Re: Compiling for ARMv8-A Using GCC 7.2.0 - Assertion error in gen-fac
Ciao, Il Ven, 6 Dicembre 2019 3:55 pm, Torbjörn Granlund ha scritto: > ni...@lysator.liu.se (Niels Möller) writes: > > > From my understanding this might be a difference in how GCC 7.2.0 > > handles unsigned longs vs GCC 4.8.5. > > Can you file a gcc bug? These constants are defined as > The first thing to try might be gcc 7.4, which was the final gcc 7 > release. There is also a 7.5 version, released Nov 14, 2019: https://gcc.gnu.org/gcc-7/ Ĝis, m -- http://bodrato.it/papers/ ___ gmp-bugs mailing list gmp-bugs@gmplib.org https://gmplib.org/mailman/listinfo/gmp-bugs
RE: Compiling for ARMv8-A Using GCC 7.2.0 - Assertion error in gen-fac
I also see no reasonable way for it to end up as 1. If I printf("%lu") those
same two variables the results are even more strange:
== GCC 4.8.5 ==
GMP_HLIMB_BIT=4294967296=1
GMP_LLIMB_MASK=4294967295=
== GCC 7.2.0 ==
GMP_HLIMB_BIT=4294967296=1
GMP_LLIMB_MASK=4294967297=10001
So it appears like the "-1" being applies to GMP_HLIMB_BIT is a +1 in GCC
7.2.0. I've not encountered behaviour like this before. Very strange.
I am currently investigating if this is an issue with how GCC handles longs
between 4.8.5 and 7.2.0 in ARM64 hosts builds.
This concludes me to believe a bug in GCC ARM64 or a bug in GMP or I am somehow
building GCC wrong but right enough that it can compile most other libraries.
I do notice in GCC 4.8.5 -mabi is not specified when compiling GMP. When GCC
7.2.0 goes to build GMP it is being explicit about the -mabi=lp64.
If anything comes to mind let me know. I'll post back here if I find out the
cause.
Thanks,
Stephen Damm
-Original Message-
From: Niels Möller [mailto:ni...@lysator.liu.se]
Sent: December 6, 2019 03:51
To: Damm, Stephen
Cc: gmp-bugs@gmplib.org
Subject: Re: Compiling for ARMv8-A Using GCC 7.2.0 - Assertion error in gen-fac
"Damm, Stephen" writes:
> I was able to narrow down the cause. In GC 7.2.0 the GMP_LLIMB_MASK is wrong:
>
> =GCC 4.8.5=
> GMP_LIMB_BITS=64
> GMP_LLIMB_MASK=4294967295=0x
>
> =GCC 7.2.0=
> GMP_LIMB_BITS=64
> GMP_LLIMB_MASK=1=0x0001
>
> From my understanding this might be a difference in how GCC 7.2.0 handles
> unsigned longs vs GCC 4.8.5. It also could be I am missing some vital
> compiler flag for GMP.
Can you file a gcc bug? These constants are defined as
#define GMP_LIMB_BITS (sizeof(mp_limb_t) * CHAR_BIT)/* 64, you say */
#define GMP_HLIMB_BIT ((mp_limb_t) 1 << (GMP_LIMB_BITS / 2)) #define
GMP_LLIMB_MASK (GMP_HLIMB_BIT - 1)
I see no reasonable way that can end up defining GMP_LLIMB_MASK as 1.
Regards,
/Niels
--
Niels Möller. PGP-encrypted email is preferred. Keyid 368C6677.
Internet email is subject to wholesale government surveillance.
