On Wed, Mar 30, 2022 at 6:45 PM Masami Hiramatsu [off-list ref] wrote:

Hi Nick,

On Wed, 30 Mar 2022 11:04:50 -0700
Nick Desaulniers [off-list ref] wrote:

quoted

Any chance we can use

CFLAGS_REMOVE_<file>.o := $(CC_FLAGS_LTO)

a la
commit d2dcd3e37475 ("x86, cpu: disable LTO for cpu.c")

Hm, this looks good to me. Let me confirm that works.
(Does this mean the bootconfig.o will be compiled to elf binary?)

I know we went with Masahiro's suggestion, which is clever and better,
but to answer this question; yes, under LTO, the linker can link
together inputs that are a mix of ELF object files (basically, no LTO
optimizations) with LLVM IR (w/ LTO optimizations between such files).
-- 
Thanks,
~Nick Desaulniers