Implement SAR

ethereumjs · Jul 23, 2018 · 4bbdf55 · 4bbdf55
1 parent 76da77d
commit 4bbdf55
Showing 1 changed file with 7 additions and 3 deletions.
diff --git a/lib/opFns.js b/lib/opFns.js
@@ -179,15 +179,19 @@ module.exports = {
     if (!runState._common.gteHardfork('constantinople')) {
       trap(ERROR.INVALID_OPCODE)
     }
-    b = b.fromTwos(256)
     if (a.gten(256)) {
-      if (b.ltn(0)) {
+      if (b.fromTwos(256).ltn(0)) {
         return new BN(-1).toTwos(256)
       } else {
         return new BN(0)
       }
     }
-    // FIXME: implement
+    var c = b.shrn(a.toNumber())
+    if (b.testn(255)) {
+      return c.iand(utils.MAX_INTEGER)
+    } else {
+      return c
+    }
   },
   // 0x20 range - crypto
   SHA3: function (offset, length, runState) {