|  | // Copyright 2019 the V8 project authors. All rights reserved. | 
|  | // Use of this source code is governed by a BSD-style license that can be | 
|  | // found in the LICENSE file. | 
|  |  | 
|  | // Flags: --allow-natives-syntax --opt --no-always-opt | 
|  |  | 
|  | let g = 0; | 
|  |  | 
|  | function f(x) { | 
|  | let y = BigInt.asUintN(64, 15n); | 
|  | // Introduce a side effect to force the construction of a FrameState that | 
|  | // captures the value of y. | 
|  | g = 42; | 
|  | try { | 
|  | return x + y; | 
|  | } catch(_) { | 
|  | return y; | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | %PrepareFunctionForOptimization(f); | 
|  | assertEquals(16n, f(1n)); | 
|  | assertEquals(17n, f(2n)); | 
|  | %OptimizeFunctionOnNextCall(f); | 
|  | assertEquals(16n, f(1n)); | 
|  | assertOptimized(f); | 
|  | assertEquals(15n, f(0)); | 
|  | assertUnoptimized(f); |