ref: 9d1b6fef2a8a8cc4a57af6bf8bed2fed645dea80
dir: /celt/arm/celt_pitch_xcorr_arm.s/
; Copyright (c) 2007-2008 CSIRO ; Copyright (c) 2007-2009 Xiph.Org Foundation ; Copyright (c) 2013 Parrot ; Written by Aurélien Zanelli ; ; 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. ; ; 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. AREA |.text|, CODE, READONLY GET celt/arm/armopts.s IF OPUS_ARM_MAY_HAVE_EDSP EXPORT celt_pitch_xcorr_edsp ENDIF IF OPUS_ARM_MAY_HAVE_NEON EXPORT celt_pitch_xcorr_neon ENDIF IF OPUS_ARM_MAY_HAVE_NEON ; Compute sum[k]=sum(x[j]*y[j+k],j=0...len-1), k=0...3 xcorr_kernel_neon PROC ; input: ; r3 = int len ; r4 = opus_val16 *x ; r5 = opus_val16 *y ; q0 = opus_val32 sum[4] ; output: ; q0 = opus_val32 sum[4] ; preserved: r0-r3, r6-r11, d2, q4-q7, q9-q15 ; internal usage: ; r12 = int j ; d3 = y_3|y_2|y_1|y_0 ; q2 = y_B|y_A|y_9|y_8|y_7|y_6|y_5|y_4 ; q3 = x_7|x_6|x_5|x_4|x_3|x_2|x_1|x_0 ; q8 = scratch ; ; Load y[0...3] ; This requires len>0 to always be valid (which we assert in the C code). VLD1.16 {d5}, [r5]! SUBS r12, r3, #8 BLE xcorr_kernel_neon_process4 ; Process 8 samples at a time. ; This loop loads one y value more than we actually need. Therefore we have to ; stop as soon as there are 8 or fewer samples left (instead of 7), to avoid ; reading past the end of the array. xcorr_kernel_neon_process8 ; This loop has 19 total instructions (10 cycles to issue, minimum), with ; - 2 cycles of ARM insrtuctions, ; - 10 cycles of load/store/byte permute instructions, and ; - 9 cycles of data processing instructions. ; On a Cortex A8, we dual-issue the maximum amount (9 cycles) between the ; latter two categories, meaning the whole loop should run in 10 cycles per ; iteration, barring cache misses. ; ; Load x[0...7] VLD1.16 {d6, d7}, [r4]! ; Unlike VMOV, VAND is a data processsing instruction (and doesn't get ; assembled to VMOV, like VORR would), so it dual-issues with the prior VLD1. VAND d3, d5, d5 SUBS r12, r12, #8 ; Load y[4...11] VLD1.16 {d4, d5}, [r5]! VMLAL.S16 q0, d3, d6[0] VEXT.16 d16, d3, d4, #1 VMLAL.S16 q0, d4, d7[0] VEXT.16 d17, d4, d5, #1 VMLAL.S16 q0, d16, d6[1] VEXT.16 d16, d3, d4, #2 VMLAL.S16 q0, d17, d7[1] VEXT.16 d17, d4, d5, #2 VMLAL.S16 q0, d16, d6[2] VEXT.16 d16, d3, d4, #3 VMLAL.S16 q0, d17, d7[2] VEXT.16 d17, d4, d5, #3 VMLAL.S16 q0, d16, d6[3] VMLAL.S16 q0, d17, d7[3] BGT xcorr_kernel_neon_process8 ; Process 4 samples here if we have > 4 left (still reading one extra y value). xcorr_kernel_neon_process4 ADDS r12, r12, #4 BLE xcorr_kernel_neon_process2 ; Load x[0...3] VLD1.16 d6, [r4]! ; Use VAND since