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Re: Compiling for ARMv8-A Using GCC 7.2.0 - Assertion error in gen-fac
ni...@lysator.liu.se (Niels Möller) writes: > I was able to narrow down the cause. In GC 7.2.0 the GMP_LLIMB_MASK is wrong: > > =GCC 4.8.5= > GMP_LIMB_BITS=64 > GMP_LLIMB_MASK=4294967295=0x > > =GCC 7.2.0= > GMP_LIMB_BITS=64 > GMP_LLIMB_MASK=1=0x0001 > > From my understanding this might be a difference in how GCC 7.2.0 > handles unsigned longs vs GCC 4.8.5. It also could be I am missing > some vital compiler flag for GMP. Can you file a gcc bug? These constants are defined as #define GMP_LIMB_BITS (sizeof(mp_limb_t) * CHAR_BIT)/* 64, you say */ #define GMP_HLIMB_BIT ((mp_limb_t) 1 << (GMP_LIMB_BITS / 2)) #define GMP_LLIMB_MASK (GMP_HLIMB_BIT - 1) I see no reasonable way that can end up defining GMP_LLIMB_MASK as 1. The first thing to try might be gcc 7.4, which was the final gcc 7 release. -- Torbjörn Please encrypt, key id 0xC8601622 ___ gmp-bugs mailing list gmp-bugs@gmplib.org https://gmplib.org/mailman/listinfo/gmp-bugs
Re: Compiling for ARMv8-A Using GCC 7.2.0 - Assertion error in gen-fac
"Damm, Stephen" writes: > I was able to narrow down the cause. In GC 7.2.0 the GMP_LLIMB_MASK is wrong: > > =GCC 4.8.5= > GMP_LIMB_BITS=64 > GMP_LLIMB_MASK=4294967295=0x > > =GCC 7.2.0= > GMP_LIMB_BITS=64 > GMP_LLIMB_MASK=1=0x0001 > > From my understanding this might be a difference in how GCC 7.2.0 handles > unsigned longs vs GCC 4.8.5. It also could be I am missing some vital > compiler flag for GMP. Can you file a gcc bug? These constants are defined as #define GMP_LIMB_BITS (sizeof(mp_limb_t) * CHAR_BIT)/* 64, you say */ #define GMP_HLIMB_BIT ((mp_limb_t) 1 << (GMP_LIMB_BITS / 2)) #define GMP_LLIMB_MASK (GMP_HLIMB_BIT - 1) I see no reasonable way that can end up defining GMP_LLIMB_MASK as 1. Regards, /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid 368C6677. Internet email is subject to wholesale government surveillance. ___ gmp-bugs mailing list gmp-bugs@gmplib.org https://gmplib.org/mailman/listinfo/gmp-bugs
Compiling for ARMv8-A Using GCC 7.2.0 - Assertion error in gen-fac
GMP-Bugs, I am trying to build GMP 6.1.2 for ARMv8-A Thunderx2t99 (AARCH64) CPU on RHEL7.4. I can build BINUTILS 2.29.1, GMP 6.1.2, and CC 7.2.0 using the system GCC 4.8.5. No errors, GMP passes its `make check` tests. The gen-fac program works. Next I use my GCC 7.2.0 to build everything again. GMP fails with an assertion error before it gets very far into its build process. During the GMP build process it builds a few programs, "gen-fac" being one of them. This is the exact command the Makefile executes: "custom_toolchain/bin/gcc -v `test -f 'gen-fac.c' || echo './'`gen-fac.c -o gen-fac" It then tries to execute: "./gen-fac 64 0" which hits an assertion error if built using my GCC 7.2.0: gen-fac: mini-gmp/mini-gmp.c:1207: mpn_limb_size_in_base_2: Assertion `u > 0' failed. /bin/sh: line 1: 9766 Aborted (core dumped) ./gen-fac 64 0 > fac_table.h It is dying due to an assertion in mpn_limb_size_in_base_2. In this case `u` is exactly 0. I was able to narrow down the cause. In GC 7.2.0 the GMP_LLIMB_MASK is wrong: =GCC 4.8.5= GMP_LIMB_BITS=64 GMP_LLIMB_MASK=4294967295=0x =GCC 7.2.0= GMP_LIMB_BITS=64 GMP_LLIMB_MASK=1=0x0001 >From my understanding this might be a difference in how GCC 7.2.0 handles >unsigned longs vs GCC 4.8.5. It also could be I am missing some vital >compiler flag for GMP. Any ideas? Thanks, Stephen Damm ___ gmp-bugs mailing list gmp-bugs@gmplib.org https://gmplib.org/mailman/listinfo/gmp-bugs
