diff --git a/clang-tools-extra/test/pp-trace/pp-trace-pragma-general.cpp b/clang-tools-extra/test/pp-trace/pp-trace-pragma-general.cpp
index f01ebd1ec67d7..b16ec56e321bd 100644
--- a/clang-tools-extra/test/pp-trace/pp-trace-pragma-general.cpp
+++ b/clang-tools-extra/test/pp-trace/pp-trace-pragma-general.cpp
@@ -21,6 +21,12 @@ void foo() {
 
 // CHECK: ---
 // CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
 // CHECK-NEXT:   Loc: "{{.*}}{{[/\\]}}pp-trace-pragma-general.cpp:3:1"
 // CHECK-NEXT:   Introducer: PIK_HashPragma
 // CHECK-NEXT: - Callback: PragmaDiagnosticPush
diff --git a/clang-tools-extra/test/pp-trace/pp-trace-pragma-ms.cpp b/clang-tools-extra/test/pp-trace/pp-trace-pragma-ms.cpp
index 932b0eb93c90e..f5bf9ac2b955d 100644
--- a/clang-tools-extra/test/pp-trace/pp-trace-pragma-ms.cpp
+++ b/clang-tools-extra/test/pp-trace/pp-trace-pragma-ms.cpp
@@ -18,6 +18,12 @@
 
 // CHECK: ---
 // CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
 // CHECK-NEXT:   Loc: "{{.*}}{{[/\\]}}pp-trace-pragma-ms.cpp:3:1"
 // CHECK-NEXT:   Introducer: PIK_HashPragma
 // CHECK-NEXT: - Callback: PragmaComment
@@ -67,7 +73,7 @@
 // CHECK-NEXT:   Introducer: PIK_HashPragma
 // CHECK-NEXT: - Callback: PragmaMessage
 // CHECK-NEXT:   Loc: "{{.*}}{{[/\\]}}pp-trace-pragma-ms.cpp:13:9"
-// CHECK-NEXT:   Namespace: 
+// CHECK-NEXT:   Namespace:
 // CHECK-NEXT:   Kind: PMK_Message
 // CHECK-NEXT:   Str: message argument
 // CHECK-NEXT: - Callback: PragmaDirective
diff --git a/clang-tools-extra/test/pp-trace/pp-trace-pragma-opencl.cpp b/clang-tools-extra/test/pp-trace/pp-trace-pragma-opencl.cpp
index 31f61027994f7..ed33d37eb3d59 100644
--- a/clang-tools-extra/test/pp-trace/pp-trace-pragma-opencl.cpp
+++ b/clang-tools-extra/test/pp-trace/pp-trace-pragma-opencl.cpp
@@ -6,6 +6,12 @@
 
 // CHECK: ---
 // CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
 // CHECK-NEXT:   Loc: "{{.*}}{{[/\\]}}pp-trace-pragma-opencl.cpp:3:1"
 // CHECK-NEXT:   Introducer: PIK_HashPragma
 // CHECK-NEXT: - Callback: PragmaOpenCLExtension
diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst
index 3bead159c8f94..ba3c0e4d23293 100644
--- a/clang/docs/LanguageExtensions.rst
+++ b/clang/docs/LanguageExtensions.rst
@@ -5571,3 +5571,25 @@ but the expression has no runtime effects.
 Type- and value-dependent expressions are not supported yet.
 
