[𝘀𝗽𝗿] initial version

Created using spr 1.3.6-beta.1

mlir/include/mlir/Dialect/Bufferization/Transforms/Passes.h

@@ -148,11 +148,17 @@ std::unique_ptr<Pass> createBufferLoopHoistingPass();
 // Options struct for BufferResultsToOutParams pass.
 // Note: defined only here, not in tablegen.
 struct BufferResultsToOutParamsOptions {
+  /// Memcpy function: Generate a memcpy between two memrefs.
+  using MemCpyFn =
+      std::function<LogicalResult(OpBuilder &, Location, Value, Value)>;
+
   // Filter function; returns true if the function should be converted.
   // Defaults to true, i.e. all functions are converted.
   llvm::function_ref<bool(func::FuncOp *)> filterFn = [](func::FuncOp *func) {
     return true;
   };
+
+  std::optional<MemCpyFn> memCpyFn;
 };
 
 /// Creates a pass that converts memref function results to out-params.

mlir/include/mlir/Dialect/EmitC/IR/EmitC.td

@@ -565,4 +565,36 @@ def EmitC_IfOp : EmitC_Op<"if",
   let hasCustomAssemblyFormat = 1;
 }
 
+def EmitC_SubscriptOp : EmitC_Op<"subscript",
+  [TypesMatchWith<"result type matches element type of 'array'",
+                  "array", "result",
+                  "::llvm::cast<ArrayType>($_self).getElementType()">]> {
+  let summary = "Array subscript operation";
+  let description = [{
+    With the `subscript` operation the subscript operator `[]` can be applied
+    to variables or arguments of array type.
+
+    Example:
+
+    ```mlir
+    %i = index.constant 1
+    %j = index.constant 7
+    %0 = emitc.subscript %arg0[%i][%j] : (!emitc.array<4x8xf32>) -> f32
+    ```
+  }];
+  let arguments = (ins Arg<EmitC_ArrayType, "the reference to load from">:$array,
+                       Variadic<Index>:$indices);
+  let results = (outs AnyType:$result);
+
+  let builders = [
+    OpBuilder<(ins "Value":$array, "ValueRange":$indices), [{
+      build($_builder, $_state, cast<ArrayType>(array.getType()).getElementType(), array, indices);
+    }]>
+  ];
+
+  let hasVerifier = 1;
+  let assemblyFormat = "$array `[` $indices `]` attr-dict `:` type($array)";
+}
+
+
 #endif // MLIR_DIALECT_EMITC_IR_EMITC

mlir/lib/Conversion/MemRefToEmitC/MemRefToEmitC.cpp

@@ -54,6 +54,60 @@ bool isSignatureLegal(FunctionType ty) {
   return isLegal(llvm::concat<const Type>(ty.getInputs(), ty.getResults()));
 }
 
+struct ConvertLoad final : public OpConversionPattern<memref::LoadOp> {
+  using OpConversionPattern::OpConversionPattern;
+
+  LogicalResult
+  matchAndRewrite(memref::LoadOp op, OpAdaptor operands,
+                  ConversionPatternRewriter &rewriter) const override {
+
+    rewriter.replaceOpWithNewOp<emitc::SubscriptOp>(op, operands.getMemref(),
+                                                    operands.getIndices());
+    return success();
+  }
+};
+
+struct ConvertStore final : public OpConversionPattern<memref::StoreOp> {
+  using OpConversionPattern::OpConversionPattern;
+
+  LogicalResult
+  matchAndRewrite(memref::StoreOp op, OpAdaptor operands,
+                  ConversionPatternRewriter &rewriter) const override {
+
+    auto subscript = rewriter.create<emitc::SubscriptOp>(
+        op.getLoc(), operands.getMemref(), operands.getIndices());
+    rewriter.replaceOpWithNewOp<emitc::AssignOp>(op, subscript,
+                                                 operands.getValue());
+    return success();
+  }
+};
+
+struct ConvertAlloca final : public OpConversionPattern<memref::AllocaOp> {
+  using OpConversionPattern::OpConversionPattern;
+
+  LogicalResult
+  matchAndRewrite(memref::AllocaOp op, OpAdaptor operands,
+                  ConversionPatternRewriter &rewriter) const override {
+
+    if (!op.getType().hasStaticShape()) {
+      return rewriter.notifyMatchFailure(
+          op.getLoc(), "cannot transform alloca with dynamic shape");
+    }
+
+    if (op.getAlignment().value_or(1) > 1) {
+      // TODO: Allow alignment if it is not more than the natural alignment
+      // of the C array.
+      return rewriter.notifyMatchFailure(
+          op.getLoc(), "cannot transform alloca with alignment requirement");
+    }
+
+    auto resultTy = getTypeConverter()->convertType(op.getType());
+    auto noInit = emitc::OpaqueAttr::get(getContext(), "");
+    rewriter.replaceOpWithNewOp<emitc::VariableOp>(op, resultTy, noInit);
+    return success();
+  }
+};
+
 struct ConvertMemRefToEmitCPass
     : public impl::ConvertMemRefToEmitCBase<ConvertMemRefToEmitCPass> {
   void runOnOperation() override {
@@ -91,6 +145,7 @@ struct ConvertMemRefToEmitCPass
     target.addDynamicallyLegalDialect<func::FuncDialect>(
         [](Operation *op) { return isLegal(op); });
     target.addIllegalDialect<memref::MemRefDialect>();
+    target.addLegalDialect<emitc::EmitCDialect>();
 
