[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[dhazeghi@yahoo.com]

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9663



------- Additional Comments From dhazeghi@yahoo.com  2003-05-26 20:55 -------
Hello,

this problem is still present on gcc 3.3 branch and mainline (20030509). Could you resend the 
patch to gcc-patches, and cc: one of the arm-maintainers? Also, can you attach the patch to this 
PR, so it doesn't get lost? Thanks,

Dara



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[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[pinskia@physics.uc.edu]

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9663


pinskia@physics.uc.edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


------- Additional Comments From pinskia@physics.uc.edu  2003-05-26 20:57 -------
See Dara's question.



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[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[dhazeghi@yahoo.com]

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9663


dhazeghi@yahoo.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
     Ever Confirmed|                            |1
  GCC build triplet|                            |i686-pc-linux-gnu
   GCC host triplet|                            |i686-pc-linux-gnu
 GCC target triplet|                            |arm-elf
   Last reconfirmed|0000-00-00 00:00:00         |2003-06-02 05:30:23
               date|                            |


------- Additional Comments From dhazeghi@yahoo.com  2003-06-02 05:30 -------
Shouldn't be in waiting. Confirmed.



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[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[pinskia at gcc dot gnu 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=9663


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
   Last reconfirmed|2003-06-02 05:30:23         |2003-10-01 04:59:02
               date|                            |

[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[dhazeghi at yahoo dot com]

------- Additional Comments From dhazeghi at yahoo dot com  2003-12-10 00:12 -------
Confirmed still not present on mainline. Richard, would you mind looking at the patch included 
here? Thanks.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rearnsha at arm dot com
           Keywords|                            |patch
   Last reconfirmed|2003-10-01 04:59:02         |2003-12-10 00:12:20
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9663

[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-21 03:54 -------
Note you have to do with -fno-inline now on the mainline as the function is inlined at -O2.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2003-12-10 00:12:20         |2004-05-21 03:54:16
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9663

[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[rearnsha at gcc dot gnu dot org]

------- Comment #9 from rearnsha at gcc dot gnu dot org  2009-03-13 09:38 -------
Now believed fixed.


-- 

rearnsha at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9663

[Bug target/9663] [arm] gcc-20030127 misses an optimization opportunity

[ramana dot r at gmail dot com]

------- Comment #8 from ramana dot r at gmail dot com  2009-02-08 05:17 -------
(In reply to comment #7)
> Note you have to do with -fno-inline now on the mainline as the function is
> inlined at -O2.
> 

It looks as though this is fixed in 4.3 and mainline today. I checked with 4.1
and saw that the problem existed in 4.1 


Looking at the assembly generated for the function, I no longer see a cmp and
mov as reported in the bug report. I see similar code generated in 4.1 but no
longer in 4.3 or 4.4. I see subs generated for 4.3 and 4.4 in the loop kernel
as of version r143940 for 4.3 and 144002 for mainline. 

Here is the snippet of code from 4.1, 4.3 and 4.4 as given below.


4.1 

.L8:
        ldr     r3, .L12
        umull   r1, r2, r3, ip
        mov     r2, r2, lsr #3
        mov     r3, r2, asl #1
        mov     r1, r2, asl #3
        add     r3, r3, r1
        rsb     r3, r3, ip
        add     r3, r3, #48
        cmp     r2, #0            ---- Insns from original bug report.
        mov     ip, r2            ----
        strb    r3, [r0, #-1]!
        bne     .L8



4.3
.L5:
        umull   r2, r3, r5, ip
        mov     r3, r3, lsr #3
        mov     r2, r3, asl #1
        mov     r1, r3, asl #3
        add     r2, r2, r1
        rsb     r2, r2, ip
        add     r2, r2, #48
        subs    ip, r3, #0
        strb    r2, [r0, #-1]!
        bne     .L5





4.4 

  .L5:
        umull   r1, r2, r4, ip
        mov     r2, r2, lsr #3
        add     r1, r2, r2, asl #2
        sub     ip, ip, r1, asl #1
        add     r1, ip, #48
        subs    ip, r2, #0
        strb    r1, [r0, #-1]!
        bne     .L5


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9663