/test/CodeGen/address-space.c
@@ -1,13 +1,13 @@
 // RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm < %s | FileCheck -enable-var-scope -check-prefixes=CHECK,X86 %s
 // RUN: %clang_cc1 -triple amdgcn -emit-llvm < %s | FileCheck -enable-var-scope -check-prefixes=CHECK,AMDGCN %s
 
-// CHECK: @foo = common addrspace(1) global
+// CHECK: @foo = addrspace(1) global
 int foo __attribute__((address_space(1)));
 
-// CHECK: @ban = common addrspace(1) global
+// CHECK: @ban = addrspace(1) global
 int ban[10] __attribute__((address_space(1)));
 
-// CHECK: @a = common global
+// CHECK: @a = global
 int a __attribute__((address_space(0)));
 
 // CHECK-LABEL: define i32 @test1()
Index: clang/test/CodeGen/alias.c
===================================================================
--- clang/test/CodeGen/alias.c
+++ clang/test/CodeGen/alias.c
@@ -5,8 +5,13 @@
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -emit-llvm -o - %s | FileCheck -check-prefix=CHECKGLOBALS %s
 
 int g0;
-// CHECKBASIC-DAG: @g0 = common global i32 0
-// CHECKASM-DAG: .comm g0,4,4
+// CHECKBASIC-DAG: @g0 = global i32 0
+// CHECKASM-DAG:  .bss
+// CHECKASM-DAG:  .globl  g0
+// CHECKASM-DAG:  .p2align  2
+// CHECKASM-DAG:  g0:
+// CHECKASM-DAG:  .long 0
+// CHECKASM-DAG:  .size g0, 4
 __thread int TL_WITH_ALIAS;
 // CHECKBASIC-DAG: @TL_WITH_ALIAS = thread_local global i32 0, align 4
 // CHECKASM-DAG: .globl TL_WITH_ALIAS
Index: clang/test/CodeGen/align-systemz.c
===================================================================
--- clang/test/CodeGen/align-systemz.c
+++ clang/test/CodeGen/align-systemz.c
@@ -7,10 +7,10 @@
 };
 
 char c;
-// CHECK-DAG: @c = common global i8 0, align 2
+// CHECK-DAG: @c = global i8 0, align 2
 
 struct test s;
-// CHECK-DAG: @s = common global %struct.test zeroinitializer, align 2
+// CHECK-DAG: @s = global %struct.test zeroinitializer, align 2
 
 extern char ec;
 // CHECK-DAG: @ec = external global i8, align 2
Index: clang/test/CodeGen/alignment.c
===================================================================
--- clang/test/CodeGen/alignment.c
+++ clang/test/CodeGen/alignment.c
@@ -7,7 +7,7 @@
 // CHECK: @b = {{.*}}zeroinitializer, align 16
 
 long long int test5[1024];
-// CHECK-DAG: @test5 = common global [1024 x i64] zeroinitializer, align 8
+// CHECK-DAG: @test5 = global [1024 x i64] zeroinitializer, align 8
 
 // PR5279 - Reduced alignment on typedef.
 typedef int myint __attribute__((aligned(1)));
Index: clang/test/CodeGen/asm-label.c
===================================================================
--- clang/test/CodeGen/asm-label.c
+++ clang/test/CodeGen/asm-label.c
@@ -11,9 +11,9 @@
 }
 
 // LINUX: @bar = internal global i32 0
-// LINUX: @foo = common global i32 0
+// LINUX: @foo = global i32 0
 // LINUX: declare i8* @alias(i32)
 
 // DARWIN: @"\01bar" = internal global i32 0
-// DARWIN: @"\01foo" = common global i32 0
+// DARWIN: @"\01foo" = global i32 0
 // DARWIN: declare i8* @"\01alias"(i32)
Index: clang/test/CodeGen/attr-weak-import.c
===================================================================
--- clang/test/CodeGen/attr-weak-import.c
+++ clang/test/CodeGen/attr-weak-import.c
@@ -20,7 +20,7 @@
 
 // CHECK: @A = global i32
 // CHECK-NOT: @B =
-// CHECK: @C = common global i32
+// CHECK: @C = global i32
 // CHECK: @D = global i32
 // CHECK: @E = global i32
 
Index: clang/test/CodeGen/attr-weakref2.c
===================================================================
--- clang/test/CodeGen/attr-weakref2.c
+++ clang/test/CodeGen/attr-weakref2.c
@@ -8,7 +8,7 @@
   return test1_g;
 }
 
-// CHECK: @test2_f = common global i32 0, align 4
+// CHECK: @test2_f = global i32 0, align 4
 int test2_f;
 static int test2_g __attribute__((weakref("test2_f")));
 int test2_h(void) {
@@ -25,7 +25,7 @@
   return test3_g;
 }
 
-// CHECK: @test4_f = common global i32 0, align 4
+// CHECK: @test4_f = global i32 0, align 4
 extern int test4_f;
 static int test4_g __attribute__((weakref("test4_f")));
 int test4_h(void) {
Index: clang/test/CodeGen/attributes.c
===================================================================
--- clang/test/CodeGen/attributes.c
+++ clang/test/CodeGen/attributes.c
@@ -20,7 +20,7 @@
 // CHECK: @t16 = extern_weak global i32
 extern int t16 __attribute__((weak_import));
 
-// CHECK: @t6 = common protected global i32 0
+// CHECK: @t6 = protected global i32 0
 int t6 __attribute__((visibility("protected")));
 
 // CHECK: @t12 = global i32 0, section "SECT"
Index: clang/test/CodeGen/blocks-windows.c
===================================================================
--- clang/test/CodeGen/blocks-windows.c
+++ clang/test/CodeGen/blocks-windows.c
@@ -68,7 +68,7 @@
 }
 
