Generate code for the various __builtin_ctz functions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@46811 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/CodeGen/CGBuiltin.cpp b/CodeGen/CGBuiltin.cpp
index 996978e138fd1c1a17dc5c2fe9d85a40ae275aff..661c09d7cd71d6c935fa3b06d0314968f2a1ab1a 100644 (file)
--- a/CodeGen/CGBuiltin.cpp
+++ b/CodeGen/CGBuiltin.cpp
@@ -149,6 +149,20 @@ RValue CodeGenFunction::EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
     
     return RValue::get(Result);
   }
+  case Builtin::BI__builtin_ctz:
+  case Builtin::BI__builtin_ctzl:
+  case Builtin::BI__builtin_ctzll: {
+    Value *ArgValue = EmitScalarExpr(E->getArg(0));
+    
+    const llvm::Type *ArgType = ArgValue->getType();
+    Value *F = CGM.getIntrinsic(Intrinsic::cttz, &ArgType, 1);
+
+    const llvm::Type *ResultType = ConvertType(E->getType());    
+    Value *Result = Builder.CreateCall(F, ArgValue, "tmp");
+    if (Result->getType() != ResultType)
+      Result = Builder.CreateIntCast(Result, ResultType, "cast");
+    return RValue::get(Result);
+  }
   case Builtin::BI__builtin_expect:
     return RValue::get(EmitScalarExpr(E->getArg(0)));
   case Builtin::BI__builtin_bswap32: