--- Comment #10 from martin dot apel at simpack dot de 2008-03-11 07:58
---
You are right, tan(PI/2) is undefined. I had this contained in some sort of
unit test comparing the results of my own formula evaluation code
and the result of the compiler. This gave the same result with gcc 4.
--- Comment #9 from rguenth at gcc dot gnu dot org 2008-03-10 17:07 ---
Obviously PI/2 isn't representable exactly here (also not the result, after
all the value is not defined, the value should approach -Inf / +Inf)
Neither ISO C nor IEEE specifies the result for exactly PI/2 (it could
--- Comment #8 from rguenth at gcc dot gnu dot org 2008-03-10 16:59 ---
Are you sure your calculator isn't wrong? ;) Gcc 4.2 produces the same result
for me (and only gcc 4.3 constant folds the result).
Of course this might be a glibc issue as indeed the 32bit version produces
./t
sin
--- Comment #7 from pinskia at gcc dot gnu dot org 2008-03-10 16:53 ---
(In reply to comment #6)
> I also get:
> [dandelion:~] pinskia% ./a.out
> sin(cos(tan(PI/2))) = -0.280611
In fact this calls the functions:
fmr f1,f0
bl L_tan$stub
fmr f0,f1
fmr f1,f0
--- Comment #6 from pinskia at gcc dot gnu dot org 2008-03-10 16:52 ---
I also get:
[dandelion:~] pinskia% ./a.out
sin(cos(tan(PI/2))) = -0.280611
Get 4.0.1 on powerpc-darwin.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35523
--- Comment #5 from pinskia at gcc dot gnu dot org 2008-03-10 16:48 ---
On i686:
[EMAIL PROTECTED] local]$ ~/gcc-local/bin/gcc t.c -fno-builtin -lm -O2
[EMAIL PROTECTED] local]$ !./
./a.out
sin(cos(tan(PI/2))) = -0.827351
[EMAIL PROTECTED] local]$ ~/gcc-local/bin/gcc t.c -lm -O2
[EMAIL
--- Comment #4 from martin dot apel at simpack dot de 2008-03-10 16:33
---
(In reply to comment #3)
> gcc-4.3 -o t t.i
> ./t
> sin(cos(tan(PI/2))) = -0.280611
>
> gcc-4.3 -o t t.i -fno-builtin -lm
> ./t
> sin(cos(tan(PI/2))) = -0.280611
>
> works for me?
>
It compiles and runs, but
--- Comment #3 from rguenth at gcc dot gnu dot org 2008-03-10 15:12 ---
gcc-4.3 -o t t.i
./t
sin(cos(tan(PI/2))) = -0.280611
gcc-4.3 -o t t.i -fno-builtin -lm
./t
sin(cos(tan(PI/2))) = -0.280611
works for me?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35523
--- Comment #2 from martin dot apel at simpack dot de 2008-03-10 10:42
---
Version information for libgmp: 4.2.2, compiled with gcc-4.2.2
Version information for libmpfr: 2.3.1, compiled with gcc-4.2.2
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35523
--- Comment #1 from martin dot apel at simpack dot de 2008-03-10 10:37
---
Created an attachment (id=15288)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15288&action=view)
Preprocessed source file producing the bug
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35523
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