     if (failed(applyPartialConversion(getOperation(), target,
                                       std::move(patterns))))
@@ -106,6 +161,8 @@ void mlir::populateMemRefToEmitCConversionPatterns(RewritePatternSet &patterns,
                                                                  converter);
   populateCallOpTypeConversionPattern(patterns, converter);
   populateReturnOpTypeConversionPattern(patterns, converter);
+  patterns.add<ConvertLoad, ConvertStore, ConvertAlloca>(converter,
+                                                         patterns.getContext());
 }
 
 std::unique_ptr<OperationPass<>> mlir::createConvertMemRefToEmitCPass() {

mlir/lib/Dialect/Bufferization/Transforms/BufferResultsToOutParams.cpp

@@ -21,6 +21,7 @@ namespace bufferization {
 } // namespace mlir
 
 using namespace mlir;
+using MemCpyFn = bufferization::BufferResultsToOutParamsOptions::MemCpyFn;
 
 /// Return `true` if the given MemRef type has a fully dynamic layout.
 static bool hasFullyDynamicLayoutMap(MemRefType type) {
@@ -97,9 +98,10 @@ updateFuncOp(func::FuncOp func,
 // Updates all ReturnOps in the scope of the given func::FuncOp by either
 // keeping them as return values or copying the associated buffer contents into
 // the given out-params.
-static void updateReturnOps(func::FuncOp func,
-                            ArrayRef<BlockArgument> appendedEntryArgs) {
-  func.walk([&](func::ReturnOp op) {
+static LogicalResult updateReturnOps(func::FuncOp func,
+                                     ArrayRef<BlockArgument> appendedEntryArgs,
+                                     MemCpyFn memCpyFn) {
+  auto res = func.walk([&](func::ReturnOp op) {
     SmallVector<Value, 6> copyIntoOutParams;
     SmallVector<Value, 6> keepAsReturnOperands;
     for (Value operand : op.getOperands()) {
@@ -109,12 +111,16 @@ static void updateReturnOps(func::FuncOp func,
         keepAsReturnOperands.push_back(operand);
     }
     OpBuilder builder(op);
-    for (auto t : llvm::zip(copyIntoOutParams, appendedEntryArgs))
-      builder.create<memref::CopyOp>(op.getLoc(), std::get<0>(t),
-                                     std::get<1>(t));
+    for (auto t : llvm::zip(copyIntoOutParams, appendedEntryArgs)) {
+      if (failed(
+              memCpyFn(builder, op.getLoc(), std::get<0>(t), std::get<1>(t))))
+        return WalkResult::interrupt();
+    }
     builder.create<func::ReturnOp>(op.getLoc(), keepAsReturnOperands);
     op.erase();
+    return WalkResult::advance();
   });
+  return failure(res.wasInterrupted());
 }
 
 // Updates all CallOps in the scope of the given ModuleOp by allocating
@@ -192,7 +198,15 @@ LogicalResult mlir::bufferization::promoteBufferResultsToOutParams(
       return failure();
     if (func.isExternal())
       continue;
-    updateReturnOps(func, appendedEntryArgs);
+    auto defaultMemCpyFn = [](OpBuilder &builder, Location loc, Value from,
+                              Value to) {
+      builder.create<memref::CopyOp>(loc, from, to);
+      return success();
+    };
+    if (failed(updateReturnOps(func, appendedEntryArgs,
+                               options.memCpyFn.value_or(defaultMemCpyFn)))) {
+      return failure();
+    }
   }
   if (failed(updateCalls(module, options)))
     return failure();

mlir/lib/Dialect/EmitC/IR/EmitC.cpp

@@ -102,9 +102,10 @@ LogicalResult ApplyOp::verify() {
 LogicalResult emitc::AssignOp::verify() {
   Value variable = getVar();
   Operation *variableDef = variable.getDefiningOp();
-  if (!variableDef || !llvm::isa<emitc::VariableOp>(variableDef))
+  if (!variableDef ||
+      !llvm::isa<emitc::VariableOp, emitc::SubscriptOp>(variableDef))
     return emitOpError() << "requires first operand (" << variable
-                         << ") to be a Variable";
+                         << ") to be a Variable or subscript";
 
