Messages in this thread | | | Subject | Re: [PATCH v5 8/8] LoongArch: Add ORC stack unwinder support | From | Tiezhu Yang <> | Date | Thu, 7 Dec 2023 15:43:04 +0800 |
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On 12/03/2023 09:20 PM, Xi Ruoyao wrote: > On Wed, 2023-11-29 at 21:07 +0800, Tiezhu Yang wrote: >> +KBUILD_AFLAGS += $(call cc-option,-mthin-add-sub) $(call cc-option,-Wa$(comma)-mthin-add-sub) >> +KBUILD_CFLAGS += $(call cc-option,-mthin-add-sub) $(call cc-option,-Wa$(comma)-mthin-add-sub) >> + >> +ifdef CONFIG_OBJTOOL >> +KBUILD_CFLAGS += -fno-optimize-sibling-calls -fno-jump-tables -falign-functions=4 -falign-labels=4 >> +endif > > I still hate regressing the optimization with a passion.
Yes, I agree in general.
> > And -falign-labels=4 implies -falign-functions=4 so at least we can > remove -falign-functions=4.
Thanks.
> > And in GCC >= 14 the defaults are -falign-labels=16 and -falign- > functions=32. These values are determined by benchmarking on LA464 so > I'd suggest using them (maybe unless CONFIG_CC_OPTIMIZE_FOR_SIZE). >
The initial aim to add "-falign-functions=4 -falign-labels=4" is to avoid generating nop instructions in .o file with -mrelax option by default, otherwise the orc info can not match the symbol address in vmlinux.
I want to add -mno-relax option and remove the extra option "-falign-functions=4 -falign-labels=4", then the offsets in each .o file and vmlinux are same, and it is not necessary to do the special handling about local labels, I think it will make life easier.
Thanks, Tiezhu
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