mirror of
https://github.com/gonum/gonum.git
synced 2025-10-19 13:35:51 +08:00
65 lines
1.9 KiB
ArmAsm
65 lines
1.9 KiB
ArmAsm
// Copyright ©2016 The Gonum Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// +build !noasm,!appengine,!safe
|
|
|
|
#include "textflag.h"
|
|
|
|
TEXT ·CumSum(SB), NOSPLIT, $0
|
|
MOVQ dst_base+0(FP), DI // DI = &dst
|
|
MOVQ dst_len+8(FP), CX // CX = len(dst)
|
|
MOVQ s_base+24(FP), SI // SI = &s
|
|
CMPQ s_len+32(FP), CX // CX = max( CX, len(s) )
|
|
CMOVQLE s_len+32(FP), CX
|
|
MOVQ CX, ret_len+56(FP) // len(ret) = CX
|
|
CMPQ CX, $0 // if CX == 0 { return }
|
|
JE cs_end
|
|
XORQ AX, AX // i = 0
|
|
PXOR X5, X5 // p_sum = 0
|
|
MOVQ CX, BX
|
|
ANDQ $3, BX // BX = CX % 4
|
|
SHRQ $2, CX // CX = floor( CX / 4 )
|
|
JZ cs_tail_start // if CX == 0 { goto cs_tail_start }
|
|
|
|
cs_loop: // Loop unrolled 4x do {
|
|
MOVUPS (SI)(AX*8), X0 // X0 = s[i:i+1]
|
|
MOVUPS 16(SI)(AX*8), X2
|
|
MOVAPS X0, X1 // X1 = X0
|
|
MOVAPS X2, X3
|
|
SHUFPD $1, X1, X1 // { X1[0], X1[1] } = { X1[1], X1[0] }
|
|
SHUFPD $1, X3, X3
|
|
ADDPD X0, X1 // X1 += X0
|
|
ADDPD X2, X3
|
|
SHUFPD $2, X1, X0 // { X0[0], X0[1] } = { X0[0], X1[1] }
|
|
SHUFPD $3, X1, X1 // { X1[0], X1[1] } = { X1[1], X1[1] }
|
|
SHUFPD $2, X3, X2
|
|
SHUFPD $3, X3, X3
|
|
ADDPD X5, X0 // X0 += p_sum
|
|
ADDPD X1, X5 // p_sum += X1
|
|
ADDPD X5, X2
|
|
MOVUPS X0, (DI)(AX*8) // dst[i] = X0
|
|
MOVUPS X2, 16(DI)(AX*8)
|
|
ADDPD X3, X5
|
|
ADDQ $4, AX // i += 4
|
|
LOOP cs_loop // } while --CX > 0
|
|
|
|
// if BX == 0 { return }
|
|
CMPQ BX, $0
|
|
JE cs_end
|
|
|
|
cs_tail_start: // Reset loop registers
|
|
MOVQ BX, CX // Loop counter: CX = BX
|
|
|
|
cs_tail: // do {
|
|
ADDSD (SI)(AX*8), X5 // p_sum *= s[i]
|
|
MOVSD X5, (DI)(AX*8) // dst[i] = p_sum
|
|
INCQ AX // ++i
|
|
LOOP cs_tail // } while --CX > 0
|
|
|
|
cs_end:
|
|
MOVQ DI, ret_base+48(FP) // &ret = &dst
|
|
MOVQ dst_cap+16(FP), SI // cap(ret) = cap(dst)
|
|
MOVQ SI, ret_cap+64(FP)
|
|
RET
|