[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v3 06/14] tcg: Allow non-constant control macros
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH v3 06/14] tcg: Allow non-constant control macros |
Date: |
Thu, 04 Jul 2013 10:28:09 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 |
On 07/04/2013 03:53 AM, Peter Maydell wrote:
> On 3 July 2013 22:29, Richard Henderson <address@hidden> wrote:
>> This allows TCG_TARGET_HAS_* to be a variable rather than a constant,
>> which allows easier support for differing ISA levels for the host.
>
> The effect of this is that TCG_OPF_NOT_PRESENT means "if set,
> op is definitely not present; if not set, op might or might
> not be present", right? Which is OK because it's just a debug
> guard/sanity check. (That might be worth noting in a comment
> I guess.)
Well, if not set, an entry must be present in the operands table.
E.g. for arm division, the { INDEX_op_div_i32, "r", "r", "r" } entry
is always there, even if TCG_TARGET_HAS_div_i32 evaluates to false
at runtime. The entry must be there Just In Case the expression might
be true.
r~
- [Qemu-devel] [PATCH v3 01/14] tcg: Add myself to general TCG maintainership, (continued)
- [Qemu-devel] [PATCH v3 01/14] tcg: Add myself to general TCG maintainership, Richard Henderson, 2013/07/03
- [Qemu-devel] [PATCH v3 02/14] tcg: Split rem requirement from div requirement, Richard Henderson, 2013/07/03
- [Qemu-devel] [PATCH v3 03/14] tcg-arm: Don't implement rem, Richard Henderson, 2013/07/03
- [Qemu-devel] [PATCH v3 04/14] tcg-ppc: Don't implement rem, Richard Henderson, 2013/07/03
- [Qemu-devel] [PATCH v3 05/14] tcg-ppc64: Don't implement rem, Richard Henderson, 2013/07/03
- [Qemu-devel] [PATCH v3 06/14] tcg: Allow non-constant control macros, Richard Henderson, 2013/07/03
- [Qemu-devel] [PATCH v3 07/14] tcg: Simplify logic using TCG_OPF_NOT_PRESENT, Richard Henderson, 2013/07/03
- [Qemu-devel] [PATCH v3 08/14] tcg-arm: Make use of conditional availability of opcodes for divide, Richard Henderson, 2013/07/03
- [Qemu-devel] [PATCH v3 09/14] tcg-arm: Simplify logic in detecting the ARM ISA in use, Richard Henderson, 2013/07/03