带有 -mavx 标志的链接器错误 GCC7

Posted 2023-02-16

【中文标题】带有 -mavx 标志的链接器错误 GCC7

【英文标题】：Linker error GCC7 with -mavx flag

【发布时间】：2017-10-16 16:18:32

【问题描述】：

使用 gcc7 或 clang 从 Intel 的 AVX 扩展编译 256 位向量数据类型 (__m256d) 失败。我能够编译和使用 128 位向量（没有 -mavx 标志）。但是，一旦我尝试使用 avx 向量，要么找不到一些汇编程序命令定义（GCC7），要么存在链接器错误（clang）。我使用 port 来安装所有的编译器或包。

程序：

#include <iostream>
#include <emmintrin.h>
#include <immintrin.h>
#include <pmmintrin.h>
#include <xmmintrin.h>

struct cpx256 
    union 
        struct 
            double r1, i1, r2, i2;
        ;
        __m256d v;
    ;
    cpx256(double r1_in, double i1_in, double r2_in, double i2_in) :
        r1(r1_in), i1(i1_in), r2(r2_in), i2(i2_in)
;

 std::ostream & operator<< (std::ostream & os, cpx256 cmplx) 
     os << cmplx.r1;
     (cmplx.i1 > 0) ? (os << "+" << cmplx.i1 << "j") : (os << cmplx.i1 << "j");
     os << " | ";
     os << cmplx.r2;
     (cmplx.i2 > 0) ? (os << "+" << cmplx.i2 << "j") : (os << cmplx.i2 << "j");
     return os;
 

int main()
    cpx256 b = cpx256(1,2, 3, 4);
    std::cout << b << std::endl;
    return 0;

使用 gcc7：

g++ -std=c++11 -Wall -Wextra -mtune=native -ffast-math -fverbose-asm -mavx avx.cpp
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:57:no such instruction: `vmovsd %xmm0, -16(%rbp)'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:58:no such instruction: `vmovsd %xmm1, -24(%rbp)'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:59:no such instruction: `vmovsd %xmm2, -32(%rbp)'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:60:no such instruction: `vmovsd %xmm3, -40(%rbp)'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:63:no such instruction: `vmovsd -16(%rbp), %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:64:no such instruction: `vmovsd %xmm0, (%rax)'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:66:no such instruction: `vmovsd -24(%rbp), %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:67:no such instruction: `vmovsd %xmm0, 8(%rax)'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:69:no such instruction: `vmovsd -32(%rbp), %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:70:no such instruction: `vmovsd %xmm0, 16(%rax)'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:72:no such instruction: `vmovsd -40(%rbp), %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:73:no such instruction: `vmovsd %xmm0, 24(%rax)'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:99:no such instruction: `vmovd %rdx, %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:103:no such instruction: `vmovsd 24(%rbp), %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:104:no such instruction: `vxorpd %xmm1, %xmm1,%xmm1'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:105:no such instruction: `vcomisd %xmm1, %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:113:no such instruction: `vmovd %rax, %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:123:no such instruction: `vmovd %rdx, %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:138:no such instruction: `vmovd %rdx, %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:142:no such instruction: `vmovsd 40(%rbp), %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:143:no such instruction: `vxorpd %xmm1, %xmm1,%xmm1'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:144:no such instruction: `vcomisd %xmm1, %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:152:no such instruction: `vmovd %rax, %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:162:no such instruction: `vmovd %rdx, %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:190:no such instruction: `vmovsd lC4(%rip), %xmm2'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:191:no such instruction: `vmovsd lC5(%rip), %xmm1'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:192:no such instruction: `vmovsd lC6(%rip), %xmm0'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:195:no such instruction: `vmovapd %xmm2, %xmm3'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:196:no such instruction: `vmovapd %xmm1, %xmm2'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:197:no such instruction: `vmovapd %xmm0, %xmm1'
/var/folders/06/hdqdxlh14czcvkk4t55894y80000gn/T//ccXFPOnA.s:198:no such instruction: `vmovd %rdx, %xmm0'

