rt-thread/bsp/stm32_radio/libwma/mdct_arm.S

cPI3_8 EQU 0x30fbc54d
cPI2_8 EQU 0x5a82799a
cPI1_8 EQU 0x7641af3d

	AREA |.text|, CODE, READONLY, ALIGN=2
	THUMB
	REQUIRE8
	PRESERVE8

mdct_butterfly_8	PROC
    add     r9,  r5,  r1                ; x4 + x0
    sub     r5,  r5,  r1                ; x4 - x0
    add     r7,  r6,  r2                ; x5 + x1
    sub     r6,  r6,  r2                ; x5 - x1
    add     r8,  r10, r3                ; x6 + x2
    sub     r10, r10, r3                ; x6 - x2
    add     r12, r11, r4                ; x7 + x3
    sub     r11, r11, r4                ; x7 - x3

    add     r1,  r10, r6                ; y0 = (x6 - x2) + (x5 - x1)
    sub     r2,  r11, r5                ; y1 = (x7 - x3) - (x4 - x0)
    sub     r3,  r10, r6                ; y2 = (x6 - x2) - (x5 - x1)
    add     r4,  r11, r5                ; y3 = (x7 - x3) + (x4 - x0)
    sub     r5,  r8,  r9                ; y4 = (x6 + x2) - (x4 + x0)
    sub     r6,  r12, r7                ; y5 = (x7 + x3) - (x5 + x1)
    add     r10, r8,  r9                ; y6 = (x6 + x2) + (x4 + x0)
    add     r11, r12, r7                ; y7 = (x7 + x3) + (x5 + x1)
    stmia   r0, {r1, r2, r3, r4, r5, r6, r10, r11}

	bx		lr
	
	ENDP

mdct_butterfly_16	PROC
    str     lr, [sp, #-4]!
    add     r1, r0, #8*4

    ldmia   r0, {r2, r3, r4, r5}
    ldmia   r1, {r6, r7, r8, r9}
    add     r6, r6, r2                  ; y8 = x8 + x0
    rsb     r2, r6, r2, lsl #1          ; x0 - x8
    add     r7, r7, r3                  ; y9 = x9 + x1
    rsb     r3, r7, r3, lsl #1          ; x1 - x9
    add     r8, r8, r4                  ; y10 = x10 + x2
    sub     r11, r8, r4, lsl #1         ; x10 - x2
    add     r9, r9, r5                  ; y11 = x11 + x3
    rsb     r10, r9, r5, lsl #1         ; x3 - x11

    stmia   r1!, {r6, r7, r8, r9}

    add     r2, r2, r3                  ; (x0 - x8) + (x1 - x9)
    rsb     r3, r2, r3, lsl #1          ; (x1 - x9) - (x0 - x8)

    ldr     r12, =cPI2_8
    smull   r8, r5, r12, r2
    smull   r8, r6, r12, r3
    mov     r5, r5, lsl #1
    mov     r6, r6, lsl #1

    stmia   r0!, {r5, r6, r10, r11}

    ldmia   r0, {r2, r3, r4, r5}
    ldmia   r1, {r6, r7, r8, r9}
    add     r6, r6, r2                  ; y12 = x12 + x4
    sub     r2, r6, r2, lsl #1          ; x12 - x4
    add     r7, r7, r3                  ; y13 = x13 + x5
    sub     r3, r7, r3, lsl #1          ; x13 - x5
    add     r8, r8, r4                  ; y10 = x14 + x6
    sub     r10, r8, r4, lsl #1         ; x14 - x6
    add     r9, r9, r5                  ; y11 = x15 + x7
    sub     r11, r9, r5, lsl #1         ; x15 - x7

    stmia   r1, {r6, r7, r8, r9}

    sub     r2, r2, r3                  ; (x12 - x4) - (x13 - x5)
    add     r3, r2, r3, lsl #1          ; (x12 - x4) + (x13 - x5)