 // CHECK-BLOCKS-IN-BLOCKS-DECL: @_NSConcreteStackBlock = external dso_local dllexport global i8*
-// CHECK-BLOCKS-IN-BLOCKS-DEFN: @_NSConcreteStackBlock = common dso_local dllexport global [5 x i32]
+// CHECK-BLOCKS-IN-BLOCKS-DEFN: @_NSConcreteStackBlock = dso_local dllexport global [5 x i32]
 // CHECK-BLOCKS-NOT-IN-BLOCKS: @_NSConcreteStackBlock = external dllimport global i8*
 // CHECK-BLOCKS-NOT-IN-BLOCKS-EXTERN: @_NSConcreteStackBlock = external dllimport global i8*
 // CHECK-BLOCKS-NOT-IN-BLOCKS-EXTERN-DLLIMPORT: @_NSConcreteStackBlock = external dllimport global i8*
Index: clang/test/CodeGen/bool-convert.c
===================================================================
--- clang/test/CodeGen/bool-convert.c
+++ clang/test/CodeGen/bool-convert.c
@@ -2,16 +2,16 @@
 // All of these should uses the memory representation of _Bool
 
 // CHECK-LABEL: %struct.teststruct1 = type { i8, i8 }
-// CHECK-LABEL: @test1 = common global %struct.teststruct1
+// CHECK-LABEL: @test1 = global %struct.teststruct1
 struct teststruct1 {_Bool a, b;} test1;
 
-// CHECK-LABEL: @test2 = common global i8* null
+// CHECK-LABEL: @test2 = global i8* null
 _Bool* test2;
 
-// CHECK-LABEL: @test3 = common global [10 x i8]
+// CHECK-LABEL: @test3 = global [10 x i8]
 _Bool test3[10];
 
-// CHECK-LABEL: @test4 = common global [0 x i8]* null
+// CHECK-LABEL: @test4 = global [0 x i8]* null
 _Bool (*test4)[];
 
 // CHECK-LABEL: define void @f(i32 %x)
Index: clang/test/CodeGen/c11atomics.c
===================================================================
--- clang/test/CodeGen/c11atomics.c
+++ clang/test/CodeGen/c11atomics.c
@@ -25,7 +25,7 @@
 // CHECK-DAG: %struct.elem = type { %struct.ptr }
 
 struct ptr object;
-// CHECK-DAG: @object = common global %struct.ptr zeroinitializer
+// CHECK-DAG: @object = global %struct.ptr zeroinitializer
 
 // CHECK-DAG: @testStructGlobal = global {{.*}} { i16 1, i16 2, i16 3, i16 4 }
 // CHECK-DAG: @testPromotedStructGlobal = global {{.*}} { %{{.*}} { i16 1, i16 2, i16 3 }, [2 x i8] zeroinitializer }
Index: clang/test/CodeGen/cfstring-elf-cfbuild-x86_64.c
===================================================================
--- clang/test/CodeGen/cfstring-elf-cfbuild-x86_64.c
+++ clang/test/CodeGen/cfstring-elf-cfbuild-x86_64.c
@@ -30,7 +30,7 @@
 
 
 // CHECK-CF-IN-CF-DECL: @__CFConstantStringClassReference = external global [0 x i32]
-// CHECK-CF-IN-CF-DEFN: @__CFConstantStringClassReference = common global [32 x i64] zeroinitializer, align 16
-// CHECK-CF: @__CFConstantStringClassReference = common global [1 x i64] zeroinitializer, align 8
+// CHECK-CF-IN-CF-DEFN: @__CFConstantStringClassReference = global [32 x i64] zeroinitializer, align 16
+// CHECK-CF: @__CFConstantStringClassReference = global [1 x i64] zeroinitializer, align 8
 // CHECK-CF-EXTERN: @__CFConstantStringClassReference = external global [0 x i32]
 // CHECK-CF-EXTERN: @.str = private unnamed_addr constant [7 x i8] c"string\00", section ".rodata", align 1
Index: clang/test/CodeGen/cfstring-windows.c
===================================================================
--- clang/test/CodeGen/cfstring-windows.c
+++ clang/test/CodeGen/cfstring-windows.c
@@ -32,7 +32,7 @@
 const CFStringRef string = (CFStringRef)__builtin___CFStringMakeConstantString("string");
 
 // CHECK-CF-IN-CF-DECL: @__CFConstantStringClassReference = external dso_local dllexport global [0 x i32]
-// CHECK-CF-IN-CF-DEFN: @__CFConstantStringClassReference = common dso_local dllexport global [32 x i32]
+// CHECK-CF-IN-CF-DEFN: @__CFConstantStringClassReference = dso_local dllexport global [32 x i32]
 // CHECK-CF: @__CFConstantStringClassReference = external dllimport global [0 x i32]
 // CHECK-CF-EXTERN: @__CFConstantStringClassReference = external dllimport global [0 x i32]
 // CHECK-CF-EXTERN-DLLIMPORT: @__CFConstantStringClassReference = external dllimport global [0 x i32]
Index: clang/test/CodeGen/default-address-space.c
===================================================================
--- clang/test/CodeGen/default-address-space.c
+++ clang/test/CodeGen/default-address-space.c
@@ -1,13 +1,13 @@
 // RUN: %clang_cc1 -triple amdgcn---amdgiz -emit-llvm < %s | FileCheck -check-prefixes=CHECK,COM %s
 
-// CHECK-DAG: @foo = common addrspace(1) global i32 0
+// CHECK-DAG: @foo = addrspace(1) global i32 0
 int foo;
 
-// CHECK-DAG: @ban = common addrspace(1) global [10 x i32] zeroinitializer
+// CHECK-DAG: @ban = addrspace(1) global [10 x i32] zeroinitializer
 int ban[10];
 
-// CHECK-DAG: @A = common addrspace(1) global i32* null
-// CHECK-DAG: @B = common addrspace(1) global i32* null
+// CHECK-DAG: @A = addrspace(1) global i32* null
+// CHECK-DAG: @B = addrspace(1) global i32* null
 int *A;
 int *B;
 
