From: Huang Pei <huangpei@loongson.cn>
To: libc-help@sourceware.org
Subject: Question about setjmp_aux.c on MIPS
Date: Thu, 26 Nov 2020 20:03:37 +0800 [thread overview]
Message-ID: <20201126120337.c7lsjbzlhrskzx7k@ambrosehua-HP-xw6600-Workstation> (raw)
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?
next reply other threads:[~2020-11-26 12:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-26 12:03 Huang Pei [this message]
2020-11-26 12:37 ` Florian Weimer
2020-11-27 7:59 ` Huang Pei
2020-11-27 8:17 ` Florian Weimer
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