Messages in this thread | | | Subject | Re: [PATCH] [2/58] x86_64: Tell gcc to only align stack to 8 bytes | From | Serge Belyshev <> | Date | Thu, 19 Jul 2007 15:50:20 +0400 |
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Andi Kleen <ak@suse.de> writes:
> Don't need 16 byte alignment because kernel doesn't use SSE2 > ... > cflags-y += -maccumulate-outgoing-args > +cflags-y += -mpreferred-stack-boundary=4 >
From gcc manpage:
-mpreferred-stack-boundary=num Attempt to keep the stack boundary aligned to a 2 raised to num byte boundary. If -mpreferred-stack-boundary is not specified, the default is 4 (16 bytes or 128 bits), except when optimizing for code size (-Os), in which case the default is the minimum correct alignment (4 bytes for x86, and 8 bytes for x86-64).
So -mpreferred-stack-boundary=4 is the default and to align stack to 8 bytes you want -mpreferred-stack-boundary=3, not 4, IIUC. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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