Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH 1/2] rtlwifi: Fix improve function 'rtl_addr_delay()' in core.c | Date | Thu, 4 Feb 2016 09:48:34 +0000 |
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From: Larry Finger > Sent: 03 February 2016 19:45 ... > The performance will depend on where you satisfy the condition. All switch cases > have the same execution time, but in the if .. else if .. else form, the earlier > tests execute more quickly. I'm not sure that one can make any blanket statement > about performance. Certainly, the switch version will be larger. For a switch > with 8 cases plus default, the object code if 43 bytes larger than the nested > ifs in a test program that I created. That is a significant penalty.
There is also the penalty of the (likely) data cache miss reading the jump table. But given this code is all about generating a variable delay the execution speed is probably irrelevant.
It would be much more interesting if the delay could be changed for sleeps.
David
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