Last Comment Bug 756247 - IonMonkey: Assertion failure: [infer failure] Missing type pushed 0: float, at jsinfer.cpp:353
: IonMonkey: Assertion failure: [infer failure] Missing type pushed 0: float, a...
: assertion, testcase
Product: Core
Classification: Components
Component: JavaScript Engine (show other bugs)
: Other Branch
: x86_64 Linux
-- major (vote)
: ---
Assigned To: Jan de Mooij [:jandem]
: Jason Orendorff [:jorendorff]
Depends on:
Blocks: langfuzz IonFuzz
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Reported: 2012-05-17 13:27 PDT by Christian Holler (:decoder)
Modified: 2013-01-14 08:31 PST (History)
6 users (show)
choller: in‑testsuite+
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Crash Signature:
QA Whiteboard:
Iteration: ---
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Has Regression Range: ---
Has STR: ---

Patch (4.98 KB, patch)
2012-05-18 06:03 PDT, Jan de Mooij [:jandem]
dvander: review+
Details | Diff | Splinter Review

Description User image Christian Holler (:decoder) 2012-05-17 13:27:37 PDT
The following testcase asserts on ionmonkey revision 14735b4dbccc (run with --ion -n -m --ion-eager):

function foo(i)  {
    var n = 0;
    for (var i = 0; i < (false  ); i++)
      n = a++;
    assertEq(n, 29);
var a = foo(10);
Comment 1 User image Jan de Mooij [:jandem] 2012-05-18 04:10:49 PDT
Reduced it a bit more:

function foo()  {
    var n = 0;
    while (false)
        n = +a;
    print(n); // bailout

The problem is that when we bailout, n is a double (0.0) instead of an integer. The inferred type of "+a" is value -> value, which we compile to MToDouble. Using MToDouble is fine for "value -> double" but for "value -> value" we should probably just call a stub.

Note that value -> int32 has the same problem (double value instead of int32). This testcase also triggers the assert:

function bar(x) {
    var y = +(x ? x : "foo");
Comment 2 User image Jan de Mooij [:jandem] 2012-05-18 06:03:12 PDT
Created attachment 625079 [details] [diff] [review]

This follows JSOP_NEG and compiles +x as x * 1. Seems like it's the simplest fix and does not regress SS/V8/Kraken.
Comment 3 User image Jan de Mooij [:jandem] 2012-05-18 12:14:47 PDT
Comment 4 User image Christian Holler (:decoder) 2012-05-18 12:45:55 PDT
JSBugMon: This bug has been automatically verified fixed.
Comment 5 User image Christian Holler (:decoder) 2013-01-14 08:31:24 PST
A testcase for this bug was automatically identified at js/src/jit-test/tests/ion/bug756247.js.

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