[CIR][ThroughMLIR] Lower structs and GetMemberOp.

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

@@ -589,8 +589,8 @@ uint64_t RecordType::getElementOffset(const ::mlir::DataLayout &dataLayout,
   // offset we are calculating.
   const llvm::Align tyAlign = llvm::Align(
       getPacked() ? 1 : dataLayout.getTypeABIAlignment(members[idx]));
-  offset = llvm::alignTo(offset, tyAlign);
 
+  offset = llvm::alignTo(offset, tyAlign);
   return offset;
 }
 
@@ -781,8 +781,8 @@ LongDoubleType::getTypeSizeInBits(const mlir::DataLayout &dataLayout,
 uint64_t
 LongDoubleType::getABIAlignment(const mlir::DataLayout &dataLayout,
                                 mlir::DataLayoutEntryListRef params) const {
-  return mlir::cast<mlir::DataLayoutTypeInterface>(getUnderlying()).getABIAlignment(
-      dataLayout, params);
+  return mlir::cast<mlir::DataLayoutTypeInterface>(getUnderlying())
+      .getABIAlignment(dataLayout, params);
 }
 
 //===----------------------------------------------------------------------===//

clang/lib/CIR/Lowering/ThroughMLIR/LowerCIRToMLIR.cpp

@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "LowerToMLIRHelpers.h"
+#include "mlir/Analysis/DataLayoutAnalysis.h"
 #include "mlir/Conversion/AffineToStandard/AffineToStandard.h"
 #include "mlir/Conversion/ArithToLLVM/ArithToLLVM.h"
 #include "mlir/Conversion/ControlFlowToLLVM/ControlFlowToLLVM.h"
@@ -35,8 +36,10 @@
 #include "mlir/IR/Operation.h"
 #include "mlir/IR/Region.h"
 #include "mlir/IR/TypeRange.h"
+#include "mlir/IR/Types.h"
 #include "mlir/IR/Value.h"
 #include "mlir/IR/ValueRange.h"
+#include "mlir/Interfaces/DataLayoutInterfaces.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Pass/PassManager.h"
 #include "mlir/Support/LLVM.h"
@@ -48,19 +51,17 @@
 #include "mlir/Transforms/DialectConversion.h"
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
+#include "clang/CIR/Interfaces/CIRLoopOpInterface.h"
 #include "clang/CIR/LowerToLLVM.h"
 #include "clang/CIR/LowerToMLIR.h"
 #include "clang/CIR/LoweringHelpers.h"
 #include "clang/CIR/Passes.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "clang/CIR/Interfaces/CIRLoopOpInterface.h"
-#include "clang/CIR/LowerToLLVM.h"
-#include "clang/CIR/Passes.h"
 #include "llvm/ADT/Sequence.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/TypeSwitch.h"
 #include "llvm/IR/Value.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/TimeProfiler.h"
 
 using namespace cir;
@@ -288,17 +289,17 @@ class CIRAllocaOpLowering : public mlir::OpConversionPattern<cir::AllocaOp> {
   matchAndRewrite(cir::AllocaOp op, OpAdaptor adaptor,
                   mlir::ConversionPatternRewriter &rewriter) const override {
 
-    mlir::Type mlirType =
-        convertTypeForMemory(*getTypeConverter(), adaptor.getAllocaType());
+    mlir::Type allocaType = adaptor.getAllocaType();
+    mlir::Type mlirType = convertTypeForMemory(*getTypeConverter(), allocaType);
 
