glibc 2.7 complex functions are possibly miscompiled by gcc 4.3 trunk

[Ismail DÃnmez <ismail at pardus dot org dot tr>]

Hi all,

I am doing glibc 4.3 regression tests using gcc 4.3 trunk nearly every day and 
I see 3 tests fail :

math/test-float
math/test-ildoubl
math/test-ifloat

The erorrs are all similar :

Failure: Test: Imaginary part of: cacosh (-0 + 0 i) == 0.0 + pi/2 i
Result:
 is:          0.00000000000000000000e+00   0x0.00000000000000000000p+0
 should be:   1.57079637050628662109e+00   0x1.921fb600000000000000p+0
 difference:  1.57079637050628662109e+00   0x1.921fb600000000000000p+0
 ulp       :  13176795.0000
 max.ulp   :  0.0000

All of the imaginary part checks fail, with the help of GFortran maintainers 
we identified 2 testcases which fail with glibc 2.7 when compiled with gcc 
4.3 trunk [0] .

This problem also causes 32 unexpected failures on gfortran regression tests. 
So I wonder if you guys can help me debug this, I checked out libc sources 
but its mostly assembly stuff for math functions. Maybe Jakub has an idea, 
not sure.

Any help/comment appreciated.

[0] http://sourceware.org/bugzilla/show_bug.cgi?id=5490

Regards,
ismail


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