From: malc <av1474@comtv.ru>
To: Max Filippov <jcmvbkbc@gmail.com>
Cc: qemu-devel@nongnu.org, Richard Henderson <rth@twiddle.net>
Subject: Re: [Qemu-devel] Shifts, ppc[64], xtensa
Date: Wed, 19 Sep 2012 16:49:20 +0400 (MSK) [thread overview]
Message-ID: <alpine.LNX.2.00.1209191646110.2485@linmac> (raw)
In-Reply-To: <CAMo8BfL9pU+ZFLWpsrMmcRXKmw=GKYWoppTuizM5GxgzMguqig@mail.gmail.com>
On Wed, 19 Sep 2012, Max Filippov wrote:
> On Tue, Sep 18, 2012 at 11:52 PM, malc <av1474@comtv.ru> wrote:
> >
> > Looks like PPC/PPC64 is also hit by shift issues, on top of that xtensa
>
> malc, could you please expand a little bit what are these shift issues?
> (sounds like a modern trend, I must have missed something)
>
Just audit op_opt output of extensa on 32bit host for shr_i32, i'm getting
things like:
OP after optimization and liveness analysis:
movi_i32 tmp0,$0xd00793f4
movi_i32 tmp1,$0x1
movi_i32 tmp2,$0x1
movi_i32 tmp3,$advance_ccount
call tmp3,$0x0,$0,env,tmp2
movi_i32 tmp2,$window_check
call tmp2,$0x0,$0,env,tmp0,tmp1
movi_i32 tmp0,$0x1
add_i32 ar4,ar4,tmp0
movi_i32 tmp1,$0xd00793f6
movi_i32 tmp2,$0x3
movi_i32 tmp3,$0x1
movi_i32 tmp4,$advance_ccount
call tmp4,$0x0,$0,env,tmp3
movi_i32 tmp3,$window_check
call tmp3,$0x0,$0,env,tmp1,tmp2
mov_i32 tmp0,ar4
qemu_ld8u ar12,tmp0,$0x0
movi_i32 tmp0,$0xffffffe0
add_i32 ar9,ar12,tmp0
<<<
movi_i32 tmp1,$0x40
shr_i32 tmp0,ar9,tmp1
<<<
# I don't get the above
movi_i32 tmp1,$0xff
and_i32 ar9,tmp0,tmp1
# Nor the continuation
movi_i32 tmp0,$0x3
movi_i32 tmp1,$advance_ccount
call tmp1,$0x0,$0,env,tmp0
brcond_i32 ar6,ar9,ltu,$0x0
nopn $0x2,$0x2
movi_i32 pc,$0xd0079402
goto_tb $0x0
exit_tb $0x4a036c68
set_label $0x0
nopn $0x2,$0x2
movi_i32 pc,$0xd0079430
goto_tb $0x1
exit_tb $0x4a036c69
end
Just adding some debugging printfs to constant shift paths in tcg target
can also be useful.
> > exposed another bug in power's tcg - gototb's target was expected to be
> > always filled via tb_set_jmp_target (even though it's clearly not what
> > tcg/README prescribes, sorry about that).
>
>
--
mailto:av1474@comtv.ru
next prev parent reply other threads:[~2012-09-19 12:49 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-18 19:52 [Qemu-devel] Shifts, ppc[64], xtensa malc
2012-09-18 23:20 ` Max Filippov
2012-09-19 12:49 ` malc [this message]
2012-09-19 15:00 ` Max Filippov
2012-09-19 0:10 ` Richard Henderson
2012-09-19 12:46 ` malc
2012-09-19 12:57 ` Peter Maydell
2012-09-19 17:00 ` Richard Henderson
2012-09-19 17:02 ` Richard Henderson
2012-09-19 17:11 ` Peter Maydell
2012-09-19 17:30 ` Richard Henderson
2012-09-19 17:51 ` Aurelien Jarno
2012-09-19 18:01 ` Richard Henderson
2012-09-19 18:30 ` Peter Maydell
2012-09-19 18:35 ` Richard Henderson
2012-09-19 19:53 ` Richard Henderson
2012-09-19 20:05 ` Peter Maydell
2012-09-19 21:21 ` Richard Henderson
2012-09-20 0:29 ` Max Filippov
2012-09-20 14:03 ` Richard Henderson
2012-09-20 14:22 ` Max Filippov
2012-09-20 22:53 ` malc
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