Handle __builtin_expect (#268)

* Handle builtin_expect

* add warning

Author: ivanradanov

tools/cgeist/Lib/CGCall.cc

@@ -561,6 +561,14 @@ ValueCategory MLIRScanner::VisitCallExpr(clang::CallExpr *expr) {
               /*isReference*/ false);
       }
     }
+  if (auto *ic = dyn_cast<ImplicitCastExpr>(expr->getCallee()))
+    if (auto *sr = dyn_cast<DeclRefExpr>(ic->getSubExpr())) {
+      if (sr->getDecl()->getIdentifier() &&
+          sr->getDecl()->getName() == "__builtin_expect") {
+        llvm::errs() << "warning, ignoring __builtin_expect\n";
+        return Visit(expr->getArg(0));
+      }
+    }
   if (auto *ic = dyn_cast<ImplicitCastExpr>(expr->getCallee()))
     if (auto *sr = dyn_cast<DeclRefExpr>(ic->getSubExpr())) {
       if (sr->getDecl()->getIdentifier() &&