use Math.imul in rand_r

1 files changed, 1 insertions, 8 deletions

diff --git a/src/library.js b/src/library.js
index bd34ac29..b4da994e 100644
--- a/src/library.js
+++ b/src/library.js
@@ -3455,14 +3455,7 @@ LibraryManager.library = {
   rand_r__deps: ['__rand_seed'],
   rand_r: function(seedp) { 
     var val = {{{ makeGetValue('seedp', 0, 'i32') }}};
-    // calculate val * 31010991 + 0x676e6177
-    // i32 multiplication will be rounded by javascript
-    var valh = val >> 16;
-    var vall = val & 0xffff;
-    var c = 31010991;
-    var ch = c >> 16;
-    var cl = c & 0xffff;
-    val = (((valh * cl + vall * ch) << 16) + vall * cl + 0x676e6177) & 0xffffffff;
+    val = (Math.imul(val, 31010991) + 0x676e6177)|0;
     {{{ makeSetValue('seedp', 0, 'val', 'i32') }}};
     return val;
   },