I agree for tx desc, the compiler would optimize. But for rx (status) desc, I didn't like multiple le64_to_cpu() for extracting various fields out of same status dword.
-Dhananjay On Wed, 26 Dec 2007, Al Viro wrote: > On Wed, Dec 26, 2007 at 10:23:59AM -0800, [EMAIL PROTECTED] wrote: > > This cleans up some unnecessary byte-swapping while setting up tx and > > interpreting rx desc. The 64 bit rx status data should be converted > > to host endian format only once and the macros just need to extract > > bitfields. > > > - (cmd_desc)->flags_opcode |= cpu_to_le16((val) & 0x7f)) > > + ((cmd_desc)->flags_opcode &= ~(0x7f), \ > > + (cmd_desc)->flags_opcode |= (val) & 0x7f) > > #define netxen_set_cmd_desc_opcode(cmd_desc, val) \ > > - ((cmd_desc)->flags_opcode &= ~cpu_to_le16(0x3f<<7), \ > > - (cmd_desc)->flags_opcode |= cpu_to_le16(((val & 0x3f)<<7))) > > + ((cmd_desc)->flags_opcode &= ~(0x3f<<7), \ > > + (cmd_desc)->flags_opcode |= ((val) & 0x3f) << 7) > > _oh_? > > That's actually a pessimisation and I'd rather see that conversion in > place gone - the thing will be less brittle that way. > > BTW, note that cpu_to_le16() et.al. get evaluated by compiler when the > argument is constant. > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
