[CIR] Upstream AddressSpace conversions support (#161212)

RiverDave · web-flow · commit 8f9071651d1d · 2025-11-12T19:35:45.000-05:00
related: #160386 Add support for address space conversions in CIR. - Added `createAddrSpaceCast` methods to `CIRBaseBuilderTy` to handle address space conversions - Implemented address space conversion handling in `emitCastLValue` and `VisitCastExpr` - Added `performAddrSpaceCast` method to `TargetCIRGenInfo` for target-specific address space casting - Added `getLangTempAllocaAddressSpace` to `CIRGenModule` to get the language-specific address space for temporary allocations - Added a test file `address-space-conversion.cpp` to verify address space conversion functionality
diff --git a/clang/include/clang/CIR/Dialect/Builder/CIRBaseBuilder.h b/clang/include/clang/CIR/Dialect/Builder/CIRBaseBuilder.h
@@ -465,6 +465,15 @@ class CIRBaseBuilderTy : public mlir::OpBuilder {
     return createCompare(ptr.getLoc(), cir::CmpOpKind::eq, ptr, nullPtr);
   }
 
+  mlir::Value createAddrSpaceCast(mlir::Location loc, mlir::Value src,
+                                  mlir::Type newTy) {
+    return createCast(loc, cir::CastKind::address_space, src, newTy);
+  }
+
+  mlir::Value createAddrSpaceCast(mlir::Value src, mlir::Type newTy) {
+    return createAddrSpaceCast(src.getLoc(), src, newTy);
+  }
+
   //===--------------------------------------------------------------------===//
   // Binary Operators
   //===--------------------------------------------------------------------===//
diff --git a/clang/include/clang/CIR/Dialect/IR/CIRTypes.h b/clang/include/clang/CIR/Dialect/IR/CIRTypes.h
@@ -13,7 +13,9 @@
 #ifndef CLANG_CIR_DIALECT_IR_CIRTYPES_H
 #define CLANG_CIR_DIALECT_IR_CIRTYPES_H
 
+#include "mlir/IR/Attributes.h"
 #include "mlir/IR/BuiltinAttributes.h"
+#include "mlir/IR/MLIRContext.h"
 #include "mlir/IR/Types.h"
 #include "mlir/Interfaces/DataLayoutInterfaces.h"
 #include "clang/Basic/AddressSpaces.h"
@@ -38,6 +40,15 @@ bool isValidFundamentalIntWidth(unsigned width);
 /// void, or abstract types.
 bool isSized(mlir::Type ty);
 
+//===----------------------------------------------------------------------===//
+// AddressSpace helpers
+//===----------------------------------------------------------------------===//
+cir::TargetAddressSpaceAttr toCIRTargetAddressSpace(mlir::MLIRContext &context,
+                                                    clang::LangAS langAS);
+
+bool isMatchingAddressSpace(cir::TargetAddressSpaceAttr cirAS,
+                            clang::LangAS as);
+
 } // namespace cir
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/CIR/CodeGen/Address.h b/clang/lib/CIR/CodeGen/Address.h
@@ -16,9 +16,11 @@
 
 #include "mlir/IR/Value.h"
 #include "clang/AST/CharUnits.h"
+#include "clang/CIR/Dialect/IR/CIRAttrs.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
 #include "clang/CIR/MissingFeatures.h"
 #include "llvm/ADT/PointerIntPair.h"
+#include "llvm/Support/Casting.h"
 
 namespace clang::CIRGen {
 
@@ -114,6 +116,11 @@ class Address {
     return elementType;
   }
 
+  cir::TargetAddressSpaceAttr getAddressSpace() const {
+    auto ptrTy = mlir::dyn_cast<cir::PointerType>(getType());
+    return ptrTy.getAddrSpace();
+  }
+
   clang::CharUnits getAlignment() const { return alignment; }
 
