ARMv6 optimized quantization

Adds new ARMv6 optimized function vp8_fast_quantize_b_armv6
to the encoder.

Change-Id: I40277ec8f82e8a6cbc453cf295a0cc9b2504b21e

1 files changed, 224 insertions, 0 deletions

diff --git a/vp8/encoder/arm/armv6/vp8_fast_quantize_b_armv6.asm b/vp8/encoder/arm/armv6/vp8_fast_quantize_b_armv6.asm
new file mode 100644
index 000000000..ae2f6030d
--- /dev/null
+++ b/vp8/encoder/arm/armv6/vp8_fast_quantize_b_armv6.asm
@@ -0,0 +1,224 @@
+;
+;  Copyright (c) 2011 The WebM project authors. All Rights Reserved.
+;
+;  Use of this source code is governed by a BSD-style license
+;  that can be found in the LICENSE file in the root of the source
+;  tree. An additional intellectual property rights grant can be found
+;  in the file PATENTS.  All contributing project authors may
+;  be found in the AUTHORS file in the root of the source tree.
+;
+
+
+    EXPORT  |vp8_fast_quantize_b_armv6|
+
+    INCLUDE asm_enc_offsets.asm
+
+    ARM
+    REQUIRE8
+    PRESERVE8
+
+    AREA ||.text||, CODE, READONLY, ALIGN=2
+
+; r0    BLOCK *b
+; r1    BLOCKD *d
+|vp8_fast_quantize_b_armv6| PROC
+    stmfd   sp!, {r1, r4-r11, lr}
+
+    ldr     r3, [r0, #vp8_block_coeff]      ; coeff
+    ldr     r4, [r0, #vp8_block_quant_fast] ; quant_fast
+    ldr     r5, [r0, #vp8_block_round]      ; round
+    ldr     r6, [r1, #vp8_blockd_qcoeff]    ; qcoeff
+    ldr     r7, [r1, #vp8_blockd_dqcoeff]   ; dqcoeff
+    ldr     r8, [r1, #vp8_blockd_dequant]   ; dequant
+
+    ldr     r2, loop_count          ; loop_count=0x1000000. 'lsls' instruction
+                                    ; is used to update the counter so that
+                                    ; it can be used to mark nonzero
+                                    ; quantized coefficient pairs.
+
+    mov     r1, #0                  ; flags for quantized coeffs
+
+    ; PART 1: quantization and dequantization loop
+loop
+    ldr     r9, [r3], #4            ; [z1 | z0]
+    ldr     r10, [r5], #4           ; [r1 | r0]
+    ldr     r11, [r4], #4           ; [q1 | q0]
+
+    ssat16  lr, #1, r9              ; [sz1 | sz0]
+    eor     r9, r9, lr              ; [z1 ^ sz1 | z0 ^ sz0]
+    ssub16  r9, r9, lr              ; x = (z ^ sz) - sz
+    sadd16  r9, r9, r10             ; [x1+r1 | x0+r0]
+
+    ldr     r12, [r3], #4           ; [z3 | z2]
+
+    smulbb  r0, r9, r11             ; [(x0+r0)*q0]
+    smultt  r9, r9, r11             ; [(x1+r1)*q1]
+
+    ldr     r10, [r5], #4           ; [r3 | r2]
+
+    ssat16  r11, #1, r12            ; [sz3 | sz2]
+    eor     r12, r12, r11           ; [z3 ^ sz3 | z2 ^ sz2]
+    pkhtb   r0, r9, r0, asr #16     ; [y1 | y0]
+    ldr     r9, [r4], #4            ; [q3 | q2]
+    ssub16  r12, r12, r11           ; x = (z ^ sz) - sz
+
+    sadd16  r12, r12, r10           ; [x3+r3 | x2+r2]
+
+    eor     r0, r0, lr              ; [(y1 ^ sz1) | (y0 ^ sz0)]
+
+    smulbb  r10, r12, r9            ; [(x2+r2)*q2]
+    smultt  r12, r12, r9            ; [(x3+r3)*q3]
+
+    ssub16  r0, r0, lr              ; x = (y ^ sz) - sz
+
+    cmp     r0, #0                  ; check if zero
+    orrne   r1, r1, r2, lsr #24     ; add flag for nonzero coeffs
+
+    str     r0, [r6], #4            ; *qcoeff++ = x
+    ldr     r9, [r8], #4            ; [dq1 | dq0]
+
+    pkhtb   r10, r12, r10, asr #16  ; [y3 | y2]
+    eor     r10, r10, r11           ; [(y3 ^ sz3) | (y2 ^ sz2)]
+    ssub16  r10, r10, r11           ; x = (y ^ sz) - sz
+
