diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index d47181bfca4fc..7d0f879b3daee 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -368,8 +368,21 @@ void AArch64TargetInfo::getTargetDefines(const LangOptions &Opts,
 
   // ACLE predefines. Many can only have one possible value on v8 AArch64.
   Builder.defineMacro("__ARM_ACLE", "200");
-  Builder.defineMacro("__ARM_ARCH",
-                      std::to_string(ArchInfo->Version.getMajor()));
+
+  // ACLE 5.4.1 ARM/Thumb instruction set architecture
+  // __ARM_ARCH is defined as an integer value indicating the current ARM ISA.
+  // For ISAs up to and including v8, __ARM_ARCH is equal to the major version
+  // number. For ISAs from v8.1 onwards, __ARM_ARCH is scaled up to include the
+  // minor version number, e.g. for ARM architecture ARMvX.Y:
+  // __ARM_ARCH = X * 100 + Y.
+  if (ArchInfo->Version.getMajor() == 8 && ArchInfo->Version.getMinor() == 0)
+    Builder.defineMacro("__ARM_ARCH",
+                        std::to_string(ArchInfo->Version.getMajor()));
+  else
+    Builder.defineMacro("__ARM_ARCH",
+                        std::to_string(ArchInfo->Version.getMajor() * 100 +
+                                       ArchInfo->Version.getMinor().value()));
+
   Builder.defineMacro("__ARM_ARCH_PROFILE",
                       std::string("'") + (char)ArchInfo->Profile + "'");
 
diff --git a/clang/lib/Basic/Targets/ARM.cpp b/clang/lib/Basic/Targets/ARM.cpp
index 55b71557452fa..9ac558caa2886 100644
--- a/clang/lib/Basic/Targets/ARM.cpp
+++ b/clang/lib/Basic/Targets/ARM.cpp
@@ -130,6 +130,7 @@ void ARMTargetInfo::setArchInfo(llvm::ARM::ArchKind Kind) {
   SubArch = llvm::ARM::getSubArch(ArchKind);
   ArchProfile = llvm::ARM::parseArchProfile(SubArch);
   ArchVersion = llvm::ARM::parseArchVersion(SubArch);
+  ArchMinorVersion = llvm::ARM::parseArchMinorVersion(SubArch);
 
   // cache CPU related strings
   CPUAttr = getCPUAttr();
@@ -736,9 +737,17 @@ void ARMTargetInfo::getTargetDefines(const LangOptions &Opts,
   if (!CPUAttr.empty())
     Builder.defineMacro("__ARM_ARCH_" + CPUAttr + "__");
 
-  // ACLE 6.4.1 ARM/Thumb instruction set architecture
-  // __ARM_ARCH is defined as an integer value indicating the current ARM ISA
-  Builder.defineMacro("__ARM_ARCH", Twine(ArchVersion));
+  // ACLE 5.4.1 ARM/Thumb instruction set architecture
+  // __ARM_ARCH is defined as an integer value indicating the current ARM ISA.
+  // For ISAs up to and including v8, __ARM_ARCH is equal to the major version
+  // number. For ISAs from v8.1 onwards, __ARM_ARCH is scaled up to include the
+  // minor version number, e.g. for ARM architecture ARMvX.Y:
+  // __ARM_ARCH = X * 100 + Y.
+  if (ArchVersion >= 9 || ArchMinorVersion != 0)
+    Builder.defineMacro("__ARM_ARCH",
+                        Twine(ArchVersion * 100 + ArchMinorVersion));
+  else
+    Builder.defineMacro("__ARM_ARCH", Twine(ArchVersion));
 