   Value value = getValue();
   if (variable.getType() != value.getType())
@@ -530,6 +531,20 @@ LogicalResult emitc::VariableOp::verify() {
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// SubscriptOp
+//===----------------------------------------------------------------------===//
+
+LogicalResult emitc::SubscriptOp::verify() {
+  if (getIndices().size() != (size_t)getArray().getType().getRank()) {
+    return emitOpError() << "requires number of indices ("
+                         << getIndices().size()
+                         << ") to match the rank of the array type ("
+                         << getArray().getType().getRank() << ")";
+  }
+  return success();
+}
+
 //===----------------------------------------------------------------------===//
 // TableGen'd op method definitions
 //===----------------------------------------------------------------------===//

mlir/lib/Target/Cpp/TranslateToCpp.cpp

@@ -122,6 +122,9 @@ struct CppEmitter {
   /// Return the existing or a new name for a Value.
   StringRef getOrCreateName(Value val);
 
+  // Returns the textual representation of a subscript operation.
+  std::string getSubscriptName(emitc::SubscriptOp op);
+
   /// Return the existing or a new label of a Block.
   StringRef getOrCreateName(Block &block);
 
@@ -251,8 +254,7 @@ static LogicalResult printOperation(CppEmitter &emitter,
 
 static LogicalResult printOperation(CppEmitter &emitter,
                                     emitc::AssignOp assignOp) {
-  auto variableOp = cast<emitc::VariableOp>(assignOp.getVar().getDefiningOp());
-  OpResult result = variableOp->getResult(0);
+  OpResult result = assignOp.getVar().getDefiningOp()->getResult(0);
 
   if (failed(emitter.emitVariableAssignment(result)))
     return failure();
@@ -262,6 +264,13 @@ static LogicalResult printOperation(CppEmitter &emitter,
   return success();
 }
 
+static LogicalResult printOperation(CppEmitter &emitter,
+                                    emitc::SubscriptOp subscriptOp) {
+  // Add name to cache so that `hasValueInScope` works.
+  emitter.getOrCreateName(subscriptOp.getResult());
+  return success();
+}
+
 static LogicalResult printBinaryOperation(CppEmitter &emitter,
                                           Operation *operation,
                                           StringRef binaryOperator) {
@@ -706,12 +715,28 @@ CppEmitter::CppEmitter(raw_ostream &os, bool declareVariablesAtTop)
   labelInScopeCount.push(0);
 }
 
+std::string CppEmitter::getSubscriptName(emitc::SubscriptOp op) {
+  std::string out;
+  llvm::raw_string_ostream ss(out);
+  ss << getOrCreateName(op.getArray());
+  for (auto index : op.getIndices()) {
+    ss << "[" << getOrCreateName(index) << "]";
+  }
+  return out;
+}
+
 /// Return the existing or a new name for a Value.
 StringRef CppEmitter::getOrCreateName(Value val) {
   if (auto literal = dyn_cast_if_present<emitc::LiteralOp>(val.getDefiningOp()))
     return literal.getValue();
-  if (!valueMapper.count(val))
-    valueMapper.insert(val, formatv("v{0}", ++valueInScopeCount.top()));
+  if (!valueMapper.count(val)) {
+    if (auto subscript =
+            dyn_cast_if_present<emitc::SubscriptOp>(val.getDefiningOp())) {
+      valueMapper.insert(val, getSubscriptName(subscript));
+    } else {
+      valueMapper.insert(val, formatv("v{0}", ++valueInScopeCount.top()));
+    }
+  }
   return *valueMapper.begin(val);
 }
 
@@ -891,6 +916,8 @@ LogicalResult CppEmitter::emitVariableAssignment(OpResult result) {
 
