Expand the MemRefToEmitC pass - Adding scalars

mlir/lib/Conversion/MemRefToEmitC/MemRefToEmitC.cpp

@@ -16,7 +16,9 @@
 #include "mlir/Dialect/EmitC/IR/EmitC.h"
 #include "mlir/Dialect/MemRef/IR/MemRef.h"
 #include "mlir/IR/Builders.h"
+#include "mlir/IR/BuiltinTypes.h"
 #include "mlir/IR/PatternMatch.h"
+#include "mlir/IR/TypeRange.h"
 #include "mlir/Transforms/DialectConversion.h"
 
 using namespace mlir;
@@ -83,7 +85,7 @@ struct ConvertGlobal final : public OpConversionPattern<memref::GlobalOp> {
   LogicalResult
   matchAndRewrite(memref::GlobalOp op, OpAdaptor operands,
                   ConversionPatternRewriter &rewriter) const override {
-
+    MemRefType type = op.getType();
     if (!op.getType().hasStaticShape()) {
       return rewriter.notifyMatchFailure(
           op.getLoc(), "cannot transform global with dynamic shape");
@@ -95,7 +97,13 @@ struct ConvertGlobal final : public OpConversionPattern<memref::GlobalOp> {
           op.getLoc(), "global variable with alignment requirement is "
                        "currently not supported");
     }
-    auto resultTy = getTypeConverter()->convertType(op.getType());
+
+    Type resultTy;
+    if (type.getRank() == 0)
+      resultTy = getTypeConverter()->convertType(type.getElementType());
+    else
+      resultTy = getTypeConverter()->convertType(type);
+
     if (!resultTy) {
       return rewriter.notifyMatchFailure(op.getLoc(),
                                          "cannot convert result type");
@@ -114,6 +122,10 @@ struct ConvertGlobal final : public OpConversionPattern<memref::GlobalOp> {
     bool externSpecifier = !staticSpecifier;
 
     Attribute initialValue = operands.getInitialValueAttr();
+    if (type.getRank() == 0) {
+      auto elementsAttr = llvm::cast<ElementsAttr>(*op.getInitialValue());
+      initialValue = elementsAttr.getSplatValue<Attribute>();
+    }
     if (isa_and_present<UnitAttr>(initialValue))
       initialValue = {};
 
@@ -132,7 +144,17 @@ struct ConvertGetGlobal final
   matchAndRewrite(memref::GetGlobalOp op, OpAdaptor operands,
                   ConversionPatternRewriter &rewriter) const override {
 
-    auto resultTy = getTypeConverter()->convertType(op.getType());
+    MemRefType type = op.getType();
+    Type resultTy;
+    if (type.getRank() == 0)
+      resultTy = emitc::LValueType::get(
+          getTypeConverter()->convertType(type.getElementType()));
+    else
+      resultTy = getTypeConverter()->convertType(type);
+
+    if (!resultTy)
+      return rewriter.notifyMatchFailure(op.getLoc(), "cannot convert type");
+
     if (!resultTy) {
       return rewriter.notifyMatchFailure(op.getLoc(),
                                          "cannot convert result type");

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

@@ -41,6 +41,8 @@ func.func @memref_load(%buff : memref<4x8xf32>, %i: index, %j: index) -> f32 {
 module @globals {
   memref.global "private" constant @internal_global : memref<3x7xf32> = dense<4.0>
   // CHECK-NEXT: emitc.global static const @internal_global : !emitc.array<3x7xf32> = dense<4.000000e+00>
+  memref.global "private" constant @__constant_xi32 : memref<i32> = dense<-1>
+  // CHECK-NEXT: emitc.global static const @__constant_xi32 : i32 = -1
   memref.global @public_global : memref<3x7xf32>
   // CHECK-NEXT: emitc.global extern @public_global : !emitc.array<3x7xf32>
   memref.global @uninitialized_global : memref<3x7xf32> = uninitialized
@@ -50,6 +52,8 @@ module @globals {
   func.func @use_global() {
     // CHECK-NEXT: emitc.get_global @public_global : !emitc.array<3x7xf32>
     %0 = memref.get_global @public_global : memref<3x7xf32>
+    // CHECK- NEXT: emitc.get_global @__constant_xi32 : !emitc.lvalue<i32>
+    %1 = memref.get_global @__constant_xi32 : memref<i32>
     return
   }
 }