[Bug c++/19661] New: many redundant atexit calls emitted into the executable for static objects with empty destructors

["yuri at tsoft dot com" <gcc-bugzilla@gcc.gnu.org>]

When some object having empty destructor is declared as static in the local
context of some function g++ still inserts <atexit> call with the empty handler
like <__tcf_0> below.

It may seem like minor issue but redundant instructions increase chances for
I-cache misses and worthen processor pipeline.

Yuri


08048800 <__tcf_0>:
 8048800:       55                      push   %ebp
 8048801:       89 e5                   mov    %esp,%ebp
 8048803:       5d                      pop    %ebp
 8048804:       c3                      ret


--testcase--
begin 644 case-empty-atexit.tgz
M'XL(`.1G^4$``^V6VVJ#0!"&O=ZG&-*;))!D/:Q>)!1"GV31:2.83=`U&$KZ
M[!U-BI)#<U%)"YT/85?\]Z#C/[.Q+G""ZZW=3[3%*K4SIW>D#&2D%+5*JLBG
M5DHW4$U[PG&E&X5>Z(>^YTC7#X/(`=7_5BXI"ZMS`&=?YNEWN@1WF&VVC]C2
M(XDOXE]-7WI>0[I2AD%P,_X4^:_XUW\`Z0//"QV0/>_C*O\\_D(\I2;.R@1A
M4$U7`R&PLI@;V&W2!,H"AZ.Y$/2-;!K#$C3=B+5.S7`$[P(@WI06%@L8H*%1
M@[J+)LGF].@TMJ/)4.^PHSF(WWY[YIK_5SVO<<__7NM_GZ2-_U7$_G\$'?\O
MTDUA<]3K9U$6J7D#H]=8;'6,4-BDR0)Y&5O*`K7SEW4&:+V]I*XY"C!I/0X'
MDC:IY-6<#Z`$<:[\.,XZ&W=D"5Y..YZ1_##G_/%CKOA_0H'I]0QPM_Y+U=;_
M*"*]HHO]_PANE?]CJ6\/`8WGN\<``#VM/<UEG&$8AF$8AF$8AF$8AF$8AF$8
-AF'^#)_;GM5=`"@`````
`
end

-- 
           Summary: many redundant atexit calls emitted into the executable
                    for static objects with empty destructors
           Product: gcc
           Version: 3.4.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: yuri at tsoft dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: n/a
GCC target triplet: n/a


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19661