[mlir][EmitC] Expand the MemRefToEmitC pass - Lowering CopyOp

mlir/include/mlir/Conversion/MemRefToEmitC/MemRefToEmitC.h

@@ -10,8 +10,11 @@
 
 constexpr const char *alignedAllocFunctionName = "aligned_alloc";
 constexpr const char *mallocFunctionName = "malloc";
+constexpr const char *memcpyFunctionName = "memcpy";
 constexpr const char *cppStandardLibraryHeader = "cstdlib";
 constexpr const char *cStandardLibraryHeader = "stdlib.h";
+constexpr const char *cppStringLibraryHeader = "cstring";
+constexpr const char *cStringLibraryHeader = "string.h";
 
 namespace mlir {
 class DialectRegistry;

mlir/lib/Conversion/MemRefToEmitC/MemRefToEmitC.cpp

@@ -17,11 +17,13 @@
 #include "mlir/Dialect/MemRef/IR/MemRef.h"
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/BuiltinTypes.h"
+#include "mlir/IR/Diagnostics.h"
 #include "mlir/IR/PatternMatch.h"
 #include "mlir/IR/TypeRange.h"
 #include "mlir/IR/Value.h"
 #include "mlir/Transforms/DialectConversion.h"
 #include <cstdint>
+#include <numeric>
 
 using namespace mlir;
 
@@ -97,6 +99,48 @@ Type convertMemRefType(MemRefType opTy, const TypeConverter *typeConverter) {
   return resultTy;
 }
 
+static Value calculateMemrefTotalSizeBytes(Location loc, MemRefType memrefType,
+                                           OpBuilder &builder) {
+  assert(isMemRefTypeLegalForEmitC(memrefType) &&
+         "incompatible memref type for EmitC conversion");
+  emitc::CallOpaqueOp elementSize = emitc::CallOpaqueOp::create(
+      builder, loc, emitc::SizeTType::get(builder.getContext()),
+      builder.getStringAttr("sizeof"), ValueRange{},
+      ArrayAttr::get(builder.getContext(),
+                     {TypeAttr::get(memrefType.getElementType())}));
+
+  IndexType indexType = builder.getIndexType();
+  int64_t numElements = std::accumulate(memrefType.getShape().begin(),
+                                        memrefType.getShape().end(), int64_t{1},
+                                        std::multiplies<int64_t>());
+  emitc::ConstantOp numElementsValue = emitc::ConstantOp::create(
+      builder, loc, indexType, builder.getIndexAttr(numElements));
+
+  Type sizeTType = emitc::SizeTType::get(builder.getContext());
+  emitc::MulOp totalSizeBytes = emitc::MulOp::create(
+      builder, loc, sizeTType, elementSize.getResult(0), numElementsValue);
+
+  return totalSizeBytes.getResult();
+}
+
+static emitc::ApplyOp
+createPointerFromEmitcArray(Location loc, OpBuilder &builder,
+                            TypedValue<emitc::ArrayType> arrayValue) {
+
+  emitc::ConstantOp zeroIndex = emitc::ConstantOp::create(
+      builder, loc, builder.getIndexType(), builder.getIndexAttr(0));
+
+  emitc::ArrayType arrayType = arrayValue.getType();
+  llvm::SmallVector<mlir::Value> indices(arrayType.getRank(), zeroIndex);
+  emitc::SubscriptOp subPtr =
+      emitc::SubscriptOp::create(builder, loc, arrayValue, ValueRange(indices));
+  emitc::ApplyOp ptr = emitc::ApplyOp::create(
+      builder, loc, emitc::PointerType::get(arrayType.getElementType()),
+      builder.getStringAttr("&"), subPtr);
+
+  return ptr;
+}
+
 struct ConvertAlloc final : public OpConversionPattern<memref::AllocOp> {
   using OpConversionPattern::OpConversionPattern;
   LogicalResult
@@ -159,6 +203,47 @@ struct ConvertAlloc final : public OpConversionPattern<memref::AllocOp> {
   }
 };
 
