test/CodeGen/asm.c

// RUN: clang -emit-llvm %s -o %t -arch=i386 
void t1(int len)
{
  __asm__ volatile("" : "=&r"(len), "+&r"(len));
}

void t2(unsigned long long t) 
{
  __asm__ volatile("" : "+m"(t));
}

void t3(unsigned char *src, unsigned long long temp)
{
  __asm__ volatile("" : "+m"(temp), "+r"(src));
}