bswapresults

Linux:
$ objdump -dC bswapcomp.o

bswapcomp.o:     file format elf64-x86-64


Disassembly of section .text:

0000000000000000 <systemswaps(unsigned long, unsigned int, unsigned short)>:
   0:	48 0f cf             	bswap  %rdi
   3:	48 89 3d 00 00 00 00 	mov    %rdi,0x0(%rip)        # a <systemswaps(unsigned long, unsigned int, unsigned short)+0xa>
   a:	0f ce                	bswap  %esi
   c:	89 35 00 00 00 00    	mov    %esi,0x0(%rip)        # 12 <systemswaps(unsigned long, unsigned int, unsigned short)+0x12>
  12:	66 c1 c2 08          	rol    $0x8,%dx
  16:	66 89 15 00 00 00 00 	mov    %dx,0x0(%rip)        # 1d <systemswaps(unsigned long, unsigned int, unsigned short)+0x1d>
  1d:	c3                   	retq   
  1e:	66 90                	xchg   %ax,%ax

0000000000000020 <myswaps(unsigned long, unsigned int, unsigned short)>:
  20:	48 0f cf             	bswap  %rdi
  23:	48 89 3d 00 00 00 00 	mov    %rdi,0x0(%rip)        # 2a <myswaps(unsigned long, unsigned int, unsigned short)+0xa>
  2a:	0f ce                	bswap  %esi
  2c:	89 35 00 00 00 00    	mov    %esi,0x0(%rip)        # 32 <myswaps(unsigned long, unsigned int, unsigned short)+0x12>
  32:	66 c1 c2 08          	rol    $0x8,%dx
  36:	66 89 15 00 00 00 00 	mov    %dx,0x0(%rip)        # 3d <myswaps(unsigned long, unsigned int, unsigned short)+0x1d>
  3d:	c3                   	retq 
  
  
  ===
  
macOS:
$ otool -t -V bswapcomp.o | c++filt
  
  bswapcomp.o:
(__TEXT,__text) section
systemswaps(unsigned long long, unsigned int, unsigned short):
0000000000000000	pushq	%rbp
0000000000000001	movq	%rsp, %rbp
0000000000000004	bswapq	%rdi
0000000000000007	movq	_out64(%rip), %rax
000000000000000e	movq	%rdi, systemswaps(unsigned long long, unsigned int, unsigned short)(%rax) ## systemswaps(unsigned long long, unsigned int, unsigned short)
0000000000000011	bswapl	%esi
0000000000000013	movq	_out32(%rip), %rax
000000000000001a	movl	%esi, systemswaps(unsigned long long, unsigned int, unsigned short)(%rax) ## systemswaps(unsigned long long, unsigned int, unsigned short)
000000000000001c	rolw	$0x8, %dx
0000000000000020	movq	_out16(%rip), %rax
0000000000000027	movw	%dx, systemswaps(unsigned long long, unsigned int, unsigned short)(%rax) ## systemswaps(unsigned long long, unsigned int, unsigned short)
000000000000002a	popq	%rbp
000000000000002b	retq
000000000000002c	nopl	(%rax)
myswaps(unsigned long long, unsigned int, unsigned short):
0000000000000030	pushq	%rbp
0000000000000031	movq	%rsp, %rbp
0000000000000034	bswapq	%rdi
0000000000000037	movq	_out64(%rip), %rax
000000000000003e	movq	%rdi, systemswaps(unsigned long long, unsigned int, unsigned short)(%rax) ## systemswaps(unsigned long long, unsigned int, unsigned short)
0000000000000041	bswapl	%esi
0000000000000043	movq	_out32(%rip), %rax
000000000000004a	movl	%esi, systemswaps(unsigned long long, unsigned int, unsigned short)(%rax) ## systemswaps(unsigned long long, unsigned int, unsigned short)
000000000000004c	rolw	$0x8, %dx
0000000000000050	movq	_out16(%rip), %rax
0000000000000057	movw	%dx, systemswaps(unsigned long long, unsigned int, unsigned short)(%rax) ## systemswaps(unsigned long long, unsigned int, unsigned short)
000000000000005a	popq	%rbp
000000000000005b	retq