Fix part of PR12457. Patch by Justin Bogner!

llvm-svn: 183886

1 files changed, 34 insertions, 0 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 21fb4599664..84f7bfdf82b 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -5691,6 +5691,40 @@ bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
     return Success(Val.byteSwap(), E);
   }
 
+  case Builtin::BI__builtin_clz:
+  case Builtin::BI__builtin_clzl:
+  case Builtin::BI__builtin_clzll: {
+    APSInt Val;
+    if (!EvaluateInteger(E->getArg(0), Val, Info))
+      return false;
+    if (!Val)
+      return Error(E);
+
+    return Success(Val.countLeadingZeros(), E);
+  }
+
+  case Builtin::BI__builtin_ctz:
+  case Builtin::BI__builtin_ctzl:
+  case Builtin::BI__builtin_ctzll: {
+    APSInt Val;
+    if (!EvaluateInteger(E->getArg(0), Val, Info))
+      return false;
+    if (!Val)
+      return Error(E);
+
+    return Success(Val.countTrailingZeros(), E);
+  }
+
+  case Builtin::BI__builtin_popcount:
+  case Builtin::BI__builtin_popcountl:
+  case Builtin::BI__builtin_popcountll: {
+    APSInt Val;
+    if (!EvaluateInteger(E->getArg(0), Val, Info))
+      return false;
+
+    return Success(Val.countPopulation(), E);
+  }
+
   case Builtin::BI__builtin_classify_type:
     return Success(EvaluateBuiltinClassifyType(E), E);