    smull   r8, r5, r12, r2
    smull   r8, r6, r12, r3
    mov     r5, r5, lsl #1
    mov     r6, r6, lsl #1
    ; no stmia here, r5, r6, r10, r11 are passed to mdct_butterfly_8

    sub     r0, r0, #4*4
    ldmia   r0, {r1, r2, r3, r4}
    bl      mdct_butterfly_8
    add     r0, r0, #8*4
    ldmia   r0, {r1, r2, r3, r4, r5, r6, r10, r11}
    bl      mdct_butterfly_8

    ldr     pc, [sp], #4

	ENDP

mdct_butterfly_32	PROC
	EXPORT mdct_butterfly_32

    stmdb   sp!, {r4-r11, lr}

    add     r1, r0, #16*4

    ldmia   r0, {r2, r3, r4, r5}
    ldmia   r1, {r6, r7, r8, r9}
    add     r6, r6, r2                  ; y16 = x16 + x0
    rsb     r2, r6, r2, lsl #1          ; x0 - x16
    add     r7, r7, r3                  ; y17 = x17 + x1
    rsb     r3, r7, r3, lsl #1          ; x1 - x17
    add     r8, r8, r4                  ; y18 = x18 + x2
    rsb     r4, r8, r4, lsl #1          ; x2 - x18
    add     r9, r9, r5                  ; y19 = x19 + x3
    rsb     r5, r9, r5, lsl #1          ; x3 - x19

    stmia   r1!, {r6, r7, r8, r9}

    ldr     r12, =cPI1_8
    ldr     lr, =cPI3_8
    smull   r10, r6, r12, r2
    rsb     r2, r2, #0
    smlal   r10, r6, lr, r3
    smull   r10, r7, r12, r3
    smlal   r10, r7, lr, r2
    mov     r6, r6, lsl #1
    mov     r7, r7, lsl #1

    add     r4, r4, r5                  ; (x3 - x19) + (x2 - x18)
    rsb     r5, r4, r5, lsl #1          ; (x3 - x19) - (x2 - x18)

    ldr     r11, =cPI2_8
    smull   r10, r8, r4, r11
    smull   r10, r9, r5, r11
    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1

    stmia   r0!, {r6, r7, r8, r9}

    ldmia   r0, {r2, r3, r4, r5}
    ldmia   r1, {r6, r7, r8, r9}
    add     r6, r6, r2                  ; y20 = x20 + x4
    rsb     r2, r6, r2, lsl #1          ; x4 - x20
    add     r7, r7, r3                  ; y21 = x21 + x5
    rsb     r3, r7, r3, lsl #1          ; x5 - x21
    add     r8, r8, r4                  ; y22 = x22 + x6
    sub     r4, r8, r4, lsl #1          ; x22 - x6
    add     r9, r9, r5                  ; y23 = x23 + x7
    rsb     r5, r9, r5, lsl #1          ; x7 - x23

    stmia   r1!, {r6, r7, r8, r9}

    smull   r10, r6, lr, r2
    rsb     r2, r2, #0
    smlal   r10, r6, r12, r3
    smull   r10, r7, lr, r3
    smlal   r10, r7, r12, r2
    mov     r6, r6, lsl #1
    mov     r7, r7, lsl #1

    mov     r8, r5
    mov     r9, r4
    stmia   r0!, {r6, r7, r8, r9}

    ldmia   r0, {r2, r3, r4, r5}
    ldmia   r1, {r6, r7, r8, r9}
    add     r6, r6, r2                  ; y24 = x24 + x8
    sub     r2, r6, r2, lsl #1          ; x24 - x8
    add     r7, r7, r3                  ; y25 = x25 + x9
    sub     r3, r7, r3, lsl #1          ; x25 - x9
    add     r8, r8, r4                  ; y26 = x26 + x10
    sub     r4, r8, r4, lsl #1          ; x26 - x10
    add     r9, r9, r5                  ; y27 = x27 + x11
    sub     r5, r9, r5, lsl #1          ; x27 - x11

