[Bug c++/33401] New: Unwanted memset in default constructor

[kbateman at seicorp dot com]

This also happens with sparc-sun-solaris2.8 4.1.2
a.cc:
struct buffer {
    char buf[65536];
};

buffer *makeBuffer() {
    return new buffer();
}
end of a.cc
g++ -O2 -S a.cc
a.s:
....
        movl    $65536, (%esp)
        call    _Znwj
        movl    %eax, %ebx
        movl    %ebx, %edx
        movl    $65536, %eax
        movl    %eax, 8(%esp)
        movl    $0, 4(%esp)
        movl    %edx, (%esp)
        call    memset
....

Give buffer a default constructor and the memset call disappears.
b.cc:
struct buffer {
    char buf[65536];
    buffer() {}
};
buffer *makeBuffer() {
    return new buffer();
}
end of b.cc
g++ -O2 -S b.cc
b.s:
...
        movl    $65536, (%esp)
        call    _Znwj
        leave
        ret
...


-- 
           Summary: Unwanted memset in default constructor
           Product: gcc
           Version: 3.4.6
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kbateman at seicorp dot com
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33401