   /// Get the operation which defines this address.
diff --git a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "CIRGenCall.h"
-#include "CIRGenConstantEmitter.h"
 #include "CIRGenFunction.h"
 #include "CIRGenModule.h"
 #include "CIRGenValue.h"
@@ -22,6 +21,7 @@
 #include "clang/AST/Expr.h"
 #include "clang/AST/GlobalDecl.h"
 #include "clang/Basic/Builtins.h"
+#include "clang/CIR/Dialect/IR/CIRTypes.h"
 #include "clang/CIR/MissingFeatures.h"
 #include "llvm/Support/ErrorHandling.h"
 
@@ -193,11 +193,16 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
     // default (e.g. in C / C++ auto vars are in the generic address space). At
     // the AST level this is handled within CreateTempAlloca et al., but for the
     // builtin / dynamic alloca we have to handle it here.
-    assert(!cir::MissingFeatures::addressSpace());
+
+    if (!cir::isMatchingAddressSpace(
+            getCIRAllocaAddressSpace(),
+            e->getType()->getPointeeType().getAddressSpace())) {
+      cgm.errorNYI(e->getSourceRange(), "Non-default address space for alloca");
+    }
 
     // Bitcast the alloca to the expected type.
-    return RValue::get(
-        builder.createBitcast(allocaAddr, builder.getVoidPtrTy()));
+    return RValue::get(builder.createBitcast(
+        allocaAddr, builder.getVoidPtrTy(getCIRAllocaAddressSpace())));
   }
 
   case Builtin::BIcos:
diff --git a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
@@ -22,7 +22,11 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
+#include "clang/Basic/AddressSpaces.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/CIR/Dialect/IR/CIRAttrs.h"
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
+#include "clang/CIR/Dialect/IR/CIRTypes.h"
 #include "clang/CIR/MissingFeatures.h"
 #include <optional>
 
@@ -1205,7 +1209,6 @@ LValue CIRGenFunction::emitCastLValue(const CastExpr *e) {
   case CK_AtomicToNonAtomic:
   case CK_ToUnion:
   case CK_BaseToDerived:
-  case CK_AddressSpaceConversion:
   case CK_ObjCObjectLValueCast:
   case CK_VectorSplat:
   case CK_ConstructorConversion:
@@ -1219,7 +1222,27 @@ LValue CIRGenFunction::emitCastLValue(const CastExpr *e) {
 
     return {};
   }
+  case CK_AddressSpaceConversion: {
+    LValue lv = emitLValue(e->getSubExpr());
+    QualType destTy = getContext().getPointerType(e->getType());
+
+    clang::LangAS srcLangAS = e->getSubExpr()->getType().getAddressSpace();
+    cir::TargetAddressSpaceAttr srcAS;
+    if (clang::isTargetAddressSpace(srcLangAS))
+      srcAS = cir::toCIRTargetAddressSpace(getMLIRContext(), srcLangAS);
+    else
+      cgm.errorNYI(
+          e->getSourceRange(),
+          "emitCastLValue: address space conversion from unknown address "
+          "space");
 
+    mlir::Value v = getTargetHooks().performAddrSpaceCast(
+        *this, lv.getPointer(), srcAS, convertType(destTy));
+
+    return makeAddrLValue(Address(v, convertTypeForMem(e->getType()),
+                                  lv.getAddress().getAlignment()),
+                          e->getType(), lv.getBaseInfo());
+  }
   case CK_LValueBitCast: {
     // This must be a reinterpret_cast (or c-style equivalent).
     const auto *ce = cast<ExplicitCastExpr>(e);
@@ -2233,6 +2256,8 @@ Address CIRGenFunction::createTempAllocaWithoutCast(
 
