1 @ Tremolo library 2 @----------------------------------------------------------------------- 3 @ Copyright (C) 2002-2009, Xiph.org Foundation 4 @ Copyright (C) 2010, Robin Watts for Pinknoise Productions Ltd 5 @ All rights reserved. 6 7 @ Redistribution and use in source and binary forms, with or without 8 @ modification, are permitted provided that the following conditions 9 @ are met: 10 11 @ * Redistributions of source code must retain the above copyright 12 @ notice, this list of conditions and the following disclaimer. 13 @ * Redistributions in binary form must reproduce the above 14 @ copyright notice, this list of conditions and the following disclaimer 15 @ in the documentation and/or other materials provided with the 16 @ distribution. 17 @ * Neither the names of the Xiph.org Foundation nor Pinknoise 18 @ Productions Ltd nor the names of its contributors may be used to 19 @ endorse or promote products derived from this software without 20 @ specific prior written permission. 21 @ 22 @ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 @ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 @ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 25 @ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 26 @ OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 27 @ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 28 @ LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 @ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 @ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 @ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 32 @ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 @ ---------------------------------------------------------------------- 34 35 .text 36 37 .global render_lineARM 38 39 render_lineARM: 40 @ r0 = n 41 @ r1 = d 42 @ r2 = floor 43 @ r3 = base 44 @ <> = err 45 @ <> = adx 46 @ <> = ady 47 MOV r12,r13 48 STMFD r13!,{r4-r6,r11,r14} 49 LDMFD r12,{r11,r12,r14} @ r11 = err 50 @ r12 = adx 51 @ r14 = ady 52 rl_loop: 53 LDR r4,[r1] @ r4 = *d 54 LDR r5,[r2],r3,LSL #2 @ r5 = *floor r2 = floor+base 55 SUBS r11,r11,r14 @ err -= ady 56 ADDLT r11,r11,r12 @ if (err < 0) err+=adx 57 SMULL r6, r5, r4, r5 @ (r6,r5) = *d * *floor 58 ADDLT r2, r2, #4 @ floor+=1 59 MOVS r6, r6, LSR #15 60 ADC r5, r6, r5, LSL #17 @ r5 = MULT31_SHIFT15 61 STR r5,[r1],#4 62 SUBS r0, r0, #1 63 BGT rl_loop 64 65 LDMFD r13!,{r4-r6,r11,PC} 66 67 @ END 68