Index: clang/test/CodeGen/dllexport-1.c
===================================================================
--- clang/test/CodeGen/dllexport-1.c
+++ clang/test/CodeGen/dllexport-1.c
@@ -9,8 +9,8 @@
 // CHECK-MSVC: @z = dso_local constant i32 4, align 4
 // CHECK-LNX: @z = constant i32 4, align 4
 
-// CHECK-MSVC: @y = common dso_local dllexport global i32 0, align 4
-// CHECK-LNX: @y = common global i32 0, align 4
+// CHECK-MSVC: @y = dso_local dllexport constant i32 0, align 4
+// CHECK-LNX: @y = constant i32 0, align 4
 
 __declspec(dllexport) int const x = 3;
 __declspec(dllexport) const int y;
Index: clang/test/CodeGen/dllexport.c
===================================================================
--- clang/test/CodeGen/dllexport.c
+++ clang/test/CodeGen/dllexport.c
@@ -14,7 +14,7 @@
 __declspec(dllexport) extern int ExternGlobalDecl;
 
 // dllexport implies a definition.
-// CHECK-DAG: @GlobalDef = common dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @GlobalDef = dso_local dllexport global i32 0, align 4
 __declspec(dllexport) int GlobalDef;
 
 // Export definition.
@@ -27,11 +27,11 @@
 int GlobalDeclInit = 1;
 
 // Redeclarations
-// CHECK-DAG: @GlobalRedecl1 = common dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @GlobalRedecl1 = dso_local dllexport global i32 0, align 4
 __declspec(dllexport) extern int GlobalRedecl1;
 __declspec(dllexport)        int GlobalRedecl1;
 
-// CHECK-DAG: @GlobalRedecl2 = common dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @GlobalRedecl2 = dso_local dllexport global i32 0, align 4
 __declspec(dllexport) extern int GlobalRedecl2;
                              int GlobalRedecl2;
 
@@ -70,13 +70,13 @@
 //===----------------------------------------------------------------------===//
 
 // dllexport takes precedence over the dllimport if both are specified.
-// CHECK-DAG: @PrecedenceGlobal1A = common dso_local dllexport global i32 0, align 4
-// CHECK-DAG: @PrecedenceGlobal1B = common dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @PrecedenceGlobal1A = dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @PrecedenceGlobal1B = dso_local dllexport global i32 0, align 4
 __attribute__((dllimport, dllexport))       int PrecedenceGlobal1A;
 __declspec(dllimport) __declspec(dllexport) int PrecedenceGlobal1B;
 
-// CHECK-DAG: @PrecedenceGlobal2A = common dso_local dllexport global i32 0, align 4
-// CHECK-DAG: @PrecedenceGlobal2B = common dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @PrecedenceGlobal2A = dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @PrecedenceGlobal2B = dso_local dllexport global i32 0, align 4
 __attribute__((dllexport, dllimport))       int PrecedenceGlobal2A;
 __declspec(dllexport) __declspec(dllimport) int PrecedenceGlobal2B;
 
@@ -84,7 +84,7 @@
 __declspec(dllexport) extern int PrecedenceGlobalRedecl1;
 __declspec(dllimport)        int PrecedenceGlobalRedecl1 = 0;
 
-// CHECK-DAG: @PrecedenceGlobalRedecl2 = common dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @PrecedenceGlobalRedecl2 = dso_local dllexport global i32 0, align 4
 __declspec(dllimport) extern int PrecedenceGlobalRedecl2;
 __declspec(dllexport)        int PrecedenceGlobalRedecl2;
 
@@ -92,7 +92,7 @@
 __attribute__((dllexport)) extern int PrecedenceGlobalMixed1;
 __declspec(dllimport)             int PrecedenceGlobalMixed1 = 1;
 
-// CHECK-DAG: @PrecedenceGlobalMixed2 = common dso_local dllexport global i32 0, align 4
+// CHECK-DAG: @PrecedenceGlobalMixed2 = dso_local dllexport global i32 0, align 4
 __attribute__((dllimport)) extern int PrecedenceGlobalMixed2;
 __declspec(dllexport)             int PrecedenceGlobalMixed2;
 
Index: clang/test/CodeGen/dllimport.c
===================================================================
--- clang/test/CodeGen/dllimport.c
+++ clang/test/CodeGen/dllimport.c
@@ -46,8 +46,8 @@
 USEVAR(GlobalRedecl3)
 
 // Make sure this works even if the decl has been used before it's defined (PR20792).
-// MS: @GlobalRedecl4 = common dso_local dllexport global i32
-// GNU: @GlobalRedecl4 = common dso_local global i32
+// MS: @GlobalRedecl4 = dso_local dllexport global i32
+// GNU: @GlobalRedecl4 = dso_local global i32
 __declspec(dllimport) extern int GlobalRedecl4;
 USEVAR(GlobalRedecl4)
                       int GlobalRedecl4; // dllimport ignored
Index: clang/test/CodeGen/microsoft-no-common-align.c
===================================================================
--- clang/test/CodeGen/microsoft-no-common-align.c
+++ clang/test/CodeGen/microsoft-no-common-align.c
@@ -5,7 +5,7 @@
 TooLargeAlignment TooBig;
 // CHECK: @TooBig = dso_local global <16 x float>  zeroinitializer, align 64
 NormalAlignment JustRight;
-// CHECK: @JustRight = common dso_local global <1 x float>  zeroinitializer, align 4
+// CHECK: @JustRight = dso_local global <1 x float>  zeroinitializer, align 4
 
