The last kernel to work for me on alpha was 2.6.14-rc3. Using the same .config 
as I used with 2.6.14-rc3 the compilation of 2.6.14 fails with   
  
  LD      .tmp_vmlinux1  
net/built-in.o(.text+0x552a0): In function `raw_rcv_skb':  
include/asm/atomic.h:145: undefined reference to `barrier'  
net/built-in.o(.text+0x552a4):include/asm/atomic.h:145: undefined reference to  
`barrier'  
net/built-in.o(.text+0x552c4):include/asm/atomic.h:157: undefined reference to  
`barrier'  
net/built-in.o(.text+0x552c8):include/asm/atomic.h:157: undefined reference to  
`barrier'  
net/built-in.o(.text+0x5539c): In function `raw_rcv':  
include/asm/atomic.h:145: undefined reference to `barrier'  
net/built-in.o(.text+0x553a0):include/asm/atomic.h:145: more undefined  
references to `barrier' follow  
make: *** [.tmp_vmlinux1] Error 1  
  
barrier is defined in linux/compiler.h  
asm-alpha/compile.h includes linux/compiler.h  
  
I added #include <asm/compiler.h> to asm-alpha/atomic.h. The kernel now  
compiles. The alpha also boots as expected.