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From: WANG Xuerui <i.qemu@xen0n.name>
To: Richard Henderson <richard.henderson@linaro.org>, qemu-devel@nongnu.org
Subject: Re: [PATCH 14/30] tcg/loongarch: Implement bswap32_i32/bswap64_i64
Date: Tue, 21 Sep 2021 14:37:14 +0800	[thread overview]
Message-ID: <f9c0c0c2-73e6-4cd3-aded-7c00b7d9b871@xen0n.name> (raw)
In-Reply-To: <7e8ae810-fd12-a62e-2039-3b1cc4c824cb@linaro.org>

Hi Richard,

On 9/20/21 23:11, Richard Henderson wrote:
> On 9/20/21 1:04 AM, WANG Xuerui wrote:
>> +    case INDEX_op_bswap32_i32:
>> +        tcg_out_opc_revb_2h(s, a0, a1);
>> +        tcg_out_opc_rotri_w(s, a0, a0, 16);
>> +        break;
>> +    case INDEX_op_bswap64_i64:
>> +        tcg_out_opc_revb_d(s, a0, a1);
>> +        break;
>
> You're missing INDEX_op_bswap32_i64, which in addition has a third 
> argument consisting of TCG_BSWAP_* bits.
>
> I would have expected revb_2w to be the preferred implementation of 
> bswap32.  I would expect something like
>
>
>     case INDEX_op_bswap32_i32:
>         /* All 32-bit values are computed sign-extended in the 
> register. */
>         a2 = TCG_BSWAP_OS;
>         /* fall through */
>     case INDEX_op_bswap32_i64:
>         tcg_out_opc_revb_2w(s, a0, a1);
>         if (a2 & TCG_BSWAP_OS) {
>             tcg_out_ext32s(s, a0, a0);
>         } else if (a2 & TCG_BSWAP_OZ) {
>             tcg_out_ext32u(s, a0, a0);
>         }
>         break;
>
You're right when we're supporting only 64-bit hosts. While I was 
writing that code I hadn't decided whether to remove support for 32-bit 
hosts, so I didn't make use of 64-bit instructions for the 32-bit ops. 
I'll fix this in v2.
>
> r~


  parent reply	other threads:[~2021-09-21  6:43 UTC|newest]

