602912 - MathUtils::parseInt() of large numbers generates values that do not match other js engines

Status: RESOLVED WONTFIX

(Tamarin Graveyard :: Virtual Machine, defect, P3)

Description

[Brent Baker]

While working on code coverage in MathUtils::parseInt() I noticed some different results between tamarin and other js engines. When parsing large numbers with:

parseInt("1234567000123456700", 8)
tamarin-redux ->  23528930381028800
all others    -> 188231443048230400 (v8, tracemonkey, webkit)

Actually looking into this a little more it appears that tamarin is parsing these numbers to match C code:

Tamarin:
parseInt("1234567000123456700", 8): 23528930381028800

c:
strtol("1234567000123456700", 8):   23528930381028800

Comment 1

[Brent Baker]

Another case where tamarin differs from both a C testcase and other javascript engines:

parseInt("1234567890123", 32)

tamarin:  38390726480134180
c:      1228503247364293699
others: 1228503247364293600

Comment 2

[Lars T Hansen]

Are you sure it's the parser and not the printer?  My money would be on the latter, though it could be the former.  One way to find this out (if you're in the mood) is to Number() the value and then serialize it into a bytearray and dump the bytes, and examine them.  (Or look at the bits in a debugger.)

I have both string->number and number->strings assigned to me, you can assign this to me too if you want and I can investigate.

Comment 3

[Brent Baker]

Attachment: parseInt() byteArray encoding sample

Sample code showing the difference of byteArray when writeDouble() is called using 2 numbers that should be equal:
    Number(1228503247364293699)
    Number(parseInt("1234567890123", 32))

Note that arr[1] is not equal in the 2 encoded numbers. 

Number(1228503247364293699)
arr[0]: 67
arr[1]: 177
arr[2]: 12
arr[3]: 133
arr[4]: 49
arr[5]: 208
arr[6]: 144
arr[7]: 4


Number(parseInt("1234567890123", 32))
arr[0]: 67
arr[1]: 97
arr[2]: 12
arr[3]: 133
arr[4]: 49
arr[5]: 208
arr[6]: 144
arr[7]: 4

Comment 4

[Lars T Hansen]

Comment on attachment 484284 [details]
parseInt() byteArray encoding sample

Looks fine.  (Obviously if you start adding cases here you'd want some more procedural abstraction.)

Comment 5

[Sylvestre Ledru [:Sylvestre]]

Tamarin is a dead project now. Mass WONTFIX.

Comment 6

[Sylvestre Ledru [:Sylvestre]]

Tamarin isn't maintained anymore. WONTFIX remaining bugs.