+struct ConvertCopy final : public OpConversionPattern<memref::CopyOp> {
+  using OpConversionPattern::OpConversionPattern;
+
+  LogicalResult
+  matchAndRewrite(memref::CopyOp copyOp, OpAdaptor operands,
+                  ConversionPatternRewriter &rewriter) const override {
+    Location loc = copyOp.getLoc();
+    MemRefType srcMemrefType = cast<MemRefType>(copyOp.getSource().getType());
+    MemRefType targetMemrefType =
+        cast<MemRefType>(copyOp.getTarget().getType());
+
+    if (!isMemRefTypeLegalForEmitC(srcMemrefType))
+      return rewriter.notifyMatchFailure(
+          loc, "incompatible source memref type for EmitC conversion");
+
+    if (!isMemRefTypeLegalForEmitC(targetMemrefType))
+      return rewriter.notifyMatchFailure(
+          loc, "incompatible target memref type for EmitC conversion");
+
+    auto srcArrayValue =
+        cast<TypedValue<emitc::ArrayType>>(operands.getSource());
+    emitc::ApplyOp srcPtr =
+        createPointerFromEmitcArray(loc, rewriter, srcArrayValue);
+
+    auto targetArrayValue =
+        cast<TypedValue<emitc::ArrayType>>(operands.getTarget());
+    emitc::ApplyOp targetPtr =
+        createPointerFromEmitcArray(loc, rewriter, targetArrayValue);
+
+    emitc::CallOpaqueOp memCpyCall = emitc::CallOpaqueOp::create(
+        rewriter, loc, TypeRange{}, "memcpy",
+        ValueRange{
+            targetPtr.getResult(), srcPtr.getResult(),
+            calculateMemrefTotalSizeBytes(loc, srcMemrefType, rewriter)});
+
+    rewriter.replaceOp(copyOp, memCpyCall.getResults());
+
+    return success();
+  }
+};
+
 struct ConvertGlobal final : public OpConversionPattern<memref::GlobalOp> {
   using OpConversionPattern::OpConversionPattern;
 
@@ -320,6 +405,7 @@ void mlir::populateMemRefToEmitCTypeConversion(TypeConverter &typeConverter) {
 
 void mlir::populateMemRefToEmitCConversionPatterns(
     RewritePatternSet &patterns, const TypeConverter &converter) {
-  patterns.add<ConvertAlloca, ConvertAlloc, ConvertGlobal, ConvertGetGlobal,
-               ConvertLoad, ConvertStore>(converter, patterns.getContext());
+  patterns.add<ConvertAlloca, ConvertAlloc, ConvertCopy, ConvertGlobal,
+               ConvertGetGlobal, ConvertLoad, ConvertStore>(
+      converter, patterns.getContext());
 }

mlir/lib/Conversion/MemRefToEmitC/MemRefToEmitCPass.cpp

@@ -18,6 +18,8 @@
 #include "mlir/IR/Attributes.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Transforms/DialectConversion.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/StringRef.h"
 
 namespace mlir {
 #define GEN_PASS_DEF_CONVERTMEMREFTOEMITC
@@ -27,6 +29,15 @@ namespace mlir {
 using namespace mlir;
 
 namespace {
+
+emitc::IncludeOp addStandardHeader(OpBuilder &builder, ModuleOp module,
+                                   StringRef headerName) {
+  StringAttr includeAttr = builder.getStringAttr(headerName);
+  return builder.create<emitc::IncludeOp>(
+      module.getLoc(), includeAttr,
+      /*is_standard_include=*/builder.getUnitAttr());
+}
+
 struct ConvertMemRefToEmitCPass
     : public impl::ConvertMemRefToEmitCBase<ConvertMemRefToEmitCPass> {
   using Base::Base;
@@ -55,34 +66,29 @@ struct ConvertMemRefToEmitCPass
       return signalPassFailure();
 
     mlir::ModuleOp module = getOperation();
+    llvm::SmallSet<StringRef, 4> existingHeaders;
+    mlir::OpBuilder builder(module.getBody(), module.getBody()->begin());
+    module.walk([&](mlir::emitc::IncludeOp includeOp) {
+      if (includeOp.getIsStandardInclude())
+        existingHeaders.insert(includeOp.getInclude());
+    });
+
     module.walk([&](mlir::emitc::CallOpaqueOp callOp) {
-      if (callOp.getCallee() != alignedAllocFunctionName &&
-          callOp.getCallee() != mallocFunctionName) {
+      StringRef expectedHeader;
+      if (callOp.getCallee() == alignedAllocFunctionName ||
+          callOp.getCallee() == mallocFunctionName)
+        expectedHeader = options.lowerToCpp ? cppStandardLibraryHeader
+                                            : cStandardLibraryHeader;
+      else if (callOp.getCallee() == memcpyFunctionName)
+        expectedHeader =
+            options.lowerToCpp ? cppStringLibraryHeader : cStringLibraryHeader;
+      else
         return mlir::WalkResult::advance();
+      if (!existingHeaders.contains(expectedHeader)) {
+        addStandardHeader(builder, module, expectedHeader);
+        existingHeaders.insert(expectedHeader);
       }
-
-      for (auto &op : *module.getBody()) {
-        emitc::IncludeOp includeOp = llvm::dyn_cast<mlir::emitc::IncludeOp>(op);
-        if (!includeOp) {
-          continue;
-        }
-        if (includeOp.getIsStandardInclude() &&
-            ((options.lowerToCpp &&
-              includeOp.getInclude() == cppStandardLibraryHeader) ||
-             (!options.lowerToCpp &&
-              includeOp.getInclude() == cStandardLibraryHeader))) {
-          return mlir::WalkResult::interrupt();
-        }
-      }
-
-      mlir::OpBuilder builder(module.getBody(), module.getBody()->begin());
-      StringAttr includeAttr =
-          builder.getStringAttr(options.lowerToCpp ? cppStandardLibraryHeader
-                                                   : cStandardLibraryHeader);
-      builder.create<mlir::emitc::IncludeOp>(
-          module.getLoc(), includeAttr,
-          /*is_standard_include=*/builder.getUnitAttr());
-      return mlir::WalkResult::interrupt();
+      return mlir::WalkResult::advance();
     });
   }
 };