it's a data processing instruction again. VAND d4, d5, d5 SUB r12, r12, #4 ; Load y[4...7] VLD1.16 d5, [r5]! VMLAL.S16 q0, d4, d6[0] VEXT.16 d16, d4, d5, #1 VMLAL.S16 q0, d16, d6[1] VEXT.16 d16, d4, d5, #2 VMLAL.S16 q0, d16, d6[2] VEXT.16 d16, d4, d5, #3 VMLAL.S16 q0, d16, d6[3] ; Process 2 samples here if we have > 2 left (still reading one extra y value). xcorr_kernel_neon_process2 ADDS r12, r12, #2 BLE xcorr_kernel_neon_process1 ; Load x[0...1] VLD2.16 {d6[],d7[]}, [r4]! ; Use VAND since it's a data processing instruction again. VAND d4, d5, d5 SUB r12, r12, #2 ; Load y[4...5] VLD1.32 {d5[]}, [r5]! VMLAL.S16 q0, d4, d6 VEXT.16 d16, d4, d5, #1 ; Replace bottom copy of {y5,y4} in d5 with {y3,y2} from d4, using VSRI ; instead of VEXT, since it's a data-processing instruction. VSRI.64 d5, d4, #32 VMLAL.S16 q0, d16, d7 ; Process 1 sample using the extra y value we loaded above. xcorr_kernel_neon_process1 ; Load next *x VLD1.16 {d6[]}, [r4]! ADDS r12, r12, #1 ; y[0...3] are left in d5 from prior iteration(s) (if any) VMLAL.S16 q0, d5, d6 MOVLE pc, lr ; Now process 1 last sample, not reading ahead. ; Load last *y VLD1.16 {d4[]}, [r5]! VSRI.64 d4, d5, #16 ; Load last *x VLD1.16 {d6[]}, [r4]! VMLAL.S16 q0, d4, d6 MOV pc, lr ENDP ; opus_val32 celt_pitch_xcorr_neon(opus_val16 *_x, opus_val16 *_y, ; opus_val32 *xcorr, int len, int max_pitch) celt_pitch_xcorr_neon PROC ; input: ; r0 = opus_val16 *_x ; r1 = opus_val16 *_y ; r2 = opus_val32 *xcorr ; r3 = int len ; output: ; r0 = int maxcorr ; internal usage: ; r4 = opus_val16 *x (for xcorr_kernel_neon()) ; r5 = opus_val16 *y (for xcorr_kernel_neon()) ; r6 = int max_pitch ; r12 = int j ; q15 = int maxcorr[4] (q15 is not used by xcorr_kernel_neon()) STMFD sp!, {r4-r6, lr} LDR r6, [sp, #16] VMOV.S32 q15, #1 ; if (max_pitch < 4) goto celt_pitch_xcorr_neon_process4_done SUBS r6, r6, #4 BLT celt_pitch_xcorr_neon_process4_done celt_pitch_xcorr_neon_process4 ; xcorr_kernel_neon parameters: ; r3 = len, r4 = _x, r5 = _y, q0 = {0, 0, 0, 0} MOV r4, r0 MOV r5, r1 VEOR q0, q0, q0 ; xcorr_kernel_neon only modifies r4, r5, r12, and q0...q3. ; So we don't save/restore any other registers. BL xcorr_kernel_neon SUBS r6, r6, #4 VST1.32 {q0}, [r2]! ; _y += 4 ADD r1, r1, #8 VMAX.S32 q15, q15, q0 ; if (max_pitch < 4) goto celt_pitch_xcorr_neon_process4_done BGE celt_pitch_xcorr_neon_process4 ; We have less than 4 sums left to compute. celt_pitch_xcorr_neon_process4_done ADDS r6, r6, #4 ; Reduce maxcorr to a single value VMAX.S32 d30, d30, d31 VPMAX.S32 d30, d30, d30 ; if (max_pitch <= 0) goto celt_pitch_xcorr_neon_done BLE