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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2005-05-03 15:34:58 +1000
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-05-03 07:38:34 -0700
commit52292c9b8c16aa9024a65aaeeca434bb8fec7d24 (patch)
tree59c7aae8cab7c4e1e557dd3a4fff6afbffab38e2
parent6628465e33ca694bd8fd5c3cf4eb7ff9177bc694 (diff)
[PATCH] ppc64: fix gcc 4.0 vs CONFIG_ALTIVEC
gcc-4.0 generates altivec code implicitly when -mcpu indicates an altivec capable CPU which is not suitable for the kernel. However, we used to set -mcpu=970 when CONFIG_ALTIVEC was set because a gcc-3.x bug prevented from using -maltivec along with -mcpu=power4, thus prevented building the RAID6 altivec code. This patch fixes all of this by testing for the gcc version. If 4.0 or later, just normally use -mcpu=power4 and let the RAID6 code add -maltivec to the few files it needs to be compiled with altivec support. For 3.x, we still use -mcpu=970 to work around the above problem, which is fine as 3.x will never implicitly generate altivec code. The Makefile hackery may not be the most lovely, I welcome anybody more skilled than me to improve it. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/ppc64/Makefile7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/ppc64/Makefile b/arch/ppc64/Makefile
index d33e20bcc52..691f3008e69 100644
--- a/arch/ppc64/Makefile
+++ b/arch/ppc64/Makefile
@@ -56,13 +56,20 @@ LDFLAGS_vmlinux := -Bstatic -e $(KERNELLOAD) -Ttext $(KERNELLOAD)
CFLAGS += -msoft-float -pipe -mminimal-toc -mtraceback=none \
-mcall-aixdesc
+GCC_VERSION := $(call cc-version)
+GCC_BROKEN_VEC := $(shell if [ $(GCC_VERSION) -lt 0400 ] ; then echo "y"; fi ;)
+
ifeq ($(CONFIG_POWER4_ONLY),y)
ifeq ($(CONFIG_ALTIVEC),y)
+ifeq ($(GCC_BROKEN_VEC),y)
CFLAGS += $(call cc-option,-mcpu=970)
else
CFLAGS += $(call cc-option,-mcpu=power4)
endif
else
+ CFLAGS += $(call cc-option,-mcpu=power4)
+endif
+else
CFLAGS += $(call cc-option,-mtune=power4)
endif