/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2004 by Jens Arnold * * All files in this archive are subject to the GNU General Public License. * See the file COPYING in the source tree root for full license agreement. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include "config.h" .section .icode,"ax",@progbits .align 2 #if CONFIG_CPU == SH7034 .global _memset .type _memset,@function /* Fills a memory region with specified byte value * This version is optimized for speed * * arguments: * r4 - start address * r5 - data * r6 - length * * return value: * r0 - start address (like ANSI version) * * register usage: * r0 - temporary * r1 - start address +11 for main loop * r4 - start address * r5 - data (spread to all 4 bytes when using long stores) * r6 - current address (runs down from end to start) * * The instruction order below is devised in a way to utilize the pipelining * of the SH1 to the max. The routine fills memory from end to start in * order to utilize the auto-decrementing store instructions. */ _memset: neg r4,r0 and #3,r0 /* r0 = (4 - align_offset) % 4 */ add #4,r0 cmp/hs r0,r6 /* at least one aligned longword to fill? */ add r4,r6 /* r6 = end_address */ bf .no_longs /* no, jump directly to byte loop */ extu.b r5,r5 /* start: spread data to all 4 bytes */ swap.b r5,r0 or r0,r5 /* data now in 2 lower bytes of r5 */ swap.w r5,r0 or r0,r5 /* data now in all 4 bytes of r5 */ mov r6,r0 tst #3,r0 /* r0 already long aligned? */ bt .end_b1 /* yes: skip loop */ /* leading byte loop: sets 0..3 bytes */ .loop_b1: mov.b r5,@-r0 /* store byte */ tst #3,r0 /* r0 long aligned? */ bf .loop_b1 /* runs r0 down until long aligned */ mov r0,r6 /* r6 = last long bound */ nop /* keep alignment */ .end_b1: mov r4,r1 /* r1 = start_address... */ add #11,r1 /* ... + 11, combined for rounding and offset */ xor r1,r0 tst #4,r0 /* bit 2 tells whether an even or odd number of */ bf .loop_odd /* longwords to set */ /* main loop: set 2 longs per pass */ .loop_2l: mov.l r5,@-r6 /* store first long */ .loop_odd: cmp/hi r1,r6 /* runs r6 down to first long bound */ mov.l r5,@-r6 /* store second long */ bt .loop_2l .no_longs: cmp/hi r4,r6 /* any bytes left? */ bf .end_b2 /* no: skip loop */ /* trailing byte loop */ .loop_b2: mov.b r5,@-r6 /* store byte */ cmp/hi r4,r6 /* runs r6 down to the start address */ bt .loop_b2 .end_b2: rts mov r4,r0 /* return start address */ .end: .size _memset,.end-_memset #elif defined(CPU_COLDFIRE) .global memset .type memset,@function /* Fills a memory region with specified byte value * This version is optimized for speed * * arguments: * (4,%sp) - start address * (8,%sp) - data * (12,%sp) - length * * return value: * %d0 - start address (like ANSI version) * * register usage: * %d0 - data (spread to all 4 bytes when using long stores) * %d1 - temporary / data (for burst transfer) * %d2 - data (for burst transfer) * %d3 - data (for burst transfer) * %a0 - start address * %a1 - current address (runs down from end to start) * * For maximum speed this routine uses both long stores and burst mode, * storing whole lines with movem.l. The routine fills memory from end * to start in order to ease returning the start address. */ memset: move.l (4,%sp),%a0 /* start address */ move.l (8,%sp),%d0 /* data */ move.l (12,%sp),%a1 /* length */ add.l %a0,%a1 /* %a1 = end address */ move.l %a0,%d1 addq.l #7,%d1 and.l #0xFFFFFFFC,%d1 /* %d1 = first long bound + 4 */ cmp.l %d1,%a1 /* at least one aligned longword to fill? */ blo.b .no_longs /* no, jump directly to byte loop */ and.l #0xFF,%d0 /* start: spread data to all 4 bytes */ move.l %d0,%d1 lsl.l #8,%d1 or.l %d1,%d0 /* data now in 2 lower bytes of %d0 */ move.l %d0,%d1 swap %d0 or.l %d1,%d0 /* data now in all 4 bytes of %d0 */ move.l %a1,%d1 and.l #0xFFFFFFFC,%d1 /* %d1 = last long bound */ cmp.l %d1,%a1 /* any bytes to set? */ bls.b .end_b1 /* no: skip byte loop */ /* leading byte loop: sets 0..3 bytes */ .loop_b1: move.b %d0,-(%a1) /* store byte */ cmp.l %d1,%a1 /* runs %a1 down to last long bound */ bhi.b .loop_b1 .end_b1: moveq.l #31,%d1 add.l %a0,%d1 and.l #0xFFFFFFF0,%d1 /* %d1 = first line bound + 16 */ cmp.l %d1,%a1 /* at least one full line to fill? */ blo.b .no_lines /* no, jump to longword loop */ mov.l %a1,%d1 and.l #0xFFFFFFF0,%d1 /* %d1 = last line bound */ cmp.l %d1,%a1 /* any longwords to set? */ bls.b .end_l1 /* no: skip longword loop */ /* leading longword loop: sets 0..3 longwords */ .loop_l1: move.l %d0,-(%a1) /* store longword */ cmp.l %d1,%a1 /* runs %a1 down to last line bound */ bhi.b .loop_l1 .end_l1: move.l %d2,-(%sp) /* free some registers */ move.l %d3,-(%sp) move.l %d0,%d1 /* spread data to 4 data registers */ move.l %d0,%d2 move.l %d0,%d3 lea.l (15,%a0),%a0 /* start address += 15, acct. for trl. data */ /* main loop: set whole lines utilising burst mode */ .loop_line: lea.l (-16,%a1),%a1 /* pre-decrement */ movem.l %d0-%d3,(%a1) /* store line */ cmp.l %a0,%a1 /* runs %a1 down to first line bound */ bhi.b .loop_line lea.l (-15,%a0),%a0 /* correct start address */ move.l (%sp)+,%d3 /* restore registers */ move.l (%sp)+,%d2 move.l %a0,%d1 /* %d1 = start address ... */ addq.l #3,%d1 /* ... +3, account for possible trailing bytes */ cmp.l %d1,%a1 /* any longwords left */ bhi.b .loop_l2 /* yes: jump to longword loop */ bra.b .no_longs /* no: skip loop */ .no_lines: move.l %a0,%d1 /* %d1 = start address ... */ addq.l #3,%d1 /* ... +3, account for possible trailing bytes */ /* trailing longword loop */ .loop_l2: move.l %d0,-(%a1) /* store longword */ cmp.l %d1,%a1 /* runs %a1 down to first long bound */ bhi.b .loop_l2 .no_longs: cmp.l %a0,%a1 /* any bytes left? */ bls.b .end_b2 /* no: skip loop */ /* trailing byte loop */ .loop_b2: move.b %d0,-(%a1) /* store byte */ cmp.l %a0,%a1 /* runs %a1 down to start address */ bhi.b .loop_b2 .end_b2: move.l %a0,%d0 /* return start address */ rts .end: .size memset,.end-memset #endif