 /// This creates a alloca and inserts it into the entry block. The alloca is
 /// casted to default address space if necessary.
+// TODO(cir): Implement address space casting to match classic codegen's
+// CreateTempAlloca behavior with DestLangAS parameter
 Address CIRGenFunction::createTempAlloca(mlir::Type ty, CharUnits align,
                                          mlir::Location loc, const Twine &name,
                                          mlir::Value arraySize,
@@ -2247,7 +2272,21 @@ Address CIRGenFunction::createTempAlloca(mlir::Type ty, CharUnits align,
   // be different from the type defined by the language. For example,
   // in C++ the auto variables are in the default address space. Therefore
   // cast alloca to the default address space when necessary.
-  assert(!cir::MissingFeatures::addressSpace());
+
+  LangAS allocaAS = alloca.getAddressSpace()
+                        ? clang::getLangASFromTargetAS(
+                              alloca.getAddressSpace().getValue().getUInt())
+                        : clang::LangAS::Default;
+  LangAS dstTyAS = clang::LangAS::Default;
+  if (getCIRAllocaAddressSpace()) {
+    dstTyAS = clang::getLangASFromTargetAS(
+        getCIRAllocaAddressSpace().getValue().getUInt());
+  }
+
+  if (dstTyAS != allocaAS) {
+    getTargetHooks().performAddrSpaceCast(*this, v, getCIRAllocaAddressSpace(),
+                                          builder.getPointerTo(ty, dstTyAS));
+  }
   return Address(v, ty, align);
 }
 
diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -15,6 +15,7 @@
 
 #include "clang/AST/Expr.h"
 #include "clang/AST/StmtVisitor.h"
+#include "clang/CIR/Dialect/IR/CIRTypes.h"
 #include "clang/CIR/MissingFeatures.h"
 
 #include "mlir/IR/Location.h"
@@ -91,6 +92,7 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
   //===--------------------------------------------------------------------===//
   //                               Utilities
   //===--------------------------------------------------------------------===//
+  mlir::Type convertType(QualType ty) { return cgf.convertType(ty); }
 
   mlir::Value emitComplexToScalarConversion(mlir::Location loc,
                                             mlir::Value value, CastKind kind,
@@ -1888,6 +1890,35 @@ mlir::Value ScalarExprEmitter::VisitCastExpr(CastExpr *ce) {
     return cgf.getBuilder().createBitcast(cgf.getLoc(subExpr->getSourceRange()),
                                           src, dstTy);
   }
+  case CK_AddressSpaceConversion: {
+    Expr::EvalResult result;
+    if (subExpr->EvaluateAsRValue(result, cgf.getContext()) &&
+        result.Val.isNullPointer()) {
+      // If e has side effect, it is emitted even if its final result is a
+      // null pointer. In that case, a DCE pass should be able to
+      // eliminate the useless instructions emitted during translating E.
+      if (result.HasSideEffects)
+        Visit(subExpr);
+      return cgf.cgm.emitNullConstant(destTy,
+                                      cgf.getLoc(subExpr->getExprLoc()));
+    }
+
+    clang::QualType srcTy = subExpr->IgnoreImpCasts()->getType();
+    if (srcTy->isPointerType() || srcTy->isReferenceType())
+      srcTy = srcTy->getPointeeType();
+
+    clang::LangAS srcLangAS = srcTy.getAddressSpace();
+    cir::TargetAddressSpaceAttr subExprAS;
+    if (clang::isTargetAddressSpace(srcLangAS))
+      subExprAS = cir::toCIRTargetAddressSpace(cgf.getMLIRContext(), srcLangAS);
+    else
+      cgf.cgm.errorNYI(subExpr->getSourceRange(),
+                       "non-target address space conversion");
+    // Since target may map different address spaces in AST to the same address
+    // space, an address space conversion may end up as a bitcast.
+    return cgf.cgm.getTargetCIRGenInfo().performAddrSpaceCast(
+        cgf, Visit(subExpr), subExprAS, convertType(destTy));
+  }
 
   case CK_AtomicToNonAtomic: {
     cgf.getCIRGenModule().errorNYI(subExpr->getSourceRange(),
diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.h b/clang/lib/CIR/CodeGen/CIRGenFunction.h
@@ -222,6 +222,10 @@ class CIRGenFunction : public CIRGenTypeCache {
   const TargetInfo &getTarget() const { return cgm.getTarget(); }
   mlir::MLIRContext &getMLIRContext() { return cgm.getMLIRContext(); }
 
