| // Copyright 2017 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| #include "textflag.h" |
| |
| // Minimax polynomial approximations |
| DATA ·tanrodataL13<> + 0(SB)/8, $0.181017336383229927e-07 |
| DATA ·tanrodataL13<> + 8(SB)/8, $-.256590857271311164e-03 |
| DATA ·tanrodataL13<> + 16(SB)/8, $-.464359274328689195e+00 |
| DATA ·tanrodataL13<> + 24(SB)/8, $1.0 |
| DATA ·tanrodataL13<> + 32(SB)/8, $-.333333333333333464e+00 |
| DATA ·tanrodataL13<> + 40(SB)/8, $0.245751217306830032e-01 |
| DATA ·tanrodataL13<> + 48(SB)/8, $-.245391301343844510e-03 |
| DATA ·tanrodataL13<> + 56(SB)/8, $0.214530914428992319e-01 |
| DATA ·tanrodataL13<> + 64(SB)/8, $0.108285667160535624e-31 |
| DATA ·tanrodataL13<> + 72(SB)/8, $0.612323399573676480e-16 |
| DATA ·tanrodataL13<> + 80(SB)/8, $0.157079632679489656e+01 |
| DATA ·tanrodataL13<> + 88(SB)/8, $0.636619772367581341e+00 |
| GLOBL ·tanrodataL13<> + 0(SB), RODATA, $96 |
| |
| // Constants |
| DATA ·tanxnan<> + 0(SB)/8, $0x7ff8000000000000 |
| GLOBL ·tanxnan<> + 0(SB), RODATA, $8 |
| DATA ·tanxlim<> + 0(SB)/8, $0x432921fb54442d19 |
| GLOBL ·tanxlim<> + 0(SB), RODATA, $8 |
| DATA ·tanxadd<> + 0(SB)/8, $0xc338000000000000 |
| GLOBL ·tanxadd<> + 0(SB), RODATA, $8 |
| |
| // Tan returns the tangent of the radian argument. |
| // |
| // Special cases are: |
| // Tan(±0) = ±0 |
| // Tan(±Inf) = NaN |
| // Tan(NaN) = NaN |
| // The algorithm used is minimax polynomial approximation using a table of |
| // polynomial coefficients determined with a Remez exchange algorithm. |
| |
| TEXT ·tanAsm(SB), NOSPLIT, $0-16 |
| FMOVD x+0(FP), F0 |
| //specail case Tan(±0) = ±0 |
| FMOVD $(0.0), F1 |
| FCMPU F0, F1 |
| BEQ atanIsZero |
| |
| MOVD $·tanrodataL13<>+0(SB), R5 |
| WORD $0xB3120000 //ltdbr %f0,%f0 |
| BLTU L10 |
| FMOVD F0, F2 |
| L2: |
| MOVD $·tanxlim<>+0(SB), R1 |
| WORD $0xED201000 //cdb %f2,0(%r1) |
| BYTE $0x00 |
| BYTE $0x19 |
| BGE L11 |
| BVS L11 |
| MOVD $·tanxadd<>+0(SB), R1 |
| FMOVD 88(R5), F6 |
| FMOVD 0(R1), F4 |
| WFMSDB V0, V6, V4, V6 |
| FMOVD 80(R5), F1 |
| FADD F6, F4 |
| FMOVD 72(R5), F2 |
| FMSUB F1, F4, F0 |
| FMOVD 64(R5), F3 |
| WFMADB V4, V2, V0, V2 |
| FMOVD 56(R5), F1 |
| WFMADB V4, V3, V2, V4 |
| FMUL F2, F2 |
| VLEG $0, 48(R5), V18 |
| WORD $0xB3CD0016 //lgdr %r1,%f6 |
| FMOVD 40(R5), F5 |
| FMOVD 32(R5), F3 |
| FMADD F1, F2, F3 |
| FMOVD 24(R5), F1 |
| FMOVD 16(R5), F7 |
| FMOVD 8(R5), F0 |
| WFMADB V2, V7, V1, V7 |
| WFMADB V2, V0, V5, V0 |
| WFMDB V2, V2, V1 |
| FMOVD 0(R5), F5 |
| WFLCDB V4, V16 |
| WFMADB V2, V5, V18, V5 |
| WFMADB V1, V0, V7, V0 |
| WORD $0xA7110001 //tmll %r1,1 |
| WFMADB V1, V5, V3, V1 |
| BNE L12 |
| WFDDB V0, V1, V0 |
| WFMDB V2, V16, V2 |
| WFMADB V2, V0, V4, V0 |
| WORD $0xB3130000 //lcdbr %f0,%f0 |
| FMOVD F0, ret+8(FP) |
| RET |
| L12: |
| WFMSDB V2, V1, V0, V2 |
| WFMDB V16, V2, V2 |
| FDIV F2, F0 |
| FMOVD F0, ret+8(FP) |
| RET |
| L11: |
| MOVD $·tanxnan<>+0(SB), R1 |
| FMOVD 0(R1), F0 |
| FMOVD F0, ret+8(FP) |
| RET |
| L10: |
| WORD $0xB3130020 //lcdbr %f2,%f0 |
| BR L2 |
| atanIsZero: |
| FMOVD F0, ret+8(FP) |
| RET |