     // FIXME: Some types can not be converted yet (e.g. struct)
     if (!mlirType)
       return mlir::LogicalResult::failure();
 
     auto memreftype = mlir::dyn_cast<mlir::MemRefType>(mlirType);
-    if (memreftype && mlir::isa<cir::ArrayType>(adaptor.getAllocaType())) {
-      // if the type is an array,
-      // we don't need to wrap with memref.
+    if (memreftype && (mlir::isa<cir::ArrayType>(allocaType) ||
+                       mlir::isa<cir::RecordType>(allocaType))) {
+      // Arrays and structs are already memref. No need to wrap another one.
     } else {
       memreftype = mlir::MemRefType::get({}, mlirType);
     }
@@ -946,8 +947,8 @@ class CIRScopeOpLowering : public mlir::OpConversionPattern<cir::ScopeOp> {
     } else {
       // For scopes with results, use scf.execute_region
       SmallVector<mlir::Type> types;
-      if (mlir::failed(
-              getTypeConverter()->convertTypes(scopeOp->getResultTypes(), types)))
+      if (mlir::failed(getTypeConverter()->convertTypes(
+              scopeOp->getResultTypes(), types)))
         return mlir::failure();
       auto exec =
           rewriter.create<mlir::scf::ExecuteRegionOp>(scopeOp.getLoc(), types);
@@ -1485,6 +1486,51 @@ class CIRPtrStrideOpLowering
   }
 };
 
+class CIRGetMemberOpLowering
+    : public mlir::OpConversionPattern<cir::GetMemberOp> {
+public:
+  CIRGetMemberOpLowering(mlir::TypeConverter &converter, mlir::MLIRContext *ctx,
+                         const mlir::DataLayout &layout)
+      : OpConversionPattern(converter, ctx), layout(layout) {}
+
+  mlir::LogicalResult
+  matchAndRewrite(cir::GetMemberOp op, OpAdaptor adaptor,
+                  mlir::ConversionPatternRewriter &rewriter) const override {
+
+    cir::PointerType ptrType = op.getAddr().getType();
+
+    auto structType = mlir::dyn_cast<cir::RecordType>(ptrType.getPointee());
+    if (!structType) {
+      return rewriter.notifyMatchFailure(
+          op, "expected RecordType as pointee of GetMemberOp base");
+    }
+
+    uint64_t byteOffset = structType.getElementOffset(layout, op.getIndex());
+    cir::PointerType fieldType = op.getResult().getType();
+    auto convertedType = getTypeConverter()->convertType(fieldType);
+    if (!convertedType) {
+      return rewriter.notifyMatchFailure(op, "failed to convert field type");
+    }
+
+    auto resultType = mlir::dyn_cast<mlir::MemRefType>(convertedType);
+    if (!resultType) {
+      return rewriter.notifyMatchFailure(
+          op, "expected MemRefType after type conversion");
+    }
+
+    mlir::Value offsetValue =
+        rewriter.create<mlir::arith::ConstantIndexOp>(op.getLoc(), byteOffset);
+
+    rewriter.replaceOpWithNewOp<mlir::memref::ViewOp>(
+        op, resultType, adaptor.getAddr(), offsetValue, mlir::ValueRange{});
+
+    return mlir::success();
+  }
+
+private:
+  const mlir::DataLayout &layout;
+};
+
 class CIRUnreachableOpLowering
     : public mlir::OpConversionPattern<cir::UnreachableOp> {
 public:
@@ -1516,37 +1562,41 @@ class CIRTrapOpLowering : public mlir::OpConversionPattern<cir::TrapOp> {
 };
 
 void populateCIRToMLIRConversionPatterns(mlir::RewritePatternSet &patterns,
-                                         mlir::TypeConverter &converter) {
+                                         mlir::TypeConverter &converter,
+                                         mlir::DataLayout layout) {
   patterns.add<CIRReturnLowering, CIRBrOpLowering>(patterns.getContext());
 
