On Fri, Apr 14, 2023 at 1:07 AM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote: > > LLVM does not implement some of -march options. However those options > are not mandatory for kernel to build for those CPUs. > > Fallback -march CFLAG to ISA level if unsupported by toolchain so > we can get those kernel to build with LLVM. > > Link: https://github.com/ClangBuiltLinux/linux/issues/1544 > Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx> > Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> Thanks for the patch! Maybe it's more obvious to folks who work on mips, but how did you determine that say `p5600` is `mips32r5` or `r10000` is `mips4`? Is there a table somewhere you used as a reference? Including such info in the commit message would help reviewers such as myself verify the patch. Also, in v1, you mentioned that -mtune is not a substitute. It would be good to record that info in the commit message as well. > --- > v2: Reword commit message > --- > arch/mips/Makefile | 30 +++++++++++++++++------------- > 1 file changed, 17 insertions(+), 13 deletions(-) > > diff --git a/arch/mips/Makefile b/arch/mips/Makefile > index af3d17ec35d3..0fa84fc395c9 100644 > --- a/arch/mips/Makefile > +++ b/arch/mips/Makefile > @@ -148,10 +148,10 @@ cflags-y += $(call cc-option,-Wa$(comma)-mno-fix-loongson3-llsc,) > # > # CPU-dependent compiler/assembler options for optimization. > # > -cflags-$(CONFIG_CPU_R3000) += -march=r3000 > -cflags-$(CONFIG_CPU_R4300) += -march=r4300 -Wa,--trap > -cflags-$(CONFIG_CPU_R4X00) += -march=r4600 -Wa,--trap > -cflags-$(CONFIG_CPU_TX49XX) += -march=r4600 -Wa,--trap > +cflags-$(CONFIG_CPU_R3000) += $(call cc-option,-march=r3000,-march=mips1) > +cflags-$(CONFIG_CPU_R4300) += $(call cc-option,-march=r4300,-march=mips3) -Wa,--trap > +cflags-$(CONFIG_CPU_R4X00) += $(call cc-option,-march=r4600,-march=mips3) -Wa,--trap > +cflags-$(CONFIG_CPU_TX49XX) += $(call cc-option,-march=r4600,-march=mips3) -Wa,--trap > cflags-$(CONFIG_CPU_MIPS32_R1) += -march=mips32 -Wa,--trap > cflags-$(CONFIG_CPU_MIPS32_R2) += -march=mips32r2 -Wa,--trap > cflags-$(CONFIG_CPU_MIPS32_R5) += -march=mips32r5 -Wa,--trap -modd-spreg > @@ -160,26 +160,30 @@ cflags-$(CONFIG_CPU_MIPS64_R1) += -march=mips64 -Wa,--trap > cflags-$(CONFIG_CPU_MIPS64_R2) += -march=mips64r2 -Wa,--trap > cflags-$(CONFIG_CPU_MIPS64_R5) += -march=mips64r5 -Wa,--trap > cflags-$(CONFIG_CPU_MIPS64_R6) += -march=mips64r6 -Wa,--trap > -cflags-$(CONFIG_CPU_P5600) += -march=p5600 -Wa,--trap -modd-spreg > -cflags-$(CONFIG_CPU_R5000) += -march=r5000 -Wa,--trap > -cflags-$(CONFIG_CPU_R5500) += $(call cc-option,-march=r5500,-march=r5000) \ > +cflags-$(CONFIG_CPU_P5600) += $(call cc-option,-march=p5600,-march=mips32r5) \ > + -Wa,--trap -modd-spreg > +cflags-$(CONFIG_CPU_R5000) += $(call cc-option,-march=r5000,-march=mips4) \ > -Wa,--trap > -cflags-$(CONFIG_CPU_NEVADA) += $(call cc-option,-march=rm5200,-march=r5000) \ > +cflags-$(CONFIG_CPU_R5500) += $(call cc-option,-march=r5500,-march=mips4) \ > -Wa,--trap > -cflags-$(CONFIG_CPU_RM7000) += $(call cc-option,-march=rm7000,-march=r5000) \ > +cflags-$(CONFIG_CPU_NEVADA) += $(call cc-option,-march=rm5200,-march=mips4) \ > -Wa,--trap > -cflags-$(CONFIG_CPU_SB1) += $(call cc-option,-march=sb1,-march=r5000) \ > +cflags-$(CONFIG_CPU_RM7000) += $(call cc-option,-march=rm7000,-march=mips4) \ > + -Wa,--trap > +cflags-$(CONFIG_CPU_SB1) += $(call cc-option,-march=sb1,-march=mips4) \ > -Wa,--trap > cflags-$(CONFIG_CPU_SB1) += $(call cc-option,-mno-mdmx) > cflags-$(CONFIG_CPU_SB1) += $(call cc-option,-mno-mips3d) > -cflags-$(CONFIG_CPU_R10000) += $(call cc-option,-march=r10000,-march=r8000) \ > +cflags-$(CONFIG_CPU_R10000) += $(call cc-option,-march=r10000,-march=mips4) \ > -Wa,--trap > cflags-$(CONFIG_CPU_CAVIUM_OCTEON) += -march=octeon -Wa,--trap > cflags-$(CONFIG_CAVIUM_CN63XXP1) += -Wa,-mfix-cn63xxp1 > cflags-$(CONFIG_CPU_BMIPS) += -march=mips32 -Wa,-mips32 -Wa,--trap > > -cflags-$(CONFIG_CPU_LOONGSON2E) += -march=loongson2e -Wa,--trap > -cflags-$(CONFIG_CPU_LOONGSON2F) += -march=loongson2f -Wa,--trap > +cflags-$(CONFIG_CPU_LOONGSON2E) += \ > + $(call cc-option,-march=loongson2e,-march=mips3) -Wa,--trap > +cflags-$(CONFIG_CPU_LOONGSON2F) += \ > + $(call cc-option,-march=loongson2f,-march=mips3) -Wa,--trap > # Some -march= flags enable MMI instructions, and GCC complains about that > # support being enabled alongside -msoft-float. Thus explicitly disable MMI. > cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call cc-option,-mno-loongson-mmi) > -- > 2.39.2 (Apple Git-143) > -- Thanks, ~Nick Desaulniers