   if (ArchVersion >= 8) {
     // ACLE 6.5.7 Crypto Extension
diff --git a/clang/lib/Basic/Targets/ARM.h b/clang/lib/Basic/Targets/ARM.h
index 9802eb01abf3c..9c4bd299f6733 100644
--- a/clang/lib/Basic/Targets/ARM.h
+++ b/clang/lib/Basic/Targets/ARM.h
@@ -60,6 +60,7 @@ class LLVM_LIBRARY_VISIBILITY ARMTargetInfo : public TargetInfo {
   llvm::ARM::ArchKind ArchKind = llvm::ARM::ArchKind::ARMV4T;
   llvm::ARM::ProfileKind ArchProfile;
   unsigned ArchVersion;
+  unsigned ArchMinorVersion;
 
   unsigned FPU : 5;
   unsigned MVE : 2;
diff --git a/clang/test/Preprocessor/arm-target-features.c b/clang/test/Preprocessor/arm-target-features.c
index 236c9f2479b70..2122082760b6f 100644
--- a/clang/test/Preprocessor/arm-target-features.c
+++ b/clang/test/Preprocessor/arm-target-features.c
@@ -737,7 +737,7 @@
 
 // Test whether predefines are as expected when targeting cortex-m55 (softfp FP ABI as default).
 // RUN: %clang -target arm-eabi -mcpu=cortex-m55 -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=M55 %s
-// M55: #define __ARM_ARCH 8
+// M55: #define __ARM_ARCH 801
 // M55: #define __ARM_ARCH_8_1M_MAIN__ 1
 // M55: #define __ARM_ARCH_EXT_IDIV__ 1
 // M55-NOT: __ARM_ARCH_ISA_ARM
@@ -764,7 +764,7 @@
 // KRAIT-ALLOW-FP-INSTR:#define  __ARM_VFPV4__ 1
 
 // RUN: %clang -target arm-arm-none-eabi -march=armv8.1-m.main -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V81M %s
-// CHECK-V81M: #define __ARM_ARCH 8
+// CHECK-V81M: #define __ARM_ARCH 801
 // CHECK-V81M: #define __ARM_ARCH_8_1M_MAIN__ 1
 // CHECK-V81M: #define __ARM_ARCH_ISA_THUMB 2
 // CHECK-V81M: #define __ARM_ARCH_PROFILE 'M'
@@ -821,14 +821,14 @@
 // CHECK-V8M-CDE-MASK2: #define __ARM_FEATURE_CDE_COPROC 0xff
 
 // RUN: %clang -target armv8.1a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V81A %s
-// CHECK-V81A: #define __ARM_ARCH 8
+// CHECK-V81A: #define __ARM_ARCH 801
 // CHECK-V81A: #define __ARM_ARCH_8_1A__ 1
 // CHECK-V81A: #define __ARM_ARCH_PROFILE 'A'
 // CHECK-V81A: #define __ARM_FEATURE_QRDMX 1
 // CHECK-V81A: #define __ARM_FP 0xe
 
 // RUN: %clang -target armv8.2a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V82A %s
-// CHECK-V82A: #define __ARM_ARCH 8
+// CHECK-V82A: #define __ARM_ARCH 802
 // CHECK-V82A: #define __ARM_ARCH_8_2A__ 1
 // CHECK-V82A: #define __ARM_ARCH_PROFILE 'A'
 // CHECK-V82A: #define __ARM_FEATURE_QRDMX 1
@@ -838,62 +838,62 @@
 // CHECK-DRIVERKIT-NOT: #define __ARM_PCS_VFP 1
 
