1 files changed, 8 insertions, 2 deletions
diff --git a/lib/Target/JSBackend/CallHandlers.h b/lib/Target/JSBackend/CallHandlers.h
index e1e8cbb46f..8ae8c26c1d 100644
--- a/lib/Target/JSBackend/CallHandlers.h
+++ b/lib/Target/JSBackend/CallHandlers.h
@@ -101,8 +101,14 @@ DEF_CALL_HANDLER(__default__, {
     }
     if (NumArgs > 0) text += ",";
   }
-  // this is an ffi call if we need casts, and it is not a Math_ builtin (with just 1 arg - Math with more args is different XXX)
-  bool FFI = NeedCasts && (NumArgs > 1 || Name.find("Math_") != 0);
+  // this is an ffi call if we need casts, and it is not a special Math_ builtin
+  bool FFI = NeedCasts;
+  if (FFI && Name.find("Math_") == 0) {
+    if (Name == "Math_ceil" || Name == "Math_floor" || Name == "Math_min" || Name == "Math_max" || Name == "Math_sqrt" || Name == "Math_abs") {
+      // This special Math builtin is optimizable with all types, including floats, so can treat it as non-ffi
+      FFI = false;
+    }
+  }
   unsigned FFI_OUT = FFI ? ASM_FFI_OUT : 0;
   for (int i = 0; i < NumArgs; i++) {
     if (!NeedCasts) {