Instructions from RISC-V's Zicbop extension can be used to implement the rte_prefetch* family of functions. On modern versions of GCC (13.1.0+) and Clang (17.0.1+), these are emitted by __builtin_prefetch() when the extension is present.
In order to support older compiler versions, this patchset manually emits these instructions using inline assembly. To do this, I have added a new flag, RTE_PREFETCH_WRITE_ARCH_DEFINED, that (similarly to RTE_WAIT_UNTIL_EQUAL_ARCH_DEFINED) hides the generic implementation of rte_prefetch*_write. I am still in the process of acquiring hardware that supports this extension, so I haven't tested how this affects performance yet. Daniel Gregory (2): eal: add flag to hide generic prefetch_write eal/riscv: add support for zicbop extension config/riscv/meson.build | 6 +++ lib/eal/include/generic/rte_prefetch.h | 47 +++++++++++++-------- lib/eal/riscv/include/rte_prefetch.h | 57 ++++++++++++++++++++++++-- 3 files changed, 90 insertions(+), 20 deletions(-) -- 2.39.2