-  patterns
-      .add<CIRATanOpLowering, CIRCmpOpLowering, CIRCallOpLowering,
-           CIRUnaryOpLowering, CIRBinOpLowering, CIRLoadOpLowering,
-           CIRConstantOpLowering, CIRStoreOpLowering, CIRAllocaOpLowering,
-           CIRFuncOpLowering, CIRBrCondOpLowering,
-           CIRTernaryOpLowering, CIRYieldOpLowering, CIRCosOpLowering,
-           CIRGlobalOpLowering, CIRGetGlobalOpLowering, CIRCastOpLowering,
-           CIRPtrStrideOpLowering, CIRGetElementOpLowering, CIRSqrtOpLowering,
-           CIRCeilOpLowering, CIRExp2OpLowering, CIRExpOpLowering,
-           CIRFAbsOpLowering, CIRAbsOpLowering, CIRFloorOpLowering,
-           CIRLog10OpLowering, CIRLog2OpLowering, CIRLogOpLowering,
-           CIRRoundOpLowering, CIRSinOpLowering, CIRShiftOpLowering,
-           CIRBitClzOpLowering, CIRBitCtzOpLowering, CIRBitPopcountOpLowering,
-           CIRBitClrsbOpLowering, CIRBitFfsOpLowering, CIRBitParityOpLowering,
-           CIRIfOpLowering, CIRVectorCreateLowering, CIRVectorInsertLowering,
-           CIRVectorExtractLowering, CIRVectorCmpOpLowering, CIRACosOpLowering,
-           CIRASinOpLowering, CIRUnreachableOpLowering, CIRTanOpLowering,
-           CIRTrapOpLowering>(converter, patterns.getContext());
+  patterns.add<
+      CIRATanOpLowering, CIRCmpOpLowering, CIRCallOpLowering,
+      CIRUnaryOpLowering, CIRBinOpLowering, CIRLoadOpLowering,
+      CIRConstantOpLowering, CIRStoreOpLowering, CIRAllocaOpLowering,
+      CIRFuncOpLowering, CIRBrCondOpLowering, CIRTernaryOpLowering,
+      CIRYieldOpLowering, CIRCosOpLowering, CIRGlobalOpLowering,
+      CIRGetGlobalOpLowering, CIRCastOpLowering, CIRPtrStrideOpLowering,
+      CIRGetElementOpLowering, CIRSqrtOpLowering, CIRCeilOpLowering,
+      CIRExp2OpLowering, CIRExpOpLowering, CIRFAbsOpLowering, CIRAbsOpLowering,
+      CIRFloorOpLowering, CIRLog10OpLowering, CIRLog2OpLowering,
+      CIRLogOpLowering, CIRRoundOpLowering, CIRSinOpLowering,
+      CIRShiftOpLowering, CIRBitClzOpLowering, CIRBitCtzOpLowering,
+      CIRBitPopcountOpLowering, CIRBitClrsbOpLowering, CIRBitFfsOpLowering,
+      CIRBitParityOpLowering, CIRIfOpLowering, CIRVectorCreateLowering,
+      CIRVectorInsertLowering, CIRVectorExtractLowering, CIRVectorCmpOpLowering,
+      CIRACosOpLowering, CIRASinOpLowering, CIRUnreachableOpLowering,
+      CIRTanOpLowering, CIRTrapOpLowering>(converter, patterns.getContext());
+
+  patterns.add<CIRGetMemberOpLowering>(converter, patterns.getContext(),
+                                       layout);
 }
 
-static mlir::TypeConverter prepareTypeConverter() {
+static mlir::TypeConverter prepareTypeConverter(mlir::DataLayout layout) {
   mlir::TypeConverter converter;
   converter.addConversion([&](cir::PointerType type) -> mlir::Type {
-    auto ty = convertTypeForMemory(converter, type.getPointee());
+    auto pointee = type.getPointee();
+    auto ty = convertTypeForMemory(converter, pointee);
     // FIXME: The pointee type might not be converted (e.g. struct)
     if (!ty)
       return nullptr;
-    if (isa<cir::ArrayType>(type.getPointee()))
+    if (isa<cir::ArrayType>(pointee) || isa<cir::RecordType>(pointee))
       return ty;
     return mlir::MemRefType::get({}, ty);
   });
@@ -1598,6 +1648,13 @@ static mlir::TypeConverter prepareTypeConverter() {
       return nullptr;
     return mlir::MemRefType::get(shape, elementType);
   });
+  converter.addConversion([&](cir::RecordType type) -> mlir::Type {
+    // Reinterpret structs as raw bytes. Don't use tuples as they can't be put
+    // in memref.
+    auto size = type.getTypeSize(layout, {});
+    auto i8 = mlir::IntegerType::get(type.getContext(), /*width=*/8);
+    return mlir::MemRefType::get(size.getFixedValue(), i8);
+  });
   converter.addConversion([&](cir::VectorType type) -> mlir::Type {
     auto ty = converter.convertType(type.getElementType());
     return mlir::VectorType::get(type.getSize(), ty);
@@ -1609,12 +1666,15 @@ void ConvertCIRToMLIRPass::runOnOperation() {
   mlir::MLIRContext *context = &getContext();
   mlir::ModuleOp theModule = getOperation();
 
