From: Richard Henderson <rth@twiddle.net>
To: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
qemu-devel@nongnu.org, Aurelien Jarno <aurelien@aurel32.net>
Subject: Re: [Qemu-devel] Shifts, ppc[64], xtensa
Date: Wed, 19 Sep 2012 12:53:44 -0700 [thread overview]
Message-ID: <505A22C8.6030409@twiddle.net> (raw)
In-Reply-To: <CAFEAcA-Bg+yv5sH1TTm9opHBtVYPJ7Vpn1t9nbwMT8yjEr7ELg@mail.gmail.com>
On 09/19/2012 11:30 AM, Peter Maydell wrote:
> ...but on the other hand that ought to work for PPC too, so
> presumably my analysis is wrong somewhere.
It isn't. It's a target-xtensa bug.
> OP:
> ---- 0xd0079cff
> movi_i32 tmp0,$0xd0079cff
> movi_i32 tmp1,$0x2
> 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
> and_i32 tmp0,ar9,ar8
> movi_i32 tmp1,$0x0
> brcond_i32 tmp0,tmp1,eq,$0x0
> movi_i32 tmp2,$0x0
> brcond_i32 LCOUNT,tmp2,eq,$0x1
> movi_i32 tmp2,$0x1
> sub_i32 LCOUNT,LCOUNT,tmp2
> movi_i32 tmp2,$0xd0079cf2
> mov_i32 pc,tmp2
> goto_tb $0x0
> exit_tb $0x4a116558
> set_label $0x1
> movi_i32 tmp2,$0xd0079d02
> mov_i32 pc,tmp2
> exit_tb $0x0
> set_label $0x0
> movi_i32 tmp2,$0xd0079d1a
> mov_i32 pc,tmp2
> goto_tb $0x1
> exit_tb $0x4a116559
> movi_i32 tmp0,$0x0
> brcond_i32 LCOUNT,tmp0,eq,$0x2
> movi_i32 tmp0,$0x1
> sub_i32 LCOUNT,LCOUNT,tmp0
> movi_i32 tmp0,$0xd0079cf2
> mov_i32 pc,tmp0
> goto_tb $0x0
> exit_tb $0x4a116558
> set_label $0x2
> movi_i32 tmp0,$0xd0079d02
> mov_i32 pc,tmp0
> exit_tb $0x0
There are two instances of goto_tb $0 in here.
And, amusingly, two checks for LCOUNT.
Since there's no disassembler for xtensa, I'll
leave it to the maintainer to track down from
whence this mistake stems.
r~
next prev parent reply other threads:[~2012-09-19 19:53 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
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 [this message]
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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