 TooLargeAlignment *IsAPointer;
-// CHECK: @IsAPointer = common dso_local global <16 x float>* null, align 8
+// CHECK: @IsAPointer = dso_local global <16 x float>* null, align 8
Index: clang/test/CodeGen/no-common.c
===================================================================
--- clang/test/CodeGen/no-common.c
+++ clang/test/CodeGen/no-common.c
@@ -1,15 +1,16 @@
 // RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s -check-prefix=CHECK-DEFAULT
-// RUN: %clang_cc1 %s -fno-common -emit-llvm -o - | FileCheck %s -check-prefix=CHECK-NOCOMMON
+// RUN: %clang_cc1 %s -fno-common -emit-llvm -o - | FileCheck %s -check-prefix=CHECK-DEFAULT
+// RUN: %clang_cc1 %s -fcommon -emit-llvm -o - | FileCheck %s -check-prefix=CHECK-COMMON
 
-// CHECK-DEFAULT: @x = common {{(dso_local )?}}global
-// CHECK-NOCOMMON: @x = {{(dso_local )?}}global
+// CHECK-COMMON: @x = common {{(dso_local )?}}global
+// CHECK-DEFAULT: @x = {{(dso_local )?}}global
 int x;
 
+// CHECK-COMMON: @ABC = {{(dso_local )?}}global
 // CHECK-DEFAULT: @ABC = {{(dso_local )?}}global
-// CHECK-NOCOMMON: @ABC = {{(dso_local )?}}global
 typedef void* (*fn_t)(long a, long b, char *f, int c);
 fn_t ABC __attribute__ ((nocommon));
 
+// CHECK-COMMON: @y = common {{(dso_local )?}}global
 // CHECK-DEFAULT: @y = common {{(dso_local )?}}global
-// CHECK-NOCOMMON: @y = common {{(dso_local )?}}global
 int y __attribute__((common));
Index: clang/test/CodeGen/pr25786.c
===================================================================
--- clang/test/CodeGen/pr25786.c
+++ clang/test/CodeGen/pr25786.c
@@ -4,8 +4,8 @@
 void (__attribute__((regparm(3), stdcall)) *pf) ();
 void (__attribute__((regparm(2), stdcall)) foo)(int a) {
 }
-// CHECK: @pf = common global void (...)* null
+// CHECK: @pf = global void (...)* null
 // CHECK: define void @foo(i32 %a)
 
-// CHECK-OK: @pf = common global void (...)* null
+// CHECK-OK: @pf = global void (...)* null
 // CHECK-OK: define x86_stdcallcc void @foo(i32 inreg %a)
Index: clang/test/CodeGen/pragma-pack-1.c
===================================================================
--- clang/test/CodeGen/pragma-pack-1.c
+++ clang/test/CodeGen/pragma-pack-1.c
@@ -64,5 +64,5 @@
 // CHECK: %struct.S4 = type { [3 x i8], %struct.T4, i32 }
 // CHECK: %struct.T4 = type <{ i8, i32 }>
 
-// CHECK: @refs = common global [[struct_ref]]
-// CHECK: @ss = common global [[struct_S]]
+// CHECK: @refs = global [[struct_ref]]
+// CHECK: @ss = global [[struct_S]]
Index: clang/test/CodeGen/pragma-weak.c
===================================================================
--- clang/test/CodeGen/pragma-weak.c
+++ clang/test/CodeGen/pragma-weak.c
@@ -1,7 +1,7 @@
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm %s -o - -verify | FileCheck %s
 
 // CHECK: @weakvar = weak global
-// CHECK: @__weakvar_alias = common global
+// CHECK: @__weakvar_alias = global
 // CHECK: @correct_linkage = weak global
 
 
Index: clang/test/CodeGen/private-extern-redef.c
===================================================================
--- clang/test/CodeGen/private-extern-redef.c
+++ clang/test/CodeGen/private-extern-redef.c
@@ -34,6 +34,6 @@
 // CHECK: @M = hidden global
 // CHECK: @O = hidden global
 // CHECK: @I = external hidden
-// CHECK: @N = common hidden global
+// CHECK: @N = hidden global
 // CHECK-NOT: @P
 
Index: clang/test/CodeGen/tentative-decls.c
===================================================================
--- clang/test/CodeGen/tentative-decls.c
+++ clang/test/CodeGen/tentative-decls.c
@@ -1,16 +1,16 @@
 // RUN: %clang_cc1 -emit-llvm -w -o - %s | FileCheck %s
 
-// CHECK-DAG: @r = common {{(dso_local )?}}global [1 x {{.*}}] zeroinitializer
+// CHECK-DAG: @r = {{(dso_local )?}}global [1 x {{.*}}] zeroinitializer
 
 int r[];
 int (*a)[] = &r;
 
 struct s0;
 struct s0 x;
-// CHECK-DAG: @x = common {{(dso_local )?}}global %struct.s0 zeroinitializer
+// CHECK-DAG: @x = {{(dso_local )?}}global %struct.s0 zeroinitializer
 
 struct s0 y;
-// CHECK-DAG: @y = common {{(dso_local )?}}global %struct.s0 zeroinitializer
+// CHECK-DAG: @y = {{(dso_local )?}}global %struct.s0 zeroinitializer
 struct s0 *f0() {
   return &y;
 }
@@ -19,14 +19,14 @@
   int x;
 };
 
-// CHECK-DAG: @b = common {{(dso_local )?}}global [1 x {{.*}}] zeroinitializer
+// CHECK-DAG: @b = {{(dso_local )?}}global [1 x {{.*}}] zeroinitializer
 int b[];
 int *f1() {
   return b;
 }
 
 // Check that the most recent tentative definition wins.
-// CHECK-DAG: @c = common {{(dso_local )?}}global [4 x {{.*}}] zeroinitializer
+// CHECK-DAG: @c = {{(dso_local )?}}global [4 x {{.*}}] zeroinitializer
 int c[];
 int c[4];
 
Index: clang/test/CodeGen/tls-model.c
===================================================================
--- clang/test/CodeGen/tls-model.c
+++ clang/test/CodeGen/tls-model.c
@@ -21,24 +21,24 @@
 
