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From: "dpozar at ecs dot umass.edu" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/98201] CSQRT function gives bad resuts at runtime
Date: Tue, 08 Dec 2020 15:47:14 +0000 [thread overview]
Message-ID: <bug-98201-4-cXqmEifXwW@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-98201-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98201
--- Comment #3 from dpozar at ecs dot umass.edu ---
Thomas,
compile time works fine; runtime not so good.
dave
Output below:
Runtime
Argument SquareRoot
SR squared
(-.1000E+02 0.1000E+00) (0.1581E-01 0.3163E+01) (-.1001E+02 0.1000E+00)
(-.1000E+03 0.1000E+00) (0.5167E-02 0.9676E+01) (-.9362E+02 0.1000E+00)
(-.1000E+04 0.1000E+00) (0.0000E+00 Infinity) ( -Infinity NaN)
(-.1000E+05 0.1000E+00) (0.0000E+00 Infinity) ( -Infinity NaN)
(-.1000E+06 0.1000E+00) (0.0000E+00 Infinity) ( -Infinity NaN)
(-.1000E+07 0.1000E+00) (0.0000E+00 Infinity) ( -Infinity NaN)
(-.1000E+08 0.1000E+00) (0.0000E+00 Infinity) ( -Infinity NaN)
(-.1000E+09 0.1000E+00) (0.0000E+00 Infinity) ( -Infinity NaN)
(-.1000E+10 0.1000E+00) (0.0000E+00 Infinity) ( -Infinity NaN)
Compile-time
(-.1000E+02 0.1000E+01) (0.1579E+00 0.3166E+01) (-.1000E+02 0.1000E+01)
(-.1000E+03 0.1000E+01) (0.5000E-01 0.1000E+02) (-.1000E+03 0.1000E+01)
(-.1000E+04 0.1000E+01) (0.1581E-01 0.3162E+02) (-.1000E+04 0.1000E+01)
(-.1000E+05 0.1000E+01) (0.5000E-02 0.1000E+03) (-.1000E+05 0.1000E+01)
(-.1000E+06 0.1000E+01) (0.1581E-02 0.3162E+03) (-.1000E+06 0.1000E+01)
(-.1000E+07 0.1000E+01) (0.5000E-03 0.1000E+04) (-.1000E+07 0.1000E+01)
(-.1000E+08 0.1000E+01) (0.1581E-03 0.3162E+04) (-.1000E+08 0.1000E+01)
(-.1000E+09 0.1000E+01) (0.5000E-04 0.1000E+05) (-.1000E+09 0.1000E+01)
(-.1000E+10 0.1000E+01) (0.1581E-04 0.3162E+05) (-.1000E+10 0.1000E+01)
Process returned 0 (0x0) execution time : 0.060 s
Press any key to continue.
________________________________
From: tkoenig at gcc dot gnu.org <gcc-bugzilla@gcc.gnu.org>
Sent: Tuesday, December 8, 2020 10:34 AM
To: David Pozar <dpozar@ecs.umass.edu>
Subject: [Bug fortran/98201] CSQRT function gives bad resuts at runtime
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98201
Thomas Koenig <tkoenig at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target| |mingw
CC| |tkoenig at gcc dot gnu.org
--- Comment #1 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
Here is a slight extension of your program, which also
checks the compile-time simplification. Can you tell me
what it does?