 This facility is designed to aid with testing name lookup machinery.
+
+Predefined Macros
+=================
+
+`__GCC_DESTRUCTIVE_SIZE` and `__GCC_CONSTRUCTIVE_SIZE`
+------------------------------------------------------
+Specify the mimum offset between two objects to avoid false sharing and the
+maximum size of contiguous memory to promote true sharing, respectively. These
+macros are predefined in all C and C++ language modes, but can be redefined on
+the command line with ``-D`` to specify different values as needed or can be
+undefined on the command line with ``-U`` to disable support for the feature.
+
+**Note: the values the macros expand to are not guaranteed to be stable. They
+are are affected by architectures and CPU tuning flags, can change between
+releases of Clang and will not match the values defined by other compilers such
+as GCC.**
+
+Compiling different TUs depending on these flags (including use of
+``std::hardware_constructive_interference`` or
+``std::hardware_destructive_interference``)  with different compilers, macro
+definitions, or architecture flags will lead to ODR violations and should be
+avoided.
\ No newline at end of file
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index aea8fda35bb29..337649371b6ea 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -89,6 +89,18 @@ sections with improvements to Clang's support for those languages.
 C++ Language Changes
 --------------------
 
+C++17 Feature Support
+^^^^^^^^^^^^^^^^^^^^^
+- Clang now exposes ``__GCC_DESTRUCTIVE_SIZE`` and ``__GCC_CONSTRUCTIVE_SIZE``
+  predefined macros to support standard library implementations of
+  ``std::hardware_destructive_interference_size`` and
+  ``std::hardware_constructive_interference_size``, respectively. These macros
+  are predefined in all C and C++ language modes. The values the macros
+  expand to are not stable between releases of Clang and do not need to match
+  the values produced by GCC, so these macros should not be used from header
+  files because they may not be stable across multiple TUs (the values may vary
+  based on compiler version as well as CPU tuning). #GH60174
+
 C++20 Feature Support
 ^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index e1ef7454f0166..3ced2e7397a75 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -40,6 +40,7 @@
 #include <cassert>
 #include <optional>
 #include <string>
+#include <utility>
 #include <vector>
 
 namespace llvm {
@@ -1792,6 +1793,15 @@ class TargetInfo : public TransferrableTargetInfo,
   /// Whether to support HIP image/texture API's.
   virtual bool hasHIPImageSupport() const { return true; }
 
+  /// The first value in the pair is the minimum offset between two objects to
+  /// avoid false sharing (destructive interference). The second value in the
+  /// pair is maximum size of contiguous memory to promote true sharing
+  /// (constructive interference). Neither of these values are considered part
+  /// of the ABI and can be changed by targets at any time.
+  virtual std::pair<unsigned, unsigned> hardwareInterferenceSizes() const {
+    return std::make_pair(64, 64);
+  }
+
 protected:
   /// Copy type and layout related info.
   void copyAuxTarget(const TargetInfo *Aux);
diff --git a/clang/lib/Basic/Targets/ARM.h b/clang/lib/Basic/Targets/ARM.h
index e69adbe754739..df9855a52e61c 100644
--- a/clang/lib/Basic/Targets/ARM.h
+++ b/clang/lib/Basic/Targets/ARM.h
@@ -225,6 +225,10 @@ class LLVM_LIBRARY_VISIBILITY ARMTargetInfo : public TargetInfo {
   bool hasBitIntType() const override { return true; }
 
   const char *getBFloat16Mangling() const override { return "u6__bf16"; };
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(getTriple().isArch64Bit() ? 256 : 64, 64);
+  }
 };
 
 class LLVM_LIBRARY_VISIBILITY ARMleTargetInfo : public ARMTargetInfo {
diff --git a/clang/lib/Basic/Targets/AVR.h b/clang/lib/Basic/Targets/AVR.h
index 9376c46cd98ca..feeb04f37eeba 100644
--- a/clang/lib/Basic/Targets/AVR.h
+++ b/clang/lib/Basic/Targets/AVR.h
@@ -175,6 +175,10 @@ class LLVM_LIBRARY_VISIBILITY AVRTargetInfo : public TargetInfo {
   std::optional<std::string> handleAsmEscapedChar(char EscChar) const override;
   StringRef getABI() const override { return ABI; }
 