Thread overview: 80+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-20  8:04 [PATCH 00/30] 64-bit LoongArch port of QEMU TCG WANG Xuerui
2021-09-20  8:04 ` [PATCH 01/30] elf: Add machine type value for LoongArch WANG Xuerui
2021-09-20  8:04 ` [PATCH 02/30] MAINTAINERS: Add tcg/loongarch entry with myself as maintainer WANG Xuerui
2021-09-20 14:50   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 03/30] tcg/loongarch: Add the tcg-target.h file WANG Xuerui
2021-09-20 14:23   ` Richard Henderson
2021-09-20 16:20     ` WANG Xuerui
2021-09-20 16:25       ` Richard Henderson
2021-09-20  8:04 ` [PATCH 04/30] tcg/loongarch: Add generated instruction opcodes and encoding helpers WANG Xuerui
2021-09-20 15:55   ` Richard Henderson
2021-09-20 16:24     ` WANG Xuerui
2021-09-21  9:58   ` Philippe Mathieu-Daudé
2021-09-21 11:40     ` WANG Xuerui
2021-09-20  8:04 ` [PATCH 05/30] tcg/loongarch: Add register names, allocation order and input/output sets WANG Xuerui
2021-09-20 15:57   ` Richard Henderson
2021-09-20 16:27     ` WANG Xuerui
2021-09-20  8:04 ` [PATCH 06/30] tcg/loongarch: Define the operand constraints WANG Xuerui
2021-09-20 14:28   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 07/30] tcg/loongarch: Implement necessary relocation operations WANG Xuerui
2021-09-20 14:36   ` Richard Henderson
2021-09-20 17:15     ` WANG Xuerui
2021-09-20  8:04 ` [PATCH 08/30] tcg/loongarch: Implement the memory barrier op WANG Xuerui
2021-09-20  8:04 ` [PATCH 09/30] tcg/loongarch: Implement tcg_out_mov and tcg_out_movi WANG Xuerui
2021-09-20 14:47   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 10/30] tcg/loongarch: Implement goto_ptr WANG Xuerui
2021-09-20 14:49   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 11/30] tcg/loongarch: Implement sign-/zero-extension ops WANG Xuerui
2021-09-20 14:50   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 12/30] tcg/loongarch: Implement not/and/or/xor/nor/andc/orc ops WANG Xuerui
2021-09-20 14:54   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 13/30] tcg/loongarch: Implement deposit/extract ops WANG Xuerui
2021-09-20 14:55   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 14/30] tcg/loongarch: Implement bswap32_i32/bswap64_i64 WANG Xuerui
2021-09-20 15:11   ` Richard Henderson
2021-09-20 18:20     ` Richard Henderson
2021-09-21  6:37     ` WANG Xuerui [this message]
2021-09-20  8:04 ` [PATCH 15/30] tcg/loongarch: Implement clz/ctz ops WANG Xuerui
2021-09-20 16:10   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 16/30] tcg/loongarch: Implement shl/shr/sar/rotl/rotr ops WANG Xuerui
2021-09-20 16:13   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 17/30] tcg/loongarch: Implement neg/add/sub ops WANG Xuerui
2021-09-20 16:16   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 18/30] tcg/loongarch: Implement mul/mulsh/muluh/div/divu/rem/remu ops WANG Xuerui
2021-09-20 16:16   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 19/30] tcg/loongarch: Implement br/brcond ops WANG Xuerui
2021-09-20 16:20   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 20/30] tcg/loongarch: Implement setcond ops WANG Xuerui
2021-09-20 16:24   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 21/30] tcg/loongarch: Implement tcg_out_call WANG Xuerui
2021-09-20 16:31   ` Richard Henderson
2021-09-20 16:35     ` Richard Henderson
2021-09-21  6:42       ` WANG Xuerui
2021-09-20  8:04 ` [PATCH 22/30] tcg/loongarch: Implement simple load/store ops WANG Xuerui
2021-09-20 16:35   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 23/30] tcg/loongarch: Add softmmu load/store helpers, implement qemu_ld/qemu_st ops WANG Xuerui
2021-09-20 17:10   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 24/30] tcg/loongarch: Implement tcg_target_qemu_prologue WANG Xuerui
2021-09-20 17:15   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 25/30] tcg/loongarch: Implement exit_tb/goto_tb WANG Xuerui
2021-09-20 17:16   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 26/30] tcg/loongarch: Implement tcg_target_init WANG Xuerui
2021-09-20 17:19   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 27/30] tcg/loongarch: Register the JIT WANG Xuerui
2021-09-20 17:21   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 28/30] configure, meson.build: Mark support for 64-bit LoongArch hosts WANG Xuerui
2021-09-20 17:23   ` Richard Henderson
2021-09-21  6:02     ` WANG Xuerui
2021-09-21  6:59       ` Philippe Mathieu-Daudé
2021-09-21  7:24         ` WANG Xuerui
2021-09-21 13:30       ` Richard Henderson
2021-09-21 14:07         ` WANG Xuerui
2021-09-21 14:10           ` WANG Xuerui
2021-09-21 14:42     ` Peter Maydell
2021-09-21 15:59       ` Richard Henderson
2021-09-21 16:09       ` WANG Xuerui
2021-09-21 17:26         ` Richard Henderson
2021-09-20  8:04 ` [PATCH 29/30] linux-user: Add host dependency for 64-bit LoongArch WANG Xuerui
2021-09-20 17:26   ` Richard Henderson
2021-09-20  8:04 ` [PATCH 30/30] accel/tcg/user-exec: Implement CPU-specific signal handler for LoongArch hosts WANG Xuerui
2021-09-20 17:31   ` Richard Henderson

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