From: Richard Henderson <richard.henderson@linaro.org>
To: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org
Cc: zhao1.liu@intel.com
Subject: Re: [PATCH v2 17/25] target/i386: move C0-FF opcodes to new decoder (except for x87)
Date: Mon, 6 May 2024 09:56:35 -0700 [thread overview]
Message-ID: <f41c96d4-7fc0-4c95-94cf-9f5cc76f2b09@linaro.org> (raw)
In-Reply-To: <20240506080957.10005-18-pbonzini@redhat.com>
On 5/6/24 01:09, Paolo Bonzini wrote:
> The shift instructions are rewritten instead of reusing code from the old
> decoder. Rotates use CC_OP_ADCOX more extensively and generally rely
> more on the optimizer, so that the code generators are shared between
> the immediate-count and variable-count cases.
>
> In particular, this makes gen_RCL and gen_RCR pretty efficient for the
> count == 1 case, which becomes (apart from a few extra movs) something like:
>
> (compute_cc_all if needed)
> // save old value for OF calculation
> mov cc_src2, T0
> // the bulk of RCL is just this!
> deposit T0, cc_src, T0, 1, TARGET_LONG_BITS - 1
> // compute carry
> shr cc_dst, cc_src2, length - 1
> and cc_dst, cc_dst, 1
> // compute overflow
> xor cc_src2, cc_src2, T0
> extract cc_src2, cc_src2, length - 1, 1
>
> 32-bit MUL and IMUL are also slightly more efficient on 64-bit hosts.
>
> Signed-off-by: Paolo Bonzini<pbonzini@redhat.com>
> ---
> target/i386/tcg/decode-new.h | 1 +
> target/i386/tcg/translate.c | 23 +-
> target/i386/tcg/decode-new.c.inc | 142 +++++
> target/i386/tcg/emit.c.inc | 1014 +++++++++++++++++++++++++++++-
> 4 files changed, 1169 insertions(+), 11 deletions(-)
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
next prev parent reply other threads:[~2024-05-06 16:57 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
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 [this message]
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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