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(32, 32);
+  }
+
 protected:
   std::string CPU;
   StringRef ABI;
diff --git a/clang/lib/Basic/Targets/BPF.h b/clang/lib/Basic/Targets/BPF.h
index 489f29fc4fead..d19b37dd4df7a 100644
--- a/clang/lib/Basic/Targets/BPF.h
+++ b/clang/lib/Basic/Targets/BPF.h
@@ -113,6 +113,10 @@ class LLVM_LIBRARY_VISIBILITY BPFTargetInfo : public TargetInfo {
     StringRef CPUName(Name);
     return isValidCPUName(CPUName);
   }
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(32, 32);
+  }
 };
 } // namespace targets
 } // namespace clang
diff --git a/clang/lib/Basic/Targets/M68k.h b/clang/lib/Basic/Targets/M68k.h
index 7ffa901127e50..b732add77e034 100644
--- a/clang/lib/Basic/Targets/M68k.h
+++ b/clang/lib/Basic/Targets/M68k.h
@@ -56,6 +56,10 @@ class LLVM_LIBRARY_VISIBILITY M68kTargetInfo : public TargetInfo {
   BuiltinVaListKind getBuiltinVaListKind() const override;
   bool setCPU(const std::string &Name) override;
   CallingConvCheckResult checkCallingConvention(CallingConv CC) const override;
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(32, 32);
+  }
 };
 
 } // namespace targets
diff --git a/clang/lib/Basic/Targets/Mips.h b/clang/lib/Basic/Targets/Mips.h
index 0d6e4b4d08089..730deb674aa57 100644
--- a/clang/lib/Basic/Targets/Mips.h
+++ b/clang/lib/Basic/Targets/Mips.h
@@ -431,6 +431,10 @@ class LLVM_LIBRARY_VISIBILITY MipsTargetInfo : public TargetInfo {
 
   bool validateTarget(DiagnosticsEngine &Diags) const override;
   bool hasBitIntType() const override { return true; }
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(32, 32);
+  }
 };
 } // namespace targets
 } // namespace clang
diff --git a/clang/lib/Basic/Targets/PPC.h b/clang/lib/Basic/Targets/PPC.h
index fa2f442e25846..3661927e159df 100644
--- a/clang/lib/Basic/Targets/PPC.h
+++ b/clang/lib/Basic/Targets/PPC.h
@@ -422,6 +422,10 @@ class LLVM_LIBRARY_VISIBILITY PPC32TargetInfo : public PPCTargetInfo {
     // This is the ELF definition
     return TargetInfo::PowerABIBuiltinVaList;
   }
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(32, 32);
+  }
 };
 
 // Note: ABI differences may eventually require us to have a separate
@@ -502,6 +506,10 @@ class LLVM_LIBRARY_VISIBILITY PPC64TargetInfo : public PPCTargetInfo {
       return CCCR_Warning;
     }
   }
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(128, 128);
+  }
 };
 
 class LLVM_LIBRARY_VISIBILITY AIXPPC32TargetInfo :
diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index 78580b5b1c106..7d482d4fd3738 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -122,6 +122,10 @@ class RISCVTargetInfo : public TargetInfo {
   void fillValidTuneCPUList(SmallVectorImpl<StringRef> &Values) const override;
   bool supportsTargetAttributeTune() const override { return true; }
   ParsedTargetAttr parseTargetAttr(StringRef Str) const override;
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(32, 32);
+  }
 };
 class LLVM_LIBRARY_VISIBILITY RISCV32TargetInfo : public RISCVTargetInfo {
 public:
diff --git a/clang/lib/Basic/Targets/Sparc.h b/clang/lib/Basic/Targets/Sparc.h
index 214fef88e1dcd..3357bee33e1ac 100644
--- a/clang/lib/Basic/Targets/Sparc.h
+++ b/clang/lib/Basic/Targets/Sparc.h
@@ -140,6 +140,10 @@ class LLVM_LIBRARY_VISIBILITY SparcTargetInfo : public TargetInfo {
     CPU = getCPUKind(Name);
     return CPU != CK_GENERIC;
   }
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(32, 32);
+  }
 };
 