使用 clang 我得到一个链接器错误：

clang -std=c++11 -Wall -Wextra -mtune=native -ffast-math -fverbose-asm -mavx avx.cpp
Undefined symbols for architecture x86_64:
  "std::__1::__basic_string_common<true>::__throw_length_error() const", referenced from:
      std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char) in avx-dfd779.o
  "std::__1::locale::use_facet(std::__1::locale::id&) const", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in avx-dfd779.o
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "std::__1::ios_base::getloc() const", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in avx-dfd779.o
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()", referenced from:
      std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char) in avx-dfd779.o
  "std::__1::basic_ostream<char, std::__1::char_traits<char> >::put(char)", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in avx-dfd779.o
  "std::__1::basic_ostream<char, std::__1::char_traits<char> >::flush()", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in avx-dfd779.o
  "std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::sentry(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::~sentry()", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "std::__1::basic_ostream<char, std::__1::char_traits<char> >::operator<<(double)", referenced from:
      operator<<(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, cpx256) in avx-dfd779.o
  "std::__1::cout", referenced from:
      _main in avx-dfd779.o
  "std::__1::ctype<char>::id", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in avx-dfd779.o
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "std::__1::locale::~locale()", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in avx-dfd779.o
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "std::__1::ios_base::__set_badbit_and_consider_rethrow()", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "std::__1::ios_base::clear(unsigned int)", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "std::terminate()", referenced from:
      ___clang_call_terminate in avx-dfd779.o
  "operator new(unsigned long)", referenced from:
      std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char) in avx-dfd779.o
  "___cxa_begin_catch", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
      ___clang_call_terminate in avx-dfd779.o
  "___cxa_end_catch", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
  "___gxx_personality_v0", referenced from:
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::endl<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in avx-dfd779.o
      std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in avx-dfd779.o
      std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char) in avx-dfd779.o
      Dwarf Exception Unwind Info (__eh_frame) in avx-dfd779.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

CL 语言：

clang version 4.0.1 (tags/RELEASE_401/final)
Target: x86_64-apple-darwin16.6.0
Thread model: posix
InstalledDir: /opt/local/libexec/llvm-4.0/bin

GCC7：

g++ (MacPorts gcc7 7-20170622_0) 7.1.1 20170622

我的笔记本电脑 CPU：2.8 GHz Intel Core i7（应该支持 AVX），Mac OS Sierra 10.12.5

我还使用端口 (ld64-latest 274.2) 更新了我的链接器，并安装并激活了 mp-clang-4.0。有什么想法吗？

【问题讨论】：

您的代码使用 Xcode 附带的普通 Apple 版本的 clang 编译和链接没有问题。看起来您的自制编译器安装已损坏？

检查您使用的汇编器版本。如果vmovd %rdx, %xmm0 没有组装，你的设置就真的坏了。

clang 似乎使用的是 8.1.0 版本。但我主要使用 GNU 编译器集合。我不知道如何检查它需要哪个版本，如果有可能它需要一个不同的版本。 llvm-gcc -v Apple LLVM version 8.1.0 (clang-802.0.42) Target: x86_64-apple-darwin16.6.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

使用g++ -v -O2 -march=native foo.cpp。 -v 将显示前端运行的命令，包括汇编程序。 （所以你可以看到它使用什么路径来运行汇编器。）IIRC 汇编器也将打印它的版本。

【参考方案1】：

同时，我再次检查了 clang 调用，发现调用 C 而不是 C++ 编译器的非常愚蠢的错误。所以这个最小的调用编译和执行没有错误：

clang++ -std=c++11 -mavx ../tests/sse_tests.cpp 

但是对于 gcc++ 版本，汇编器似乎没有正确链接，我不知道如何检查。