4 files changed, 15 insertions, 9 deletions
diff --git a/src/jsifier.js b/src/jsifier.js
index 262dd3eb..2cf94a0d 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -1606,7 +1606,7 @@ function JSify(data, functionsOnly, givenFunctions) {
     // "Final shape that will be created").
     if (PRECISE_I64_MATH && Types.preciseI64MathUsed) {
       if (!INCLUDE_FULL_LIBRARY) {
-        ['i64Add', 'bitshift64Shl', 'bitshift64Lshr', 'bitshift64Ashr'].forEach(function(func) {
+        ['i64Add', 'i64Subtract', 'bitshift64Shl', 'bitshift64Lshr', 'bitshift64Ashr'].forEach(function(func) {
           print(processLibraryFunction(LibraryManager.library[func], func)); // must be first to be close to generated code
           Functions.implementedFunctions['_' + func] = LibraryManager.library[func + '__sig'];
         });
diff --git a/src/library.js b/src/library.js
index f9864134..a792a681 100644
--- a/src/library.js
+++ b/src/library.js
@@ -7490,6 +7490,19 @@ LibraryManager.library = {
     {{{ makeStructuralReturn(['l|0', 'h', 'overflow'], true) }}};
   },
 
+  i64Subtract__asm: true,
+  i64Subtract__sig: 'iiiii',
+  i64Subtract: function(a, b, c, d) {
+    a = a|0; b = b|0; c = c|0; d = d|0;
+    var l = 0, h = 0;
+    l = (a - c)>>>0;
+    h = (b - d)>>>0;
+    if ((l>>>0) > (a>>>0)) { // iff we overflowed
+      h = (h-1)>>>0;
+    }
+    {{{ makeStructuralReturn(['l|0', 'h'], true) }}};
+  },
+
   bitshift64Shl__asm: true,
   bitshift64Shl__sig: 'iiii',
   bitshift64Shl: function(low, high, bits) {
diff --git a/src/long.js b/src/long.js
index 6d0e873d..b3d19bd3 100644
--- a/src/long.js
+++ b/src/long.js
@@ -1530,13 +1530,6 @@ var i64Math = (function() { // Emscripten wrapper
 
   // Emscripten wrapper
   var Wrapper = {
-    subtract: function(xl, xh, yl, yh) {
-      var x = new goog.math.Long(xl, xh);
-      var y = new goog.math.Long(yl, yh);
-      var ret = x.subtract(y);
-      HEAP32[tempDoublePtr>>2] = ret.low_;
-      HEAP32[tempDoublePtr+4>>2] = ret.high_;
-    },
     multiply: function(xl, xh, yl, yh) {
       var x = new goog.math.Long(xl, xh);
       var y = new goog.math.Long(yl, yh);
diff --git a/src/parseTools.js b/src/parseTools.js
index 010f4988..a568b718 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -2062,7 +2062,7 @@ function processMathop(item) {
       }
       case 'sub': {
         if (PRECISE_I64_MATH) {
-          return i64PreciseOp('subtract');
+          return i64PreciseLib('subtract');
         } else {
           warnI64_1();
           return finish(splitI64(mergeI64(idents[0]) + '-' + mergeI64(idents[1]), true));