xmmintrin.h cannot be compiled

[NamjaeChoi]

Hi,

I'm trying to reinstall libMesh with the latest MOOSE submodule.
During configuration, I see the following message, which tells me to report it to here:

configure: WARNING: xmmintrin.h: present but cannot be compiled
configure: WARNING: xmmintrin.h:     check for missing prerequisite headers?
configure: WARNING: xmmintrin.h: see the Autoconf documentation
configure: WARNING: xmmintrin.h:     section "Present But Cannot Be Compiled"
configure: WARNING: xmmintrin.h: proceeding with the compiler's result
configure: WARNING:     ## ------------------------------------------------------------- ##
configure: WARNING:     ## Report this to https://github.com/libMesh/libmesh/discussions ##
configure: WARNING:     ## ------------------------------------------------------------- ##

Could you tell me what this is about?

Thanks.

[roystgnr]

We look for a useful header, with AC_CHECK_HEADERS(xmmintrin.h), because if we find that header on your system then it's one option for an API with which to turn hardware FPE (floating point exceptions) off and on.

We're actually happy enough to find it present or absent (if we don't find a usable fenv.h or xmmintrin.h then our FPE-behavior-altering options don't work, though you can still run libMesh code with whatever the default system behavior is) ... but the default autoconf behavior is to scream warnings at you (and to append the URL we specified for generic warnings) if it finds an inconsistent header - something that works in a preprocessor test but not in a compiler test. Which actually is pretty weird, and I'd be curious about what your config.log said. But as far as functionality is concerned, as long as fenv.h was found then FPE can still be turned on and off at runtime.

[jwpeterson]

If you look at the lines preceding these warnings in your config.log file, it may actually tell you what the compiler error was that led to this warning. You didn't mention if the resulting build worked for you or not, but presumably you did not run into any other issues?

[NamjaeChoi]

Thank you for the replies. fenv.h was found and compiled normally. Also, there is no other issue.
The following is the error message, which seems to be a compatibility issue for ARM:

configure:45655: checking xmmintrin.h usability
configure:45655: mpicxx -c  -O2 -felide-constructors -g -pedantic -W -Wall -Wextra -Wno-long-long -Wunused-parameter -Wunused -Wpointer-arith -Wformat -Wparentheses -Wuninitialized -Qunused-arguments -Woverloaded-virtual -fno-limit-debug-info    -D_FORTIFY_SOURCE=2 -isystem /Users/choin/mambaforge3/envs/moose/include conftest.cpp >&5
In file included from conftest.cpp:130:
In file included from /Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/xmmintrin.h:13:
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:33:5: error: use of undeclared identifier '__builtin_ia32_emms'; did you mean '__builtin_isless'?
    __builtin_ia32_emms();
    ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:33:5: note: '__builtin_isless' declared here
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:33:25: error: too few arguments to function call, expected 2, have 0
    __builtin_ia32_emms();
    ~~~~~~~~~~~~~~~~~~~~^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:50:19: error: use of undeclared identifier '__builtin_ia32_vec_init_v2si'
    return (__m64)__builtin_ia32_vec_init_v2si(__i, 0);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:67:12: error: use of undeclared identifier '__builtin_ia32_vec_ext_v2si'
    return __builtin_ia32_vec_ext_v2si((__v2si)__m, 0);
           ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:129:19: error: use of undeclared identifier '__builtin_ia32_packsswb'
    return (__m64)__builtin_ia32_packsswb((__v4hi)__m1, (__v4hi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:159:19: error: use of undeclared identifier '__builtin_ia32_packssdw'
    return (__m64)__builtin_ia32_packssdw((__v2si)__m1, (__v2si)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:189:19: error: use of undeclared identifier '__builtin_ia32_packuswb'
    return (__m64)__builtin_ia32_packuswb((__v4hi)__m1, (__v4hi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:216:19: error: use of undeclared identifier '__builtin_ia32_punpckhbw'
    return (__m64)__builtin_ia32_punpckhbw((__v8qi)__m1, (__v8qi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:239:19: error: use of undeclared identifier '__builtin_ia32_punpckhwd'
    return (__m64)__builtin_ia32_punpckhwd((__v4hi)__m1, (__v4hi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:260:19: error: use of undeclared identifier '__builtin_ia32_punpckhdq'
    return (__m64)__builtin_ia32_punpckhdq((__v2si)__m1, (__v2si)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:287:19: error: use of undeclared identifier '__builtin_ia32_punpcklbw'
    return (__m64)__builtin_ia32_punpcklbw((__v8qi)__m1, (__v8qi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:310:19: error: use of undeclared identifier '__builtin_ia32_punpcklwd'
    return (__m64)__builtin_ia32_punpcklwd((__v4hi)__m1, (__v4hi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:331:19: error: use of undeclared identifier '__builtin_ia32_punpckldq'
    return (__m64)__builtin_ia32_punpckldq((__v2si)__m1, (__v2si)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:352:19: error: use of undeclared identifier '__builtin_ia32_paddb'; did you mean '__builtin_arm_addg'?
    return (__m64)__builtin_ia32_paddb((__v8qi)__m1, (__v8qi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:352:19: note: '__builtin_arm_addg' declared here
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:352:19: error: first argument of MTE builtin function must be a pointer ('__v8qi' (vector of 8 'char' values) invalid)
    return (__m64)__builtin_ia32_paddb((__v8qi)__m1, (__v8qi)__m2);
                  ^                    ~~~~~~~~~~~~
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:373:19: error: use of undeclared identifier '__builtin_ia32_paddw'; did you mean '__builtin_arm_addg'?
    return (__m64)__builtin_ia32_paddw((__v4hi)__m1, (__v4hi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:352:19: note: '__builtin_arm_addg' declared here
    return (__m64)__builtin_ia32_paddb((__v8qi)__m1, (__v8qi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:373:19: error: first argument of MTE builtin function must be a pointer ('__v4hi' (vector of 4 'short' values) invalid)
    return (__m64)__builtin_ia32_paddw((__v4hi)__m1, (__v4hi)__m2);
                  ^                    ~~~~~~~~~~~~
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:394:19: error: use of undeclared identifier '__builtin_ia32_paddd'; did you mean '__builtin_arm_addg'?
    return (__m64)__builtin_ia32_paddd((__v2si)__m1, (__v2si)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:352:19: note: '__builtin_arm_addg' declared here
    return (__m64)__builtin_ia32_paddb((__v8qi)__m1, (__v8qi)__m2);
                  ^
/Users/choin/mambaforge3/envs/moose/lib/clang/12.0.1/include/mmintrin.h:394:19: error: first argument of MTE builtin function must be a pointer ('__v2si' (vector of 2 'int' values) invalid)
    return (__m64)__builtin_ia32_paddd((__v2si)__m1, (__v2si)__m2);
                  ^                    ~~~~~~~~~~~~
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.

