https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108764
Kito Cheng <kito at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |kito at gcc dot gnu.org
--- Comment #3 from Kito Cheng <kito at gcc dot gnu.org> ---
> I think one solution is to change the cost model of such complex instructions
> to the sum of the cost for each part. E.g.
> cost for shNadd = COSTS_N_INSNS (SINGLE_SHIFT_COST) + COSTS_N_INSNS (1) #
> cost of addition
Some RISC-V core implementation did has one cycle for shNadd operation as I
know, but I know it's not true for every implementation.
Anyway, it's really uarch dependent, so I would prefer keep as it for now, and
then extend the cost model function to easier handle different uarch (-mtune)
when GCC 14 is open.
