On Fri, Apr 12, 2024 at 10:34:28AM -0700, Charlie Jenkins wrote: > On Fri, Apr 12, 2024 at 11:40:38AM +0100, Conor Dooley wrote: > > On Thu, Apr 11, 2024 at 09:11:13PM -0700, Charlie Jenkins wrote: > > > When alternatives are disabled, riscv_cpu_isa_extension_(un)likely() > > > checks if the current cpu supports the selected extension if not all > > > cpus support the extension. It is sufficient to only check if the > > > current cpu supports the extension. > > > > > > The alternatives code to handle if all cpus support an extension is > > > factored out into a new function to support this. > > > > > > Signed-off-by: Charlie Jenkins <charlie@xxxxxxxxxxxx> > > > --- > > > > > static __always_inline bool riscv_cpu_has_extension_unlikely(int cpu, const unsigned long ext) > > > { > > > - if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_unlikely(ext)) > > > - return true; > > > + compiletime_assert(ext < RISCV_ISA_EXT_MAX, > > > + "ext must be < RISCV_ISA_EXT_MAX"); > > > > > > - return __riscv_isa_extension_available(hart_isa[cpu].isa, ext); > > > + if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && __riscv_has_extension_unlikely_alternatives(ext)) > > > + return true; > > > + else > > > + return __riscv_isa_extension_available(hart_isa[cpu].isa, ext); > > > } > > > > static __always_inline bool riscv_cpu_has_extension_likely(int cpu, const unsigned long ext) > > { > > if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_likely(ext)) > > return true; > > > > return __riscv_isa_extension_available(hart_isa[cpu].isa, ext); > > } > > > > This is the code as things stand. If alternatives are disabled, the if > > statement becomes if (0 && foo) which will lead to the function call > > getting constant folded away and all you end up with is the call to > > __riscv_isa_extension_available(). Unless I am missing something, I don't > > think this patch has any affect? > > Yeah I fumbled this one it appears. I got thrown off by the nested > IS_ENABLED(CONFIG_RISCV_ALTERNATIVE). This patch eliminates the need for > this and maybe can avoid avoid confusion in the future. I think it just creates unneeded functions and can/should be dropped.
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