Current libcore/libstd single-argument panic call overhead

gistfile1.txt

libcore panic!("message")
-------------------------

12 bytes:

   48 8d 3d 53 dc 3a 00    lea    0x3adc53(%rip),%rdi  #_MSG_FILE_LINE
   e8 ce d7 ff ff          callq  ba540                # core::panicking::panic

40 bytes excluding string bytes:

_MSG_FILE_LINE:
    .quad   str1034
    .quad   7
    .quad   str1035
    .quad   7
    .long   6
    .zero   4
    .size   _MSG_FILE_LINE, 40

str1034:
    .ascii  "message"
    .size   str1034, 7

str1035:
    .ascii  "test.rs"
    .size   str1035, 7



libstd panic!("message")
------------------------

27 bytes:

   0f 10 05 d0 da 3a 00    movups 0x3adad0(%rip),%xmm0      # const12
   0f 29 04 24             movaps %xmm0,(%rsp)
   48 8d 35 d5 da 3a 00    lea    0x3adad5(%rip),%rsi       # _FILE_LINE
   48 8d 3c 24             lea    (%rsp),%rdi
   e8 0c 00 00 00          callq  bceb0                     # rt::unwind::begin_unwind

40 bytes excluding string bytes:

const12:
    .quad   str1105
    .quad   7
    .size   const12, 16

_FILE_LINE:
    .quad   str1106
    .quad   7
    .quad   6
    .size   _FILE_LINE, 24

str1105:
    .ascii  "message"
    .size   str1105, 7

str1106:
    .ascii  "test.rs"
    .size   str1106, 7



libcore panic!("message",)
--------------------------

[The trailing comma forces the unoptimized panic_fmt code path.  It should
presumably be rejected instead, as it is with libstd panic!.]

54 bytes on x86_64:

   0f 10 05 00 db 3a 00    movups 0x3adb00(%rip),%xmm0        # _STATIC_FMTSTR
   0f 29 04 24             movaps %xmm0,(%rsp)
   0f 57 c0                xorps  %xmm0,%xmm0
   0f 29 44 24 10          movaps %xmm0,0x10(%rsp)
   48 8d 44 24 30          lea    0x30(%rsp),%rax
   48 89 44 24 20          mov    %rax,0x20(%rsp)
   48 c7 44 24 28 00 00    movq   $0x0,0x28(%rsp)
   00 00 
   48 8d 35 ea da 3a 00    lea    0x3adaea(%rip),%rsi        # _FILE_LINE
   48 8d 3c 24             lea    (%rsp),%rdi
   e8 e1 c0 ff ff          callq  b8f80                      # core::panicking::panic_fmt

56 bytes excluding string bytes:

_STATIC_FMTSTR:
    .quad   ref35
    .quad   1
    .size   _STATIC_FMTSTR, 16

ref35:
    .quad   str1133
    .quad   7
    .size   ref35, 16

_FILE_LINE:
    .quad   str1134
    .quad   7
    .long   6
    .zero   4
    .size   _FILE_LINE, 24

str1133:
    .ascii  "message"
    .size   str1133, 7

str1134:
    .ascii  "test.rs"
    .size   str1134, 7