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From: "zsojka at seznam dot cz" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/105384] compilation never (?) finishes with __builtin_yn{,f,l} at -O and above
Date: Tue, 26 Apr 2022 07:37:17 +0000 [thread overview]
Message-ID: <bug-105384-4-FVkDSKC046@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-105384-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105384
--- Comment #6 from Zdenek Sojka <zsojka at seznam dot cz> ---
(In reply to Richard Biener from comment #5)
> The bessel functions are known to take a lot of time, there are (fixed?)
> older bugreports about those and we do take some measures to speed up the
> computation.
> We might want to give up the idea on producing correctly rounded results and
> simply invoke the host library routines here ...
$ cat testcase.c
double
foo(double a, double b)
{
return __builtin_yn(a, b);
}
double
bar(double a, double b)
{
return __builtin_jn(a, b);
}
int main()
{
foo(0x220f0985, 0xbc7bc234);
bar(4292622104, 0xff00ff00ff00ff00);
return 0;
}
$ gcc testcase.c -lm -O1
$ time ./a.out
real 0m2.825s
user 0m2.815s
sys 0m0.010s
It takes quite some time at runtime, but the compilation time evaluation takes
several magnitudes more time (PR105384) and/or memory (PR105385).
next prev parent reply other threads:[~2022-04-26 7:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-25 19:42 [Bug tree-optimization/105384] New: " zsojka at seznam dot cz
2022-04-25 19:45 ` [Bug tree-optimization/105384] " pinskia at gcc dot gnu.org
2022-04-25 19:46 ` pinskia at gcc dot gnu.org
2022-04-25 19:52 ` zsojka at seznam dot cz
2022-04-25 20:44 ` marxin at gcc dot gnu.org
2022-04-26 6:52 ` rguenth at gcc dot gnu.org
2022-04-26 7:37 ` zsojka at seznam dot cz [this message]
2022-04-26 18:04 ` joseph at codesourcery dot com
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