function pointers

fp-optimized.asm

0000000100000f40 <__Z1av>:
   100000f40:	55                   	push   rbp
   100000f41:	48 89 e5             	mov    rbp,rsp
   100000f44:	b8 03 00 00 00       	mov    eax,0x3
   100000f49:	5d                   	pop    rbp
   100000f4a:	c3                   	ret
   100000f4b:	0f 1f 44 00 00       	nop    DWORD PTR [rax+rax*1+0x0]

0000000100000f50 <_main>:
   100000f50:	55                   	push   rbp
   100000f51:	48 89 e5             	mov    rbp,rsp
   100000f54:	48 8d 05 ef ff ff ff 	lea    rax,[rip+0xffffffffffffffef]        # 100000f4a <__Z1av+0xa>
   100000f5b:	48 89 05 b6 00 00 00 	mov    QWORD PTR [rip+0xb6],rax        # 100001018 <_f>
   100000f62:	ff d0                	call   rax
   100000f64:	89 c1                	mov    ecx,eax
   100000f66:	48 8d 3d 2d 00 00 00 	lea    rdi,[rip+0x2d]        # 100000f9a <_main+0x4a>
   100000f6d:	31 c0                	xor    eax,eax
   100000f6f:	89 ce                	mov    esi,ecx
   100000f71:	e8 04 00 00 00       	call   100000f7a <_main+0x2a>
   100000f76:	31 c0                	xor    eax,eax
   100000f78:	5d                   	pop    rbp
   100000f79:	c3                   	ret

fp.asm

0000000100000f10 <__Z1av>:
   100000f10:	55                   	push   rbp
   100000f11:	48 89 e5             	mov    rbp,rsp
   100000f14:	b8 03 00 00 00       	mov    eax,0x3
   100000f19:	5d                   	pop    rbp
   100000f1a:	c3                   	ret
   100000f1b:	0f 1f 44 00 00       	nop    DWORD PTR [rax+rax*1+0x0]

0000000100000f20 <_main>:
   100000f20:	55                   	push   rbp
   100000f21:	48 89 e5             	mov    rbp,rsp
   100000f24:	48 83 ec 10          	sub    rsp,0x10
   100000f28:	48 8d 05 e1 ff ff ff 	lea    rax,[rip+0xffffffffffffffe1]        # 100000f10 <__Z1av>
   100000f2f:	c7 45 fc 00 00 00 00 	mov    DWORD PTR [rbp-0x4],0x0
   100000f36:	48 89 05 db 00 00 00 	mov    QWORD PTR [rip+0xdb],rax        # 100001018 <_f>
   100000f3d:	48 8b 05 d4 00 00 00 	mov    rax,QWORD PTR [rip+0xd4]        # 100001018 <_f>
   100000f44:	48 05 0a 00 00 00    	add    rax,0xa
   100000f4a:	48 89 05 c7 00 00 00 	mov    QWORD PTR [rip+0xc7],rax        # 100001018 <_f>
   100000f51:	ff 15 c1 00 00 00    	call   QWORD PTR [rip+0xc1]        # 100001018 <_f>
   100000f57:	48 8d 3d 38 00 00 00 	lea    rdi,[rip+0x38]        # 100000f96 <_main+0x76>
   100000f5e:	89 c6                	mov    esi,eax
   100000f60:	b0 00                	mov    al,0x0
   100000f62:	e8 0d 00 00 00       	call   100000f74 <_main+0x54>
   100000f67:	31 f6                	xor    esi,esi
   100000f69:	89 45 f8             	mov    DWORD PTR [rbp-0x8],eax
   100000f6c:	89 f0                	mov    eax,esi
   100000f6e:	48 83 c4 10          	add    rsp,0x10
   100000f72:	5d                   	pop    rbp
   100000f73:	c3                   	ret

fp.cpp

#include <stdio.h>
int (*f)();
int a() {
	return 3;
}
int main() {
	f = &a;
	f = (int(*)()) (((char*) f) + 10);
	printf("%d\n", f());
	return 0;
}