 // SPARC v8 is the 32-bit mode selected by Triple::sparc.
diff --git a/clang/lib/Basic/Targets/SystemZ.h b/clang/lib/Basic/Targets/SystemZ.h
index 8e302acd51b8a..73d3aa01a043f 100644
--- a/clang/lib/Basic/Targets/SystemZ.h
+++ b/clang/lib/Basic/Targets/SystemZ.h
@@ -220,6 +220,10 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public TargetInfo {
   int getEHDataRegisterNumber(unsigned RegNo) const override {
     return RegNo < 4 ? 6 + RegNo : -1;
   }
+
+  std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
+    return std::make_pair(256, 256);
+  }
 };
 } // namespace targets
 } // namespace clang
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 4f44c3b7b89d4..db53ef5bf32b9 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -1309,6 +1309,16 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
     Builder.defineMacro("__GCC_ATOMIC_TEST_AND_SET_TRUEVAL", "1");
   }
 
+  // GCC defines these macros in both C and C++ modes despite them being needed
+  // mostly for STL implementations in C++.
+  auto [Destructive, Constructive] = TI.hardwareInterferenceSizes();
+  Builder.defineMacro("__GCC_DESTRUCTIVE_SIZE", Twine(Destructive));
+  Builder.defineMacro("__GCC_CONSTRUCTIVE_SIZE", Twine(Constructive));
+  // We need to use push_macro to allow users to redefine these macros from the
+  // command line with -D and not issue a -Wmacro-redefined warning.
+  Builder.append("#pragma push_macro(\"__GCC_DESTRUCTIVE_SIZE\")");
+  Builder.append("#pragma push_macro(\"__GCC_CONSTRUCTIVE_SIZE\")");
+
   auto addLockFreeMacros = [&](const llvm::Twine &Prefix) {
     // Used by libc++ and libstdc++ to implement ATOMIC_<foo>_LOCK_FREE.
 #define DEFINE_LOCK_FREE_MACRO(TYPE, Type)                                     \
diff --git a/clang/test/AST/ast-dump-macro-json.c b/clang/test/AST/ast-dump-macro-json.c
index 96f4be6fec3dd..fb9b4118b4f17 100644
--- a/clang/test/AST/ast-dump-macro-json.c
+++ b/clang/test/AST/ast-dump-macro-json.c
@@ -132,7 +132,7 @@ void BLAP(foo, __COUNTER__)(void);
 // CHECK-NEXT:   "spellingLoc": {
 // CHECK-NEXT:    "offset": {{[0-9]+}},
 // CHECK-NEXT:    "file": "<scratch space>",
-// CHECK-NEXT:    "line": 3,
+// CHECK-NEXT:    "line": 5,
 // CHECK-NEXT:    "col": 1,
 // CHECK-NEXT:    "tokLen": 4
 // CHECK-NEXT:   },
@@ -169,7 +169,7 @@ void BLAP(foo, __COUNTER__)(void);
 // CHECK-NEXT:   "spellingLoc": {
 // CHECK-NEXT:    "offset": {{[0-9]+}},
 // CHECK-NEXT:    "file": "<scratch space>",
-// CHECK-NEXT:    "line": 5,
+// CHECK-NEXT:    "line": 7,
 // CHECK-NEXT:    "col": 1,
 // CHECK-NEXT:    "tokLen": 4
 // CHECK-NEXT:   },
diff --git a/clang/test/Analysis/html_diagnostics/relevant_lines/multifile.c b/clang/test/Analysis/html_diagnostics/relevant_lines/multifile.c
index 3abffd609b5be..1998c9383d9d3 100644
