[Bug optimization/3995] i386 optimisation: joining tests

[debian-gcc at lists dot debian dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=3995


debian-gcc at lists dot debian dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |herbert at gondor dot apana
                   |                            |dot org dot au


------- Additional Comments From debian-gcc at lists dot debian dot org  2003-08-10 15:32 -------
Herbert Xu writes:

This bug is mostly fixed, but one small detail remains.  The final 
jump back to the leave+ret sequence is still there. 
 
Since leave+ret is a two-byte sequence, it makes sense to replace the 
jump with a leave+ret. 
 
Here is the -S -O2 output with gcc 3.3: 

 
foo: 
        pushl   %ebp 
        movl    %esp, %ebp 
        subl    $8, %esp 
        cmpb    $0, 8(%ebp) 
        jle     .L2 
        call    a 
.L3: 
        leave 
        ret 
        .p2align 2,,3 
.L2: 
        call    b 
        jmp     .L3 
 
The last jmp should become 
 
        leave 
        ret 
--