[Bug math/27617] New: tgamma integer wrapping results in inaccurate result.

[Bug math/27617] New: tgamma integer wrapping results in inaccurate result.

[brchrisman at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27617

            Bug ID: 27617
           Summary: tgamma integer wrapping results in inaccurate result.
           Product: glibc
           Version: 2.32
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: math
          Assignee: unassigned at sourceware dot org
          Reporter: brchrisman at gmail dot com
  Target Milestone: ---

For integer parameters greater than 6, tgamma(n+1) != n!
(note: 719 and beyond are off-by-one, while the real parameter at the bottom
results in 720)

#include <iostream>
#include <cmath>
using namespace std;
int main(void)
{
        uint64_t foo;
        for(int i=0; i < 10; i++)
        {
                foo = tgamma(i);
                cout << foo << "\n";
        }
        cout << tgamma(7.0) << "\n";
}

0
1
1
2
6
24
120
719
5039
40319
720

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug math/27617] tgamma integer wrapping results in inaccurate result.

[brchrisman at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27617

Brian Chrisman <brchrisman at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |brchrisman at gmail dot com

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug math/27617] tgamma integer wrapping results in inaccurate result.

[brchrisman at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27617

--- Comment #1 from Brian Chrisman <brchrisman at gmail dot com> ---
Apologies, this is not a bug as I misread the return types supported to include
integers when they don't.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug math/27617] tgamma integer wrapping results in inaccurate result.

[brchrisman at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27617

Brian Chrisman <brchrisman at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |NOTABUG
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #2 from Brian Chrisman <brchrisman at gmail dot com> ---
tgamma(7) correctly returns 719.9999...

-- 
You are receiving this mail because:
You are on the CC list for the bug.