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Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions th
From: |
Aurelien Jarno |
Subject: |
Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed. |
Date: |
Fri, 11 Jun 2010 10:06:34 +0200 |
User-agent: |
Mutt/1.5.20 (2009-06-14) |
On Thu, Jun 10, 2010 at 03:19:25PM -0700, Richard Henderson wrote:
> On 06/10/2010 03:28 AM, Aurelien Jarno wrote:
> >> + asm volatile(".word 0xb2b0,0x1000"
> >> + : "=r"(r0) : "0"(0), "r"(r1) : "memory", "cc");
> >
> > Wouldn't it be possible to use the instruction directly instead of
> > dumping the opcode values? Same below
>
> No, they aren't recognized by older assemblers. For instance, the one shipped
> with RHEL 5.5, and possibly even by Debian Lenny (I don't currently have
> access
> to that machine to check). Apparently some of these are quite new insns --
> 2008 era.
>
> That said, all the hardware to which either I or agraf have access are the
> latest
> z10 machines. Frankly I expect that to be true of most if not all machines,
> since
> I think it's just a microcode update which everyone with an active support
> contract
> can get.
>
FYI, that's the /proc/cpuinfo of s390 machines I have (more or less)
access:
features : esan3 zarch msa ldisp
features : esan3 zarch stfle msa ldisp eimm dfp
features : esan3 zarch stfle msa ldisp eimm dfp etf3eh highgprs
So that's seems fine. However, looking more in details in the code
again, I do wonder about this part:
> + /* Test for z/Architecture. Required even in 31-bit mode. */
> + got_sigill = 0;
> + /* agr %r0,%r0 */
> + asm volatile(".word 0xb908,0x0000" : "=r"(r0) : : "cc");
> + if (!got_sigill) {
> + facilities |= FACILITY_ZARCH | FACILITY_ZARCH_ACTIVE;
> + }
> +
What's the difference between FACILITY_ZARCH and FACILITY_ZARCH_ACTIVE,
as both are actually flagged together. My guess is that
FACILITY_ZARCH_ACTIVE is needed in 64-bit mode, why FACILITY_ZARCH is
only needed for a possible future 32-bit mode. Is it correct?
--
Aurelien Jarno GPG: 1024D/F1BCDB73
address@hidden http://www.aurel32.net
- Re: [Qemu-devel] [PATCH 10/35] tcg-s390: New TCG target, (continued)
- [Qemu-devel] [PATCH 12/35] tcg-s390: Define TCG_TMP0., Richard Henderson, 2010/06/04
- [Qemu-devel] [PATCH 13/35] tcg-s390: Tidy regset initialization; use R14 as temporary., Richard Henderson, 2010/06/04
- [Qemu-devel] [PATCH 14/35] tcg-s390: Rearrange register allocation order., Richard Henderson, 2010/06/04
- [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Richard Henderson, 2010/06/04
- Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Aurelien Jarno, 2010/06/10
- Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Richard Henderson, 2010/06/11
- Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Aurelien Jarno, 2010/06/13
- Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Richard Henderson, 2010/06/13
- Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Aurelien Jarno, 2010/06/13
- Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Alexander Graf, 2010/06/13
- Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Richard Henderson, 2010/06/14
- Re: [Qemu-devel] [PATCH 15/35] tcg-s390: Query instruction extensions that are installed., Alexander Graf, 2010/06/14
[Qemu-devel] [PATCH 16/35] tcg-s390: Re-implement tcg_out_movi., Richard Henderson, 2010/06/04