 // CHECK-GD: @z1 = global i32 0
 // CHECK-GD: @f.y = internal thread_local global i32 0
-// CHECK-GD: @z2 = common global i32 0
+// CHECK-GD: @z2 = global i32 0
 // CHECK-GD: @x = thread_local global i32 0
 // CHECK-GD: @z = thread_local(initialexec) global i32 0
 
 // CHECK-LD: @z1 = global i32 0
 // CHECK-LD: @f.y = internal thread_local(localdynamic) global i32 0
-// CHECK-LD: @z2 = common global i32 0
+// CHECK-LD: @z2 = global i32 0
 // CHECK-LD: @x = thread_local(localdynamic) global i32 0
 // CHECK-LD: @z = thread_local(initialexec) global i32 0
 
 // CHECK-IE: @z1 = global i32 0
 // CHECK-IE: @f.y = internal thread_local(initialexec) global i32 0
-// CHECK-IE: @z2 = common global i32 0
+// CHECK-IE: @z2 = global i32 0
 // CHECK-IE: @x = thread_local(initialexec) global i32 0
 // CHECK-IE: @z = thread_local(initialexec) global i32 0
 
 // CHECK-LE: @z1 = global i32 0
 // CHECK-LE: @f.y = internal thread_local(localexec) global i32 0
-// CHECK-LE: @z2 = common global i32 0
+// CHECK-LE: @z2 = global i32 0
 // CHECK-LE: @x = thread_local(localexec) global i32 0
 // CHECK-LE: @z = thread_local(initialexec) global i32 0
Index: clang/test/CodeGen/visibility.c
===================================================================
--- clang/test/CodeGen/visibility.c
+++ clang/test/CodeGen/visibility.c
@@ -3,15 +3,15 @@
 // RUN: %clang_cc1 %s -triple i386-unknown-unknown -fvisibility hidden -emit-llvm -o - | FileCheck %s -check-prefix=CHECK-HIDDEN
 
 // CHECK-DEFAULT: @g_def = global i32 0
-// CHECK-DEFAULT: @g_com = common global i32 0
+// CHECK-DEFAULT: @g_com = global i32 0
 // CHECK-DEFAULT: @g_ext = external global i32
 // CHECK-DEFAULT: @g_deferred = internal global
 // CHECK-PROTECTED: @g_def = protected global i32 0
-// CHECK-PROTECTED: @g_com = common protected global i32 0
+// CHECK-PROTECTED: @g_com = protected global i32 0
 // CHECK-PROTECTED: @g_ext = external global i32
 // CHECK-PROTECTED: @g_deferred = internal global
 // CHECK-HIDDEN: @g_def = hidden global i32 0
-// CHECK-HIDDEN: @g_com = common hidden global i32 0
+// CHECK-HIDDEN: @g_com = hidden global i32 0
 // CHECK-HIDDEN: @g_ext = external global i32
 // CHECK-HIDDEN: @g_deferred = internal global
 int g_com;
Index: clang/test/CodeGen/vlt_to_pointer.c
===================================================================
--- clang/test/CodeGen/vlt_to_pointer.c
+++ clang/test/CodeGen/vlt_to_pointer.c
@@ -1,7 +1,7 @@
 // RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s
 
 int c[1][3*2];
-// CHECK: @{{.+}} = {{.*}} global [1 x [6 x {{i[0-9]+}}]] zeroinitializer
+// CHECK: @{{.+}} = global [1 x [6 x {{i[0-9]+}}]] zeroinitializer
 
 // CHECK-LABEL: @f
 int f(int * const m, int (**v)[*m * 2])
Index: clang/test/CodeGen/volatile-1.c
===================================================================
--- clang/test/CodeGen/volatile-1.c
+++ clang/test/CodeGen/volatile-1.c
@@ -1,10 +1,10 @@
 // RUN: %clang_cc1 -Wno-return-type -Wno-unused-value -emit-llvm %s -w -o - | FileCheck %s
 
-// CHECK: @i = common {{(dso_local )?}}global [[INT:i[0-9]+]] 0
+// CHECK: @i = {{(dso_local )?}}global [[INT:i[0-9]+]] 0
 volatile int i, j, k;
 volatile int ar[5];
 volatile char c;
-// CHECK: @ci = common {{(dso_local )?}}global [[CINT:.*]] zeroinitializer
+// CHECK: @ci = {{(dso_local )?}}global [[CINT:.*]] zeroinitializer
 volatile _Complex int ci;
 volatile struct S {
 #ifdef __cplusplus
Index: clang/test/CodeGen/weak-global.c
===================================================================
--- clang/test/CodeGen/weak-global.c
+++ /dev/null
@@ -1,3 +0,0 @@
-// RUN: %clang_cc1 -emit-llvm < %s | grep common
-
-int i;
Index: clang/test/CodeGen/windows-on-arm-dllimport-dllexport.c
===================================================================
--- clang/test/CodeGen/windows-on-arm-dllimport-dllexport.c
+++ clang/test/CodeGen/windows-on-arm-dllimport-dllexport.c
@@ -17,7 +17,7 @@
 }
 
 // CHECK: @import_int = external dllimport global i32
-// CHECK: @export_int = common dso_local dllexport global i32 0, align 4
+// CHECK: @export_int = dso_local dllexport global i32 0, align 4
 
 // CHECK: define dso_local dllexport arm_aapcs_vfpcc void @export_implemented_function()
 
Index: clang/test/CodeGenCXX/clang-sections-tentative.c
===================================================================
--- clang/test/CodeGenCXX/clang-sections-tentative.c
+++ clang/test/CodeGenCXX/clang-sections-tentative.c
@@ -30,7 +30,7 @@
 