[jwpeterson]

OK, so I guess on your system, one cannot simply #include "xmmintrin.h" without getting a bunch of undeclared identifier errors, but that is presumably OK because no actual system header files include xmmintrin.h without first including some other required headers and/or setting proper #defines. We should maybe consider removing AC_CHECK_HEADERS(xmmintrin.h) from libmesh_compiler_features.m4. I'm not sure whether this is our own m4 creation or it was just copied from somewhere else.

[roystgnr]

Would we remove the LIBMESH_HAVE_XMMINTRIN_H cases from libmesh.C too? The original patch (committed by Ben but log says it's from Cody) had:

+#elif defined(LIBMESH_HAVE_XMMINTRIN_H)
+#  include <xmmintrin.h>
+#  define __APPLE_fpe__

and I guess I've just been assuming that we were still hitting those code paths on OSX to this day.

[jwpeterson]

Wow, that's a genuinely old line of code!

commit 42685fae404e712027c051200ac3e631ce221f71
Author: Benjamin S. Kirk <benkirk@users.sourceforge.net>
Date:   Fri Aug 10 19:06:17 2012 +0000

    preliminary support for --enable-fpe from Cody et al

I think it would probably be safe to remove. Although there's no way of telling how long this configure test has been failing, it seems like something that would have been relevant only in the OSX releases of a decade-plus ago.

[roystgnr]

Is it failing? It's warning about a wonky header, and it's proceeding after defining the header as unusable, both of which sound like what I'd want it to do.

But yeah, I just checked on my half-decade-ago MacBook, and LIBMESH_HAVE_FENV_H is defined there; I'd be okay with removing the probably-atavistic backup if you want.

[jwpeterson]

Is it failing?

Sorry, failing in the sense of "not succeeding at compiling the header". So.... working as intended I guess.

I'd also be OK with leaving it in place if we could silence all the

configure: WARNING: xmmintrin.h: present but cannot be compiled

warning lines which are currently (?) being sent to the terminal, since that's pretty annoying for users.