Messages in this thread | | | Date | Mon, 20 Mar 2006 09:25:06 +0200 | From | "Pekka Enberg" <> | Subject | Re: [PATCH]use kzalloc in vfs where appropriate |
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Hi Oliver,
On 3/19/06, Oliver Neukum <oliver@neukum.org> wrote: > Yes it is. The generated code is identical. But on second thought this is still > not optimal. A full division is generated: > > xorl %edx, %edx > movl $2147483647, %eax > movq $0, 40(%rsp) > divq %rcx > movl $8, %edx > cmpq %rax, %rdx > ja .L313 > > Rewriting the test as: > n!=0 && n > INT_MAX / size > saves the division because size is much likelier to be a constant, and indeed > the code is better: > > cmpq $268435455, %rax > movq $0, 40(%rsp) > ja .L313 > > Is there anything I am missing?
Did you check allyesconfig vmlinux size before and after? If it helps, like it probably does, post a patch!
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