+######
+# gcc support functions
+# See documentation in Documentation/kbuild/makefiles.txt
+
+# output directory for tests below
+TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/)
+
+# as-option
+# Usage: cflags-y += $(call as-option, -Wa$(comma)-isa=foo,)
+
+as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \
+ -xassembler /dev/null > /dev/null 2>&1; then echo "$(1)"; \
+ else echo "$(2)"; fi ;)
+
+# as-instr
+# Usage: cflags-y += $(call as-instr, instr, option1, option2)
+
+as-instr = $(shell if echo -e "$(1)" | \
+ $(CC) $(AFLAGS) -c -xassembler - \
+ -o $(TMPOUT)astest$$$$.out > /dev/null 2>&1; \
+ then rm $(TMPOUT)astest$$$$.out; echo "$(2)"; \
+ else echo "$(3)"; fi)
+
+# cc-option
+# Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586)
+
+cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
+ > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
+
+# cc-option-yn
+# Usage: flag := $(call cc-option-yn, -march=winchip-c6)
+cc-option-yn = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
+ > /dev/null 2>&1; then echo "y"; else echo "n"; fi;)
+
+# cc-option-align
+# Prefix align with either -falign or -malign
+cc-option-align = $(subst -functions=0,,\
+ $(call cc-option,-falign-functions=0,-malign-functions=0))
+
+# cc-version
+# Usage gcc-ver := $(call cc-version, $(CC))
+cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
+
+# cc-ifversion
+# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
+cc-ifversion = $(shell if [ $(call cc-version, $(CC)) $(1) $(2) ]; then \
+ echo $(3); fi;)
+
+# ld-option
+# Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)
+ld-option = $(shell if $(CC) $(1) -nostdlib -xc /dev/null \
+ -o $(TMPOUT)ldtest$$$$.out > /dev/null 2>&1; \
+ then rm $(TMPOUT)ldtest$$$$.out; echo "$(1)"; \
+ else echo "$(2)"; fi)
+