[CIR][Dialect] Add address space attribute to global op (llvm#779)

This PR adds the CIR address space attribute to GlobalOp and starts to
resolve the missing feature flag `addressSpaceInGlobalVar`.

The same asm format in pointer type is used:

```
cir.global external addrspace(offload_global) @addrspace1 = #cir.int<1> : !s32i
```

The parsing and printing helper is extracted into a common function to
be reused by both `GlobalOp` and `PointerType` with two custom format
proxy to it. That's because the signature of ODS generated method
differs from the one for PointerType.

Lowering to LLVM IR and CIRGen will come sequentially.

Author: seven-mile

clang/include/clang/CIR/Dialect/IR/CIROps.td

@@ -2157,6 +2157,7 @@ def GlobalOp : CIR_Op<"global",
                        OptionalAttr<StrAttr>:$sym_visibility,
                        TypeAttr:$sym_type,
                        Arg<GlobalLinkageKind, "linkage type">:$linkage,
+                       OptionalAttr<AddressSpaceAttr>:$addr_space,
                        OptionalAttr<TLSModel>:$tls_model,
                        // Note this can also be a FlatSymbolRefAttr
                        OptionalAttr<AnyAttr>:$initial_value,
@@ -2175,6 +2176,7 @@ def GlobalOp : CIR_Op<"global",
        (`comdat` $comdat^)?
        ($tls_model^)?
        (`dsolocal` $dsolocal^)?
+       (`addrspace` `(` custom<GlobalOpAddrSpace>($addr_space)^ `)`)?
        $sym_name
        custom<GlobalOpTypeAndInitialValue>($sym_type, $initial_value, $ctorRegion, $dtorRegion)
        attr-dict
@@ -2202,6 +2204,7 @@ def GlobalOp : CIR_Op<"global",
       // CIR defaults to external linkage.
       CArg<"cir::GlobalLinkageKind",
             "cir::GlobalLinkageKind::ExternalLinkage">:$linkage,
+      CArg<"cir::AddressSpaceAttr", "{}">:$addrSpace,
       CArg<"function_ref<void(OpBuilder &, Location)>",
            "nullptr">:$ctorBuilder,
       CArg<"function_ref<void(OpBuilder &, Location)>",

clang/include/clang/CIR/Dialect/IR/CIRTypes.h

@@ -183,6 +183,11 @@ bool isFPOrFPVectorTy(mlir::Type);
 } // namespace cir
 } // namespace mlir
 
+mlir::ParseResult parseAddrSpaceAttribute(mlir::AsmParser &p,
+                                          mlir::Attribute &addrSpaceAttr);
+void printAddrSpaceAttribute(mlir::AsmPrinter &p,
+                             mlir::Attribute addrSpaceAttr);
+
 //===----------------------------------------------------------------------===//
 // CIR Dialect Tablegen'd Types
 //===----------------------------------------------------------------------===//

clang/lib/CIR/CodeGen/CIRGenBuilder.h

@@ -655,10 +655,12 @@ class CIRGenBuilderTy : public CIRBaseBuilderTy {
   [[nodiscard]] mlir::cir::GlobalOp
   createGlobal(mlir::ModuleOp module, mlir::Location loc, mlir::StringRef name,
                mlir::Type type, bool isConst,
-               mlir::cir::GlobalLinkageKind linkage) {
+               mlir::cir::GlobalLinkageKind linkage,
+               mlir::cir::AddressSpaceAttr addrSpace = {}) {
     mlir::OpBuilder::InsertionGuard guard(*this);
     setInsertionPointToStart(module.getBody());
-    return create<mlir::cir::GlobalOp>(loc, name, type, isConst, linkage);
+    return create<mlir::cir::GlobalOp>(loc, name, type, isConst, linkage,
+                                       addrSpace);
   }
 
   /// Creates a versioned global variable. If the symbol is already taken, an ID
@@ -667,15 +669,17 @@ class CIRGenBuilderTy : public CIRBaseBuilderTy {
   [[nodiscard]] mlir::cir::GlobalOp
   createVersionedGlobal(mlir::ModuleOp module, mlir::Location loc,
                         mlir::StringRef name, mlir::Type type, bool isConst,
-                        mlir::cir::GlobalLinkageKind linkage) {
+                        mlir::cir::GlobalLinkageKind linkage,
+                        mlir::cir::AddressSpaceAttr addrSpace = {}) {
     // Create a unique name if the given name is already taken.
     std::string uniqueName;
     if (unsigned version = GlobalsVersioning[name.str()]++)
       uniqueName = name.str() + "." + std::to_string(version);
     else
       uniqueName = name.str();
 
-    return createGlobal(module, loc, uniqueName, type, isConst, linkage);
+    return createGlobal(module, loc, uniqueName, type, isConst, linkage,
+                        addrSpace);
   }
 
   mlir::Value createGetGlobal(mlir::cir::GlobalOp global,

clang/lib/CIR/Dialect/IR/CIRDialect.cpp

@@ -1781,6 +1781,16 @@ static void printConstant(OpAsmPrinter &p, Attribute value) {
   p.printAttribute(value);
 }
 
