[CIR][CIRGen] Add initial __thread support

Author: bcardosolopes

clang/lib/CIR/CodeGen/CIRGenModule.cpp

@@ -609,16 +609,33 @@ void CIRGenModule::replaceGlobal(mlir::cir::GlobalOp Old,
   Old.erase();
 }
 
+mlir::cir::TLS_Model CIRGenModule::GetDefaultCIRTLSModel() const {
+  switch (getCodeGenOpts().getDefaultTLSModel()) {
+  case CodeGenOptions::GeneralDynamicTLSModel:
+    return mlir::cir::TLS_Model::GeneralDynamic;
+  case CodeGenOptions::LocalDynamicTLSModel:
+    return mlir::cir::TLS_Model::LocalDynamic;
+  case CodeGenOptions::InitialExecTLSModel:
+    return mlir::cir::TLS_Model::InitialExec;
+  case CodeGenOptions::LocalExecTLSModel:
+    return mlir::cir::TLS_Model::LocalExec;
+  }
+  llvm_unreachable("Invalid TLS model!");
+}
+
 void CIRGenModule::setTLSMode(mlir::Operation *Op, const VarDecl &D) const {
   assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
-  llvm_unreachable("NYI");
+
+  auto TLM = GetDefaultCIRTLSModel();
 
   // Override the TLS model if it is explicitly specified.
   if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
     llvm_unreachable("NYI");
   }
 
-  llvm_unreachable("NYI");
+  auto global = dyn_cast<mlir::cir::GlobalOp>(Op);
+  assert(global && "NYI for other operations");
+  global.setTlsModel(TLM);
 }
 
 /// If the specified mangled name is not in the module,
@@ -1115,9 +1132,10 @@ void CIRGenModule::buildGlobalVarDefinition(const clang::VarDecl *D,
 
   // TODO(cir): setNonAliasAttributes(D, GV);
 
-  // TODO(cir): handle TLSKind if GV is not thread local
-  if (D->getTLSKind()) { // && !GV->isThreadLocal())
-    assert(0 && "not implemented");
+  if (D->getTLSKind() && !GV.getTlsModelAttr()) {
+    if (D->getTLSKind() == VarDecl::TLS_Dynamic)
+      llvm_unreachable("NYI");
+    setTLSMode(GV, *D);
   }
 
   // TODO(cir): maybeSetTrivialComdat(*D, *GV);

clang/lib/CIR/CodeGen/CIRGenModule.h

@@ -471,6 +471,9 @@ class CIRGenModule : public CIRGenTypeCache {
   /// variable declaration D.
   void setTLSMode(mlir::Operation *Op, const VarDecl &D) const;
 
+  /// Get TLS mode from CodeGenOptions.
+  mlir::cir::TLS_Model GetDefaultCIRTLSModel() const;
+
   /// Replace the present global `Old` with the given global `New`. Their symbol
   /// names must match; their types can be different. Usages of the old global
   /// will be automatically updated if their types mismatch.

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -1727,9 +1727,12 @@ class CIRGlobalOpLowering
   inline void setupRegionInitializedLLVMGlobalOp(
       mlir::cir::GlobalOp op, mlir::ConversionPatternRewriter &rewriter) const {
     const auto llvmType = getTypeConverter()->convertType(op.getSymType());
+    SmallVector<mlir::NamedAttribute> attributes;
     auto newGlobalOp = rewriter.replaceOpWithNewOp<mlir::LLVM::GlobalOp>(
         op, llvmType, op.getConstant(), convertLinkage(op.getLinkage()),
-        op.getSymName(), nullptr);
+        op.getSymName(), nullptr, /*alignment*/ 0, /*addrSpace*/ 0,
+        /*dsoLocal*/ false, /*threadLocal*/ (bool)op.getTlsModelAttr(),
+        /*comdat*/ mlir::SymbolRefAttr(), attributes);
     newGlobalOp.getRegion().push_back(new mlir::Block());
     rewriter.setInsertionPointToEnd(newGlobalOp.getInitializerBlock());
   }
@@ -1757,7 +1760,7 @@ class CIRGlobalOpLowering
       rewriter.replaceOpWithNewOp<mlir::LLVM::GlobalOp>(
           op, llvmType, isConst, linkage, symbol, mlir::Attribute(),
           /*alignment*/ 0, /*addrSpace*/ 0,
-          /*dsoLocal*/ false, /*threadLocal*/ false,
+          /*dsoLocal*/ false, /*threadLocal*/ (bool)op.getTlsModelAttr(),
           /*comdat*/ mlir::SymbolRefAttr(), attributes);
       return mlir::success();
     }
@@ -1837,7 +1840,7 @@ class CIRGlobalOpLowering
     rewriter.replaceOpWithNewOp<mlir::LLVM::GlobalOp>(
         op, llvmType, isConst, linkage, symbol, init.value(),
         /*alignment*/ 0, /*addrSpace*/ 0,
-        /*dsoLocal*/ false, /*threadLocal*/ false,
+        /*dsoLocal*/ false, /*threadLocal*/ (bool)op.getTlsModelAttr(),
         /*comdat*/ mlir::SymbolRefAttr(), attributes);
     return mlir::success();
   }

clang/test/CIR/CodeGen/tls.c

@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir-enable -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir-enable -emit-llvm %s -o %t.ll
+// RUN: FileCheck --check-prefix=LLVM --input-file=%t.ll %s
+
+__thread int a;
+// CIR: cir.global external tls_dyn @a = #cir.int<0> : !s32i
+// LLVM: @a = thread_local global i32 0