clang-cl.exe crash

clangCrash.cc

#include <stdlib.h>
#include <intrin.h>

int
main()
{
   __m128i var = {};

   // Create an unaligned _m128i pointer.
   __m128i* elem = (__m128i*) ( (char*)malloc(sizeof(__m128i) + 1) + 1 );
   *elem = var;  // Will crash on Windows 10 x64 with clang-cl.exe LLVM 9.0

   /**
   cl.exe generates (rax holds the elem pointer):
      movdqa      xmm0,xmmword ptr [var]
      movdqu      xmmword ptr [rax],xmm0

   clang-cl.exe generates:
      movdqa      xmmword ptr [rax],xmm0

      which traps, since movdqa requires memory destinations to be 16-byte aligned.

   **/

   return 0;
}