Messages in this thread | | | From | Nick Warne <> | Subject | CPU type .config <-> i386/Makefile question[s] | Date | Sun, 5 Jun 2005 14:58:50 +0100 |
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Hello all,
I am still a n00b here learning, so by all means tell me to get lost if what I am about to say is total bollocks...
I was just running through building the new 2.4.31 kernel on my Quake2 box, with looking at building this time with a few optimisations.
I noticed that arch/i386/Makefile uses generic -march= options.
I can have either Pentium-MMX or PentiumPro - But not Pentium2?
From GCC 3.4.x docs:
pentium-mmx Intel PentiumMMX CPU based on Pentium core with MMX instruction set support.
i686, pentiumpro Intel PentiumPro CPU.
pentium2 Intel Pentium2 CPU based on PentiumPro core with MMX instruction set support.
from i386/Makefile:
ifdef CONFIG_M586MMX CFLAGS += -march=i586 endif
ifdef CONFIG_M686 CFLAGS += -march=i686 endif
ifdef CONFIG_MPENTIUMIII CFLAGS += -march=i686 endif
Is there a specific reason why the flags aren't -march=pentium2, pentiumpro etc?
Also I notice that if I changed the top level Makefile to include my specific CPU, then the i386/Makefile adds += -march=i686 to the build lines AFTER CFLAGS~ thus the second one will take precedence (I guess) anyway, and the -march CFLAG changes are basically over-ridden?
Regards,
Nick -- "When you're chewing on life's gristle, Don't grumble, Give a whistle..." - 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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