[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] target-ppc: add extended opcodes for dcbt
From: |
Cedric Le Goater |
Subject: |
Re: [Qemu-devel] [PATCH] target-ppc: add extended opcodes for dcbt |
Date: |
Thu, 20 Feb 2014 14:09:11 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20131104 Icedove/17.0.10 |
On 02/20/2014 02:07 PM, Alexander Graf wrote:
>
> On 20.02.2014, at 14:01, Cédric Le Goater <address@hidden> wrote:
>
>> The latest glibc provides a memrchr routine using an extended opcode
>> of the 'dcbt' instruction :
>>
>> 00000000000a7cc0 <memrchr>:
>> a7cc0: 11 00 4c 3c addis r2,r12,17
>> a7cc4: b8 f8 42 38 addi r2,r2,-1864
>> a7cc8: 14 2a e3 7c add r7,r3,r5
>> a7ccc: d0 00 07 7c neg r0,r7
>> a7cd0: ff ff e7 38 addi r7,r7,-1
>> a7cd4: 78 1b 6a 7c mr r10,r3
>> a7cd8: 24 06 e6 78 rldicr r6,r7,0,56
>> a7cdc: 60 00 20 39 li r9,96
>> a7ce0: 2c 32 09 7e dcbtt r9,r6
>> ....
>>
>> which breaks grep, and other commands, in TCG mode :
>>
>> invalid bits: 02000000 for opcode: 1f - 16 - 08 (7e09322c) 00003fff799feca0
>>
>> This patch adds the extended opcodes as no-ops just like the 'dcbt'
>> instruction. Other 'dcb*' instructions might be impacted but they
>> have not showed up yet.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>
> Please also remove the 0x02 bit from dcbtst. I don't see anything in 2.07
> indicating that that bit should be reserved and I prefer to have those two
> instructions be consistent with each other.
ok. I will send a v2.
Thanks,
C.