+  const TargetCIRGenInfo &getTargetHooks() const {
+    return cgm.getTargetCIRGenInfo();
+  }
+
   // ---------------------
   // Opaque value handling
   // ---------------------
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
@@ -1424,6 +1424,23 @@ CIRGenModule::getAddrOfConstantStringFromLiteral(const StringLiteral *s,
   return builder.getGlobalViewAttr(ptrTy, gv);
 }
 
+// TODO(cir): this could be a common AST helper for both CIR and LLVM codegen.
+LangAS CIRGenModule::getLangTempAllocaAddressSpace() const {
+  if (getLangOpts().OpenCL)
+    return LangAS::opencl_private;
+
+  // For temporaries inside functions, CUDA treats them as normal variables.
+  // LangAS::cuda_device, on the other hand, is reserved for those variables
+  // explicitly marked with __device__.
+  if (getLangOpts().CUDAIsDevice)
+    return LangAS::Default;
+
+  if (getLangOpts().SYCLIsDevice ||
+      (getLangOpts().OpenMP && getLangOpts().OpenMPIsTargetDevice))
+    errorNYI("SYCL or OpenMP temp address space");
+  return LangAS::Default;
+}
+
 void CIRGenModule::emitExplicitCastExprType(const ExplicitCastExpr *e,
                                             CIRGenFunction *cgf) {
   if (cgf && e->getType()->isVariablyModifiedType())
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.h b/clang/lib/CIR/CodeGen/CIRGenModule.h
@@ -297,6 +297,12 @@ class CIRGenModule : public CIRGenTypeCache {
   getAddrOfConstantStringFromLiteral(const StringLiteral *s,
                                      llvm::StringRef name = ".str");
 
+  /// Returns the address space for temporary allocations in the language. This
+  /// ensures that the allocated variable's address space matches the
+  /// expectations of the AST, rather than using the target's allocation address
+  /// space, which may lead to type mismatches in other parts of the IR.
+  LangAS getLangTempAllocaAddressSpace() const;
+
   /// Set attributes which are common to any form of a global definition (alias,
   /// Objective-C method, function, global variable).
   ///
diff --git a/clang/lib/CIR/CodeGen/CIRGenTypes.cpp b/clang/lib/CIR/CodeGen/CIRGenTypes.cpp
@@ -404,7 +404,7 @@ mlir::Type CIRGenTypes::convertType(QualType type) {
     const ReferenceType *refTy = cast<ReferenceType>(ty);
     QualType elemTy = refTy->getPointeeType();
     auto pointeeType = convertTypeForMem(elemTy);
-    resultType = builder.getPointerTo(pointeeType);
+    resultType = builder.getPointerTo(pointeeType, elemTy.getAddressSpace());
     assert(resultType && "Cannot get pointer type?");
     break;
   }
diff --git a/clang/lib/CIR/CodeGen/TargetInfo.cpp b/clang/lib/CIR/CodeGen/TargetInfo.cpp
@@ -1,5 +1,8 @@
 #include "TargetInfo.h"
 #include "ABIInfo.h"
+#include "CIRGenFunction.h"
+#include "clang/CIR/Dialect/IR/CIRAttrs.h"
+#include "clang/CIR/Dialect/IR/CIRDialect.h"
 
 using namespace clang;
 using namespace clang::CIRGen;
@@ -68,3 +71,14 @@ bool TargetCIRGenInfo::isNoProtoCallVariadic(
   // For everything else, we just prefer false unless we opt out.
   return false;
 }
+
+mlir::Value TargetCIRGenInfo::performAddrSpaceCast(
+    CIRGenFunction &cgf, mlir::Value v, cir::TargetAddressSpaceAttr srcAddr,
+    mlir::Type destTy, bool isNonNull) const {
+  // Since target may map different address spaces in AST to the same address
+  // space, an address space conversion may end up as a bitcast.
+  if (cir::GlobalOp globalOp = v.getDefiningOp<cir::GlobalOp>())
+    cgf.cgm.errorNYI("Global op addrspace cast");
+  // Try to preserve the source's name to make IR more readable.
+  return cgf.getBuilder().createAddrSpaceCast(v, destTy);
+}
diff --git a/clang/lib/CIR/CodeGen/TargetInfo.h b/clang/lib/CIR/CodeGen/TargetInfo.h
@@ -17,6 +17,7 @@
 #include "ABIInfo.h"
 #include "CIRGenTypes.h"
 #include "clang/Basic/AddressSpaces.h"
+#include "clang/CIR/Dialect/IR/CIRAttrs.h"
 
