Support case statement ranges.

llvm-svn: 42648

2 files changed, 30 insertions, 3 deletions

diff --git a/clang/CodeGen/CGStmt.cpp b/clang/CodeGen/CGStmt.cpp
index 2b9a72be531..c07929d107c 100644
--- a/clang/CodeGen/CGStmt.cpp
+++ b/clang/CodeGen/CGStmt.cpp
@@ -356,9 +356,21 @@ void CodeGenFunction::EmitContinueStmt() {
 
 void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) {
   StartBlock("sw.bb");
-  llvm::Value *V = EmitScalarExpr(S.getLHS());
-  SwitchInsn->addCase(cast<llvm::ConstantInt>(V), Builder.GetInsertBlock());
-  assert (!S.getRHS() && "Case statement range is not yet supported");
+  llvm::BasicBlock *CaseDest = Builder.GetInsertBlock();
+  llvm::ConstantInt *LV = cast<llvm::ConstantInt>(EmitScalarExpr(S.getLHS()));
+  SwitchInsn->addCase(LV, CaseDest);
+  if (const Expr *R = S.getRHS()) {
+    llvm::ConstantInt *RV = cast<llvm::ConstantInt>(EmitScalarExpr(R));
+    llvm::APInt LHS = LV->getValue();
+    llvm::APInt RHS = RV->getValue();
+    LHS++;
+    while (LHS != RHS) {
+      SwitchInsn->addCase(llvm::ConstantInt::get(LHS), CaseDest);
+      LHS++;
+    }
+    SwitchInsn->addCase(llvm::ConstantInt::get(LHS), CaseDest);
+  }
+
   EmitStmt(S.getSubStmt());
 }
 
diff --git a/clang/test/CodeGen/switch.c b/clang/test/CodeGen/switch.c
index 690c11e9f36..25602e93c37 100644
--- a/clang/test/CodeGen/switch.c
+++ b/clang/test/CodeGen/switch.c
@@ -15,3 +15,18 @@ int foo(int i) {
 }
 
     
+int foo2(int i) {
+  int j = 0;
+  switch (i) {
+  case 1 : 
+    j = 2; break;
+  case 2 ... 10:
+    j = 3; break;
+  default:
+    j = 42; break;
+  }
+  j = j + 1;
+  return j;
+}
+
+