On 12/06/2013 07:39 AM, Peter Chen wrote: > On Thu, Dec 05, 2013 at 12:32:55PM +0100, Marc Kleine-Budde wrote: >> Hello Peter, >> >> these patches are for your ci-for-usb-next branch. The repmap handling is >> streamlined and the kernel shrinks by 706 bytes on i.MX28: >> >> add/remove: 0/0 grow/shrink: 0/30 up/down: 0/-706 (-706) >> function old new delta >> hw_wait_reg 164 160 -4 >> hw_port_test_get 24 20 -4 >> hw_ep_flush 132 128 -4 >> ep_enable 392 388 -4 >> ep_disable 252 248 -4 >> ci_otg_work 248 244 -4 >> ci_otg_role 24 20 -4 >> ci_hdrc_host_init 148 144 -4 >> ci_hdrc_gadget_init 736 732 -4 >> ci_handle_vbus_change 92 88 -4 >> isr_setup_status_complete 156 148 -8 >> hw_port_test_set 64 56 -8 >> host_start 360 352 -8 >> ci_udc_pullup 84 76 -8 >> ci_hdrc_remove 100 92 -8 >> ci_udc_wakeup 172 160 -12 >> udc_id_switch_for_host 76 60 -16 >> udc_id_switch_for_device 80 64 -16 >> ci_hdrc_otg_destroy 92 76 -16 >> ci_hdrc_enter_lpm 204 188 -16 >> ci_irq 264 244 -20 >> hw_device_state 120 96 -24 >> _ep_queue.isra 1056 1028 -28 >> ci_regs_nolpm 76 19 -57 >> ci_regs_lpm 76 19 -57 >> hw_device_reset 416 352 -64 >> ep_set_halt 500 436 -64 >> hw_alloc_regmap 204 136 -68 >> ci_hdrc_probe 1512 1444 -68 >> udc_irq 3236 3136 -100 >> > > Hi Marc, > > Thanks for doing that, would you explain more why the function > code size can be smaller with your two patches? In the functions one instruction (4 Bytes) is saved per register access. When the array is embedded into the hw_bank there is one indirection less: For example, the original code: 870: e591301c ldr r3, [r1, #28] 874: e593302c ldr r3, [r3, #44] ; 0x2c 878: e5932000 ldr r2, [r3] 87c: e5d13030 ldrb r3, [r1, #48] ; 0x30 With my first patch applied: 7d8: e5913048 ldr r3, [r1, #72] ; 0x48 7dc: e5932000 ldr r2, [r3] 7e0: e5d130b4 ldrb r3, [r1, #180] ; 0xb4 With the second patch applied, we save some mem in ci_regs_nolpm and ci_regs_lpm, because an entry only takes 1 Byte instead of 4. Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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