// Copyright 2018 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 // This tests that NumberAdd passes on the right truncations // even if it figures out during SimplifiedLowering that it // can indeed do a Word32 operation (based on the feedback // baked in for its inputs by other operators). (function() { // We need a + with Number feedback to get to a NumberAdd // during the typed lowering pass of TurboFan's frontend. function foo(x, y) { return x + y; } foo(0.1, 0.2); foo(0.1, 0.2); // Now we need to fool TurboFan to think that it has to // perform the `foo(x,-1)` on Float64 values until the // very last moment (after the RETYPE phase of the // SimplifiedLowering) where it realizes that the inputs // and outputs of the NumberAdd allow it perform the // operation on Word32. function bar(x) { x = Math.trunc(foo(x - 1, 1)); return foo(x, -1); } assertEquals(0, bar(1)); assertEquals(1, bar(2)); %OptimizeFunctionOnNextCall(bar); assertEquals(2, bar(3)); })(); // This tests that SpeculativeNumberAdd can still lower to // Int32Add in SimplifiedLowering, which requires some magic // to make sure that SpeculativeNumberAdd survives to that // point, especially the JSTypedLowering needs to be unable // to tell that the inputs to SpeculativeNumberAdd are non // String primitives. (function() { // We need a function that has a + with feedback Number or // NumberOrOddball, but for whose inputs the JSTypedLowering // cannot reduce it to NumberAdd (with SpeculativeToNumber // conversions). We achieve this utilizing an object literal // indirection here. function baz(x) { return {x}.x + x; } baz(null); baz(undefined); // Now we just need to truncate the result. function foo(x) { return baz(1) | 0; } assertEquals(2, foo()); assertEquals(2, foo()); %OptimizeFunctionOnNextCall(foo); assertEquals(2, foo()); })();