Hi Michael,
On 08/03/2012 09:07 PM, Michael Schnell wrote:
On 08/03/2012 11:48 AM, Luis Alves wrote:
At the moment I'm still using gcc 4.2.x
I would be thankful If you could check whether in your projects, gcc
creates code that sets ad checks bits in memory and does memory/memory
operations when appropriate.
I feel
volatile int xx, xy; xx |= 0x80; yx |= 0x0x80000000;
should create
BSET 7, xx+3 and BSET 7, xy
and
if (xy & 0x4000)
should create BTST 6, xy+2
and xy=xx
should create MOVE.L xx, xy
Heres one result. I am using a gcc-4.5.1 based toolchain. This code:
foo(void)
{
volatile int xx, xy;
xx |= 0x80;
xy |= 0x80000000;
if (xy & 0x4000)
xx = xy;
}
Compiled with this command line:
m68k-linux-gcc -mcpu32 -O2 -c foo.c
Produced this code:
00000000 <foo>:
0: 4e56 fff8 linkw %fp,#-8
4: 202e fffc movel %fp@(-4),%d0
8: 727f moveq #127,%d1
a: 4601 notb %d1
c: 8081 orl %d1,%d0
e: 2d40 fffc movel %d0,%fp@(-4)
12: 202e fff8 movel %fp@(-8),%d0
16: 08c0 001f bset #31,%d0
1a: 2d40 fff8 movel %d0,%fp@(-8)
1e: 202e fff8 movel %fp@(-8),%d0
22: 0800 000e btst #14,%d0
26: 6708 beqs 30 <foo+0x30>
28: 202e fff8 movel %fp@(-8),%d0
2c: 2d40 fffc movel %d0,%fp@(-4)
30: 4e5e unlk %fp
32: 4e75 rts
Regards
Greg
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: g...@snapgear.com
SnapGear Group, McAfee PHONE: +61 7 3435 2888
8 Gardner Close, FAX: +61 7 3891 3630
Milton, QLD, 4064, Australia WEB: http://www.SnapGear.com
_______________________________________________
uClinux-dev mailing list
uClinux-dev@uclinux.org
http://mailman.uclinux.org/mailman/listinfo/uclinux-dev
This message was resent by uclinux-dev@uclinux.org
To unsubscribe see:
http://mailman.uclinux.org/mailman/options/uclinux-dev
