openwrtv4/target/linux/generic/patches-2.6.37/012-extra_optimization.patch
Felix Fietkau b2b0770576 kernel: use -fno-caller-saves
SVN-Revision: 26301
2011-03-26 01:07:16 +00:00

24 lines
647 B
Diff

--- a/Makefile
+++ b/Makefile
@@ -538,9 +538,9 @@
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 @@
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,)