> From: Stephen Hemminger [mailto:step...@networkplumber.org] 1/5] config/riscv: add flag for using Zbc extension > > On Tue, 18 Jun 2024 18:41:29 +0100 > Daniel Gregory <daniel.greg...@bytedance.com> wrote: > > > diff --git a/config/riscv/meson.build b/config/riscv/meson.build > > index 07d7d9da23..4bda4089bd 100644 > > --- a/config/riscv/meson.build > > +++ b/config/riscv/meson.build > > @@ -26,6 +26,13 @@ flags_common = [ > > # read from /proc/device-tree/cpus/timebase-frequency. This property is > > # guaranteed on Linux, as riscv time_init() requires it. > > ['RTE_RISCV_TIME_FREQ', 0], > > + > > + # Use RISC-V Carry-less multiplication extension (Zbc) for hardware > > + # implementations of CRC-32C (lib/hash/rte_crc_riscv64.h), CRC-32 and > CRC-16 > > + # (lib/net/net_crc_zbc.c). Requires intrinsics available in GCC 14.1.0+ > and > > + # Clang 18.1.0+ > > + # Make sure to add '_zbc' to your target's -march below > > + ['RTE_RISCV_ZBC', false], > > ] > > Please do not add more config options via compile flags. > It makes it impossible for distros to ship one version. > > Instead, detect at compile or runtime
Build time detection is not possible for cross builds.