    stmia   r1!, {r6, r7, r8, r9}

    smull   r10, r7, lr, r3
    rsb     r3, r3, #0
    smlal   r10, r7, r12, r2
    smull   r10, r6, r12, r3
    smlal   r10, r6, lr, r2
    mov     r6, r6, lsl #1
    mov     r7, r7, lsl #1

    sub     r4, r4, r5                  ; (x26 - x10) - (x27 - x11)
    add     r5, r4, r5, lsl #1          ; (x26 - x10) + (x27 - x11)

    ldr     r11, =cPI2_8
    smull   r10, r8, r11, r4
    smull   r10, r9, r11, r5
    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1

    stmia   r0!, {r6, r7, r8, r9}

    ldmia   r0, {r2, r3, r4, r5}
    ldmia   r1, {r6, r7, r8, r9}
    add     r6, r6, r2                  ; y28 = x28 + x12
    sub     r2, r6, r2, lsl #1          ; x28 - x12
    add     r7, r7, r3                  ; y29 = x29 + x13
    sub     r3, r7, r3, lsl #1          ; x29 - x13
    add     r8, r8, r4                  ; y30 = x30 + x14
    sub     r4, r8, r4, lsl #1          ; x30 - x14
    add     r9, r9, r5                  ; y31 = x31 + x15
    sub     r5, r9, r5, lsl #1          ; x31 - x15

    stmia   r1, {r6, r7, r8, r9}

    smull   r10, r7, r12, r3
    rsb     r3, r3, #0
    smlal   r10, r7, lr, r2
    smull   r10, r6, lr, r3
    smlal   r10, r6, r12, r2
    mov     r6, r6, lsl #1
    mov     r7, r7, lsl #1

    mov     r8, r4
    mov     r9, r5
    stmia   r0, {r6, r7, r8, r9}

    sub     r0, r0, #12*4
    str     r0, [sp, #-4]!
    bl      mdct_butterfly_16

    ldr     r0, [sp], #4
    add     r0, r0, #16*4
    bl      mdct_butterfly_16

    ldmia   sp!, {r4-r11, pc}

    ENDP

    ; mdct_butterfly_generic_loop(x1, x2, T0, step, Ttop)
mdct_butterfly_generic_loop PROC
	EXPORT mdct_butterfly_generic_loop
    stmdb   sp!, {r4-r11, lr}
    str     r2, [sp, #-4]
    ldr     r4, [sp, #36]

label_1
    ldmdb   r0, {r6, r7, r8, r9}
    ldmdb   r1, {r10, r11, r12, r14}

    add     r6, r6, r10
    sub     r10, r6, r10, lsl #1
    add     r7, r7, r11
    rsb     r11, r7, r11, lsl #1
    add     r8, r8, r12
    sub     r12, r8, r12, lsl #1
    add     r9, r9, r14
    rsb     r14, r9, r14, lsl #1

    stmdb   r0!, {r6, r7, r8, r9}

    ldmia   r2, {r6, r7}
    smull   r5, r8, r6, r14
    rsb     r14, r14, #0
    smlal   r5, r8, r7, r12
    smull   r5, r9, r6, r12
    smlal   r5, r9, r7, r14

    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1
    stmdb   r1!, {r8, r9}
    add     r2, r2, r3, lsl #2

    ldmia   r2, {r6, r7}
    smull   r5, r8, r6, r11
    rsb     r11, r11, #0
    smlal   r5, r8, r7, r10
    smull   r5, r9, r6, r10
    smlal   r5, r9, r7, r11