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

@@ -0,0 +1,50 @@
+// RUN: mlir-opt -convert-memref-to-emitc="lower-to-cpp=true" %s -split-input-file | FileCheck %s --check-prefix=CPP
+// RUN: mlir-opt -convert-memref-to-emitc="lower-to-cpp=false" %s -split-input-file | FileCheck %s --check-prefix=NOCPP
+
+func.func @alloc_copy(%arg0: memref<999xi32>) {
+  %alloc = memref.alloc() : memref<999xi32>
+  memref.copy %arg0, %alloc : memref<999xi32> to memref<999xi32>
+  %alloc_1 = memref.alloc() : memref<999xi32>
+  memref.copy %arg0, %alloc_1 : memref<999xi32> to memref<999xi32>
+  return
+} 
+
+// CHECK: module {
+// NOCPP:  emitc.include <"stdlib.h">
+// NOCPP-NEXT:  emitc.include <"string.h">
+
+// CPP:  emitc.include <"cstdlib">
+// CPP-NEXT:  emitc.include <"cstring">
+
+// CHECK-LABEL: alloc_copy
+// CHECK-SAME: %[[arg0:.*]]: memref<999xi32>
+// CHECK-NEXT:  builtin.unrealized_conversion_cast %arg0 : memref<999xi32> to !emitc.array<999xi32> 
+// CHECK-NEXT:  emitc.call_opaque "sizeof"() {args = [i32]} : () -> !emitc.size_t 
+// CHECK-NEXT:  "emitc.constant"() <{value = 999 : index}> : () -> index 
+// CHECK-NEXT:  emitc.mul %1, %2 : (!emitc.size_t, index) -> !emitc.size_t 
+// CHECK-NEXT:  emitc.call_opaque "malloc"(%3) : (!emitc.size_t) -> !emitc.ptr<!emitc.opaque<"void">> 
+// CHECK-NEXT:  emitc.cast %4 : !emitc.ptr<!emitc.opaque<"void">> to !emitc.ptr<i32> 
+// CHECK-NEXT:  builtin.unrealized_conversion_cast %5 : !emitc.ptr<i32> to !emitc.array<999xi32> 
+// CHECK-NEXT:  "emitc.constant"() <{value = 0 : index}> : () -> index 
+// CHECK-NEXT:  emitc.subscript %0[%7] : (!emitc.array<999xi32>, index) -> !emitc.lvalue<i32> 
+// CHECK-NEXT:  emitc.apply "&"(%8) : (!emitc.lvalue<i32>) -> !emitc.ptr<i32> 
+// CHECK-NEXT:  emitc.call_opaque "sizeof"() {args = [i32]} : () -> !emitc.size_t
+// CHECK-NEXT:  "emitc.constant"() <{value = 999 : index}> : () -> index
+// CHECK-NEXT:  emitc.mul %12, %13 : (!emitc.size_t, index) -> !emitc.size_t
+// CHECK-NEXT:  emitc.call_opaque "memcpy"(%11, %9, %14) : (!emitc.ptr<i32>, !emitc.ptr<i32>, !emitc.size_t) -> ()
+// CHECK-NEXT:  emitc.call_opaque "sizeof"() {args = [i32]} : () -> !emitc.size_t
+// CHECK-NEXT:  "emitc.constant"() <{value = 999 : index}> : () -> index
+// CHECK-NEXT:  emitc.mul %15, %16 : (!emitc.size_t, index) -> !emitc.size_t
+// CHECK-NEXT:  emitc.call_opaque "malloc"(%17) : (!emitc.size_t) -> !emitc.ptr<!emitc.opaque<"void">>
+// CHECK-NEXT:  emitc.cast %18 : !emitc.ptr<!emitc.opaque<"void">> to !emitc.ptr<i32>
+// CHECK-NEXT:  builtin.unrealized_conversion_cast %19 : !emitc.ptr<i32> to !emitc.array<999xi32>
+// CHECK-NEXT:  "emitc.constant"() <{value = 0 : index}> : () -> index
+// CHECK-NEXT:  emitc.subscript %0[%21] : (!emitc.array<999xi32>, index) -> !emitc.lvalue<i32>
+// CHECK-NEXT:  emitc.apply "&"(%22) : (!emitc.lvalue<i32>) -> !emitc.ptr<i32>
+// CHECK-NEXT:  emitc.subscript %20[%21] : (!emitc.array<999xi32>, index) -> !emitc.lvalue<i32>
+// CHECK-NEXT:  emitc.apply "&"(%24) : (!emitc.lvalue<i32>) -> !emitc.ptr<i32>
+// CHECK-NEXT:  emitc.call_opaque "sizeof"() {args = [i32]} : () -> !emitc.size_t
+// CHECK-NEXT:  "emitc.constant"() <{value = 999 : index}> : () -> index
+// CHECK-NEXT:  emitc.mul %26, %27 : (!emitc.size_t, index) -> !emitc.size_t
+// CHECK-NEXT:  emitc.call_opaque "memcpy"(%25, %23, %28) : (!emitc.ptr<i32>, !emitc.ptr<i32>, !emitc.size_t) -> ()
+// CHECK-NEXT:    return

