vq_cortexm3.s

基于 STM32 PCM语音编/解码代码

  
  SECTION .text:CODE(2)
  
  EXPORT vq_nbest

#define t          r0
#define resp2      r1
#define E          r2

#define dist       r3

#define E_k        r4

#define t_0        r4
#define t_1        r5
#define t_2        r4
#define t_3        r5
#define t_4        r4
#define t_5        r5
#define t_6        r4
#define t_7        r5
#define t_8        r4
#define t_9        r5

#define codebook_1   r7
#define codebook_2   r8

#define best_index r10
#define best_dist  lr

#define k          r6





vq_nbest

	PUSH   {r4-r10,lr}
	MOV    k, #0x00 ; 32
	LDR    E, [sp, #32]
Loop
		
	LDRSH  codebook_1, [resp2], #2
	LDRSH  codebook_2, [resp2], #2
	LDRSH  t_0, [t, #0x0]
	LDRSH  t_1, [t, #0x2]	
	MUL    dist, t_0, codebook_1	
        MLA    dist, t_1, codebook_2, dist

	LDRSH  codebook_1, [resp2], #2
	LDRSH  t_2, [t, #0x4]
	LDRSH  codebook_2, [resp2], #2
	LDRSH  t_3, [t, #0x6]    
	MLA    dist, t_2, codebook_1, dist
	MLA    dist, t_3, codebook_2, dist

	LDRSH  codebook_1, [resp2], #2
	LDRSH  t_4, [t, #0x8]   
	LDRSH  codebook_2, [resp2], #2
	LDRSH  t_5, [t, #0xA]
        MLA    dist, t_4, codebook_1, dist
	MLA    dist, t_5, codebook_2, dist

	LDRSH  codebook_1, [resp2], #2
	LDRSH  t_6, [t, #0xC]
        LDRSH  codebook_2, [resp2], #2
	LDRSH  t_7, [t, #0xE]
	MLA    dist, t_6, codebook_1, dist
        MLA    dist, t_7, codebook_2, dist

	LDRSH  codebook_1, [resp2], #2
	LDRSH  t_8, [t, #0x10]    
	LDRSH  codebook_2, [resp2], #2
	LDRSH  t_9, [t, #0x12]
        MLA    dist, t_8, codebook_1, dist
	MLA    dist, t_9, codebook_2, dist
	
	LDR    E_k, [E], #4
	RSB    dist, dist, E_k, ASR #1

	CMP      k,#0x01
	ITEE     GE
	CMPGE    dist, best_dist
	MOVLT    best_dist, dist
	MOVLT    best_index, k
	 
        ADDS  k, k, #1
	CMP   k, #0x20
	BLT   Loop

        LDR   dist, [sp,#40]
	STR   best_index, [dist]
	LDR   dist, [sp,#44]
	STR   best_dist, [dist]

	POP   {r4-r10,pc}

   END