[MacPorts] #54771: gcc7 -march=native fails on compile for corei7

[MacPorts]

#54771: gcc7 -march=native fails on compile for corei7
---------------------+-------------------
 Reporter:  bdmckay  |      Owner:
     Type:  defect   |     Status:  new
 Priority:  Normal   |  Milestone:
Component:  ports    |    Version:  2.4.1
 Keywords:           |       Port:  gcc7
---------------------+-------------------
 %% /opt/local/bin/gcc-mp-7 -v

 {{{
 Using built-in specs.
 COLLECT_GCC=gcc7
 COLLECT_LTO_WRAPPER=/opt/local/libexec/gcc/x86_64-apple-darwin16/7.2.0
 /lto-wrapper
 Target: x86_64-apple-darwin16
 Configured with:
 /opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_lang_gcc7/gcc7/work/gcc-7.2.0/configure
 --prefix=/opt/local --build=x86_64-apple-darwin16 --enable-
 languages=c,c++,objc,obj-c++,lto,fortran --libdir=/opt/local/lib/gcc7
 --includedir=/opt/local/include/gcc7 --infodir=/opt/local/share/info
 --mandir=/opt/local/share/man --datarootdir=/opt/local/share/gcc-7 --with-
 local-prefix=/opt/local --with-system-zlib --disable-nls --program-
 suffix=-mp-7 --with-gxx-include-dir=/opt/local/include/gcc7/c++/ --with-
 gmp=/opt/local --with-mpfr=/opt/local --with-mpc=/opt/local --with-
 isl=/opt/local --enable-stage1-checking --disable-multilib --enable-lto
 --enable-libstdcxx-time --with-build-config=bootstrap-debug --with-
 as=/opt/local/bin/as --with-ld=/opt/local/bin/ld --with-
 ar=/opt/local/bin/ar --with-bugurl=https://trac.macports.org/newticket
 --disable-tls --with-pkgversion='MacPorts gcc7 7.2.0_0'
 Thread model: posix
 gcc version 7.2.0 (MacPorts gcc7 7.2.0_0)
 }}}

 %% cat basic.c

 {{{
 #include <stdio.h>

 int main()
 {
      double t;
      long int q;

      scanf("%ld",&q);
      t = q;
      printf("t = %f\n",t);

      return 0;
 }
 }}}

 %% /opt/local/bin/gcc-mp-7 -c -march=native basic.c

 {{{
 /var/folders/vc/6bfn_k1j1bgbls8f6xg0pn8h0000gq/T//ccIvauBW.s:21:no such
 instruction: `vcvtsi2sdq %rax, %xmm0,%xmm0'
 /var/folders/vc/6bfn_k1j1bgbls8f6xg0pn8h0000gq/T//ccIvauBW.s:22:no such
 instruction: `vmovsd %xmm0, -8(%rbp)'
 /var/folders/vc/6bfn_k1j1bgbls8f6xg0pn8h0000gq/T//ccIvauBW.s:24:no such
 instruction: `vmovd %rax, %xmm0'
 }}}

 Comments:  The hardware is a MacBook Pro, 13in Late 2012, 2.9 GHz Intel
 Core i7 processor.
 The instruction vcvtsi2sdq is in the AVX2 set, which corei7 does not
 support, so it should not be authorized by "-march=native".  The i/o
 statements in the test program are just to prevent the compiler from
 optimizing away the type conversion; otherwise they don't seem relevant.
 The error goes away if "-march=native" is replaced by "-march=corei7" or
 replaced by "-march=native -mno-avx".  The same problems occurred for gcc
 7.1.1.  Apologies if this is not macports-specific; I don't have an easy
 way to tell.  If there is a better place to report this, please let me
 know.

--
Ticket URL: <https://trac.macports.org/ticket/54771>
MacPorts <https://www.macports.org/>
Ports system for macOS