When compiled with GCC 8.1, vmlinux is significantly bigger than with GCC 4.8.
When looking at the generated code with objdump, we notice that all functions and loops when a 16 bytes alignment. This significantly increases the size of the kernel. It is pointless and even counterproductive as on the 8xx 'nop' also consumes one clock cycle. Size of vmlinux with GCC 4.8: text data bss dec hex filename 5801948 1626076 457796 7885820 7853fc vmlinux Size of vmlinux with GCC 8.1: text data bss dec hex filename 6764592 1630652 456476 8851720 871108 vmlinux Size of vmlinux with GCC 8.1 and this patch: text data bss dec hex filename 6331544 1631756 456476 8419776 8079c0 vmlinux Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> --- arch/powerpc/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 6a050b42a9f2..26ccd0b91512 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -178,6 +178,7 @@ CFLAGS-$(CONFIG_POWER6_CPU) += $(call cc-option,-mcpu=power6) CFLAGS-$(CONFIG_POWER7_CPU) += $(call cc-option,-mcpu=power7) CFLAGS-$(CONFIG_POWER8_CPU) += $(call cc-option,-mcpu=power8) CFLAGS-$(CONFIG_POWER9_CPU) += $(call cc-option,-mcpu=power9) +CFLAGS-$(CONFIG_PPC_8xx) += $(call cc-option,-mcpu=860) # Altivec option not allowed with e500mc64 in GCC. ifeq ($(CONFIG_ALTIVEC),y) -- 2.13.3
