openwrtv4/target/linux/generic/patches-2.6.37/012-extra_optimization.patch
Hauke Mehrtens 50c743e79e kernel: Update to version 2.6.37.6
Thank you Peter Wagner for the patch

SVN-Revision: 26441
2011-04-03 13:59:07 +00:00

24 lines
675 B
Diff

--- a/Makefile
+++ b/Makefile
@@ -538,9 +538,9 @@ endif # $(dot-config)
all: vmlinux
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS += -Os
+KBUILD_CFLAGS += -Os -fno-caller-saves
else
-KBUILD_CFLAGS += -O2
+KBUILD_CFLAGS += -O2 -fno-reorder-blocks -fno-tree-ch -fno-caller-saves
endif
include $(srctree)/arch/$(SRCARCH)/Makefile
@@ -595,6 +595,9 @@ endif
NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
CHECKFLAGS += $(NOSTDINC_FLAGS)
+# improve gcc optimization
+CFLAGS += $(call cc-option,-funit-at-a-time,)
+
# warn about C99 declaration after statement
KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)