[PATCH] uml: reuse i386 cpu-specific tuning
Make UML share the underlying cpu-specific tuning done on i386.
Actually, for now many config options aren't used a lot - but that can be done
later. Also, UML relies on GCC optimization for things like memcpy and such
more than i386, so specifying the correct -march and -mtune should be enough.
Later, we may want to correct some other stuff.
For instance, since FPU context switching, for us, is done (at least
partially, i.e. between our kernelspace and userspace) by the host, we may
allow usage of FPU operations by GCC. This doesn't hold for kernelspace vs.
kernelspace, but we don't support preemption.
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>
2005-10-31 00:00:07 +01:00
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# 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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[PATCH] i386: use -mcpu, not -mtune, for GCCs older than 3.4
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>
2005-10-31 00:00:09 +01:00
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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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[PATCH] uml: reuse i386 cpu-specific tuning
Make UML share the underlying cpu-specific tuning done on i386.
Actually, for now many config options aren't used a lot - but that can be done
later. Also, UML relies on GCC optimization for things like memcpy and such
more than i386, so specifying the correct -march and -mtune should be enough.
Later, we may want to correct some other stuff.
For instance, since FPU context switching, for us, is done (at least
partially, i.e. between our kernelspace and userspace) by the host, we may
allow usage of FPU operations by GCC. This doesn't hold for kernelspace vs.
kernelspace, but we don't support preemption.
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>
2005-10-31 00:00:07 +01:00
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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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[PATCH] i386: use -mcpu, not -mtune, for GCCs older than 3.4
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) += $(call check_gcc,-march=pentium4,-march=i686)
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-31 00:00:09 +01:00
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cflags-$(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 $(call tune,pentium4)
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[PATCH] uml: reuse i386 cpu-specific tuning
Make UML share the underlying cpu-specific tuning done on i386.
Actually, for now many config options aren't used a lot - but that can be done
later. Also, UML relies on GCC optimization for things like memcpy and such
more than i386, so specifying the correct -march and -mtune should be enough.
Later, we may want to correct some other stuff.
For instance, since FPU context switching, for us, is done (at least
partially, i.e. between our kernelspace and userspace) by the host, we may
allow usage of FPU operations by GCC. This doesn't hold for kernelspace vs.
kernelspace, but we don't support preemption.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-31 00:00:07 +01:00
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cflags-$(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 $(align)-loops=0
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[PATCH] i386: use -mcpu, not -mtune, for GCCs older than 3.4
I just noted that -mtune is used, which is only supported on recent GCCs; by
reading http://gcc.gnu.org/gcc-3.4/changes.html, you see "-mcpu has been
renamed to -mtune.", so for GCC < 3.4 we're not using any specific tuning in
the appropriate cases. However -mcpu is deprecated, so use -mtune when
possible.
This was introduced by commit e9d4dce954a60dc23dd1d967766ca2347b780e54 of the
old tree (between 2.6.10-rc3 and 2.6.10) by Linus Torvalds, to remove the use
of -march, since that could trigger gcc using SSE on its own. But no
attention was used about using -mcpu vs. -mtune.
And btw, the old 2.6.4 code (for instance) was:
cflags-$(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) += $(call check_gcc,-march=pentium4,-march=i686)
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-31 00:00:09 +01:00
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cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
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[PATCH] uml: reuse i386 cpu-specific tuning
Make UML share the underlying cpu-specific tuning done on i386.
Actually, for now many config options aren't used a lot - but that can be done
later. Also, UML relies on GCC optimization for things like memcpy and such
more than i386, so specifying the correct -march and -mtune should be enough.
Later, we may want to correct some other stuff.
For instance, since FPU context switching, for us, is done (at least
partially, i.e. between our kernelspace and userspace) by the host, we may
allow usage of FPU operations by GCC. This doesn't hold for kernelspace vs.
kernelspace, but we don't support preemption.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-31 00:00:07 +01:00
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cflags-$(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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