--- a/clang/test/Analysis/html_diagnostics/relevant_lines/multifile.c
+++ b/clang/test/Analysis/html_diagnostics/relevant_lines/multifile.c
@@ -11,4 +11,4 @@ int f(int coin) {
 // RUN: rm -rf %t.output
 // RUN: %clang_analyze_cc1 -analyze -analyzer-checker=core -analyzer-output html -o %t.output %s
 // RUN: cat %t.output/* | FileCheck %s --match-full-lines
-// CHECK: var relevant_lines = {"1": {"3": 1, "4": 1, "5": 1, "6": 1}, "3": {"3": 1, "4": 1, "5": 1, "6": 1, "7": 1}};
+// CHECK: var relevant_lines = {"1": {"3": 1, "4": 1, "5": 1, "6": 1}, "4": {"3": 1, "4": 1, "5": 1, "6": 1, "7": 1}};
diff --git a/clang/test/Lexer/update_consecutive_macro_address_space.c b/clang/test/Lexer/update_consecutive_macro_address_space.c
index 80ef4557591c3..6f74709556c01 100644
--- a/clang/test/Lexer/update_consecutive_macro_address_space.c
+++ b/clang/test/Lexer/update_consecutive_macro_address_space.c
@@ -1,14 +1,15 @@
 // RUN: %clang -cc1 -print-stats %s 2>&1 | FileCheck %s
-// CHECK: 6 local SLocEntries allocated
+// CHECK: 7 local SLocEntries allocated
 //
-// Verify that the macro arg expansion is split to two file ids, we have 6 file
-// ids rather than 5:
+// Verify that the macro arg expansion is split to two file ids, we have 7 file
+// ids rather than 6:
 //   0: invalid file id
 //   1: main file
 //   2: builtin file
-//   3: macro expansion for X
-//   4: macro arg expansions for 1
-//   5: macro arg expansions for == 2
+//   3: scratch space for __GCC_[CON|DE]STRUCTIVE_SIZE macros
+//   4: macro expansion for X
+//   5: macro arg expansions for 1
+//   6: macro arg expansions for == 2
 #define X(x) (int)(x);
 void func() {
   X(1
diff --git a/clang/test/Preprocessor/hardware_interference.cpp b/clang/test/Preprocessor/hardware_interference.cpp
new file mode 100644
index 0000000000000..f3727aadd32a2
--- /dev/null
+++ b/clang/test/Preprocessor/hardware_interference.cpp
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -E -dM -D__GCC_CONSTRUCTIVE_SIZE=1000 -D__GCC_DESTRUCTIVE_SIZE=1001 %s -verify -Weverything | FileCheck %s
+// RUN: %clang_cc1 -D__GCC_CONSTRUCTIVE_SIZE=1000 -D__GCC_DESTRUCTIVE_SIZE=1001 %s -verify -Weverything
+// RUN: %clang_cc1 -E -dM -U__GCC_CONSTRUCTIVE_SIZE -U__GCC_DESTRUCTIVE_SIZE %s -verify -Weverything | FileCheck --check-prefix DISABLED %s
+// expected-no-diagnostics
+
+// Validate that we can set a new value on the command line without issuing any
+// diagnostics and that we can disabled the macro on the command line without
+// issuing any diagnostics.
+
+// CHECK: #define __GCC_CONSTRUCTIVE_SIZE 1000
+// CHECK: #define __GCC_DESTRUCTIVE_SIZE 1001
+// DISABLED-NOT: __GCC_CONSTRUCTIVE_SIZE
+// DISABLED-NOT: __GCC_DESTRUCTIVE_SIZE
+
+int main() {
+  return 0;
+}
diff --git a/clang/test/Preprocessor/init-aarch64.c b/clang/test/Preprocessor/init-aarch64.c
