------- Comment #17 from rakdver at kam dot mff dot cuni dot cz 2010-02-05
13:58 -------
Subject: Re: Inefficient loop unrolling
> But if I adjust the cost to make
> "index" cost only 1 or 2, I get this:
>
> <bb 2>:
> pretmp.11_26 = (int) s_11(D);
> ivtmp.25_28 = (long unsigned int) b_inout_5(D);
>
> <bb 3>:
> # i_20 = PHI <i_14(4), 0(2)>
> # ivtmp.25_25 = PHI <ivtmp.25_24(4), ivtmp.25_28(2)>
> D.1846_29 = (void *) ivtmp.25_25;
> D.1814_10 = MEM[base: D.1846_29]{*D.1813};
> D.1816_13 = D.1814_10 * pretmp.11_26;
> D.1847_30 = (void *) ivtmp.25_25;
> MEM[base: D.1847_30]{*D.1813} = D.1816_13;
> ivtmp.25_24 = ivtmp.25_25 + 4;
> i_14 = i_20 + 1;
> if (i_14 != 64)
> goto <bb 4>;
> else
> goto <bb 5>;
>
> <bb 4>:
> goto <bb 3>;
>
> <bb 5>:
> return;
what configuration and flags are you using? For me, replacing
arm_arm_address_cost with return 1 resulted
in
<bb 3>:
# ivtmp.25_25 = PHI <ivtmp.25_24(3), ivtmp.25_28(2)>
D.1816_29 = (void *) ivtmp.25_25;
D.1784_10 = MEM[base: D.1816_29]{*D.1783};
D.1786_13 = pretmp.11_26 * D.1784_10;
MEM[base: D.1816_29]{*D.1783} = D.1786_13;
ivtmp.25_24 = ivtmp.25_25 + 4;
if (ivtmp.25_24 != D.1819_32)
Zdenek
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36712