 // CHECK: @x = global i32 0, align 4 #0
 // CHECK: @y = global i32 0, align 4 #1
-// CHECK: @z = common global i32 0, align 4
+// CHECK: @z = global i32 0, align 4
 // CHECK: @cx = constant i32 0, align 4 #2
 // CHECK: @cy = constant i32 0, align 4 #3
 // CHECK: @cz = constant i32 0, align 4 #1
Index: clang/test/CodeGenObjC/constant-string-class.m
===================================================================
--- clang/test/CodeGenObjC/constant-string-class.m
+++ clang/test/CodeGenObjC/constant-string-class.m
@@ -30,6 +30,6 @@
   return 0;
 }
 
-// CHECK-FRAGILE: @_FooClassReference = common global
+// CHECK-FRAGILE: @_FooClassReference = global
 // CHECK-NONFRAGILE: @"OBJC_CLASS_$_Object" = external global
 // CHECK-NONFRAGILE: "OBJC_CLASS_$_Foo" = global
Index: clang/test/CodeGenObjC/tentative-cfconstantstring.m
===================================================================
--- clang/test/CodeGenObjC/tentative-cfconstantstring.m
+++ clang/test/CodeGenObjC/tentative-cfconstantstring.m
@@ -31,7 +31,7 @@
 }
 @end
 
-// CHECK: @__CFConstantStringClassReference = common global [24 x i32] zeroinitializer, align 16
+// CHECK: @__CFConstantStringClassReference = global [24 x i32] zeroinitializer, align 16
 // CHECK: @_unnamed_cfstring_{{.*}} = private global %struct.__NSConstantString_tag { i32* getelementptr inbounds ([24 x i32], [24 x i32]* @__CFConstantStringClassReference, i32 0, i32 0)
 
 // CHECK-LABEL: define internal void @_inlineFunction()
Index: clang/test/CodeGenOpenCL/address-spaces.cl
===================================================================
--- clang/test/CodeGenOpenCL/address-spaces.cl
+++ clang/test/CodeGenOpenCL/address-spaces.cl
@@ -53,10 +53,10 @@
 
 #ifdef CL20
 int i;
-// CL20-DAG: @i = common {{(dso_local )?}}addrspace(1) global i32 0
+// CL20-DAG: @i = {{(dso_local )?}}addrspace(1) global i32 0
 int *ptr;
 // CL20SPIR-DAG: @ptr = {{(common )?}}{{(dso_local )?}}addrspace(1) global i32 addrspace(4)* null
-// CL20AMDGCN-DAG: @ptr = common {{(dso_local )?}}addrspace(1) global i32* null
+// CL20AMDGCN-DAG: @ptr = {{(dso_local )?}}addrspace(1) global i32* null
 #endif
 
 // SPIR: i32* %arg
Index: clang/test/CodeGenOpenCL/amdgpu-nullptr.cl
===================================================================
--- clang/test/CodeGenOpenCL/amdgpu-nullptr.cl
+++ clang/test/CodeGenOpenCL/amdgpu-nullptr.cl
@@ -16,9 +16,6 @@
   generic char *p5;
 } StructTy2;
 
-// LLVM requests global variable with common linkage to be initialized with zeroinitializer, therefore use -fno-common
-// to suppress common linkage for tentative definition.
-
 // Test 0 as initializer.
 
 // CHECK: @private_p = local_unnamed_addr addrspace(1) global i8 addrspace(5)* null, align 4
@@ -183,34 +180,34 @@
 // cannot have common linkage since common linkage requires zero initialization
 // and does not have explicit section.
 
-// CHECK: @p1 = common local_unnamed_addr addrspace(1) global i8 addrspace(5)* null, align 4
+// CHECK: @p1 = local_unnamed_addr addrspace(1) global i8 addrspace(5)* null, align 4
 private char *p1;
 
-// CHECK: @p2 = weak local_unnamed_addr addrspace(1) global i8 addrspace(3)* addrspacecast (i8* null to i8 addrspace(3)*), align 4
+// CHECK: @p2 = local_unnamed_addr addrspace(1) global i8 addrspace(3)* addrspacecast (i8* null to i8 addrspace(3)*), align 4
 local char *p2;
 
-// CHECK: @p3 = common local_unnamed_addr addrspace(1) global i8 addrspace(4)* null, align 8
+// CHECK: @p3 = local_unnamed_addr addrspace(1) global i8 addrspace(4)* null, align 8
 constant char *p3;
 
-// CHECK: @p4 = common local_unnamed_addr addrspace(1) global i8 addrspace(1)* null, align 8
+// CHECK: @p4 = local_unnamed_addr addrspace(1) global i8 addrspace(1)* null, align 8
 global char *p4;
 
-// CHECK: @p5 = common local_unnamed_addr addrspace(1) global i8* null, align 8
+// CHECK: @p5 = local_unnamed_addr addrspace(1) global i8* null, align 8
 generic char *p5;
 
 // Test default initialization of structure.
 
-// CHECK: @S1 = weak local_unnamed_addr addrspace(1) global %struct.StructTy1 { i8 addrspace(5)* null, i8 addrspace(3)* addrspacecast (i8* null to i8 addrspace(3)*), i8 addrspace(4)* null, i8 addrspace(1)* null, i8* null }, align 8
+// CHECK: @S1 = local_unnamed_addr addrspace(1) global %struct.StructTy1 { i8 addrspace(5)* null, i8 addrspace(3)* addrspacecast (i8* null to i8 addrspace(3)*), i8 addrspace(4)* null, i8 addrspace(1)* null, i8* null }, align 8
 StructTy1 S1;
 
-// CHECK: @S2 = common local_unnamed_addr addrspace(1) global %struct.StructTy2 zeroinitializer, align 8
+// CHECK: @S2 = local_unnamed_addr addrspace(1) global %struct.StructTy2 zeroinitializer, align 8
 StructTy2 S2;
 
