1b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ 2b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. 3b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ 4b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ Use of this source code is governed by a BSD-style license 5b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ that can be found in the LICENSE file in the root of the source 6b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ tree. An additional intellectual property rights grant can be found 7b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ in the file PATENTS. All contributing project authors may 8b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ be found in the AUTHORS file in the root of the source tree. 9b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ 10b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 11b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ This file contains the function WebRtcSpl_ComplexBitReverse(), optimized 12b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ for ARMv5 platforms. 13b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ Reference C code is in file complex_bit_reverse.c. Bit-exact. 14b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 15b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org#include "webrtc/system_wrappers/interface/asm_defines.h" 16b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 17b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.orgGLOBAL_FUNCTION WebRtcSpl_ComplexBitReverse 18b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org.align 2 19b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.orgDEFINE_FUNCTION WebRtcSpl_ComplexBitReverse 20b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org push {r4-r7} 21b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 22b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org cmp r1, #7 23b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org adr r3, index_7 @ Table pointer. 24b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org mov r4, #112 @ Number of interations. 25b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org beq PRE_LOOP_STAGES_7_OR_8 26b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 27b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org cmp r1, #8 28b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org adr r3, index_8 @ Table pointer. 29b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org mov r4, #240 @ Number of interations. 30b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org beq PRE_LOOP_STAGES_7_OR_8 31b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 32b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org mov r3, #1 @ Initialize m. 33b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org mov r1, r3, asl r1 @ n = 1 << stages; 34b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org subs r6, r1, #1 @ nn = n - 1; 35b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ble END 36b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org mov r5, r0 @ &complex_data 38b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org mov r4, #0 @ ml 39b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 40b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgLOOP_GENERIC: 41b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org rsb r12, r4, r6 @ l > nn - mr 42b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org mov r2, r1 @ n 43b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 44b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgLOOP_SHIFT: 45b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org asr r2, #1 @ l >>= 1; 46b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org cmp r2, r12 47b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org bgt LOOP_SHIFT 48b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 49b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org sub r12, r2, #1 50b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org and r4, r12, r4 51b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org add r4, r2 @ mr = (mr & (l - 1)) + l; 52b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org cmp r4, r3 @ mr <= m ? 53b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ble UPDATE_REGISTERS 54b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 55b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org mov r12, r4, asl #2 56b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ldr r7, [r5, #4] @ complex_data[2 * m, 2 * m + 1]. 57b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org @ Offset 4 due to m incrementing from 1. 58b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ldr r2, [r0, r12] @ complex_data[2 * mr, 2 * mr + 1]. 59b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org str r7, [r0, r12] 60b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org str r2, [r5, #4] 61b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 62b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgUPDATE_REGISTERS: 63b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org add r3, r3, #1 64b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org add r5, #4 65b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org cmp r3, r1 66b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org bne LOOP_GENERIC 67b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 68b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org b END 69b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 70b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgPRE_LOOP_STAGES_7_OR_8: 71b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org add r4, r3, r4, asl #1 72b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 73b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgLOOP_STAGES_7_OR_8: 74b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ldrsh r2, [r3], #2 @ index[m] 75b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ldrsh r5, [r3], #2 @ index[m + 1] 76b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ldr r1, [r0, r2] @ complex_data[index[m], index[m] + 1] 77b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ldr r12, [r0, r5] @ complex_data[index[m + 1], index[m + 1] + 1] 78b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org cmp r3, r4 79b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org str r1, [r0, r5] 80b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org str r12, [r0, r2] 81b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org bne LOOP_STAGES_7_OR_8 82b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 83b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgEND: 84b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org pop {r4-r7} 85b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org bx lr 86b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 87b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ The index tables. Note the values are doubles of the actual indexes for 16-bit 88b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ elements, different from the generic C code. It actually provides byte offsets 89b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org@ for the indexes. 90b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 91b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org.align 2 92b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgindex_7: @ Indexes for stages == 7. 93b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 4, 256, 8, 128, 12, 384, 16, 64, 20, 320, 24, 192, 28, 448, 36, 288 94b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 40, 160, 44, 416, 48, 96, 52, 352, 56, 224, 60, 480, 68, 272, 72, 144 95b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 76, 400, 84, 336, 88, 208, 92, 464, 100, 304, 104, 176, 108, 432, 116 96b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 368, 120, 240, 124, 496, 132, 264, 140, 392, 148, 328, 152, 200, 156 97b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 456, 164, 296, 172, 424, 180, 360, 184, 232, 188, 488, 196, 280, 204 98b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 408, 212, 344, 220, 472, 228, 312, 236, 440, 244, 376, 252, 504, 268 99b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 388, 276, 324, 284, 452, 300, 420, 308, 356, 316, 484, 332, 404, 348 100b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 468, 364, 436, 380, 500, 412, 460, 444, 492 101b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 102b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgindex_8: @ Indexes for stages == 8. 103b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 4, 512, 8, 256, 12, 768, 16, 128, 20, 640, 24, 384, 28, 896, 32, 64 104b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 36, 576, 40, 320, 44, 832, 48, 192, 52, 704, 56, 448, 60, 960, 68, 544 105b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 72, 288, 76, 800, 80, 160, 84, 672, 88, 416, 92, 928, 100, 608, 104 106b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 352, 108, 864, 112, 224, 116, 736, 120, 480, 124, 992, 132, 528, 136 107b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 272, 140, 784, 148, 656, 152, 400, 156, 912, 164, 592, 168, 336, 172 108b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 848, 176, 208, 180, 720, 184, 464, 188, 976, 196, 560, 200, 304, 204 109b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 816, 212, 688, 216, 432, 220, 944, 228, 624, 232, 368, 236, 880, 244 110b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 752, 248, 496, 252, 1008, 260, 520, 268, 776, 276, 648, 280, 392, 284 111b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 904, 292, 584, 296, 328, 300, 840, 308, 712, 312, 456, 316, 968, 324 112b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 552, 332, 808, 340, 680, 344, 424, 348, 936, 356, 616, 364, 872, 372 113b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 744, 376, 488, 380, 1000, 388, 536, 396, 792, 404, 664, 412, 920, 420 114b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 600, 428, 856, 436, 728, 440, 472, 444, 984, 452, 568, 460, 824, 468 115b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 696, 476, 952, 484, 632, 492, 888, 500, 760, 508, 1016, 524, 772, 532 116b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 644, 540, 900, 548, 580, 556, 836, 564, 708, 572, 964, 588, 804, 596 117b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 676, 604, 932, 620, 868, 628, 740, 636, 996, 652, 788, 668, 916, 684 118b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 852, 692, 724, 700, 980, 716, 820, 732, 948, 748, 884, 764, 1012, 796 119b238acaca55b4b345f0e37b82f8bbd9851c8bb6dkma@webrtc.org .short 908, 812, 844, 828, 972, 860, 940, 892, 1004, 956, 988 120