From: Richard Henderson <richard.henderson@linaro.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org, zhao1.liu@intel.com
Subject: Re: [PATCH v2 05/25] target/i386: cleanup cc_op changes for REP/REPZ/REPNZ
Date: Mon, 6 May 2024 09:39:48 -0700 [thread overview]
Message-ID: <80b692cb-cce0-4477-aa98-c3db5642386b@linaro.org> (raw)
In-Reply-To: <CABgObfbDg99rNDQcBD2HZ3njkGmif2fQxRXFYqmwmGXXvXKa0A@mail.gmail.com>
On 5/6/24 09:31, Paolo Bonzini wrote:
> The comment deals with the former, the removal with the latter.
>
> The idea of the comment is that after SCAS/CMPS you have CC_OP_SUB*,
> so in principle you may expect that you need to set CC_OP_DYNAMIC
> explicitly at the end of a REPZ/REPNZ, which is where the CX != 0 and
> CX == 0 paths join. But this is not necessary, because there is
> nothing after that instruction - the translation block ends.
>
> So I guess the comment could instead be placed at the end of the function?
>
> /*
> * Only one iteration is done at a time, so the translation
> * block has ended unconditionally at this point and there
> * is no control flow junction - no need to set CC_OP_DYNAMIC.
> */
>
> What do you think?
Just before gen_jmp_rel_csize? Yes, that seems good.
r~
next prev parent reply other threads:[~2024-05-06 16:40 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-06 8:09 [PATCH v2 00/25] target/i386: convert 1-byte opcodes to new decoder Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 01/25] target/i386: use TSTEQ/TSTNE to test low bits Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 02/25] target/i386: use TSTEQ/TSTNE to check flags Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 03/25] target/i386: remove mask from CCPrepare Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 04/25] target/i386: cc_op is not dynamic in gen_jcc1 Paolo Bonzini
2024-05-06 15:53 ` Richard Henderson
2024-05-06 8:09 ` [PATCH v2 05/25] target/i386: cleanup cc_op changes for REP/REPZ/REPNZ Paolo Bonzini
2024-05-06 16:07 ` Richard Henderson
2024-05-06 16:31 ` Paolo Bonzini
2024-05-06 16:39 ` Richard Henderson [this message]
2024-05-06 8:09 ` [PATCH v2 06/25] target/i386: pull cc_op update to callers of gen_jmp_rel{, _csize} Paolo Bonzini
2024-05-06 16:12 ` [PATCH v2 06/25] target/i386: pull cc_op update to callers of gen_jmp_rel{,_csize} Richard Henderson
2024-05-06 8:09 ` [PATCH v2 07/25] target/i386: extend cc_* when using them to compute flags Paolo Bonzini
2024-05-06 16:16 ` Richard Henderson
2024-05-06 8:09 ` [PATCH v2 08/25] target/i386: do not use s->T0 and s->T1 as scratch registers for CCPrepare Paolo Bonzini
2024-05-06 16:18 ` Richard Henderson
2024-05-06 8:09 ` [PATCH v2 09/25] target/i386: clarify the "reg" argument of functions returning CCPrepare Paolo Bonzini
2024-05-06 16:19 ` Richard Henderson
2024-05-06 8:09 ` [PATCH v2 10/25] target/i386: cleanup *gen_eob* Paolo Bonzini
2024-05-06 16:21 ` Richard Henderson
2024-05-06 8:09 ` [PATCH v2 11/25] target/i386: reintroduce debugging mechanism Paolo Bonzini
2024-05-06 16:23 ` Richard Henderson
2024-05-06 8:09 ` [PATCH v2 12/25] target/i386: move 00-5F opcodes to new decoder Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 13/25] target/i386: extract gen_far_call/jmp, reordering temporaries Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 14/25] target/i386: allow instructions with more than one immediate Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 15/25] target/i386: move 60-BF opcodes to new decoder Paolo Bonzini
2024-05-06 16:44 ` Richard Henderson
2024-05-06 8:09 ` [PATCH v2 16/25] target/i386: generalize gen_movl_seg_T0 Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 17/25] target/i386: move C0-FF opcodes to new decoder (except for x87) Paolo Bonzini
2024-05-06 16:56 ` Richard Henderson
2024-05-06 8:09 ` [PATCH v2 18/25] target/i386: merge and enlarge a few ranges for call to disas_insn_new Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 19/25] target/i386: move remaining conditional operations to new decoder Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 20/25] target/i386: move BSWAP " Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 21/25] target/i386: port extensions of one-byte opcodes " Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 22/25] target/i386: remove now-converted opcodes from old decoder Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 23/25] target/i386: decode x87 instructions in a separate function Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 24/25] target/i386: split legacy decoder into " Paolo Bonzini
2024-05-06 8:09 ` [PATCH v2 25/25] target/i386: remove duplicate prefix decoding Paolo Bonzini
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