index cf96870b27acb..f0845985c9efc 100644
--- a/clang/test/Preprocessor/init-aarch64.c
+++ b/clang/test/Preprocessor/init-aarch64.c
@@ -119,6 +119,8 @@
 // AARCH64-NEXT: #define __FP_FAST_FMA 1
 // AARCH64-NEXT: #define __FP_FAST_FMAF 1
 // AARCH64-NEXT: #define __GCC_ASM_FLAG_OUTPUTS__ 1
+// AARCH64-NEXT: #define __GCC_CONSTRUCTIVE_SIZE {{.+}}
+// AARCH64-NEXT: #define __GCC_DESTRUCTIVE_SIZE {{.+}}
 // AARCH64-NEXT: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
 // AARCH64-NEXT: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 1
 // AARCH64-NEXT: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
@@ -220,11 +222,11 @@
 // AARCH64-NEXT: #define __LONG_MAX__ 9223372036854775807L
 // AARCH64-NEXT: #define __LONG_WIDTH__ 64
 // AARCH64-NEXT: #define __LP64__ 1
-// AARCH64-NEXT: #define __MEMORY_SCOPE_DEVICE 1 
-// AARCH64-NEXT: #define __MEMORY_SCOPE_SINGLE 4 
-// AARCH64-NEXT: #define __MEMORY_SCOPE_SYSTEM 0 
-// AARCH64-NEXT: #define __MEMORY_SCOPE_WRKGRP 2 
-// AARCH64-NEXT: #define __MEMORY_SCOPE_WVFRNT 3 
+// AARCH64-NEXT: #define __MEMORY_SCOPE_DEVICE 1
+// AARCH64-NEXT: #define __MEMORY_SCOPE_SINGLE 4
+// AARCH64-NEXT: #define __MEMORY_SCOPE_SYSTEM 0
+// AARCH64-NEXT: #define __MEMORY_SCOPE_WRKGRP 2
+// AARCH64-NEXT: #define __MEMORY_SCOPE_WVFRNT 3
 // AARCH64-NEXT: #define __NO_INLINE__ 1
 // AARCH64-NEXT: #define __NO_MATH_ERRNO__ 1
 // AARCH64-NEXT: #define __OBJC_BOOL_IS_BOOL 0
diff --git a/clang/test/Preprocessor/init.c b/clang/test/Preprocessor/init.c
index c4a55efca6f71..2641fee940231 100644
--- a/clang/test/Preprocessor/init.c
+++ b/clang/test/Preprocessor/init.c
@@ -1,3 +1,10 @@
+// RUN: %clang_cc1 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix INTERFERENCE %s
+//
+// We purposefully do not test the values produced, only that the macros are
+// predefined to some value.
+// INTERFERENCE:#define __GCC_CONSTRUCTIVE_SIZE {{.+}}
+// INTERFERENCE:#define __GCC_DESTRUCTIVE_SIZE {{.+}}
+
 // RUN: %clang_cc1 -E -dM -x assembler-with-cpp < /dev/null | FileCheck -match-full-lines -check-prefix ASM %s
 //
 // ASM:#define __ASSEMBLER__ 1
@@ -1697,6 +1704,8 @@
 // WEBASSEMBLY-NEXT:#define __GCC_ATOMIC_SHORT_LOCK_FREE 2
 // WEBASSEMBLY-NEXT:#define __GCC_ATOMIC_TEST_AND_SET_TRUEVAL 1
 // WEBASSEMBLY-NEXT:#define __GCC_ATOMIC_WCHAR_T_LOCK_FREE 2
+// WEBASSEMBLY-NEXT:#define __GCC_CONSTRUCTIVE_SIZE {{.+}}
+// WEBASSEMBLY-NEXT:#define __GCC_DESTRUCTIVE_SIZE {{.+}}
 // WEBASSEMBLY-NEXT:#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
 // WEBASSEMBLY-NEXT:#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
 // WEBASSEMBLY-NEXT:#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
@@ -1806,11 +1815,11 @@
 // WEBASSEMBLY64-NEXT:#define __LONG_MAX__ 9223372036854775807L
