[CIR][CodeGen] Add basic support for unary plus/minus

Author: cmarcelo

clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp

@@ -334,11 +334,44 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
     llvm_unreachable("NYI");
   }
   mlir::Value VisitUnaryPlus(const UnaryOperator *E) {
-    llvm_unreachable("NYI");
+    // NOTE(cir): QualType function parameter still not used, so don´t replicate
+    // it here yet.
+    QualType promotionTy = getPromotionType(E->getSubExpr()->getType());
+    auto result = VisitPlus(E, promotionTy);
+    if (result && !promotionTy.isNull())
+      assert(0 && "not implemented yet");
+    return buildUnaryOp(E, mlir::cir::UnaryOpKind::Plus, result);
+  }
+
+  mlir::Value VisitPlus(const UnaryOperator *E, QualType PromotionType) {
+    // This differs from gcc, though, most likely due to a bug in gcc.
+    TestAndClearIgnoreResultAssign();
+    if (!PromotionType.isNull())
+      assert(0 && "scalar promotion not implemented yet");
+    return Visit(E->getSubExpr());
   }
+
   mlir::Value VisitUnaryMinus(const UnaryOperator *E) {
-    llvm_unreachable("NYI");
+    // NOTE(cir): QualType function parameter still not used, so don´t replicate
+    // it here yet.
+    QualType promotionTy = getPromotionType(E->getSubExpr()->getType());
+    auto result = VisitMinus(E, promotionTy);
+    if (result && !promotionTy.isNull())
+      assert(0 && "not implemented yet");
+    return buildUnaryOp(E, mlir::cir::UnaryOpKind::Minus, result);
+  }
+
+  mlir::Value VisitMinus(const UnaryOperator *E, QualType PromotionType) {
+    TestAndClearIgnoreResultAssign();
+    if (!PromotionType.isNull())
+      assert(0 && "scalar promotion not implemented yet");
+
+    // NOTE: LLVM codegen will lower this directly to either a FNeg
+    // or a Sub instruction.  In CIR this will be handled later in LowerToLLVM.
+
+    return Visit(E->getSubExpr());
   }
+
   mlir::Value VisitUnaryNot(const UnaryOperator *E) { llvm_unreachable("NYI"); }
   mlir::Value VisitUnaryLNot(const UnaryOperator *E) {
     llvm_unreachable("NYI");
@@ -592,6 +625,22 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
   buildCompoundAssign(const CompoundAssignOperator *E,
                       mlir::Value (ScalarExprEmitter::*F)(const BinOpInfo &));
 
+  // TODO(cir): Candidate to be in a common AST helper between CIR and LLVM codegen.
+  QualType getPromotionType(QualType Ty) {
+    if (CGF.getContext()
+            .getTargetInfo()
+            .shouldEmitFloat16WithExcessPrecision()) {
+      if (Ty->isAnyComplexType()) {
+        QualType ElementType = Ty->castAs<ComplexType>()->getElementType();
+        if (ElementType->isFloat16Type())
+          return CGF.getContext().getComplexType(CGF.getContext().FloatTy);
+      }
+      if (Ty->isFloat16Type())
+        return CGF.getContext().FloatTy;
+    }
+    return QualType();
+  }
+
   // Binary operators and binary compound assignment operators.
 #define HANDLEBINOP(OP)                                                        \
   mlir::Value VisitBin##OP(const BinaryOperator *E) {                          \

clang/test/CIR/CodeGen/unary.cpp

@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir-enable -Wno-unused-value -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s
+
+unsigned up0() {
+  unsigned a = 1;
+  return +a;
+}
+
+// CHECK: cir.func @_Z3up0v() -> i32 {
+// CHECK: %[[#RET:]] = cir.alloca i32, cir.ptr <i32>, ["__retval"]
+// CHECK: %[[#A:]] = cir.alloca i32, cir.ptr <i32>, ["a", init]
+// CHECK: %[[#INPUT:]] = cir.load %[[#A]]
+// CHECK: %[[#OUTPUT:]] = cir.unary(plus, %[[#INPUT]])
+// CHECK: cir.store %[[#OUTPUT]], %[[#RET]]
+
+unsigned um0() {
+  unsigned a = 1;
+  return -a;
+}
+
+// CHECK: cir.func @_Z3um0v() -> i32 {
+// CHECK: %[[#RET:]] = cir.alloca i32, cir.ptr <i32>, ["__retval"]
+// CHECK: %[[#A:]] = cir.alloca i32, cir.ptr <i32>, ["a", init]
+// CHECK: %[[#INPUT:]] = cir.load %[[#A]]
+// CHECK: %[[#OUTPUT:]] = cir.unary(minus, %[[#INPUT]])
+// CHECK: cir.store %[[#OUTPUT]], %[[#RET]]