 // Test default initialization of array.
-// CHECK: @A1 = weak local_unnamed_addr addrspace(1) global [2 x %struct.StructTy1] [%struct.StructTy1 { i8 addrspace(5)* null, i8 addrspace(3)* addrspacecast (i8* null to i8 addrspace(3)*), i8 addrspace(4)* null, i8 addrspace(1)* null, i8* null }, %struct.StructTy1 { i8 addrspace(5)* null, i8 addrspace(3)* addrspacecast (i8* null to i8 addrspace(3)*), i8 addrspace(4)* null, i8 addrspace(1)* null, i8* null }], align 8
+// CHECK: @A1 = local_unnamed_addr addrspace(1) global [2 x %struct.StructTy1] [%struct.StructTy1 { i8 addrspace(5)* null, i8 addrspace(3)* addrspacecast (i8* null to i8 addrspace(3)*), i8 addrspace(4)* null, i8 addrspace(1)* null, i8* null }, %struct.StructTy1 { i8 addrspace(5)* null, i8 addrspace(3)* addrspacecast (i8* null to i8 addrspace(3)*), i8 addrspace(4)* null, i8 addrspace(1)* null, i8* null }], align 8
 StructTy1 A1[2];
 
-// CHECK: @A2 = common local_unnamed_addr addrspace(1) global [2 x %struct.StructTy2] zeroinitializer, align 8
+// CHECK: @A2 = local_unnamed_addr addrspace(1) global [2 x %struct.StructTy2] zeroinitializer, align 8
 StructTy2 A2[2];
 
 // Test comparison with 0.
Index: clang/test/Driver/apple-kext-mkernel.c
===================================================================
--- clang/test/Driver/apple-kext-mkernel.c
+++ clang/test/Driver/apple-kext-mkernel.c
@@ -4,7 +4,7 @@
 // CHECK-X86: "-disable-red-zone"
 // CHECK-X86: "-fno-builtin"
 // CHECK-X86: "-fno-rtti"
-// CHECK-X86: "-fno-common"
+// CHECK-X86-NOT: "-fcommon"
 
 // RUN: %clang -target x86_64-apple-darwin10 -mkernel -### -fsyntax-only -fbuiltin -fcommon %s 2>&1 | FileCheck --check-prefix=CHECK-X86-2 %s
 
@@ -21,7 +21,7 @@
 // CHECK-ARM-NOT: "-target-feature" "+strict-align"
 // CHECK-ARM: "-fno-builtin"
 // CHECK-ARM: "-fno-rtti"
-// CHECK-ARM: "-fno-common"
+// CHECK-ARM-NOT: "-fcommon"
 
 // RUN: %clang -target x86_64-apple-darwin10 \
 // RUN:   -Werror -fno-builtin -fno-exceptions -fno-common -fno-rtti \
Index: clang/test/Driver/clang_f_opts.c
===================================================================
--- clang/test/Driver/clang_f_opts.c
+++ clang/test/Driver/clang_f_opts.c
@@ -12,7 +12,7 @@
 // CHECK-OPTIONS2: -fno-gnu-keywords
 // CHECK-OPTIONS2: -fno-builtin
 // CHECK-OPTIONS2: -fshort-enums
-// CHECK-OPTIONS2: -fno-common
+// CHECK-OPTIONS2-NOT: -fcommon
 // CHECK-OPTIONS2: -fno-show-source-location
 
 // RUN: %clang -### -S -Wwrite-strings %s 2>&1 | FileCheck -check-prefix=WRITE-STRINGS1 %s
Index: clang/test/Driver/fuchsia.c
===================================================================
--- clang/test/Driver/fuchsia.c
+++ clang/test/Driver/fuchsia.c
@@ -22,7 +22,7 @@
 // CHECK-AARCH64: "-fsanitize=shadow-call-stack"
 // CHECK-X86_64: "-fsanitize=safe-stack"
 // CHECK: "-stack-protector" "2"
-// CHECK: "-fno-common"
+// CHECK-NOT: "-fcommon"
 // CHECK: {{.*}}ld.lld{{.*}}" "-z" "now" "-z" "rodynamic" "-z" "separate-loadable-segments"
 // CHECK: "--sysroot=[[SYSROOT]]"
 // CHECK: "-pie"
Index: clang/test/Driver/no-common.c
===================================================================
--- /dev/null
+++ clang/test/Driver/no-common.c
@@ -0,0 +1,9 @@
+// RUN: %clang -target %itanium_abi_triple -### -c %s 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=DEFAULT
+// RUN: %clang -target %itanium_abi_triple -fno-common -### -c %s 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=DEFAULT
+// RUN: %clang -target %itanium_abi_triple -fno-common -fcommon -### -c %s 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=COMMON
+
+// DEFAULT-NOT: "-fcommon"
+// COMMON:      "-fcommon"
Index: clang/test/Driver/xcore-opts.c
===================================================================
--- clang/test/Driver/xcore-opts.c
+++ clang/test/Driver/xcore-opts.c
@@ -9,7 +9,7 @@
 // CHECK: "-fno-use-cxa-atexit"
 // CHECK-NOT: "-fcxx-exceptions"
 // CHECK-NOT: "-fexceptions"
-// CHECK: "-fno-common"
+// CHECK-NOT: "-fcommon"
 // CHECK: xcc" "-o"
 // CHECK-NOT: "-fexceptions"
 // CHECK: "-c" "-v" "-g" "-fverbose-asm" "A1Arg" "A2Arg"
@@ -21,7 +21,7 @@
 // CHECK-EXCEP: "-fno-use-cxa-atexit"
 // CHECK-EXCEP: "-fcxx-exceptions"
 // CHECK-EXCEP: "-fexceptions"
-// CHECK-EXCEP: "-fno-common"
+// CHECK-EXCEP-NOT: "-fcommon"
 // CHECK-EXCEP: xcc" "-o"
 // CHECK-EXCEP-NOT: "-fexceptions"
 // CHECK-EXCEP: xcc" "-o"
Index: clang/test/Frontend/ast-codegen.c
===================================================================
--- clang/test/Frontend/ast-codegen.c
+++ clang/test/Frontend/ast-codegen.c
@@ -5,7 +5,7 @@
 // CHECK: module asm "foo"
 __asm__("foo");
 
