From: WANG Xuerui <i.qemu@xen0n.name>
To: Richard Henderson <richard.henderson@linaro.org>, qemu-devel@nongnu.org
Subject: Re: [PATCH 21/30] tcg/loongarch: Implement tcg_out_call
Date: Tue, 21 Sep 2021 14:42:59 +0800 [thread overview]
Message-ID: <733b9bb1-fd35-dd7f-2162-3362659e864f@xen0n.name> (raw)
In-Reply-To: <9c4f7220-1c6a-03f4-f265-b337909583e5@linaro.org>
Hi Richard,
On 9/21/21 00:35, Richard Henderson wrote:
> On 9/20/21 9:31 AM, Richard Henderson wrote:
>> On 9/20/21 1:04 AM, WANG Xuerui wrote:
>>> + } else if (TCG_TARGET_REG_BITS == 32 || offset ==
>>> (int32_t)offset) {
>>> + /* long jump: +/- 2GiB */
>>> + tcg_out_opc_pcaddu12i(s, TCG_REG_TMP0, 0);
>>> + tcg_out_opc_jirl(s, link, TCG_REG_TMP0, 0);
>>> + ret = reloc_call(s->code_ptr - 2, arg);
>>> + tcg_debug_assert(ret == true);
>>
>> Just inline reloc_call here, so that you can provide the correct
>> offsets to the pcadd and jirl instructions directly. The assert will
>> vanish, because you've already done the range check with "offset ==
>> (int32_t)offset".
>
> Actually, don't you want offset == sextract64(offset, 0, 34), and use
> pcaddu18i? Depending on the memory map of qemu, those extra bits could
> make the difference in directly reaching the main executable.
>
Whoa, silly me, I actually didn't realize a single expected use case of
pcaddu18i until I read this, the low 2 bits are always clear so 18 is
exactly the amount of shift needed when paired with jirl!
I'll of course rework this to use pcaddu18i+jirl instead.
>
> r~
next prev parent reply other threads:[~2021-09-21 6:47 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
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 [this message]
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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