 // WEBASSEMBLY64-NEXT:#define __LONG_WIDTH__ 64
 // WEBASSEMBLY64-NEXT:#define __LP64__ 1
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_DEVICE 1 
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_SINGLE 4 
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_SYSTEM 0 
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_WRKGRP 2 
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_WVFRNT 3 
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_DEVICE 1
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_SINGLE 4
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_SYSTEM 0
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_WRKGRP 2
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_WVFRNT 3
 // WEBASSEMBLY-NEXT:#define __NO_INLINE__ 1
 // WEBASSEMBLY-NEXT:#define __NO_MATH_ERRNO__ 1
 // WEBASSEMBLY-NEXT:#define __OBJC_BOOL_IS_BOOL 0
@@ -2126,11 +2135,11 @@
 // AVR:#define __LDBL_MIN__ 1.17549435e-38L
 // AVR:#define __LONG_LONG_MAX__ 9223372036854775807LL
 // AVR:#define __LONG_MAX__ 2147483647L
-// AVR:#define __MEMORY_SCOPE_DEVICE 1 
-// AVR:#define __MEMORY_SCOPE_SINGLE 4 
-// AVR:#define __MEMORY_SCOPE_SYSTEM 0 
-// AVR:#define __MEMORY_SCOPE_WRKGRP 2 
-// AVR:#define __MEMORY_SCOPE_WVFRNT 3 
+// AVR:#define __MEMORY_SCOPE_DEVICE 1
+// AVR:#define __MEMORY_SCOPE_SINGLE 4
+// AVR:#define __MEMORY_SCOPE_SYSTEM 0
+// AVR:#define __MEMORY_SCOPE_WRKGRP 2
+// AVR:#define __MEMORY_SCOPE_WVFRNT 3
 // AVR:#define __NO_INLINE__ 1
 // AVR:#define __ORDER_BIG_ENDIAN__ 4321
 // AVR:#define __ORDER_LITTLE_ENDIAN__ 1234
@@ -2422,11 +2431,11 @@
 // RISCV32: #define __LITTLE_ENDIAN__ 1
 // RISCV32: #define __LONG_LONG_MAX__ 9223372036854775807LL
 // RISCV32: #define __LONG_MAX__ 2147483647L
-// RISCV32: #define __MEMORY_SCOPE_DEVICE 1 
-// RISCV32: #define __MEMORY_SCOPE_SINGLE 4 
-// RISCV32: #define __MEMORY_SCOPE_SYSTEM 0 
-// RISCV32: #define __MEMORY_SCOPE_WRKGRP 2 
-// RISCV32: #define __MEMORY_SCOPE_WVFRNT 3 
+// RISCV32: #define __MEMORY_SCOPE_DEVICE 1
+// RISCV32: #define __MEMORY_SCOPE_SINGLE 4
+// RISCV32: #define __MEMORY_SCOPE_SYSTEM 0
+// RISCV32: #define __MEMORY_SCOPE_WRKGRP 2
+// RISCV32: #define __MEMORY_SCOPE_WVFRNT 3
 // RISCV32: #define __NO_INLINE__ 1
 // RISCV32: #define __POINTER_WIDTH__ 32
 // RISCV32: #define __PRAGMA_REDEFINE_EXTNAME 1
@@ -2634,11 +2643,11 @@
 // RISCV64: #define __LONG_LONG_MAX__ 9223372036854775807LL
 // RISCV64: #define __LONG_MAX__ 9223372036854775807L
 // RISCV64: #define __LP64__ 1
-// RISCV64: #define __MEMORY_SCOPE_DEVICE 1 
-// RISCV64: #define __MEMORY_SCOPE_SINGLE 4 
-// RISCV64: #define __MEMORY_SCOPE_SYSTEM 0 
-// RISCV64: #define __MEMORY_SCOPE_WRKGRP 2 
-// RISCV64: #define __MEMORY_SCOPE_WVFRNT 3 
+// RISCV64: #define __MEMORY_SCOPE_DEVICE 1
+// RISCV64: #define __MEMORY_SCOPE_SINGLE 4