-  auto converter = prepareTypeConverter();
-
+  mlir::DataLayoutAnalysis layoutAnalysis(theModule);
+  const mlir::DataLayout &layout = layoutAnalysis.getAtOrAbove(theModule);
+
+  auto converter = prepareTypeConverter(layout);
+
   mlir::RewritePatternSet patterns(&getContext());
 
   populateCIRLoopToSCFConversionPatterns(patterns, converter);
-  populateCIRToMLIRConversionPatterns(patterns, converter);
+  populateCIRToMLIRConversionPatterns(patterns, converter, layout);
 
   mlir::ConversionTarget target(getContext());
   target.addLegalOp<mlir::ModuleOp>();
@@ -1628,10 +1688,11 @@ void ConvertCIRToMLIRPass::runOnOperation() {
   // cir dialect, for example the `cir.continue`. If we marked cir as illegal
   // here, then MLIR would think any remaining `cir.continue` indicates a
   // failure, which is not what we want.
-
-  patterns.add<CIRCastOpLowering, CIRIfOpLowering, CIRScopeOpLowering, CIRYieldOpLowering>(converter, context);
 
-  if (mlir::failed(mlir::applyPartialConversion(theModule, target, 
+  patterns.add<CIRCastOpLowering, CIRIfOpLowering, CIRScopeOpLowering,
+               CIRYieldOpLowering>(converter, context);
+
+  if (mlir::failed(mlir::applyPartialConversion(theModule, target,
                                                 std::move(patterns)))) {
     signalPassFailure();
   }

clang/test/CIR/Lowering/ThroughMLIR/struct.cir

@@ -0,0 +1,25 @@
+// RUN: cir-opt %s -cir-to-mlir -o %t.mlir
+// RUN: FileCheck --input-file=%t.mlir %s
+
+!s32i = !cir.int<s, 32>
+!u8i = !cir.int<u, 8>
+!u32i = !cir.int<u, 32>
+!ty_S = !cir.record<struct "S" {!u8i, !s32i}>
+
+module {
+  cir.func @test() {
+    %1 = cir.alloca !ty_S, !cir.ptr<!ty_S>, ["x"] {alignment = 8 : i64}
+    %3 = cir.get_member %1[0] {name = "c"} : !cir.ptr<!ty_S> -> !cir.ptr<!u8i>
+    %5 = cir.get_member %1[1] {name = "i"} : !cir.ptr<!ty_S> -> !cir.ptr<!s32i>
+    cir.return
+  }
+
+  // CHECK: func.func @test() {
+  // CHECK:   %[[alloca:[a-z0-9]+]] = memref.alloca() {alignment = 8 : i64} : memref<8xi8>
+  // CHECK:   %[[zero:[a-z0-9]+]] = arith.constant 0 : index
+  // CHECK:   memref.view %[[alloca]][%[[zero]]][] : memref<8xi8> to memref<i8>
+  // CHECK:   %[[four:[a-z0-9]+]] = arith.constant 4 : index
+  // CHECK:   %view_0 = memref.view %[[alloca]][%[[four]]][] : memref<8xi8> to memref<i32>
+  // CHECK:   return
+  // CHECK: }
+}