From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by sourceware.org (Postfix) with ESMTP id EC8C63857C46 for ; Thu, 26 Nov 2020 12:03:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org EC8C63857C46 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=huangpei@loongson.cn Received: from ambrosehua-HP-xw6600-Workstation (unknown [182.149.161.68]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9AxetGZmb9fqvwWAA--.14255S2; Thu, 26 Nov 2020 20:03:39 +0800 (CST) Date: Thu, 26 Nov 2020 20:03:37 +0800 From: Huang Pei To: libc-help@sourceware.org Subject: Question about setjmp_aux.c on MIPS Message-ID: <20201126120337.c7lsjbzlhrskzx7k@ambrosehua-HP-xw6600-Workstation> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: NeoMutt/20171215 X-CM-TRANSID: AQAAf9AxetGZmb9fqvwWAA--.14255S2 X-Coremail-Antispam: 1UD129KBjvdXoWrtF4rCFy5GFy8KFW5Zw1kKrg_yoW3WwcE9F 4kXFZxCr1UWwsIgr92yF4xXas3uw48ZF45tw4jvFWkCrn5Aan3CF4Duryjq3y8tFZFvr9x A392qryYvr12vjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb78YjsxI4VWkKwAYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM2 8CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0 cI8IcVCY1x0267AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z2 80aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAK zVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx 8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcVAKI48JMxkIecxEwVAFwVW5JwCF04k20xvY0x0E wIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E74 80Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jr0_JrylIxkGc2Ij64vIr41lIxAIcVC0 I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04 k26cxKx2IYs7xG6rWUJVWrZr1UMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIE c7CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU5QtxPUUUUU== X-CM-SenderInfo: xkxd0whshlqz5rrqw2lrqou0/ X-Spam-Status: No, score=-4.5 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-help@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-help mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Nov 2020 12:03:45 -0000 Hi everyone, I add 'dummy' event to do_cpu in Linux/MIPS, and use perf tool with Uprobe and dummy event, found my CU1 exception came from ld.so For ld.so, it is not intended to use floating point instruction, but the __sigsetjmp from _dl_catch_exception touch FP regs repeatedly as loading DSOs, which cause unneeded FP context saving and restoring between tasks that does not use FP at all, I wonder if this can be avoided. +. MIPS, link other RISC with hard floating point suppport need to save callee-saved FP in setjmp_aux.c, but setjmp.S for x86/x86_64 DOES NOT save any x87/SSE regs, does anyone know why? +. Does MIPS need to save MSA reg as PowerPC does for VSX in setjmp_aux.c? +. I see x86/x86-64/ARM64 say no need to save sigmask in ld.so, can MIPS does this too?