Compiler Fedora9 Kernel issue

willylinux · 11-17-2008, 09:52 PM

Dear All:
I compiler Kernel in the Fedora9 O.S,but I got undefined reference to `__umoddi3'
,this error message

and I search google,I edit Makefile file as below:

CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -fno-common

change to：

CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -fno-common \
-fno-tree-scev-cprop

and then I recompiler kernel again,It is working,

So anybody can tell me why???,it is recompiler working

thanks a lot

Mara · 11-18-2008, 04:39 PM

As the archives say, in this case gcc changed a loop into a division (original: loop with substraction), while the code that makes the actual division wasn't delivered. With the added option, the compiler is forces to use a loop.

Not a very elegant solution, but works until it if fixed in either gcc or the kernel.