-// CHECK: @g0 = common dso_local global i32 0, align 4
+// CHECK: @g0 = dso_local global i32 0, align 4
 int g0;
 
 // CHECK: define dso_local i32 @f0()
Index: clang/test/Headers/xmmintrin.c
===================================================================
--- clang/test/Headers/xmmintrin.c
+++ clang/test/Headers/xmmintrin.c
@@ -7,7 +7,7 @@
 // REQUIRES: x86-registered-target
 #include <xmmintrin.h>
 
-// CHECK: @c = common global i8 0, align 16
+// CHECK: @c = global i8 0, align 16
 _MM_ALIGN16 char c;
 
 // Make sure the last step of _mm_cvtps_pi16 converts <4 x i32> to <4 x i16> by
Index: clang/test/PCH/chain-external-defs.c
===================================================================
--- clang/test/PCH/chain-external-defs.c
+++ clang/test/PCH/chain-external-defs.c
@@ -16,11 +16,11 @@
 
 // Z-NOT: @z
 
-// XA: @x = common global i32 0
-// XA-NOT: @x = common global i32 0
+// XA: @x = global i32 0
+// XA-NOT: @x = global i32 0
 
-// YA: @y = common global i32 0
-// YA-NOT: @y = common global i32 0
+// YA: @y = global i32 0
+// YA-NOT: @y = global i32 0
 
 // XB: @x2 = global i32 19
 // XB-NOT: @x2 = global i32 19
@@ -29,17 +29,17 @@
 // YB-NOT: @y2 = global i32 18
 int y2 = 18;
 
-// AA: @incomplete_array = common global [1 x i32]
-// AA-NOT: @incomplete_array = common global [1 x i32]
-// AB: @incomplete_array2 = common global [17 x i32]
-// AB-NOT: @incomplete_array2 = common global [17 x i32]
+// AA: @incomplete_array = global [1 x i32]
+// AA-NOT: @incomplete_array = global [1 x i32]
+// AB: @incomplete_array2 = global [17 x i32]
+// AB-NOT: @incomplete_array2 = global [17 x i32]
 int incomplete_array2[17];
-// AC: @incomplete_array3 = common global [1 x i32]
-// AC-NOT: @incomplete_array3 = common global [1 x i32]
+// AC: @incomplete_array3 = global [1 x i32]
+// AC-NOT: @incomplete_array3 = global [1 x i32]
 int incomplete_array3[];
 
-// S: @s = common global %struct.S
-// S-NOT: @s = common global %struct.S
+// S: @s = global %struct.S
+// S-NOT: @s = global %struct.S
 struct S {
   int x, y;
 };
Index: clang/test/PCH/external-defs.c
===================================================================
--- clang/test/PCH/external-defs.c
+++ clang/test/PCH/external-defs.c
@@ -3,16 +3,16 @@
 // RUN: %clang_cc1 -triple x86_64-apple-darwin9 -emit-pch -o %t.pch %S/external-defs.h
 // RUN: %clang_cc1 -triple x86_64-apple-darwin9 -include-pch %t.pch -emit-llvm -o %t %s
 
-// RUN: grep "@x = common global i32 0" %t | count 1
+// RUN: grep "@x = global i32 0" %t | count 1
 // RUN: not grep "@z" %t
 
 // RUN: grep "@x2 = global i32 19" %t | count 1
 int x2 = 19;
 
-// RUN: grep "@incomplete_array = common global .*1 x i32" %t | count 1
-// RUN: grep "@incomplete_array2 = common global .*17 x i32" %t | count 1
+// RUN: grep "@incomplete_array = global .*1 x i32" %t | count 1
+// RUN: grep "@incomplete_array2 = global .*17 x i32" %t | count 1
 int incomplete_array2[17];
-// RUN: grep "@incomplete_array3 = common global .*1 x i32" %t | count 1
+// RUN: grep "@incomplete_array3 = global .*1 x i32" %t | count 1
 int incomplete_array3[];
 
 struct S {
Index: clang/test/PCH/tentative-defs.c
===================================================================
--- clang/test/PCH/tentative-defs.c
+++ clang/test/PCH/tentative-defs.c
@@ -1,6 +1,6 @@
 // Test with pch.
-// RUN: %clang_cc1 -triple x86_64-apple-darwin9 -emit-pch -o %t.pch %S/tentative-defs.h
-// RUN: %clang_cc1 -triple x86_64-apple-darwin9 -include-pch %t.pch -verify -emit-llvm -o %t %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin9 -fcommon -emit-pch -o %t.pch %S/tentative-defs.h
+// RUN: %clang_cc1 -triple x86_64-apple-darwin9 -fcommon -include-pch %t.pch -verify -emit-llvm -o %t %s
 // REQUIRES: x86-registered-target
 
 // RUN: grep "@variable = common global i32 0" %t | count 1
Index: clang/test/Parser/pragma-visibility2.c
===================================================================
--- clang/test/Parser/pragma-visibility2.c
+++ clang/test/Parser/pragma-visibility2.c
@@ -6,14 +6,14 @@
 #pragma GCC visibility push(hidden)
 
 int v1;
-// CHECK: @v1 = common hidden global i32 0, align 4
+// CHECK: @v1 = hidden global i32 0, align 4
 
 #pragma GCC visibility pop
 
 int v2;
-// CHECK: @v2 = common global i32 0, align 4
+// CHECK: @v2 = global i32 0, align 4
 
 _Pragma("GCC visibility push(hidden)");
 
 int v3;
-// CHECK: @v3 = common hidden global i32 0, align 4
+// CHECK: @v3 = hidden global i32 0, align 4