do not js-optimize away rounding corrections

1 files changed, 2 insertions, 1 deletions

diff --git a/src/parseTools.js b/src/parseTools.js
index 520d278e..0e6ddee8 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -1537,7 +1537,8 @@ function makeRounding(value, bits, signed, floatConversion) {
   // TODO: handle roundings of i64s
   assert(bits);
   // C rounds to 0 (-5.5 to -5, +5.5 to 5), while JS has no direct way to do that.
-  if (bits <= 32 && signed) return '((' + value + ')|0)'; // This is fast and even correct, for all cases
+  if (bits <= 32 && signed) return '((' + value + ')&-1)'; // This is fast and even correct, for all cases. Note that it is the same
+                                                           // as |0, but &-1 hints to the js optimizer that this is a rounding correction
   // Do Math.floor, which is reasonably fast, if we either don't care, or if we can be sure
   // the value is non-negative
   if (!correctRoundings() || (!signed && !floatConversion)) return 'Math.floor(' + value + ')';