 // RUN: %clang -target armv8.3a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V83A %s
-// CHECK-V83A: #define __ARM_ARCH 8
+// CHECK-V83A: #define __ARM_ARCH 803
 // CHECK-V83A: #define __ARM_ARCH_8_3A__ 1
 // CHECK-V83A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv8.4a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V84A %s
-// CHECK-V84A: #define __ARM_ARCH 8
+// CHECK-V84A: #define __ARM_ARCH 804
 // CHECK-V84A: #define __ARM_ARCH_8_4A__ 1
 // CHECK-V84A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv8.5a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V85A %s
-// CHECK-V85A: #define __ARM_ARCH 8
+// CHECK-V85A: #define __ARM_ARCH 805
 // CHECK-V85A: #define __ARM_ARCH_8_5A__ 1
 // CHECK-V85A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv8.6a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V86A %s
-// CHECK-V86A: #define __ARM_ARCH 8
+// CHECK-V86A: #define __ARM_ARCH 806
 // CHECK-V86A: #define __ARM_ARCH_8_6A__ 1
 // CHECK-V86A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv8.7a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V87A %s
-// CHECK-V87A: #define __ARM_ARCH 8
+// CHECK-V87A: #define __ARM_ARCH 807
 // CHECK-V87A: #define __ARM_ARCH_8_7A__ 1
 // CHECK-V87A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv8.8a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V88A %s
-// CHECK-V88A: #define __ARM_ARCH 8
+// CHECK-V88A: #define __ARM_ARCH 808
 // CHECK-V88A: #define __ARM_ARCH_8_8A__ 1
 // CHECK-V88A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv8.9a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V89A %s
-// CHECK-V89A: #define __ARM_ARCH 8
+// CHECK-V89A: #define __ARM_ARCH 809
 // CHECK-V89A: #define __ARM_ARCH_8_9A__ 1
 // CHECK-V89A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv9a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V9A %s
-// CHECK-V9A: #define __ARM_ARCH 9
+// CHECK-V9A: #define __ARM_ARCH 900
 // CHECK-V9A: #define __ARM_ARCH_9A__ 1
 // CHECK-V9A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv9.1a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V91A %s
-// CHECK-V91A: #define __ARM_ARCH 9
+// CHECK-V91A: #define __ARM_ARCH 901
 // CHECK-V91A: #define __ARM_ARCH_9_1A__ 1
 // CHECK-V91A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv9.2a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V92A %s
-// CHECK-V92A: #define __ARM_ARCH 9
+// CHECK-V92A: #define __ARM_ARCH 902
 // CHECK-V92A: #define __ARM_ARCH_9_2A__ 1
 // CHECK-V92A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv9.3a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V93A %s
-// CHECK-V93A: #define __ARM_ARCH 9
+// CHECK-V93A: #define __ARM_ARCH 903
 // CHECK-V93A: #define __ARM_ARCH_9_3A__ 1
 // CHECK-V93A: #define __ARM_ARCH_PROFILE 'A'
 
 // RUN: %clang -target armv9.4a-none-none-eabi -x c -E -dM %s -o - | FileCheck -match-full-lines --check-prefix=CHECK-V94A %s
-// CHECK-V94A: #define __ARM_ARCH 9
+// CHECK-V94A: #define __ARM_ARCH 904
 // CHECK-V94A: #define __ARM_ARCH_9_4A__ 1
 // CHECK-V94A: #define __ARM_ARCH_PROFILE 'A'
 
diff --git a/llvm/include/llvm/TargetParser/ARMTargetParser.h b/llvm/include/llvm/TargetParser/ARMTargetParser.h
index c42d66f048fcc..ec3817134a5ac 100644
--- a/llvm/include/llvm/TargetParser/ARMTargetParser.h
+++ b/llvm/include/llvm/TargetParser/ARMTargetParser.h
@@ -258,6 +258,7 @@ uint64_t parseArchExt(StringRef ArchExt);
 ArchKind parseCPUArch(StringRef CPU);
 ProfileKind parseArchProfile(StringRef Arch);
 unsigned parseArchVersion(StringRef Arch);
+unsigned parseArchMinorVersion(StringRef Arch);
 
 void fillValidCPUArchList(SmallVectorImpl<StringRef> &Values);
 StringRef computeDefaultTargetABI(const Triple &TT, StringRef CPU);
diff --git a/llvm/lib/TargetParser/ARMTargetParser.cpp b/llvm/lib/TargetParser/ARMTargetParser.cpp
index 67f937ebc33f9..dfbc2ff57ad16 100644
--- a/llvm/lib/TargetParser/ARMTargetParser.cpp
+++ b/llvm/lib/TargetParser/ARMTargetParser.cpp
@@ -94,6 +94,66 @@ unsigned ARM::parseArchVersion(StringRef Arch) {
   llvm_unreachable("Unhandled architecture");
 }
 