 LogicalResult CppEmitter::emitVariableDeclaration(OpResult result,
                                                   bool trailingSemicolon) {
+  if (isa<emitc::SubscriptOp>(result.getDefiningOp()))
+    return success();
   if (hasValueInScope(result)) {
     return result.getDefiningOp()->emitError(
         "result variable for the operation already declared");
@@ -957,7 +984,7 @@ LogicalResult CppEmitter::emitOperation(Operation &op, bool trailingSemicolon) {
                 emitc::CallOpaqueOp, emitc::CastOp, emitc::CmpOp,
                 emitc::ConstantOp, emitc::DivOp, emitc::ForOp, emitc::IfOp,
                 emitc::IncludeOp, emitc::MulOp, emitc::RemOp, emitc::SubOp,
-                emitc::VariableOp>(
+                emitc::SubscriptOp, emitc::VariableOp>(
               [&](auto op) { return printOperation(*this, op); })
           // Func ops.
           .Case<func::CallOp, func::ConstantOp, func::FuncOp, func::ReturnOp>(
@@ -973,7 +1000,7 @@ LogicalResult CppEmitter::emitOperation(Operation &op, bool trailingSemicolon) {
   if (failed(status))
     return failure();
 
-  if (isa<emitc::LiteralOp>(op))
+  if (isa<emitc::LiteralOp, emitc::SubscriptOp>(op))
     return success();
 
   os << (trailingSemicolon ? ";\n" : "\n");

mlir/test/Conversion/MemRefToEmitC/memref-to-emit-failed.mlir

@@ -22,3 +22,20 @@ func.func @memref_op(%arg0 : memref<2x4xf32>) {
   memref.copy %arg0, %arg0 : memref<2x4xf32> to memref<2x4xf32>
   return
 }
+
+// -----
+
+func.func @alloca_with_dynamic_shape() {
+  %0 = index.constant 1
+  // expected-error@+1 {{failed to legalize operation 'memref.alloca' that was explicitly marked illegal}}
+  %1 = memref.alloca(%0) : memref<4x?xf32>
+  return
+}
+
+// -----
+
+func.func @alloca_with_alignment() {
+  // expected-error@+1 {{failed to legalize operation 'memref.alloca' that was explicitly marked illegal}}
+  %1 = memref.alloca() {alignment = 64 : i64}: memref<4xf32>
+  return
+}

mlir/test/Conversion/MemRefToEmitC/memref-to-emitc.mlir

@@ -22,3 +22,26 @@ func.func @memref_call(%arg0 : memref<32xf32>) {
   func.call @memref_return(%arg0) : (memref<32xf32>) -> memref<32xf32>
   func.return
 }
+
+// -----
+
+// CHECK-LABEL: memref_load_store
+// CHECK-SAME:  %[[arg0:.*]]: !emitc.array<4x8xf32>, %[[arg1:.*]]: !emitc.array<3x5xf32>
+// CHECK-SAME:  %[[i:.*]]: index, %[[j:.*]]: index
+func.func @memref_load_store(%in: memref<4x8xf32>, %out: memref<3x5xf32>, %i: index, %j: index) {
+  // CHECK: %[[load:.*]] = emitc.subscript %[[arg0]][%[[i]], %[[j]]] : <4x8xf32>
+  %0 = memref.load %in[%i, %j] : memref<4x8xf32>
+  // CHECK: %[[store_loc:.*]] = emitc.subscript %[[arg1]][%[[i]], %[[j]]] : <3x5xf32>
+  // CHECK: emitc.assign %[[load]] : f32 to %[[store_loc:.*]] : f32
+  memref.store %0, %out[%i, %j] : memref<3x5xf32>
+  return
+}
+
+// -----
+
+// CHECK-LABEL: alloca
+func.func @alloca() {
+  // CHECK "emitc.variable"() <{value = #emitc.opaque<"">}> : () -> !emitc.array<4x8xf32>
+  %0 = memref.alloca() : memref<4x8xf32>
+  return
+}

mlir/test/Dialect/EmitC/invalid_ops.mlir

@@ -224,3 +224,11 @@ func.func @test_assign_type_mismatch(%arg1: f32) {
   emitc.assign %arg1 : f32 to %v : i32
   return
 }
+
+// -----
+
+func.func @test_subscript_indices_mismatch(%arg0: !emitc.array<4x8xf32>, %arg2: index) {
+  // expected-error @+1 {{'emitc.subscript' op requires number of indices (1) to match the rank of the array type (2)}}
+  %0 = emitc.subscript %arg0[%arg2] : <4x8xf32>
+  return
+}

mlir/test/Dialect/EmitC/ops.mlir

@@ -149,3 +149,11 @@ func.func @test_for_not_index_induction(%arg0 : i16, %arg1 : i16, %arg2 : i16) {
   }
   return
 }
+
+func.func @test_subscript(%arg0: !emitc.array<4x8xf32>, %arg1: !emitc.array<3x5xf32>,
+                          %arg2: index, %arg3: index) {
+  %0 = emitc.subscript %arg0[%arg2, %arg3] : <4x8xf32>
+  %1 = emitc.subscript %arg1[%arg2, %arg3] : <3x5xf32>
+  emitc.assign %0 : f32 to %1 : f32
+  return
+}