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

@@ -0,0 +1,29 @@
+// RUN: mlir-opt -convert-memref-to-emitc="lower-to-cpp=true" %s -split-input-file | FileCheck %s --check-prefix=CPP
+// RUN: mlir-opt -convert-memref-to-emitc="lower-to-cpp=false" %s -split-input-file | FileCheck %s --check-prefix=NOCPP
+
+func.func @copying(%arg0 : memref<9x4x5x7xf32>, %arg1 : memref<9x4x5x7xf32>) {
+  memref.copy %arg0, %arg1 : memref<9x4x5x7xf32> to memref<9x4x5x7xf32>
+  return
+}
+
+// CHECK: module {
+// NOCPP:  emitc.include <"string.h">
+// CPP:  emitc.include <"cstring">
+
+// CHECK-LABEL:  copying
+// CHECK-SAME: %[[arg0:.*]]: memref<9x4x5x7xf32>, %[[arg1:.*]]: memref<9x4x5x7xf32>
+// CHECK-NEXT: %0 = builtin.unrealized_conversion_cast %arg1 : memref<9x4x5x7xf32> to !emitc.array<9x4x5x7xf32>
+// CHECK-NEXT: %1 = builtin.unrealized_conversion_cast %arg0 : memref<9x4x5x7xf32> to !emitc.array<9x4x5x7xf32>
+// CHECK-NEXT: %2 = "emitc.constant"() <{value = 0 : index}> : () -> index
+// CHECK-NEXT: %3 = emitc.subscript %1[%2, %2, %2, %2] : (!emitc.array<9x4x5x7xf32>, index, index, index, index) -> !emitc.lvalue<f32>
+// CHECK-NEXT: %4 = emitc.apply "&"(%3) : (!emitc.lvalue<f32>) -> !emitc.ptr<f32>
+// CHECK-NEXT: %5 = emitc.subscript %0[%2, %2, %2, %2] : (!emitc.array<9x4x5x7xf32>, index, index, index, index) -> !emitc.lvalue<f32>
+// CHECK-NEXT: %6 = emitc.apply "&"(%5) : (!emitc.lvalue<f32>) -> !emitc.ptr<f32>
+// CHECK-NEXT: %7 = emitc.call_opaque "sizeof"() {args = [f32]} : () -> !emitc.size_t
+// CHECK-NEXT: %8 = "emitc.constant"() <{value = 1260 : index}> : () -> index
+// CHECK-NEXT: %9 = emitc.mul %7, %8 : (!emitc.size_t, index) -> !emitc.size_t
+// CHECK-NEXT: emitc.call_opaque "memcpy"(%6, %4, %9) : (!emitc.ptr<f32>, !emitc.ptr<f32>, !emitc.size_t) -> ()
+// CHECK-NEXT:    return
+// CHECK-NEXT:  }
+// CHECK-NEXT:}
+

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

@@ -1,13 +1,5 @@
 // RUN: mlir-opt -convert-memref-to-emitc %s -split-input-file -verify-diagnostics
 
-func.func @memref_op(%arg0 : memref<2x4xf32>) {
-  // expected-error@+1 {{failed to legalize operation 'memref.copy'}}
-  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'}}