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Re: no quadmath.h on ppc64 ?



On 12/04/18 01:39 PM, Dennis Clarke wrote:
On 05/04/18 01:24 AM, John Paul Adrian Glaubitz wrote:
On 04/05/2018 12:01 AM, Dennis Clarke wrote:
So there we see "--disable-libquadmath --disable-libquadmath-support".

damn.   :-(

Please file a bug report against Debian's gcc-5, gcc-6, gcc-7 and gcc-8
packages if you think that libquadmath must be enabled.

There are usually good reasons for such defaults but sometimes they might
just be a historic artifact and you were the first person to stumble
over it.

Working on it :

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=895452

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82686


Dennis


Managed a bootstrap that didn't blow up.

At the moment the assembly output from a trivial test shows that the IBM extended precision long double type is the default unless one actually asks for the IEEE754-2008 128-bit datatype.

dclarke@nix:~/pgm/C/ieee754$ PATH=/usr/local/build/gcc-7.3.0_linux_4.15.0-2-powerpc64_ppc64.005/gcc:$PATH xgcc -I/usr/local/build/gcc-7.3.0_linux_4.15.0-2-powerpc64_ppc64.005/gcc/include -m64 -g -Wl,-rpath=/usr/local/lib -mcpu=970 -maltivec -mfull-toc -mregnames -mabi=ieeelongdouble -S -o ld.s ld.c
xgcc: warning: using IEEE extended precision long double
cc1: warning: using IEEE extended precision long double
dclarke@nix:~/pgm/C/ieee754$ grep "quad" ld.s | grep "0x"
        .quad   0x4000921fb54442d1,0x8469898cc51701b8

That data is correct.

dclarke@nix:~/pgm/C/ieee754$ PATH=/usr/local/build/gcc-7.3.0_linux_4.15.0-2-powerpc64_ppc64.005/gcc:$PATH xgcc -I/usr/local/build/gcc-7.3.0_linux_4.15.0-2-powerpc64_ppc64.005/gcc/include -m64 -g -Wl,-rpath=/usr/local/lib -mcpu=970 -maltivec -mfull-toc -mregnames -mabi=ibmlongdouble -S -o ld.s ld.c
xgcc: warning: using IBM extended precision long double
cc1: warning: using IBM extended precision long double
dclarke@nix:~/pgm/C/ieee754$ grep "quad" ld.s | grep "0x"
        .quad   0x400921fb54442d18,0x3ca1a62633145c06

That is a whole other beast of a different colour.

dclarke@nix:~/pgm/C/ieee754$ PATH=/usr/local/build/gcc-7.3.0_linux_4.15.0-2-powerpc64_ppc64.005/gcc:$PATH xgcc -I/usr/local/build/gcc-7.3.0_linux_4.15.0-2-powerpc64_ppc64.005/gcc/include -m64 -g -Wl,-rpath=/usr/local/lib -mcpu=970 -maltivec -mfull-toc -mregnames -S -o ld.s ld.c
dclarke@nix:~/pgm/C/ieee754$ grep "quad" ld.s | grep "0x"
        .quad   0x400921fb54442d18,0x3ca1a62633145c06
dclarke@nix:~/pgm/C/ieee754$

So the default is the IBM type. No idea on the libquadmath yet.
I should have more info on this issue in another 16 or 20 hours.

Dennis





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