    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1
    stmdb   r1!, {r8, r9}
    add     r2, r2, r3, lsl #2

    cmp     r2, r4
    blo     label_1

    ldr     r4, [sp, #-4]

label_2
    ldmdb   r0, {r6, r7, r8, r9}
    ldmdb   r1, {r10, r11, r12, r14}

    add     r6, r6, r10
    sub     r10, r6, r10, lsl #1
    add     r7, r7, r11
    sub     r11, r7, r11, lsl #1
    add     r8, r8, r12
    sub     r12, r8, r12, lsl #1
    add     r9, r9, r14
    sub     r14, r9, r14, lsl #1

    stmdb   r0!, {r6, r7, r8, r9}

    ldmia   r2, {r6, r7}
    smull   r5, r9, r6, r14
    rsb     r14, r14, #0
    smlal   r5, r9, r7, r12
    smull   r5, r8, r6, r12
    smlal   r5, r8, r7, r14

    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1
    stmdb   r1!, {r8, r9}
    sub     r2, r2, r3, lsl #2

    ldmia   r2, {r6, r7}
    smull   r5, r9, r6, r11
    rsb     r11, r11, #0
    smlal   r5, r9, r7, r10
    smull   r5, r8, r6, r10
    smlal   r5, r8, r7, r11

    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1
    stmdb   r1!, {r8, r9}
    sub     r2, r2, r3, lsl #2

    cmp     r2, r4
    bhi     label_2

    ldr     r4, [sp, #36]

label_3
    ldmdb   r0, {r6, r7, r8, r9}
    ldmdb   r1, {r10, r11, r12, r14}

    add     r6, r6, r10
    rsb     r10, r6, r10, lsl #1
    add     r7, r7, r11
    rsb     r11, r7, r11, lsl #1
    add     r8, r8, r12
    rsb     r12, r8, r12, lsl #1
    add     r9, r9, r14
    rsb     r14, r9, r14, lsl #1

    stmdb   r0!, {r6, r7, r8, r9}

    ldmia   r2, {r6, r7}
    smull   r5, r8, r6, r12
    rsb     r12, r12, #0
    smlal   r5, r8, r7, r14
    smull   r5, r9, r6, r14
    smlal   r5, r9, r7, r12

    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1
    stmdb   r1!, {r8, r9}
    add     r2, r2, r3, lsl #2

    ldmia   r2, {r6, r7}
    smull   r5, r8, r6, r10
    rsb     r10, r10, #0
    smlal   r5, r8, r7, r11
    smull   r5, r9, r6, r11
    smlal   r5, r9, r7, r10

    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1
    stmdb   r1!, {r8, r9}
    add     r2, r2, r3, lsl #2

    cmp     r2, r4
    blo     label_3

    ldr     r4, [sp, #-4]

label_4
    ldmdb   r0, {r6, r7, r8, r9}
    ldmdb   r1, {r10, r11, r12, r14}

    add     r6, r6, r10
    sub     r10, r6, r10, lsl #1
    add     r7, r7, r11
    rsb     r11, r7, r11, lsl #1
    add     r8, r8, r12
    sub     r12, r8, r12, lsl #1
    add     r9, r9, r14
    rsb     r14, r9, r14, lsl #1

    stmdb   r0!, {r6, r7, r8, r9}

    ldmia   r2, {r6, r7}
    smull   r5, r9, r6, r12
    smlal   r5, r9, r7, r14
    rsb     r12, r12, #0
    smull   r5, r8, r6, r14
    smlal   r5, r8, r7, r12

    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1
    stmdb   r1!, {r8, r9}
    sub     r2, r2, r3, lsl #2

    ldmia   r2, {r6, r7}
    smull   r5, r9, r6, r10
    rsb     r10, r10, #0
    smlal   r5, r9, r7, r11
    smull   r5, r8, r6, r11
    smlal   r5, r8, r7, r10

    mov     r8, r8, lsl #1
    mov     r9, r9, lsl #1
    stmdb   r1!, {r8, r9}
    sub     r2, r2, r3, lsl #2

    cmp     r2, r4
    bhi     label_4

    ldmia   sp!, {r4-r11, pc}

	ENDP

	END