 #include <memory>
 #include <utility>
@@ -33,6 +34,8 @@ bool isEmptyFieldForLayout(const ASTContext &context, const FieldDecl *fd);
 /// if the [[no_unique_address]] attribute would have made them empty.
 bool isEmptyRecordForLayout(const ASTContext &context, QualType t);
 
+class CIRGenFunction;
+
 class TargetCIRGenInfo {
   std::unique_ptr<ABIInfo> info;
 
@@ -48,6 +51,15 @@ class TargetCIRGenInfo {
   virtual cir::TargetAddressSpaceAttr getCIRAllocaAddressSpace() const {
     return {};
   }
+  /// Perform address space cast of an expression of pointer type.
+  /// \param V is the value to be casted to another address space.
+  /// \param DestTy is the destination pointer type.
+  /// \param srcAS is theaddress space of \p V.
+  /// \param IsNonNull is the flag indicating \p V is known to be non null.
+  virtual mlir::Value performAddrSpaceCast(CIRGenFunction &cgf, mlir::Value v,
+                                           cir::TargetAddressSpaceAttr srcAddr,
+                                           mlir::Type destTy,
+                                           bool isNonNull = false) const;
 
   /// Determine whether a call to an unprototyped functions under
   /// the given calling convention should use the variadic
diff --git a/clang/lib/CIR/Dialect/IR/CIRDialect.cpp b/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
@@ -383,6 +383,16 @@ LogicalResult cir::CastOp::verify() {
   mlir::Type resType = getType();
   mlir::Type srcType = getSrc().getType();
 
+  // Verify address space casts for pointer types. given that
+  // casts for within a different address space are illegal.
+  auto srcPtrTy = mlir::dyn_cast<cir::PointerType>(srcType);
+  auto resPtrTy = mlir::dyn_cast<cir::PointerType>(resType);
+  if (srcPtrTy && resPtrTy && (getKind() != cir::CastKind::address_space))
+    if (srcPtrTy.getAddrSpace() != resPtrTy.getAddrSpace()) {
+      return emitOpError() << "result type address space does not match the "
+                              "address space of the operand";
+    }
+
   if (mlir::isa<cir::VectorType>(srcType) &&
       mlir::isa<cir::VectorType>(resType)) {
     // Use the element type of the vector to verify the cast kind. (Except for
diff --git a/clang/lib/CIR/Dialect/IR/CIRTypes.cpp b/clang/lib/CIR/Dialect/IR/CIRTypes.cpp
diff --git a/clang/test/CIR/CodeGen/address-space-conversion.cpp b/clang/test/CIR/CodeGen/address-space-conversion.cpp
diff --git a/clang/test/CIR/IR/invalid-addrspace.cir b/clang/test/CIR/IR/invalid-addrspace.cir

Original file line number	Diff line number	Diff line change
`@@ -404,7 +404,7 @@ mlir::Type CIRGenTypes::convertType(QualType type) {`
`404`	`404`	`const ReferenceType *refTy = cast<ReferenceType>(ty);`
`405`	`405`	`QualType elemTy = refTy->getPointeeType();`
`406`	`406`	`auto pointeeType = convertTypeForMem(elemTy);`
`407`		`- resultType = builder.getPointerTo(pointeeType);`
	`407`	`+ resultType = builder.getPointerTo(pointeeType, elemTy.getAddressSpace());`
`408`	`408`	`assert(resultType && "Cannot get pointer type?");`
`409`	`409`	`break;`
`410`	`410`	`}`