+unsigned ARM::parseArchMinorVersion(StringRef Arch) {
+  Arch = getCanonicalArchName(Arch);
+  switch (parseArch(Arch)) {
+  case ArchKind::ARMV4:
+  case ArchKind::ARMV4T:
+  case ArchKind::ARMV5T:
+  case ArchKind::ARMV5TE:
+  case ArchKind::IWMMXT:
+  case ArchKind::IWMMXT2:
+  case ArchKind::XSCALE:
+  case ArchKind::ARMV5TEJ:
+  case ArchKind::ARMV6:
+  case ArchKind::ARMV6K:
+  case ArchKind::ARMV6T2:
+  case ArchKind::ARMV6KZ:
+  case ArchKind::ARMV6M:
+  case ArchKind::ARMV7A:
+  case ArchKind::ARMV7VE:
+  case ArchKind::ARMV7R:
+  case ArchKind::ARMV7AR:
+  case ArchKind::ARMV7M:
+  case ArchKind::ARMV7S:
+  case ArchKind::ARMV7EM:
+  case ArchKind::ARMV7K:
+  case ArchKind::ARMV8AR:
+  case ArchKind::ARMV8A:
+  case ArchKind::ARMV8R:
+  case ArchKind::ARMV8MBaseline:
+  case ArchKind::ARMV8MMainline:
+  case ArchKind::ARMV9A:
+  case ArchKind::INVALID:
+    return 0;
+  case ArchKind::ARMV8_1A:
+  case ArchKind::ARMV8_1MMainline:
+  case ArchKind::ARMV9_1A:
+    return 1;
+  case ArchKind::ARMV8_2A:
+  case ArchKind::ARMV8_2MMainline:
+  case ArchKind::ARMV9_2A:
+    return 2;
+  case ArchKind::ARMV8_3A:
+  case ArchKind::ARMV9_3A:
+    return 3;
+  case ArchKind::ARMV8_4A:
+  case ArchKind::ARMV9_4A:
+    return 4;
+  case ArchKind::ARMV8_5A:
+    return 5;
+  case ArchKind::ARMV8_6A:
+    return 6;
+  case ArchKind::ARMV8_7A:
+    return 7;
+  case ArchKind::ARMV8_8A:
+    return 8;
+  case ArchKind::ARMV8_9A:
+    return 9;
+  }
+  llvm_unreachable("Unhandled architecture");
+}
+
 static ARM::ProfileKind getProfileKind(ARM::ArchKind AK) {
   switch (AK) {
   case ARM::ArchKind::ARMV6M:
diff --git a/llvm/unittests/TargetParser/TargetParserTest.cpp b/llvm/unittests/TargetParser/TargetParserTest.cpp
index d31fcd1bb1b00..e3de01c18d657 100644
--- a/llvm/unittests/TargetParser/TargetParserTest.cpp
+++ b/llvm/unittests/TargetParser/TargetParserTest.cpp
@@ -961,6 +961,14 @@ TEST(TargetParserTest, ARMparseArchVersion) {
       EXPECT_EQ(5u, ARM::parseArchVersion(ARMArch[i]));
 }
 
+TEST(TargetParserTest, ARMparseArchMinorVersion) {
+  for (unsigned i = 0; i < std::size(ARMArch); i++)
+    if (((std::string)ARMArch[i]).find(".") == 5)
+      EXPECT_EQ((ARMArch[i][6] - 48u), ARM::parseArchMinorVersion(ARMArch[i]));
+    else
+      EXPECT_EQ(0u, ARM::parseArchMinorVersion(ARMArch[i]));
+}
+
 TEST(TargetParserTest, getARMCPUForArch) {
   // Platform specific defaults.
   {