Add PtrToBoolOp and its conversion pattern for pointer to bool casting

Signed-off-by: Roberto Raggi <roberto.raggi@gmail.com>

Author: robertoraggi

src/mlir/cxx/mlir/CxxOps.td

@@ -228,6 +228,12 @@ def Cxx_IntToBoolOp : Cxx_Op<"int_to_bool"> {
   let results = (outs Cxx_BoolType:$result);
 }
 
+def Cxx_PtrToBoolOp : Cxx_Op<"ptr_to_bool"> {
+  let arguments = (ins Cxx_PointerType:$value);
+
+  let results = (outs Cxx_BoolType:$result);
+}
+
 def Cxx_BoolToIntOp : Cxx_Op<"bool_to_int"> {
   let arguments = (ins Cxx_BoolType:$value);
 

src/mlir/cxx/mlir/codegen_expressions.cc

@@ -1337,6 +1337,20 @@ auto Codegen::ExpressionVisitor::operator()(ImplicitCastExpressionAST* ast)
       return expressionResult;
     }
 
+    case ImplicitCastKind::kBooleanConversion: {
+      if (control()->is_pointer(ast->expression->type)) {
+        // generate a pointer to bool cast
+        auto expressionResult = gen.expression(ast->expression);
+        auto resultType = gen.convertType(ast->type);
+
+        auto op = mlir::cxx::PtrToBoolOp::create(gen.builder_, loc, resultType,
+                                                 expressionResult.value);
+
+        return {op};
+      }
+      break;
+    }
+
     default:
       break;
 

src/mlir/cxx/mlir/cxx_dialect_conversions.cc

@@ -549,6 +549,32 @@ class IntToBoolOpLowering : public OpConversionPattern<cxx::IntToBoolOp> {
   }
 };
 
+class PtrToBoolOpLowering : public OpConversionPattern<cxx::PtrToBoolOp> {
+ public:
+  using OpConversionPattern::OpConversionPattern;
+
+  auto matchAndRewrite(cxx::PtrToBoolOp op, OpAdaptor adaptor,
+                       ConversionPatternRewriter& rewriter) const
+      -> LogicalResult override {
+    auto typeConverter = getTypeConverter();
+    auto context = getContext();
+
+    auto resultType = typeConverter->convertType(op.getType());
+    if (!resultType) {
+      return rewriter.notifyMatchFailure(
+          op, "failed to convert pointer to bool type");
+    }
+
+    auto zero = LLVM::ZeroOp::create(rewriter, op.getLoc(),
+                                     adaptor.getValue().getType());
+
+    rewriter.replaceOpWithNewOp<LLVM::ICmpOp>(
+        op, resultType, LLVM::ICmpPredicate::ne, adaptor.getValue(), zero);
+
+    return success();
+  }
+};
+
 class ArrayToPointerOpLowering
     : public OpConversionPattern<cxx::ArrayToPointerOp> {
  public:
@@ -1419,7 +1445,7 @@ void CxxToLLVMLoweringPass::runOnOperation() {
                                                          dataLayout, context);
 
   // cast operations
-  patterns.insert<IntToBoolOpLowering, BoolToIntOpLowering,
+  patterns.insert<IntToBoolOpLowering, PtrToBoolOpLowering, BoolToIntOpLowering,
                   IntegralCastOpLowering, ArrayToPointerOpLowering>(
       typeConverter, context);