target/linux/generic/patches-2.6.38/012-extra_optimization.patch

   1 --- a/Makefile
   2 +++ b/Makefile
   3 @@ -539,9 +539,9 @@ endif # $(dot-config)
   4  all: vmlinux
   5
   6  ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
   7 -KBUILD_CFLAGS  += -Os
   8 +KBUILD_CFLAGS  += -Os -fno-caller-saves
   9  else
  10 -KBUILD_CFLAGS  += -O2
  11 +KBUILD_CFLAGS  += -O2 -fno-reorder-blocks -fno-tree-ch -fno-caller-saves
  12  endif
  13
  14  include $(srctree)/arch/$(SRCARCH)/Makefile
  15 @@ -596,6 +596,9 @@ endif
  16  NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
  17  CHECKFLAGS     += $(NOSTDINC_FLAGS)
  18
  19 +# improve gcc optimization
  20 +CFLAGS += $(call cc-option,-funit-at-a-time,)
  21 +
  22  # warn about C99 declaration after statement
  23  KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
  24