[Clang][AArch64] Change SME attributes for shared/new/preserved state. (#76971)

This patch replaces the `__arm_new_za`, `__arm_shared_za` and
`__arm_preserves_za` attributes in favour of:
* `__arm_new("za")`
* `__arm_in("za")`
* `__arm_out("za")`
* `__arm_inout("za")`
* `__arm_preserves("za")`

As described in https://github.com/ARM-software/acle/pull/276.

One change is that `__arm_in/out/inout/preserves(S)` are all mutually
exclusive, whereas previously it was fine to write `__arm_shared_za
__arm_preserves_za`. This case is now represented with `__arm_in("za")`.

The current implementation uses the same LLVM attributes under the hood,
since `__arm_in/out/inout` are all variations of "shared ZA", so can use
the existing `aarch64_pstate_za_shared` attribute in LLVM.

#77941 will add support for the new "zt0" state as introduced
with SME2.

4 files changed, 34 insertions, 25 deletions

diff --git a/clang/utils/TableGen/ClangAttrEmitter.cpp b/clang/utils/TableGen/ClangAttrEmitter.cpp
index 4ec0057..c35490c 100644
--- a/clang/utils/TableGen/ClangAttrEmitter.cpp
+++ b/clang/utils/TableGen/ClangAttrEmitter.cpp
@@ -3547,23 +3547,27 @@ static void GenerateHasAttrSpellingStringSwitch(
   OS << "    .Default(0);\n";
 }
 
-// Emits the list of tokens for regular keyword attributes.
-void EmitClangAttrTokenKinds(RecordKeeper &Records, raw_ostream &OS) {
-  emitSourceFileHeader("A list of tokens generated from the attribute"
-                       " definitions",
-                       OS);
+// Emits list of regular keyword attributes with info about their arguments.
+void EmitClangRegularKeywordAttributeInfo(RecordKeeper &Records,
+                                          raw_ostream &OS) {
+  emitSourceFileHeader(
+      "A list of regular keyword attributes generated from the attribute"
+      " definitions",
+      OS);
   // Assume for now that the same token is not used in multiple regular
   // keyword attributes.
   for (auto *R : Records.getAllDerivedDefinitions("Attr"))
-    for (const auto &S : GetFlattenedSpellings(*R))
-      if (isRegularKeywordAttribute(S)) {
-        if (!R->getValueAsListOfDefs("Args").empty())
-          PrintError(R->getLoc(),
-                     "RegularKeyword attributes with arguments are not "
-                     "yet supported");
-        OS << "KEYWORD_ATTRIBUTE("
-           << S.getSpellingRecord().getValueAsString("Name") << ")\n";
-      }
+    for (const auto &S : GetFlattenedSpellings(*R)) {
+      if (!isRegularKeywordAttribute(S))
+        continue;
+      std::vector<Record *> Args = R->getValueAsListOfDefs("Args");
+      bool HasArgs = llvm::any_of(
+          Args, [](const Record *Arg) { return !Arg->getValueAsBit("Fake"); });
+
+      OS << "KEYWORD_ATTRIBUTE("
+         << S.getSpellingRecord().getValueAsString("Name") << ", "
+         << (HasArgs ? "true" : "false") << ")\n";
+    }
   OS << "#undef KEYWORD_ATTRIBUTE\n";
 }
 
diff --git a/clang/utils/TableGen/SveEmitter.cpp b/clang/utils/TableGen/SveEmitter.cpp
index 5de2223..060d79a 100644
--- a/clang/utils/TableGen/SveEmitter.cpp
+++ b/clang/utils/TableGen/SveEmitter.cpp
@@ -1619,7 +1619,7 @@ void SVEEmitter::createSMEHeader(raw_ostream &OS) {
   OS << "}\n\n";
 
