Marsaglia's XORSHIFT32 in PSIMD

Here's a simple C program using PSIMD to implement Marsaglia's XORSHIFT32 PRNG with four parallel generators.

#include "psimd.h"
#include <stdio.h>

PSIMD_INTRINSIC psimd_u32 psimd_lsr_u32(psimd_u32 a, uint32_t b)  {return a >> b;}
PSIMD_INTRINSIC psimd_u32 psimd_lsl_u32(psimd_u32 a, uint32_t b)  {return a << b;}
PSIMD_INTRINSIC psimd_u32 psimd_xor_u32(psimd_u32 a, psimd_u32 b) {return a ^  b;}

psimd_u32 xorshift32_4( psimd_u32 x )
{
    x = psimd_xor_u32( x,  psimd_lsl_u32( x, 13 ) );
    x = psimd_xor_u32( x,  psimd_lsr_u32( x, 17 ) );
    x = psimd_xor_u32( x,  psimd_lsl_u32( x, 5  ) );
    return x;
}

uint32_t xorshift32(uint32_t x)
{
    x ^= x << 13;
    x ^= x >> 17;
    x ^= x << 5;
    return x;
}

#define print_psimd_u32( _x ) printf("%08x %08x %08x %08x\n", _x[0], _x[1], _x[2], _x[3] )

int main()
{
psimd_u32 state_start = { 1, 2, 3, 4 };
print_psimd_u32( state_start );

psimd_u32 state_vector = xorshift32_4( state_start );
print_psimd_u32( state_vector );

psimd_u32 state_scalar = { xorshift32(state_start[0]),xorshift32(state_start[1]),xorshift32(state_start[2]),xorshift32(state_start[3]) };
print_psimd_u32( state_vector );

return 0;
}

And we get the same results for both PSIMD and scalar execution

0x00000001	0x00000002	0x00000003	0x00000004	Starting States
0x00042021	0x00084042	0x000c6063	0x00108084	PSIMD States
0x00042021	0x00084042	0x000c6063	0x00108084	Scalar States

With GCC6.3, -O3, assembly for the two algorithms comes out to the same number of instructions, even though one does four times the work.

xorshift32_4:
    .cfi_startproc
    movdqa  %xmm0, %xmm1
    pslld   $13, %xmm1
    pxor    %xmm0, %xmm1
    movdqa  %xmm1, %xmm0
    psrld   $17, %xmm0
    pxor    %xmm1, %xmm0
    movdqa  %xmm0, %xmm1
    pslld   $5, %xmm1
    pxor    %xmm1, %xmm0
    ret
    .cfi_endproc

xorshift32:
    .cfi_startproc
    movl    %edi, %eax
    sall    $13, %edi
    xorl    %edi, %eax
    movl    %eax, %edi
    shrl    $17, %edi
    xorl    %edi, %eax
    movl    %eax, %edi
    sall    $5, %edi
    xorl    %edi, %eax
    ret
    .cfi_endproc