+static ParseResult parseGlobalOpAddrSpace(OpAsmParser &p,
+                                          AddressSpaceAttr &addrSpaceAttr) {
+  return parseAddrSpaceAttribute(p, addrSpaceAttr);
+}
+
+static void printGlobalOpAddrSpace(OpAsmPrinter &p, GlobalOp op,
+                                   AddressSpaceAttr addrSpaceAttr) {
+  printAddrSpaceAttribute(p, addrSpaceAttr);
+}
+
 static void printGlobalOpTypeAndInitialValue(OpAsmPrinter &p, GlobalOp op,
                                              TypeAttr type, Attribute initAttr,
                                              mlir::Region &ctorRegion,
@@ -1954,6 +1964,7 @@ LogicalResult GlobalOp::verify() {
 void GlobalOp::build(OpBuilder &odsBuilder, OperationState &odsState,
                      StringRef sym_name, Type sym_type, bool isConstant,
                      cir::GlobalLinkageKind linkage,
+                     cir::AddressSpaceAttr addrSpace,
                      function_ref<void(OpBuilder &, Location)> ctorBuilder,
                      function_ref<void(OpBuilder &, Location)> dtorBuilder) {
   odsState.addAttribute(getSymNameAttrName(odsState.name),
@@ -1968,6 +1979,9 @@ void GlobalOp::build(OpBuilder &odsBuilder, OperationState &odsState,
       cir::GlobalLinkageKindAttr::get(odsBuilder.getContext(), linkage);
   odsState.addAttribute(getLinkageAttrName(odsState.name), linkageAttr);
 
+  if (addrSpace)
+    odsState.addAttribute(getAddrSpaceAttrName(odsState.name), addrSpace);
+
   Region *ctorRegion = odsState.addRegion();
   if (ctorBuilder) {
     odsBuilder.createBlock(ctorRegion);

clang/lib/CIR/Dialect/IR/CIRTypes.cpp

@@ -945,8 +945,8 @@ PointerType::verify(llvm::function_ref<mlir::InFlightDiagnostic()> emitError,
   return mlir::success();
 }
 
-mlir::ParseResult parsePointerAddrSpace(mlir::AsmParser &p,
-                                        mlir::Attribute &addrSpaceAttr) {
+mlir::ParseResult parseAddrSpaceAttribute(mlir::AsmParser &p,
+                                          mlir::Attribute &addrSpaceAttr) {
   using mlir::cir::AddressSpaceAttr;
   auto attrLoc = p.getCurrentLocation();
 
@@ -978,8 +978,8 @@ mlir::ParseResult parsePointerAddrSpace(mlir::AsmParser &p,
   return mlir::success();
 }
 
-void printPointerAddrSpace(mlir::AsmPrinter &p,
-                           mlir::Attribute rawAddrSpaceAttr) {
+void printAddrSpaceAttribute(mlir::AsmPrinter &p,
+                             mlir::Attribute rawAddrSpaceAttr) {
   using mlir::cir::AddressSpaceAttr;
   auto addrSpaceAttr = mlir::cast<AddressSpaceAttr>(rawAddrSpaceAttr);
   if (addrSpaceAttr.isTarget()) {
@@ -990,6 +990,16 @@ void printPointerAddrSpace(mlir::AsmPrinter &p,
   }
 }
 
+mlir::ParseResult parsePointerAddrSpace(mlir::AsmParser &p,
+                                        mlir::Attribute &addrSpaceAttr) {
+  return parseAddrSpaceAttribute(p, addrSpaceAttr);
+}
+
+void printPointerAddrSpace(mlir::AsmPrinter &p,
+                           mlir::Attribute rawAddrSpaceAttr) {
+  printAddrSpaceAttribute(p, rawAddrSpaceAttr);
+}
+
 //===----------------------------------------------------------------------===//
 // CIR Dialect
 //===----------------------------------------------------------------------===//

clang/test/CIR/IR/global.cir

@@ -69,6 +69,10 @@ module {
     %0 = cir.get_global thread_local @batata : !cir.ptr<!s32i>
     cir.return
   }
+
+  cir.global external addrspace(offload_global) @addrspace1 = #cir.int<1> : !s32i
+  cir.global "private" internal addrspace(offload_local) @addrspace2 : !s32i
+  cir.global external addrspace(target<1>) @addrspace3 = #cir.int<3> : !s32i
 }
 
 // CHECK: cir.global external @a = #cir.int<3> : !s32i
@@ -103,4 +107,8 @@ module {
 // CHECK: cir.func @f35() {
 // CHECK:   %0 = cir.get_global thread_local @batata : !cir.ptr<!s32i>
 // CHECK:   cir.return
-// CHECK: }
+// CHECK: }
+
+// CHECK: cir.global external addrspace(offload_global) @addrspace1 = #cir.int<1> : !s32i
+// CHECK: cir.global "private" internal addrspace(offload_local) @addrspace2 : !s32i
+// CHECK: cir.global external addrspace(target<1>) @addrspace3 = #cir.int<3> : !s32i