#include <stdio.h>
typedef unsigned long int uL;
typedef struct{uL q; uL r;} res;
typedef long long v2di __attribute__ ((__vector_size__ (16)));
int main(){
v2di a, b;
v2di x = __builtin_ia32_pclmulqdq128(a, b, 0);
return 0;}
/* clang mp.c -mpclmul -g; gdb a.out
instruction at 0x100000f63
Below are bytes 0x100000f6x beginning with high addr.
0f660000 0000b800 c1443a0f 66d04d28
Dump of assembler code for function main:
0x0000000100000f50 <main+0>:	push   %rbp
0x0000000100000f51 <main+1>:	mov    %rsp,%rbp
0x0000000100000f54 <main+4>:	movl   $0x0,-0x4(%rbp)
0x0000000100000f5b <main+11>:	movaps -0x20(%rbp),%xmm0
0x0000000100000f5f <main+15>:	movaps -0x30(%rbp),%xmm1
0x0000000100000f63 <main+19>:	data16
0x0000000100000f64 <main+20>:	(bad)  
0x0000000100000f67 <main+23>:	roll   $0xb8,(%rax)
0x0000000100000f6a <main+26>:	add    %al,(%rax)
0x0000000100000f6c <main+28>:	add    %al,(%rax)
0x0000000100000f6e <main+30>:	movdqa %xmm0,-0x40(%rbp)
0x0000000100000f73 <main+35>:	pop    %rbp
0x0000000100000f74 <main+36>:	retq   
*/