   OS << "__ai __attribute__((target(\"sme\"))) void svundef_za(void) "
-        "__arm_streaming_compatible __arm_shared_za "
+        "__arm_streaming_compatible __arm_out(\"za\") "
         "{ }\n\n";
 
   createCoreHeaderIntrinsics(OS, *this, ACLEKind::SME);
diff --git a/clang/utils/TableGen/TableGen.cpp b/clang/utils/TableGen/TableGen.cpp
index 3859555..158d10e 100644
--- a/clang/utils/TableGen/TableGen.cpp
+++ b/clang/utils/TableGen/TableGen.cpp
@@ -37,7 +37,7 @@ enum ActionType {
   GenClangAttrSubjectMatchRuleList,
   GenClangAttrPCHRead,
   GenClangAttrPCHWrite,
-  GenClangAttrTokenKinds,
+  GenClangRegularKeywordAttributeInfo,
   GenClangAttrHasAttributeImpl,
   GenClangAttrSpellingListIndex,
   GenClangAttrASTVisitor,
@@ -150,8 +150,10 @@ cl::opt<ActionType> Action(
                    "Generate clang PCH attribute reader"),
         clEnumValN(GenClangAttrPCHWrite, "gen-clang-attr-pch-write",
                    "Generate clang PCH attribute writer"),
-        clEnumValN(GenClangAttrTokenKinds, "gen-clang-attr-token-kinds",
-                   "Generate a list of attribute-related clang tokens"),
+        clEnumValN(GenClangRegularKeywordAttributeInfo,
+                   "gen-clang-regular-keyword-attr-info",
+                   "Generate a list of regular keyword attributes with info "
+                   "about their arguments"),
         clEnumValN(GenClangAttrHasAttributeImpl,
                    "gen-clang-attr-has-attribute-impl",
                    "Generate a clang attribute spelling list"),
@@ -291,11 +293,14 @@ cl::opt<ActionType> Action(
                    "Generate riscv_vector_builtin_cg.inc for clang"),
         clEnumValN(GenRISCVVectorBuiltinSema, "gen-riscv-vector-builtin-sema",
                    "Generate riscv_vector_builtin_sema.inc for clang"),
-        clEnumValN(GenRISCVSiFiveVectorBuiltins, "gen-riscv-sifive-vector-builtins",
+        clEnumValN(GenRISCVSiFiveVectorBuiltins,
+                   "gen-riscv-sifive-vector-builtins",
                    "Generate riscv_sifive_vector_builtins.inc for clang"),
-        clEnumValN(GenRISCVSiFiveVectorBuiltinCG, "gen-riscv-sifive-vector-builtin-codegen",
+        clEnumValN(GenRISCVSiFiveVectorBuiltinCG,
+                   "gen-riscv-sifive-vector-builtin-codegen",
                    "Generate riscv_sifive_vector_builtin_cg.inc for clang"),
-        clEnumValN(GenRISCVSiFiveVectorBuiltinSema, "gen-riscv-sifive-vector-builtin-sema",
+        clEnumValN(GenRISCVSiFiveVectorBuiltinSema,
+                   "gen-riscv-sifive-vector-builtin-sema",
                    "Generate riscv_sifive_vector_builtin_sema.inc for clang"),
         clEnumValN(GenAttrDocs, "gen-attr-docs",
                    "Generate attribute documentation"),
@@ -355,8 +360,8 @@ bool ClangTableGenMain(raw_ostream &OS, RecordKeeper &Records) {
   case GenClangAttrPCHWrite:
     EmitClangAttrPCHWrite(Records, OS);
     break;
-  case GenClangAttrTokenKinds:
-    EmitClangAttrTokenKinds(Records, OS);
+  case GenClangRegularKeywordAttributeInfo:
+    EmitClangRegularKeywordAttributeInfo(Records, OS);
     break;
   case GenClangAttrHasAttributeImpl:
     EmitClangAttrHasAttrImpl(Records, OS);
diff --git a/clang/utils/TableGen/TableGenBackends.h b/clang/utils/TableGen/TableGenBackends.h
index faa0c5d..58a4af3 100644
--- a/clang/utils/TableGen/TableGenBackends.h
+++ b/clang/utils/TableGen/TableGenBackends.h
@@ -53,8 +53,8 @@ void EmitClangAttrSubjectMatchRuleList(llvm::RecordKeeper &Records,
                                        llvm::raw_ostream &OS);
 void EmitClangAttrPCHRead(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
 void EmitClangAttrPCHWrite(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
-void EmitClangAttrTokenKinds(llvm::RecordKeeper &Records,
-                             llvm::raw_ostream &OS);
+void EmitClangRegularKeywordAttributeInfo(llvm::RecordKeeper &Records,
+                                          llvm::raw_ostream &OS);
 void EmitClangAttrHasAttrImpl(llvm::RecordKeeper &Records,
                               llvm::raw_ostream &OS);
 void EmitClangAttrSpellingListIndex(llvm::RecordKeeper &Records,