[Clang][AArch64] Add missing SME macros (#80293)

__ARM_STATE_ZA and __ARM_STATE_ZT0 are set when the compiler can parse 
the "za" and "zt0" strings in the SME attributes.

__ARM_FEATURE_SME and __ARM_FEATURE_SME2 are set when the compiler can 
generate code for attributes with "za" and "zt0" state, respectively.

__ARM_FEATURE_LOCALLY_STREAMING is set when the compiler supports the
__arm_locally_streaming attribute.

Author: sdesmalen-arm

clang/lib/Basic/Targets/AArch64.cpp

@@ -386,6 +386,11 @@ void AArch64TargetInfo::getTargetDefines(const LangOptions &Opts,
 
   Builder.defineMacro("__ARM_ALIGN_MAX_STACK_PWR", "4");
 
+  // These macros are set when Clang can parse declarations with these
+  // attributes.
+  Builder.defineMacro("__ARM_STATE_ZA", "1");
+  Builder.defineMacro("__ARM_STATE_ZT0", "1");
+
   // 0xe implies support for half, single and double precision operations.
   if (FPU & FPUMode)
     Builder.defineMacro("__ARM_FP", "0xE");
@@ -430,6 +435,17 @@ void AArch64TargetInfo::getTargetDefines(const LangOptions &Opts,
   if (HasSVE2 && HasSVE2SM4)
     Builder.defineMacro("__ARM_FEATURE_SVE2_SM4", "1");
 
+  if (HasSME) {
+    Builder.defineMacro("__ARM_FEATURE_SME");
+    Builder.defineMacro("__ARM_FEATURE_LOCALLY_STREAMING", "1");
+  }
+
+  if (HasSME2) {
+    Builder.defineMacro("__ARM_FEATURE_SME");
+    Builder.defineMacro("__ARM_FEATURE_SME2");
+    Builder.defineMacro("__ARM_FEATURE_LOCALLY_STREAMING", "1");
+  }
+
   if (HasCRC)
     Builder.defineMacro("__ARM_FEATURE_CRC32", "1");
 
@@ -692,6 +708,7 @@ bool AArch64TargetInfo::hasFeature(StringRef Feature) const {
       .Case("sve2-sha3", FPU & SveMode && HasSVE2SHA3)
       .Case("sve2-sm4", FPU & SveMode && HasSVE2SM4)
       .Case("sme", HasSME)
+      .Case("sme2", HasSME2)
       .Case("sme-f64f64", HasSMEF64F64)
       .Case("sme-i16i64", HasSMEI16I64)
       .Case("sme-fa64", HasSMEFA64)
@@ -812,6 +829,12 @@ bool AArch64TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
       HasBFloat16 = true;
       HasFullFP16 = true;
     }
+    if (Feature == "+sme2") {
+      HasSME = true;
+      HasSME2 = true;
+      HasBFloat16 = true;
+      HasFullFP16 = true;
+    }
     if (Feature == "+sme-f64f64") {
       HasSME = true;
       HasSMEF64F64 = true;

clang/lib/Basic/Targets/AArch64.h

@@ -68,6 +68,7 @@ class LLVM_LIBRARY_VISIBILITY AArch64TargetInfo : public TargetInfo {
   bool HasCCDP = false;
   bool HasFRInt3264 = false;
   bool HasSME = false;
+  bool HasSME2 = false;
   bool HasSMEF64F64 = false;
   bool HasSMEI16I64 = false;
   bool HasSB = false;

clang/test/Preprocessor/aarch64-target-features.c

@@ -60,6 +60,10 @@
 // CHECK-NOT: __ARM_FEATURE_SVE_BITS 512
 // CHECK-NOT: __ARM_FEATURE_SVE_BITS 1024
 // CHECK-NOT: __ARM_FEATURE_SVE_BITS 2048
+// CHECK: __ARM_STATE_ZA 1
+// CHECK: __ARM_STATE_ZT0 1
+// CHECK-NOT: __ARM_FEATURE_SME
+// CHECK-NOT: __ARM_FEATURE_SME2
 
 // RUN: %clang -target aarch64-none-elf -march=armv8-r -x c -E -dM %s -o - | FileCheck %s -check-prefix CHECK-R-PROFILE
 // RUN: %clang -target arm64-none-linux-gnu -march=armv8-r -x c -E -dM %s -o - | FileCheck %s -check-prefix CHECK-R-PROFILE
@@ -672,3 +676,12 @@
 
 // RUN: %clang --target=aarch64 -march=armv8.2-a+rcpc3 -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-RCPC3 %s
 // CHECK-RCPC3: __ARM_FEATURE_RCPC 3
+
+// RUN: %clang --target=aarch64 -march=armv9-a+sme -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-SME %s
+// CHECK-SME: __ARM_FEATURE_LOCALLY_STREAMING 1
+// CHECK-SME: __ARM_FEATURE_SME 1
+//
+// RUN: %clang --target=aarch64 -march=armv9-a+sme2 -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-SME2 %s
+// CHECK-SME2: __ARM_FEATURE_LOCALLY_STREAMING 1
+// CHECK-SME2: __ARM_FEATURE_SME 1
+// CHECK-SME2: __ARM_FEATURE_SME2 1

clang/test/Preprocessor/init-aarch64.c

@@ -32,6 +32,8 @@
 // AARCH64-NEXT: #define __ARM_PCS_AAPCS64 1
 // AARCH64-NEXT: #define __ARM_SIZEOF_MINIMAL_ENUM 4
 // AARCH64-NEXT: #define __ARM_SIZEOF_WCHAR_T 4
+// AARCH64-NEXT: #define __ARM_STATE_ZA 1
+// AARCH64-NEXT: #define __ARM_STATE_ZT0 1
 // AARCH64-NEXT: #define __ATOMIC_ACQUIRE 2
 // AARCH64-NEXT: #define __ATOMIC_ACQ_REL 4
 // AARCH64-NEXT: #define __ATOMIC_CONSUME 1