[Bug target/9703] [arm] Accessing data through constant pool more times could be solved in less instructions

[lac@rgai.hu]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9703



------- Additional Comments From lac@rgai.hu  2003-05-27 14:05 -------
Subject: Re:  [arm] Accessing data through constant pool
 more times could be solved in less instructions

Hello!

Thanks for your question! The problem still exists... I commented your
code below. The relevant part is function f1. The ldr insn is unnecessary
at (*) when in (**) offset is used. With sequential cpool accesses 1 insn
per access should be dropped.
Regards,
Laszlo

On Mon, 26 May 2003, dhazeghi@yahoo.com wrote:

> PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9703
>
>
>
> ------- Additional Comments From dhazeghi@yahoo.com  2003-05-26 20:59 -------
> Hello,
>
> with gcc 3.3 branch and mainline (20030509) I get the following code. Could you confirm whether
> this still exhibits the problem you noted? Thanks,
>
> Dara
>
>         .file   "01.i"
>         .global globvar1
>         .bss
>         .global globvar1
>         .align  2
>         .type   globvar1, %object
>         .size   globvar1, 4
> globvar1:
>         .space  4
>         .global globvar2
>         .global globvar2
>         .align  2
>         .type   globvar2, %object
>         .size   globvar2, 4
> globvar2:
>         .space  4
>         .text
>         .align  2
>         .global f1
>         .type   f1, %function
> f1:
>         @ args = 0, pretend = 0, frame = 0
>         @ frame_needed = 0, uses_anonymous_args = 0
>         @ link register save eliminated.
>         ldr     r3, .L2
>         mov     r2, #12
>         str     r2, [r3, #0]
>         ldr     r3, .L2+4		; (*) can be removed
>         mov     r0, #11
>         @ lr needed for prologue
>         str     r0, [r3, #0] 		; (**) with offset instead of #0
>         mov     pc, lr
> .L3:
>         .align  2
> .L2:
>         .word   globvar2
>         .word   globvar1
>         .size   f1, .-f1
>         .align  2
>         .global main
>         .type   main, %function
> main:
>         @ args = 0, pretend = 0, frame = 0
>         @ frame_needed = 0, uses_anonymous_args = 0
>         @ link register save eliminated.
>         @ lr needed for prologue
>         b       f1
>         .size   main, .-main
>         .ident  "GCC: (GNU) 3.3 20030508 (prerelease)"
>
>
>
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