1 // Copyright ©2016 The Gonum Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // +build !noasm,!appengine
9 // func DivTo(dst, x, y []float64)
10 TEXT ·DivTo(SB), NOSPLIT, $0
11 MOVQ dst_base+0(FP), DI // DI = &dst
12 MOVQ dst_len+8(FP), CX // CX = len(dst)
13 MOVQ x_base+24(FP), SI // SI = &x
14 MOVQ y_base+48(FP), DX // DX = &y
15 CMPQ x_len+32(FP), CX // CX = max( len(dst), len(x), len(y) )
16 CMOVQLE x_len+32(FP), CX
18 CMOVQLE y_len+56(FP), CX
19 MOVQ CX, ret_len+80(FP) // len(ret) = CX
20 CMPQ CX, $0 // if CX == 0 { return }
24 ANDQ $15, BX // BX = &y & OxF
25 JZ div_no_trim // if BX == 0 { goto div_no_trim }
27 // Align on 16-bit boundary
28 MOVSD (SI)(AX*8), X0 // X0 = s[i]
29 DIVSD (DX)(AX*8), X0 // X0 /= t[i]
30 MOVSD X0, (DI)(AX*8) // dst[i] = X0
33 JZ div_end // if CX == 0 { return }
37 ANDQ $7, BX // BX = len(dst) % 8
38 SHRQ $3, CX // CX = floor( len(dst) / 8 )
39 JZ div_tail_start // if CX == 0 { goto div_tail_start }
41 div_loop: // Loop unrolled 8x do {
42 MOVUPS (SI)(AX*8), X0 // X0 = x[i:i+1]
43 MOVUPS 16(SI)(AX*8), X1
44 MOVUPS 32(SI)(AX*8), X2
45 MOVUPS 48(SI)(AX*8), X3
46 DIVPD (DX)(AX*8), X0 // X0 /= y[i:i+1]
47 DIVPD 16(DX)(AX*8), X1
48 DIVPD 32(DX)(AX*8), X2
49 DIVPD 48(DX)(AX*8), X3
50 MOVUPS X0, (DI)(AX*8) // dst[i:i+1] = X0
51 MOVUPS X1, 16(DI)(AX*8)
52 MOVUPS X2, 32(DI)(AX*8)
53 MOVUPS X3, 48(DI)(AX*8)
55 LOOP div_loop // } while --CX > 0
56 CMPQ BX, $0 // if BX == 0 { return }
59 div_tail_start: // Reset loop registers
60 MOVQ BX, CX // Loop counter: CX = BX
63 MOVSD (SI)(AX*8), X0 // X0 = x[i]
64 DIVSD (DX)(AX*8), X0 // X0 /= y[i]
67 LOOP div_tail // } while --CX > 0
70 MOVQ DI, ret_base+72(FP) // &ret = &dst
71 MOVQ dst_cap+16(FP), DI // cap(ret) = cap(dst)
72 MOVQ DI, ret_cap+88(FP)