bcec8b0b21
This is from the upstream library commit id 3326535126e435f1ba647885ce43a8f0f3d317eb, corresponding to Chromium 88.0.4290.1.
120 lines
4.5 KiB
ArmAsm
120 lines
4.5 KiB
ArmAsm
@
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@ Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
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@
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@ Use of this source code is governed by a BSD-style license
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@ that can be found in the LICENSE file in the root of the source
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@ tree. An additional intellectual property rights grant can be found
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@ in the file PATENTS. All contributing project authors may
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@ be found in the AUTHORS file in the root of the source tree.
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@
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@ This file contains the function WebRtcSpl_ComplexBitReverse(), optimized
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@ for ARMv5 platforms.
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@ Reference C code is in file complex_bit_reverse.c. Bit-exact.
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#include "rtc_base/system/asm_defines.h"
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GLOBAL_FUNCTION WebRtcSpl_ComplexBitReverse
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.align 2
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DEFINE_FUNCTION WebRtcSpl_ComplexBitReverse
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push {r4-r7}
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cmp r1, #7
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adr r3, index_7 @ Table pointer.
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mov r4, #112 @ Number of interations.
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beq PRE_LOOP_STAGES_7_OR_8
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cmp r1, #8
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adr r3, index_8 @ Table pointer.
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mov r4, #240 @ Number of interations.
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beq PRE_LOOP_STAGES_7_OR_8
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mov r3, #1 @ Initialize m.
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mov r1, r3, asl r1 @ n = 1 << stages;
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subs r6, r1, #1 @ nn = n - 1;
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ble END
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mov r5, r0 @ &complex_data
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mov r4, #0 @ ml
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LOOP_GENERIC:
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rsb r12, r4, r6 @ l > nn - mr
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mov r2, r1 @ n
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LOOP_SHIFT:
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asr r2, #1 @ l >>= 1;
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cmp r2, r12
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bgt LOOP_SHIFT
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sub r12, r2, #1
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and r4, r12, r4
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add r4, r2 @ mr = (mr & (l - 1)) + l;
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cmp r4, r3 @ mr <= m ?
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ble UPDATE_REGISTERS
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mov r12, r4, asl #2
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ldr r7, [r5, #4] @ complex_data[2 * m, 2 * m + 1].
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@ Offset 4 due to m incrementing from 1.
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ldr r2, [r0, r12] @ complex_data[2 * mr, 2 * mr + 1].
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str r7, [r0, r12]
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str r2, [r5, #4]
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UPDATE_REGISTERS:
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add r3, r3, #1
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add r5, #4
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cmp r3, r1
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bne LOOP_GENERIC
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b END
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PRE_LOOP_STAGES_7_OR_8:
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add r4, r3, r4, asl #1
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LOOP_STAGES_7_OR_8:
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ldrsh r2, [r3], #2 @ index[m]
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ldrsh r5, [r3], #2 @ index[m + 1]
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ldr r1, [r0, r2] @ complex_data[index[m], index[m] + 1]
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ldr r12, [r0, r5] @ complex_data[index[m + 1], index[m + 1] + 1]
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cmp r3, r4
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str r1, [r0, r5]
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str r12, [r0, r2]
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bne LOOP_STAGES_7_OR_8
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END:
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pop {r4-r7}
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bx lr
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@ The index tables. Note the values are doubles of the actual indexes for 16-bit
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@ elements, different from the generic C code. It actually provides byte offsets
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@ for the indexes.
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.align 2
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index_7: @ Indexes for stages == 7.
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.short 4, 256, 8, 128, 12, 384, 16, 64, 20, 320, 24, 192, 28, 448, 36, 288
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.short 40, 160, 44, 416, 48, 96, 52, 352, 56, 224, 60, 480, 68, 272, 72, 144
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.short 76, 400, 84, 336, 88, 208, 92, 464, 100, 304, 104, 176, 108, 432, 116
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.short 368, 120, 240, 124, 496, 132, 264, 140, 392, 148, 328, 152, 200, 156
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.short 456, 164, 296, 172, 424, 180, 360, 184, 232, 188, 488, 196, 280, 204
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.short 408, 212, 344, 220, 472, 228, 312, 236, 440, 244, 376, 252, 504, 268
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.short 388, 276, 324, 284, 452, 300, 420, 308, 356, 316, 484, 332, 404, 348
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.short 468, 364, 436, 380, 500, 412, 460, 444, 492
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index_8: @ Indexes for stages == 8.
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.short 4, 512, 8, 256, 12, 768, 16, 128, 20, 640, 24, 384, 28, 896, 32, 64
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.short 36, 576, 40, 320, 44, 832, 48, 192, 52, 704, 56, 448, 60, 960, 68, 544
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.short 72, 288, 76, 800, 80, 160, 84, 672, 88, 416, 92, 928, 100, 608, 104
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.short 352, 108, 864, 112, 224, 116, 736, 120, 480, 124, 992, 132, 528, 136
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.short 272, 140, 784, 148, 656, 152, 400, 156, 912, 164, 592, 168, 336, 172
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.short 848, 176, 208, 180, 720, 184, 464, 188, 976, 196, 560, 200, 304, 204
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.short 816, 212, 688, 216, 432, 220, 944, 228, 624, 232, 368, 236, 880, 244
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.short 752, 248, 496, 252, 1008, 260, 520, 268, 776, 276, 648, 280, 392, 284
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.short 904, 292, 584, 296, 328, 300, 840, 308, 712, 312, 456, 316, 968, 324
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.short 552, 332, 808, 340, 680, 344, 424, 348, 936, 356, 616, 364, 872, 372
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.short 744, 376, 488, 380, 1000, 388, 536, 396, 792, 404, 664, 412, 920, 420
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.short 600, 428, 856, 436, 728, 440, 472, 444, 984, 452, 568, 460, 824, 468
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.short 696, 476, 952, 484, 632, 492, 888, 500, 760, 508, 1016, 524, 772, 532
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.short 644, 540, 900, 548, 580, 556, 836, 564, 708, 572, 964, 588, 804, 596
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.short 676, 604, 932, 620, 868, 628, 740, 636, 996, 652, 788, 668, 916, 684
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.short 852, 692, 724, 700, 980, 716, 820, 732, 948, 748, 884, 764, 1012, 796
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.short 908, 812, 844, 828, 972, 860, 940, 892, 1004, 956, 988
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