program main
implicit none
integer :: i,n
complex z, sq
complex, parameter, dimension(9) :: zp = [(-10.**i+(0.,1.),i=1,9)]
complex, parameter, dimension(9) :: sqp = sqrt(zp)
write (*,*) "Runtime"
write (*,*) " Argument SquareRoot SR
squared"
do n=1,9
z=-10.**n+(0.,.1)
sq=csqrt(z)
write(*,1) z, sq, sq*sq
end do
write (*,*) "Compile-time"
do n=1,9
write (*,1) zp(n), sqp(n), sqp(n)**2
end do
1 format(3("(",e10.4,2x,e10.4,")",3x))
end
On my Linux box, it prints
Runtime
Argument SquareRoot SR squared
(-.1000E+02 0.1000E+00) (0.1581E-01 0.3162E+01) (-.1000E+02 0.1000E+00)
(-.1000E+03 0.1000E+00) (0.5000E-02 0.1000E+02) (-.1000E+03 0.1000E+00)
(-.1000E+04 0.1000E+00) (0.1581E-02 0.3162E+02) (-.1000E+04 0.1000E+00)
(-.1000E+05 0.1000E+00) (0.5000E-03 0.1000E+03) (-.1000E+05 0.1000E+00)
(-.1000E+06 0.1000E+00) (0.1581E-03 0.3162E+03) (-.1000E+06 0.1000E+00)
(-.1000E+07 0.1000E+00) (0.5000E-04 0.1000E+04) (-.1000E+07 0.1000E+00)
(-.1000E+08 0.1000E+00) (0.1581E-04 0.3162E+04) (-.1000E+08 0.1000E+00)
(-.1000E+09 0.1000E+00) (0.5000E-05 0.1000E+05) (-.1000E+09 0.1000E+00)
(-.1000E+10 0.1000E+00) (0.1581E-05 0.3162E+05) (-.1000E+10 0.1000E+00)
Compile-time
(-.1000E+02 0.1000E+01) (0.1579E+00 0.3166E+01) (-.1000E+02 0.1000E+01)
(-.1000E+03 0.1000E+01) (0.5000E-01 0.1000E+02) (-.1000E+03 0.1000E+01)
(-.1000E+04 0.1000E+01) (0.1581E-01 0.3162E+02) (-.1000E+04 0.1000E+01)
(-.1000E+05 0.1000E+01) (0.5000E-02 0.1000E+03) (-.1000E+05 0.1000E+01)
(-.1000E+06 0.1000E+01) (0.1581E-02 0.3162E+03) (-.1000E+06 0.1000E+01)
(-.1000E+07 0.1000E+01) (0.5000E-03 0.1000E+04) (-.1000E+07 0.1000E+01)
(-.1000E+08 0.1000E+01) (0.1581E-03 0.3162E+04) (-.1000E+08 0.1000E+01)
(-.1000E+09 0.1000E+01) (0.5000E-04 0.1000E+05) (-.1000E+09 0.1000E+01)
(-.1000E+10 0.1000E+01) (0.1581E-04 0.3162E+05) (-.1000E+10 0.1000E+01)
so there is a slight difference in one value, but nothing as
completely wrong as what you show.
What is the output of that program on your system?
And what is the output of "gfortran -v" ?
--
You are receiving this mail because:
You reported the bug.
next prev parent reply other threads:[~2020-12-08 15:47 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-08 14:44 [Bug fortran/98201] New: " pozar at ecs dot umass.edu
2020-12-08 15:34 ` [Bug fortran/98201] " tkoenig at gcc dot gnu.org
2020-12-08 15:35 ` dominiq at lps dot ens.fr
2020-12-08 15:47 ` dpozar at ecs dot umass.edu [this message]
2020-12-08 15:54 ` dpozar at ecs dot umass.edu
2020-12-08 15:55 ` tkoenig at gcc dot gnu.org
2020-12-08 16:27 ` dpozar at ecs dot umass.edu
2020-12-08 17:36 ` kargl at gcc dot gnu.org
2020-12-08 18:19 ` tkoenig at gcc dot gnu.org
2020-12-08 19:13 ` dpozar at ecs dot umass.edu
2020-12-08 19:27 ` tkoenig at gcc dot gnu.org
2020-12-08 20:46 ` dpozar at ecs dot umass.edu
2020-12-08 22:06 ` kargl at gcc dot gnu.org
2020-12-09 0:28 ` dpozar at ecs dot umass.edu
2020-12-09 4:38 ` sgk at troutmask dot apl.washington.edu
2020-12-09 13:24 ` dpozar at ecs dot umass.edu
2020-12-09 15:37 ` sgk at troutmask dot apl.washington.edu
2020-12-09 16:04 ` dpozar at ecs dot umass.edu
2021-03-28 12:38 ` dominiq at lps dot ens.fr
2021-03-28 13:05 ` dpozar at ecs dot umass.edu
2021-03-28 13:16 ` dominiq at lps dot ens.fr
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