switch support gnu range

Author: wenpen

clang/lib/CIR/CodeGen/CIRGenStmt.cpp

@@ -619,11 +619,21 @@ CIRGenFunction::foldCaseStmt(const clang::CaseStmt &S, mlir::Type condType,
   // Fold cascading cases whenever possible to simplify codegen a bit.
   while (caseStmt) {
     lastCase = caseStmt;
-    auto intVal = caseStmt->getLHS()->EvaluateKnownConstInt(getContext());
-    caseEltValueListAttr.push_back(mlir::cir::IntAttr::get(condType, intVal));
+
+    auto startVal = caseStmt->getLHS()->EvaluateKnownConstInt(getContext());
+    auto endVal = startVal;
+    if (auto *rhs = caseStmt->getRHS()) {
+      endVal = rhs->EvaluateKnownConstInt(getContext());
+    }
+    for (auto intVal = startVal; intVal <= endVal; ++intVal) {
+      caseEltValueListAttr.push_back(mlir::cir::IntAttr::get(condType, intVal));
+    }
+
     caseStmt = dyn_cast_or_null<CaseStmt>(caseStmt->getSubStmt());
   }
 
+  assert(!caseEltValueListAttr.empty() && "empty case value NYI");
+
   auto *ctxt = builder.getContext();
 
   auto caseAttr = mlir::cir::CaseAttr::get(
@@ -672,9 +682,6 @@ mlir::LogicalResult CIRGenFunction::buildCaseDefaultCascade(
 mlir::LogicalResult
 CIRGenFunction::buildCaseStmt(const CaseStmt &S, mlir::Type condType,
                               SmallVector<mlir::Attribute, 4> &caseAttrs) {
-  assert((!S.getRHS() || !S.caseStmtIsGNURange()) &&
-         "case ranges not implemented");
-
   auto *caseStmt = foldCaseStmt(S, condType, caseAttrs);
   return buildCaseDefaultCascade(caseStmt, condType, caseAttrs);
 }

clang/test/CIR/CodeGen/switch.cpp

@@ -327,3 +327,31 @@ void fallthrough(int x) {
 // CHECK-NEXT:      }
 // CHECK-NEXT:      ]
 // CHECK-NEXT:    }
+
+enum letter {
+ A, B, C, D, E, F, G, H, I, J, L
+};
+
+int gnurange(enum letter c) {
+  switch (c) { 
+    case A ... C:
+    case D:
+    case E ... F:
+    case L ... A:
+      return 1;
+    default: 
+      return 0;
+  }
+}
+
+//      CHECK:  cir.func @_Z8gnurange6letter
+//      CHECK:    cir.scope {
+//      CHECK:      cir.switch
+// CHECK-NEXT:      case (anyof, [0, 1, 2, 3, 4, 5] : !s32i) {
+//      CHECK:        cir.return
+// CHECK-NEXT:      },
+// CHECK-NEXT:      case (default) {
+//      CHECK:        cir.return
+// CHECK-NEXT:      }
+// CHECK-NEXT:      ]
+// CHECK-NEXT:    }