+    cmp     r10, #0                 ; check if zero
+    orrne   r1, r1, r2, lsr #23     ; add flag for nonzero coeffs
+
+    str     r10, [r6], #4           ; *qcoeff++ = x
+    ldr     r11, [r8], #4           ; [dq3 | dq2]
+
+    smulbb  r12, r0, r9             ; [x0*dq0]
+    smultt  r0, r0, r9              ; [x1*dq1]
+
+    smulbb  r9, r10, r11            ; [x2*dq2]
+    smultt  r10, r10, r11           ; [x3*dq3]
+
+    lsls    r2, r2, #2              ; update loop counter
+    strh    r12, [r7, #0]           ; dqcoeff[0] = [x0*dq0]
+    strh    r0, [r7, #2]            ; dqcoeff[1] = [x1*dq1]
+    strh    r9, [r7, #4]            ; dqcoeff[2] = [x2*dq2]
+    strh    r10, [r7, #6]           ; dqcoeff[3] = [x3*dq3]
+    add     r7, r7, #8              ; dqcoeff += 8
+    bne     loop
+
+    ; PART 2: check position for eob...
+    mov     lr, #0                  ; init eob
+    cmp     r1, #0                  ; coeffs after quantization?
+    ldr     r11, [sp, #0]           ; restore BLOCKD pointer
+    beq     end                     ; skip eob calculations if all zero
+
+    ldr     r0, [r11, #vp8_blockd_qcoeff]
+
+    ; check shortcut for nonzero qcoeffs
+    tst    r1, #0x80
+    bne    quant_coeff_15_14
+    tst    r1, #0x20
+    bne    quant_coeff_13_11
+    tst    r1, #0x8
+    bne    quant_coeff_12_7
+    tst    r1, #0x40
+    bne    quant_coeff_10_9
+    tst    r1, #0x10
+    bne    quant_coeff_8_3
+    tst    r1, #0x2
+    bne    quant_coeff_6_5
+    tst    r1, #0x4
+    bne    quant_coeff_4_2
+    b      quant_coeff_1_0
+
+quant_coeff_15_14
+    ldrh    r2, [r0, #30]       ; rc=15, i=15
+    mov     lr, #16
+    cmp     r2, #0
+    bne     end
+
+    ldrh    r3, [r0, #28]       ; rc=14, i=14
+    mov     lr, #15
+    cmp     r3, #0
+    bne     end
+
+quant_coeff_13_11
+    ldrh    r2, [r0, #22]       ; rc=11, i=13
+    mov     lr, #14
+    cmp     r2, #0
+    bne     end
+
+quant_coeff_12_7
+    ldrh    r3, [r0, #14]       ; rc=7,  i=12
+    mov     lr, #13
+    cmp     r3, #0
+    bne     end
+
+    ldrh    r2, [r0, #20]       ; rc=10, i=11
+    mov     lr, #12
+    cmp     r2, #0
+    bne     end
+
+quant_coeff_10_9
+    ldrh    r3, [r0, #26]       ; rc=13, i=10
+    mov     lr, #11
+    cmp     r3, #0
+    bne     end
+
+    ldrh    r2, [r0, #24]       ; rc=12, i=9
+    mov     lr, #10
+    cmp     r2, #0
+    bne     end
+
+quant_coeff_8_3
+    ldrh    r3, [r0, #18]       ; rc=9,  i=8
+    mov     lr, #9
+    cmp     r3, #0
+    bne     end
+
+    ldrh    r2, [r0, #12]       ; rc=6,  i=7
+    mov     lr, #8
+    cmp     r2, #0
+    bne     end
+
+quant_coeff_6_5
+    ldrh    r3, [r0, #6]        ; rc=3,  i=6
+    mov     lr, #7
+    cmp     r3, #0
+    bne     end
+
+    ldrh    r2, [r0, #4]        ; rc=2,  i=5
+    mov     lr, #6
+    cmp     r2, #0
+    bne     end
+
+quant_coeff_4_2
+    ldrh    r3, [r0, #10]       ; rc=5,  i=4
+    mov     lr, #5
+    cmp     r3, #0
+    bne     end
+
+    ldrh    r2, [r0, #16]       ; rc=8,  i=3
+    mov     lr, #4
+    cmp     r2, #0
+    bne     end
+
+    ldrh    r3, [r0, #8]        ; rc=4,  i=2
+    mov     lr, #3
+    cmp     r3, #0
+    bne     end
+
+quant_coeff_1_0
+    ldrh    r2, [r0, #2]        ; rc=1,  i=1
+    mov     lr, #2
+    cmp     r2, #0
+    bne     end
+
+    mov     lr, #1              ; rc=0,  i=0
+
+end
+    str     lr, [r11, #vp8_blockd_eob]
+    ldmfd   sp!, {r1, r4-r11, pc}
+
+    ENDP
+
+loop_count
+    DCD     0x1000000
+
+    END
+