celt_pitch_xcorr_neon_done ; Now compute each remaining sum one at a time. celt_pitch_xcorr_neon_process_remaining MOV r4, r0 MOV r5, r1 VMOV.I32 q0, #0 SUBS r12, r3, #8 BLT celt_pitch_xcorr_neon_process_remaining4 ; Sum terms 8 at a time. celt_pitch_xcorr_neon_process_remaining_loop8 ; Load x[0...7] VLD1.16 {q1}, [r4]! ; Load y[0...7] VLD1.16 {q2}, [r5]! SUBS r12, r12, #8 VMLAL.S16 q0, d4, d2 VMLAL.S16 q0, d5, d3 BGE celt_pitch_xcorr_neon_process_remaining_loop8 ; Sum terms 4 at a time. celt_pitch_xcorr_neon_process_remaining4 ADDS r12, r12, #4 BLT celt_pitch_xcorr_neon_process_remaining4_done ; Load x[0...3] VLD1.16 {d2}, [r4]! ; Load y[0...3] VLD1.16 {d3}, [r5]! SUB r12, r12, #4 VMLAL.S16 q0, d3, d2 celt_pitch_xcorr_neon_process_remaining4_done ; Reduce the sum to a single value. VADD.S32 d0, d0, d1 VPADDL.S32 d0, d0 ADDS r12, r12, #4 BLE celt_pitch_xcorr_neon_process_remaining_loop_done ; Sum terms 1 at a time. celt_pitch_xcorr_neon_process_remaining_loop1 VLD1.16 {d2[]}, [r4]! VLD1.16 {d3[]}, [r5]! SUBS r12, r12, #1 VMLAL.S16 q0, d2, d3 BGT celt_pitch_xcorr_neon_process_remaining_loop1 celt_pitch_xcorr_neon_process_remaining_loop_done VST1.32 {d0[0]}, [r2]! VMAX.S32 d30, d30, d0 SUBS r6, r6, #1 ; _y++ ADD r1, r1, #2 ; if (--max_pitch > 0) goto celt_pitch_xcorr_neon_process_remaining BGT celt_pitch_xcorr_neon_process_remaining celt_pitch_xcorr_neon_done VMOV.32 r0, d30[0] LDMFD sp!, {r4-r6, pc} ENDP ENDIF IF OPUS_ARM_MAY_HAVE_EDSP ; This will get used on ARMv7 devices without NEON, so it has been optimized ; to take advantage of dual-issuing where possible. xcorr_kernel_edsp PROC ; input: ; r3 = int len ; r4 = opus_val16 *_x (must be 32-bit aligned) ; r5 = opus_val16 *_y (must be 32-bit aligned) ; r6...r9 = opus_val32 sum[4] ; output: ; r6...r9 = opus_val32 sum[4] ; preserved: r0-r5 ; internal usage ; r2 = int j ; r12,r14 = opus_val16 x[4] ; r10,r11 = opus_val16 y[4] STMFD sp!, {r2,r4,r5,lr} LDR r10, [r5], #4 ; Load y[0...1] SUBS r2, r3, #4 ; j = len-4 LDR r11, [r5], #4 ; Load y[2...3] BLE xcorr_kernel_edsp_process4_done LDR r12, [r4], #4 ; Load x[0...1] ; Stall xcorr_kernel_edsp_process4 ; The multiplies must issue from pipeline 0, and can't dual-issue with each ; other. Every other instruction here dual-issues with a multiply, and is ; thus "free". There should be no stalls in the body of the loop. SMLABB r6, r12, r10, r6 ; sum[0] = MAC16_16(sum[0],x_0,y_0) LDR r14, [r4], #4 ; Load x[2...3] SMLABT r7, r12, r10, r7 ; sum[1] = MAC16_16(sum[1],x_0,y_1) SUBS r2, r2, #4 ; j-=4 SMLABB r8, r12, r11, r8 ; sum[2] = MAC16_16(sum[2],x_0,y_2) SMLABT r9, r12, r11, r9 ; sum[3] = MAC16_16(sum[3],x_0,y_3) SMLATT r6, r12, r10, r6 ; sum[0] = MAC16_16(sum[0],x_1,y_1) LDR r10, [r5], #4 ; Load y[4...5] SMLATB r7, r12, r11, r7 ; sum[1] = MAC16_16(sum[1],x_1,y_2) SMLATT r8, r12, r11, r8 ; sum[2] = MAC16_16(sum[2],x_1,y_3) SMLATB r9, r12, r10, r9 ; sum[3] = MAC16_16(sum[3],x_1,y_4) LDRGT r12, [r4], #4 ; Load x[0...1] SMLABB r6, r14, r11, r6 ; sum[0] = MAC16_16(sum[0],x_2,y_2) SMLABT r7, r14, r11, r7 ; sum[1] = MAC16_16(sum[1],x_2,y_3) SMLABB r8, r14, r10, r8 ; sum[2] = MAC16_16(sum[2],x_2,y_4) SMLABT r9, r14, r10, r9 ; sum[3] = MAC16_16(sum[3],x_2,y_5) SMLATT r6, r14, r11, r6 ; sum[0] = MAC16_16(sum[0],x_3,y_3) LDR r11, [r5], #4 ; Load y[6...7] SMLATB r7, r14, r10, r7 ; sum[1] = MAC16_16(sum[1],x_3,y_4) SMLATT r8, r14, r10, r8 ; sum[2] = MAC16_16(sum[2],x_3,y_5) SMLATB r9, r14, r11, r9 ; sum[3] = MAC16_16(sum[3],x_3,y_6) BGT xcorr_kernel_edsp_process4 xcorr_kernel_edsp_process4_done ADDS r2, r2, #4 BLE xcorr_kernel_edsp_done LDRH r12, [r4], #2 ; r12 = *x++ SUBS r2, r2, #1 ; j-- ; Stall SMLABB r6, r12, r10, r6 ; sum[0] = MAC16_16(sum[0],x,y_0) LDRGTH r14, [r4], #2 ; r14 = *x++ SMLABT r7, r12, r10, r7 ; sum[1] = MAC16_16(sum[1],x,y_1) SMLABB r8, r12, r11, r8 ; sum[2] = MAC16_16(sum[2],x,y_2) SMLABT r9, r12, r11, r9 ; sum[3] = MAC16_16(sum[3],x,y_3) BLE xcorr_kernel_edsp_done SMLABT r6, r14, r10, r6 ; sum[0] = MAC16_16(sum[0],x,y_1) SUBS r2, r2, #1 ; j-- SMLABB r7, r14, r11, r7 ; sum[1] = MAC16_16(sum[1],x,y_2) LDRH r10, [r5], #2 ; r10 = y_4 = *y++ SMLABT r8, r14, r11, r8 ; sum[2] = MAC16_16(sum[2],x,y_3) LDRGTH r12, [r4], #2 ; r12 = *x++ SMLABB r9, r14, r10, r9 ; sum[3] = MAC16_16(sum[3],x,y_4) BLE xcorr_kernel_edsp_done SMLABB r6, r12, r11, r6 ; sum[0] = MAC16_16(sum[0],tmp,y_2) CMP r2, #1 ; j-- SMLABT r7, r12, r11, r7 ; sum[1] = MAC16_16(sum[1],tmp,y_3) LDRH r2, [r5], #2 ; r2 = y_5 = *y++ SMLABB r8, r12, r10, r8 ; sum[2] = MAC16_16(sum[2],tmp,y_4) LDRGTH r14, [r4] ; r14 = *x SMLABB r9, r12, r2, r9 ; sum[3] = MAC16_16(sum[3],tmp,y_5) BLE xcorr_kernel_edsp_done SMLABT r6, r14, r11, r6 ; sum[0] = MAC16_16(sum[0],tmp,y_3) LDRH r11, [r5] ; r11 = y_6 = *y SMLABB r7, r14, r10, r7 ; sum[1] = MAC16_16(sum[1],tmp,y_4) SMLABB r8, r14, r2, r8 ; sum[2] = MAC16_16(sum[2],tmp,y_5) SMLABB r9, r14, r11, r9 ; sum[3] = MAC16_16(sum[3],tmp,y_6) xcorr_kernel_edsp_done LDMFD sp!, {r2,r4,r5,pc} ENDP celt_pitch_xcorr_edsp PROC ; input: ; r0 = opus_val16 *_x (must be 32-bit aligned) ; r1 = opus_val16 *_y (only needs to be 16-bit aligned) ; r2 = opus_val32 *xcorr ; r3 = int len ; output: ; r0 = maxcorr ; internal usage ; r4 = opus_val16 *x ; r5 = opus_val16 *y ; r6 = opus_val32 sum0 ; r7 = opus_val32 sum1 ; r8 = opus_val32 sum2 ; r9 = opus_val32 sum3 ; r1 = int max_pitch ; r12 = int j STMFD sp!, {r4-r11, lr} MOV r5, r1 LDR r1, [sp, #36] MOV r4, r0 TST r5, #3 ; maxcorr = 1 MOV r0, #1 BEQ celt_pitch_xcorr_edsp_process1u_done ; Compute one sum at the start to make y 32-bit aligned. SUBS r12, r3, #4 ; r14 = sum = 0 MOV r14, #0 LDRH r8, [r5], #2 BLE celt_pitch_xcorr_edsp_process1u_loop4_done LDR r6, [r4], #4 MOV r8, r8, LSL #16 celt_pitch_xcorr_edsp_process1u_loop4 LDR r9, [r5], #4 SMLABT r14, r6, r8, r14 ; sum = MAC16_16(sum, x_0, y_0) LDR r7, [r4], #4 SMLATB r14, r6, r9, r14 ; sum = MAC16_16(sum, x_1, y_1) LDR r8, [r5], #4 SMLABT r14, r7, r9, r14 ; sum = MAC16_16(sum, x_2, y_2) SUBS r12, r12, #4 ; j-=4 SMLATB r14, r7, r8, r14 ; sum = MAC16_16(sum, x_3, y_3) LDRGT r6, [r4], #4 BGT celt_pitch_xcorr_edsp_process1u_loop4 MOV r8, r8, LSR #16 celt_pitch_xcorr_edsp_process1u_loop4_done ADDS r12, r12, #4 celt_pitch_xcorr_edsp_process1u_loop1 LDRGEH r6, [r4], #2 ; Stall SMLABBGE r14, r6, r8, r14 ; sum = MAC16_16(sum, *x, *y) SUBGES r12, r12, #1 LDRGTH r8, [r5], #2 BGT celt_pitch_xcorr_edsp_process1u_loop1 ; Restore _x SUB r4, r4, r3, LSL #1 ; Restore and advance _y SUB r5, r5, r3, LSL #1 ; maxcorr = max(maxcorr, sum) CMP r0, r14 ADD r5, r5, #2 MOVLT r0, r14 SUBS r1, r1, #1 ; xcorr[i] = sum STR r14, [r2], #4 BLE celt_pitch_xcorr_edsp_done celt_pitch_xcorr_edsp_process1u_done ; if (max_pitch < 4) goto celt_pitch_xcorr_edsp_process2 SUBS r1, r1, #4 BLT celt_pitch_xcorr_edsp_process2 celt_pitch_xcorr_edsp_process4 ; xcorr_kernel_edsp parameters: ; r3 = len, r4 = _x, r5 = _y, r6...r9 = sum[4] = {0, 0, 0, 0} MOV r6, #0 MOV r7, #0 MOV r8, #0 MOV r9, #0 BL xcorr_kernel_edsp ; xcorr_kernel_edsp(_x, _y+i, xcorr+i, len) ; maxcorr = max(maxcorr, sum0, sum1, sum2, sum3) CMP r0, r6 ; _y+=4 ADD r5, r5, #8 MOVLT r0, r6 CMP r0, r7 MOVLT r0, r7 CMP r0, r8 MOVLT r0, r8 CMP r0, r9 MOVLT r0, r9 STMIA r2!, {r6-r9} SUBS r1, r1, #4 BGE celt_pitch_xcorr_edsp_process4 celt_pitch_xcorr_edsp_process2 ADDS r1, r1, #2 BLT celt_pitch_xcorr_edsp_process1a SUBS r12, r3, #4 ; {r10, r11} = {sum0, sum1} = {0, 0} MOV r10, #0 MOV r11, #0 LDR r8, [r5], #4 BLE celt_pitch_xcorr_edsp_process2_loop_done LDR r6, [r4], #4 LDR r9, [r5], #4 celt_pitch_xcorr_edsp_process2_loop4 SMLABB r10, r6, r8, r10 ; sum0 = MAC16_16(sum0, x_0, y_0) LDR r7, [r4], #4 SMLABT r11, r6, r8, r11 ; sum1 = MAC16_16(sum1, x_0, y_1) SUBS r12, r12, #4 ; j-=4 SMLATT r10, r6, r8, r10 ; sum0 = MAC16_16(sum0, x_1, y_1) LDR r8, [r5], #4 SMLATB r11, r6, r9, r11 ; sum1 = MAC16_16(sum1, x_1, y_2) LDRGT r6, [r4], #4 SMLABB r10, r7, r9, r10 ; sum0 = MAC16_16(sum0, x_2, y_2) SMLABT r11, r7, r9, r11 ; sum1 = MAC16_16(sum1, x_2, y_3) SMLATT r10, r7, r9, r10 ; sum0 = MAC16_16(sum0, x_3, y_3) LDRGT r9, [r5], #4 SMLATB r11, r7, r8, r11 ; sum1 = MAC16_16(sum1, x_3, y_4) BGT celt_pitch_xcorr_edsp_process2_loop4 celt_pitch_xcorr_edsp_process2_loop_done ADDS r12, r12, #2 BLE celt_pitch_xcorr_edsp_process2_1 LDR r6, [r4], #4 ; Stall SMLABB r10, r6, r8, r10 ; sum0 = MAC16_16(sum0, x_0, y_0) LDR r9, [r5], #4 SMLABT r11, r6, r8, r11 ; sum1 = MAC16_16(sum1, x_0, y_1) SUB r12, r12, #2 SMLATT r10, r6, r8, r10 ; sum0 = MAC16_16(sum0, x_1, y_1) MOV r8, r9 SMLATB r11, r6, r9, r11 ; sum1 = MAC16_16(sum1, x_1, y_2) celt_pitch_xcorr_edsp_process2_1 LDRH r6, [r4], #2 ADDS r12, r12, #1 ; Stall SMLABB r10, r6, r8, r10 ; sum0 = MAC16_16(sum0, x_0, y_0) LDRGTH r7, [r4], #2 SMLABT r11, r6, r8, r11 ; sum1 = MAC16_16(sum1, x_0, y_1) BLE celt_pitch_xcorr_edsp_process2_done LDRH r9, [r5], #2 SMLABT r10, r7, r8, r10 ; sum0 = MAC16_16(sum0, x_0, y_1) SMLABB r11, r7, r9, r11 ; sum1 = MAC16_16(sum1, x_0, y_2) celt_pitch_xcorr_edsp_process2_done ; Restore _x SUB r4, r4, r3, LSL #1 ; Restore and advance _y SUB r5, r5, r3, LSL #1 ; maxcorr = max(maxcorr, sum0) CMP r0, r10 ADD r5, r5, #2 MOVLT r0, r10 SUB r1, r1, #2 ; maxcorr = max(maxcorr, sum1) CMP r0, r11 ; xcorr[i] = sum STR r10, [r2], #4 MOVLT r0, r11 STR r11, [r2], #4 celt_pitch_xcorr_edsp_process1a ADDS r1, r1, #1 BLT celt_pitch_xcorr_edsp_done SUBS r12, r3, #4 ; r14 = sum = 0 MOV r14, #0 BLT celt_pitch_xcorr_edsp_process1a_loop_done LDR r6, [r4], #4 LDR r8, [r5], #4 LDR r7, [r4], #4 LDR r9, [r5], #4 celt_pitch_xcorr_edsp_process1a_loop4 SMLABB r14, r6, r8, r14 ; sum = MAC16_16(sum, x_0, y_0) SUBS r12, r12, #4 ; j-=4 SMLATT r14, r6, r8, r14 ; sum = MAC16_16(sum, x_1, y_1) LDRGE r6, [r4], #4 SMLABB r14, r7, r9, r14 ; sum = MAC16_16(sum, x_2, y_2) LDRGE r8, [r5], #4 SMLATT r14, r7, r9, r14 ; sum = MAC16_16(sum, x_3, y_3) LDRGE r7, [r4], #4 LDRGE r9, [r5], #4 BGE celt_pitch_xcorr_edsp_process1a_loop4 celt_pitch_xcorr_edsp_process1a_loop_done ADDS r12, r12, #2 LDRGE r6, [r4], #4 LDRGE r8, [r5], #4 ; Stall SMLABBGE r14, r6, r8, r14 ; sum = MAC16_16(sum, x_0, y_0) SUBGE r12, r12, #2 SMLATTGE r14, r6, r8, r14 ; sum = MAC16_16(sum, x_1, y_1) ADDS r12, r12, #1 LDRGEH r6, [r4], #2 LDRGEH r8, [r5], #2 ; Stall SMLABBGE r14, r6, r8, r14 ; sum = MAC16_16(sum, *x, *y) ; maxcorr = max(maxcorr, sum) CMP r0, r14 ; xcorr[i] = sum STR r14, [r2], #4 MOVLT r0, r14 celt_pitch_xcorr_edsp_done LDMFD sp!, {r4-r11, pc} ENDP ENDIF END