d89ea9b8bb
I just noted that -mtune is used, which is only supported on recent GCCs; by reading http://gcc.gnu.org/gcc-3.4/changes.html, you see "-mcpu has been renamed to -mtune.", so for GCC < 3.4 we're not using any specific tuning in the appropriate cases. However -mcpu is deprecated, so use -mtune when possible. This was introduced by commit e9d4dce954a60dc23dd1d967766ca2347b780e54 of the old tree (between 2.6.10-rc3 and 2.6.10) by Linus Torvalds, to remove the use of -march, since that could trigger gcc using SSE on its own. But no attention was used about using -mcpu vs. -mtune. And btw, the old 2.6.4 code (for instance) was: cflags-$(CONFIG_MPENTIUMII) += $(call check_gcc,-march=pentium2,-march=i686) cflags-$(CONFIG_MPENTIUMIII) += $(call check_gcc,-march=pentium3,-march=i686) cflags-$(CONFIG_MPENTIUMM) += $(call check_gcc,-march=pentium3,-march=i686) cflags-$(CONFIG_MPENTIUM4) += $(call check_gcc,-march=pentium4,-march=i686) Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
42 lines
2.1 KiB
Makefile
42 lines
2.1 KiB
Makefile
# CPU tuning section - shared with UML.
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# Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML.
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#-mtune exists since gcc 3.4, and some -mcpu flavors didn't exist in gcc 2.95.
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HAS_MTUNE := $(call cc-option-yn, -mtune=i386)
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ifeq ($(HAS_MTUNE),y)
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tune = $(call cc-option,-mtune=$(1),)
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else
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tune = $(call cc-option,-mcpu=$(1),)
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endif
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align := $(cc-option-align)
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cflags-$(CONFIG_M386) += -march=i386
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cflags-$(CONFIG_M486) += -march=i486
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cflags-$(CONFIG_M586) += -march=i586
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cflags-$(CONFIG_M586TSC) += -march=i586
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cflags-$(CONFIG_M586MMX) += $(call cc-option,-march=pentium-mmx,-march=i586)
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cflags-$(CONFIG_M686) += -march=i686
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cflags-$(CONFIG_MPENTIUMII) += -march=i686 $(call tune,pentium2)
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cflags-$(CONFIG_MPENTIUMIII) += -march=i686 $(call tune,pentium3)
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cflags-$(CONFIG_MPENTIUMM) += -march=i686 $(call tune,pentium3)
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cflags-$(CONFIG_MPENTIUM4) += -march=i686 $(call tune,pentium4)
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cflags-$(CONFIG_MK6) += -march=k6
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# Please note, that patches that add -march=athlon-xp and friends are pointless.
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# They make zero difference whatsosever to performance at this time.
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cflags-$(CONFIG_MK7) += $(call cc-option,-march=athlon,-march=i686 $(align)-functions=4)
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cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8,$(call cc-option,-march=athlon,-march=i686 $(align)-functions=4))
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cflags-$(CONFIG_MCRUSOE) += -march=i686 $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
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cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
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cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586)
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cflags-$(CONFIG_MWINCHIP2) += $(call cc-option,-march=winchip2,-march=i586)
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cflags-$(CONFIG_MWINCHIP3D) += $(call cc-option,-march=winchip2,-march=i586)
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cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
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cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686)
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# AMD Elan support
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cflags-$(CONFIG_X86_ELAN) += -march=i486
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# Geode GX1 support
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cflags-$(CONFIG_MGEODEGX1) += $(call cc-option,-march=pentium-mmx,-march=i486)
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