summaryrefslogtreecommitdiff
path: root/platform/CMSIS/DSP_Lib/Source/TransformFunctions/arm_bitreversal2.S
blob: 7211d0f496fc390f68470a169f7051f58ffcd7e8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
;/* ----------------------------------------------------------------------
;* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
;*
;* $Date:       12. March 2014
;* $Revision: 	V1.4.4
;*
;* Project: 	CMSIS DSP Library
;* Title:	    arm_bitreversal2.S
;*
;* Description:	This is the arm_bitreversal_32 function done in
;*              assembly for maximum speed.  This function is called
;*              after doing an fft to reorder the output.  The function
;*              is loop unrolled by 2. arm_bitreversal_16 as well.
;*
;* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
;*
;* Redistribution and use in source and binary forms, with or without
;* modification, are permitted provided that the following conditions
;* are met:
;*   - Redistributions of source code must retain the above copyright
;*     notice, this list of conditions and the following disclaimer.
;*   - Redistributions in binary form must reproduce the above copyright
;*     notice, this list of conditions and the following disclaimer in
;*     the documentation and/or other materials provided with the
;*     distribution.
;*   - Neither the name of ARM LIMITED nor the names of its contributors
;*     may be used to endorse or promote products derived from this
;*     software without specific prior written permission.
;*
;* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
;* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
;* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
;* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
;* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
;* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
;* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
;* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
;* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
;* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
;* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
;* POSSIBILITY OF SUCH DAMAGE.
;* -------------------------------------------------------------------- */
#if defined(__CC_ARM)       // Keil
    #define CODESECT AREA     ||.text||, CODE, READONLY, ALIGN=2
    #define LABEL
#elif defined(__IASMARM__)  // IAR
    #define CODESECT SECTION `.text`:CODE
    #define PROC
    #define LABEL
    #define ENDP
    #define EXPORT PUBLIC
#elif defined(__CSMC__)		/* Cosmic */
	#define	CODESECT	switch .text
	#define THUMB
	#define EXPORT	xdef
	#define PROC	:
	#define LABEL	:
	#define ENDP
	#define arm_bitreversal_32 _arm_bitreversal_32
#elif defined (__GNUC__)    // GCC
    #define THUMB .thumb
    #define CODESECT .section .text
    #define EXPORT .global
    #define PROC :
    #define LABEL :
    #define ENDP
    #define END

    .syntax unified
#endif

	CODESECT
	THUMB

;/*
;* @brief  In-place bit reversal function.
;* @param[in, out] *pSrc        points to the in-place buffer of unknown 32-bit data type.
;* @param[in]      bitRevLen    bit reversal table length
;* @param[in]      *pBitRevTab  points to bit reversal table.
;* @return none.
;*/
	EXPORT arm_bitreversal_32
	EXPORT arm_bitreversal_16

#if defined(ARM_MATH_CM0) || defined(ARM_MATH_CM0PLUS)

arm_bitreversal_32 PROC
	ADDS     r3,r1,#1
	PUSH     {r4-r6}
	ADDS     r1,r2,#0
	LSRS     r3,r3,#1
arm_bitreversal_32_0 LABEL
	LDRH     r2,[r1,#2]
	LDRH     r6,[r1,#0]
	ADD      r2,r0,r2
	ADD      r6,r0,r6
	LDR      r5,[r2,#0]
	LDR      r4,[r6,#0]
	STR      r5,[r6,#0]
	STR      r4,[r2,#0]
	LDR      r5,[r2,#4]
	LDR      r4,[r6,#4]
	STR      r5,[r6,#4]
	STR      r4,[r2,#4]
	ADDS     r1,r1,#4
	SUBS     r3,r3,#1
	BNE      arm_bitreversal_32_0
	POP      {r4-r6}
	BX       lr
	ENDP

arm_bitreversal_16 PROC
	ADDS     r3,r1,#1
	PUSH     {r4-r6}
	ADDS     r1,r2,#0
	LSRS     r3,r3,#1
arm_bitreversal_16_0 LABEL
	LDRH     r2,[r1,#2]
	LDRH     r6,[r1,#0]
    LSRS     r2,r2,#1
    LSRS     r6,r6,#1
	ADD      r2,r0,r2
	ADD      r6,r0,r6
	LDR      r5,[r2,#0]
	LDR      r4,[r6,#0]
	STR      r5,[r6,#0]
	STR      r4,[r2,#0]
	ADDS     r1,r1,#4
	SUBS     r3,r3,#1
	BNE      arm_bitreversal_16_0
	POP      {r4-r6}
	BX       lr
	ENDP

#else

arm_bitreversal_32 PROC
	ADDS     r3,r1,#1
	CMP      r3,#1
	IT       LS
	BXLS     lr
	PUSH     {r4-r9}
	ADDS     r1,r2,#2
	LSRS     r3,r3,#2
arm_bitreversal_32_0 LABEL       ;/* loop unrolled by 2 */
	LDRH     r8,[r1,#4]
	LDRH     r9,[r1,#2]
	LDRH     r2,[r1,#0]
	LDRH     r12,[r1,#-2]
	ADD      r8,r0,r8
	ADD      r9,r0,r9
	ADD      r2,r0,r2
	ADD      r12,r0,r12
	LDR      r7,[r9,#0]
	LDR      r6,[r8,#0]
	LDR      r5,[r2,#0]
	LDR      r4,[r12,#0]
	STR      r6,[r9,#0]
	STR      r7,[r8,#0]
	STR      r5,[r12,#0]
	STR      r4,[r2,#0]
	LDR      r7,[r9,#4]
	LDR      r6,[r8,#4]
	LDR      r5,[r2,#4]
	LDR      r4,[r12,#4]
	STR      r6,[r9,#4]
	STR      r7,[r8,#4]
	STR      r5,[r12,#4]
	STR      r4,[r2,#4]
	ADDS     r1,r1,#8
	SUBS     r3,r3,#1
	BNE      arm_bitreversal_32_0
	POP      {r4-r9}
	BX       lr
	ENDP

arm_bitreversal_16 PROC
	ADDS     r3,r1,#1
	CMP      r3,#1
	IT       LS
	BXLS     lr
	PUSH     {r4-r9}
	ADDS     r1,r2,#2
	LSRS     r3,r3,#2
arm_bitreversal_16_0 LABEL       ;/* loop unrolled by 2 */
	LDRH     r8,[r1,#4]
	LDRH     r9,[r1,#2]
	LDRH     r2,[r1,#0]
	LDRH     r12,[r1,#-2]
	ADD      r8,r0,r8,LSR #1
	ADD      r9,r0,r9,LSR #1
	ADD      r2,r0,r2,LSR #1
	ADD      r12,r0,r12,LSR #1
	LDR      r7,[r9,#0]
	LDR      r6,[r8,#0]
	LDR      r5,[r2,#0]
	LDR      r4,[r12,#0]
	STR      r6,[r9,#0]
	STR      r7,[r8,#0]
	STR      r5,[r12,#0]
	STR      r4,[r2,#0]
	ADDS     r1,r1,#8
	SUBS     r3,r3,#1
	BNE      arm_bitreversal_16_0
	POP      {r4-r9}
	BX       lr
	ENDP

#endif

	END