Commit b4652239 authored May 17, 2007 by Linus Torvalds

Revert "[PATCH] x86: Drop cc-options call for all options supported in gcc 3.2+"



This reverts commit c8fdd247.

It turns out the kernel was correct, and the gcc complaint was a gcc
bug.  The preferred stack boundary is expressed not in bytes, but in the
the log2() of the preferred boundary, so "-mpreferred-stack-boundary=2"
is in fact exactly what we want, but a gcc that is compiled for x86-64
will consider it an error (because the 64-bit calling sequence says that
the stack should be 16-byte aligned) even if we are then using "-m32" to
generate 32-bit code.

Noted-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Jan Hubicka <jh@suse.cz>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b42895d6

Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -491,7 +491,7 @@ endif
		include $(srctree)/arch/$(ARCH)/Makefile

		ifdef CONFIG_FRAME_POINTER
		CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
		CFLAGS += -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
		else
		CFLAGS += -fomit-frame-pointer
		endif

arch/i386/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -34,7 +34,7 @@ CHECKFLAGS += -D__i386__
		CFLAGS += -pipe -msoft-float -mregparm=3 -freg-struct-return

		# prevent gcc from keeping the stack 16 byte aligned
		CFLAGS += -mpreferred-stack-boundary=4
		CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)

		# CPU-specific tuning. Anything which can be shared with UML should go here.
		include $(srctree)/arch/i386/Makefile.cpu

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