GCC generates bad code?

Question

C++ / C#

Keys:

-m64 -ffreestanding -nostdlib -mcmodel=large -mno-red-zone -mno-mmx -mno-sse -mno-sse2 -mno-sse3 -mno-3dnow -pedantic

These are usually recommended for kernel development. Played with the keys, did not help.
Simple preparation:

inline thread_t* schedule(thread_t* current, tss_t* tss) {
  tss->rsp[0] = sizeof(x86_64_state_t)+(uint64_t)current;
  return current;
}

turns into:

0000000000000000 <schedule>:
   0:	55                   	push   %rbp
   1:	48 89 e5             	mov    %rsp,%rbp
   4:	48 89 7d f8          	mov    %rdi,-0x8(%rbp)
   8:	48 89 75 f0          	mov    %rsi,-0x10(%rbp)
   c:	48 8b 45 f8          	mov    -0x8(%rbp),%rax
  10:	48 8d 90 b0 01 00 00 	lea    0x1b0(%rax),%rdx
  17:	48 8b 45 f0          	mov    -0x10(%rbp),%rax
  1b:	48 89 50 04          	mov    %rdx,0x4(%rax)
  1f:	48 8b 45 f8          	mov    -0x8(%rbp),%rax
  23:	5d                   	pop    %rbp
  24:	c3                   	retq

First of all, it doesn't inline, but okay. The same can be written in three lines with one memory access. Maybe I don't know some magic key, or this is how GCC optimizes. You can rewrite such places in assembler, but still you want to achieve something from the compiler.

Answer 1

-O2

Answer 2

Check out:
gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
In general, the documentation of GCC itself is a much more reliable source of information than unnamed uncles who "usually recommend" something there.