+// RISCV64: #define __MEMORY_SCOPE_SYSTEM 0
+// RISCV64: #define __MEMORY_SCOPE_WRKGRP 2
+// RISCV64: #define __MEMORY_SCOPE_WVFRNT 3
 // RISCV64: #define __NO_INLINE__ 1
 // RISCV64: #define __POINTER_WIDTH__ 64
 // RISCV64: #define __PRAGMA_REDEFINE_EXTNAME 1
diff --git a/clang/test/Preprocessor/predefined-win-macros.c b/clang/test/Preprocessor/predefined-win-macros.c
index b830dc39d477d..14e2f584bd093 100644
--- a/clang/test/Preprocessor/predefined-win-macros.c
+++ b/clang/test/Preprocessor/predefined-win-macros.c
@@ -3,7 +3,7 @@
 // RUN: %clang_cc1 %s -x c++ -E -dM -triple x86_64-pc-win32 -fms-extensions -fms-compatibility \
 // RUN:     -fms-compatibility-version=19.00 -std=c++14 -o - | FileCheck -match-full-lines %s --check-prefix=CHECK-MS64
 // RUN: %clang_cc1 %s -x c++ -E -dM -triple x86_64-pc-win32 -fms-extensions -fms-compatibility \
-// RUN:     -fms-compatibility-version=19.00 -std=c++14 -o - | grep GCC | count 5
+// RUN:     -fms-compatibility-version=19.00 -std=c++14 -o - | grep GCC | count 7
 // CHECK-MS64: #define _INTEGRAL_MAX_BITS 64
 // CHECK-MS64: #define _ISO_VOLATILE 1
 // CHECK-MS64: #define _MSC_EXTENSIONS 1
@@ -26,7 +26,7 @@
 // RUN: %clang_cc1 %s -x c++ -E -dM -triple i686-pc-win32 -fms-extensions -fms-compatibility \
 // RUN:     -fms-compatibility-version=19.00 -std=c++17 -o - | FileCheck -match-full-lines %s --check-prefix=CHECK-MS
 // RUN: %clang_cc1 %s -x c++ -E -dM -triple i686-pc-win32 -fms-extensions -fms-compatibility \
-// RUN:     -fms-compatibility-version=19.00 -std=c++17 -o - | grep GCC | count 5
+// RUN:     -fms-compatibility-version=19.00 -std=c++17 -o - | grep GCC | count 7
 // CHECK-MS: #define _INTEGRAL_MAX_BITS 64
 // CHECK-MS: #define _ISO_VOLATILE 1
 // CHECK-MS: #define _MSC_EXTENSIONS 1
@@ -39,6 +39,8 @@
 // CHECK-MS-NOT: GNU
 // CHECK-MS-NOT: GXX
 // CHECK-MS: #define __GCC_ASM_FLAG_OUTPUTS__ 1
+// CHECK-MS: #define __GCC_CONSTRUCTIVE_SIZE {{.+}}
+// CHECK-MS: #define __GCC_DESTRUCTIVE_SIZE {{.+}}
 // CHECK-MS: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
 // CHECK-MS: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
 // CHECK-MS: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
diff --git a/libcxx/test/std/language.support/support.dynamic/hardware_inference_size.compile.pass.cpp b/libcxx/test/std/language.support/support.dynamic/hardware_inference_size.compile.pass.cpp
index ae277d53e46fd..2656f0595bf50 100644
--- a/libcxx/test/std/language.support/support.dynamic/hardware_inference_size.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/hardware_inference_size.compile.pass.cpp
@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14
-// XFAIL: (clang || apple-clang) && stdlib=libc++
+// UNSUPPORTED: (clang || apple-clang) && stdlib=libc++
 
 #include <new>