1 // Copyright ©2017 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
19 #define MOVDDUP_X2_X3 LONG $0xDA120FF2 // MOVDDUP X2, X3
20 #define MOVDDUP_X4_X5 LONG $0xEC120FF2 // MOVDDUP X4, X5
21 #define MOVDDUP_X6_X7 LONG $0xFE120FF2 // MOVDDUP X6, X7
22 #define MOVDDUP_X8_X9 LONG $0x120F45F2; BYTE $0xC8 // MOVDDUP X8, X9
24 #define ADDSUBPD_X2_X3 LONG $0xDAD00F66 // ADDSUBPD X2, X3
25 #define ADDSUBPD_X4_X5 LONG $0xECD00F66 // ADDSUBPD X4, X5
26 #define ADDSUBPD_X6_X7 LONG $0xFED00F66 // ADDSUBPD X6, X7
27 #define ADDSUBPD_X8_X9 LONG $0xD00F4566; BYTE $0xC8 // ADDSUBPD X8, X9
29 // func ScalUnitary(alpha complex128, x []complex128)
30 TEXT ·ScalUnitary(SB), NOSPLIT, $0
31 MOVQ x_base+16(FP), SRC // SRC = &x
32 MOVQ x_len+24(FP), LEN // LEN = len(x)
33 CMPQ LEN, $0 // if LEN == 0 { return }
36 MOVUPS alpha+0(FP), ALPHA // ALPHA = { imag(alpha), real(alpha) }
38 SHUFPD $0x1, ALPHA_C, ALPHA_C // ALPHA_C = { real(alpha), imag(alpha) }
40 XORQ IDX, IDX // IDX = 0
41 MOVAPS ALPHA, ALPHA2 // Copy ALPHA and ALPHA_C for pipelining
42 MOVAPS ALPHA_C, ALPHA_C2
44 SHRQ $2, LEN // LEN = floor( n / 4 )
45 JZ scal_tail // if BX == 0 { goto scal_tail }
48 MOVUPS (SRC)(IDX*8), X2 // X_i = { imag(x[i]), real(x[i]) }
49 MOVUPS 16(SRC)(IDX*8), X4
50 MOVUPS 32(SRC)(IDX*8), X6
51 MOVUPS 48(SRC)(IDX*8), X8
53 // X_(i+1) = { real(x[i], real(x[i]) }
59 // X_i = { imag(x[i]), imag(x[i]) }
65 // X_i = { real(ALPHA) * imag(x[i]), imag(ALPHA) * imag(x[i]) }
66 // X_(i+1) = { imag(ALPHA) * real(x[i]), real(ALPHA) * real(x[i]) }
77 // imag(result[i]): imag(ALPHA)*real(x[i]) + real(ALPHA)*imag(x[i]),
78 // real(result[i]): real(ALPHA)*real(x[i]) - imag(ALPHA)*imag(x[i])
85 MOVUPS X3, (DST)(IDX*8) // x[i] = X_(i+1)
86 MOVUPS X5, 16(DST)(IDX*8)
87 MOVUPS X7, 32(DST)(IDX*8)
88 MOVUPS X9, 48(DST)(IDX*8)
89 ADDQ $8, IDX // IDX += 8
91 JNZ scal_loop // } while --LEN > 0
94 ANDQ $3, TAIL // TAIL = TAIL % 4
95 JZ scal_end // if TAIL == 0 { return }
97 scal_tail_loop: // do {
98 MOVUPS (SRC)(IDX*8), X2 // X_i = { imag(x[i]), real(x[i]) }
99 MOVDDUP_X2_X3 // X_(i+1) = { real(x[i], real(x[i]) }
100 SHUFPD $0x3, X2, X2 // X_i = { imag(x[i]), imag(x[i]) }
101 MULPD ALPHA_C, X2 // X_i = { real(ALPHA) * imag(x[i]), imag(ALPHA) * imag(x[i]) }
102 MULPD ALPHA, X3 // X_(i+1) = { imag(ALPHA) * real(x[i]), real(ALPHA) * real(x[i]) }
105 // imag(result[i]): imag(ALPHA)*real(x[i]) + real(ALPHA)*imag(x[i]),
106 // real(result[i]): real(ALPHA)*real(x[i]) - imag(ALPHA)*imag(x[i])
110 MOVUPS X3, (DST)(IDX*8) // x[i] = X_(i+1)
111 ADDQ $2, IDX // IDX += 2
113 JNZ scal_tail_loop // } while --LEN > 0