tan_s390x.s

     1  // Copyright 2017 The Go 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.
     4  
     5  #include "textflag.h"
     6  
     7  // Minimax polynomial approximations
     8  DATA ·tanrodataL13<> + 0(SB)/8, $0.181017336383229927e-07
     9  DATA ·tanrodataL13<> + 8(SB)/8, $-.256590857271311164e-03
    10  DATA ·tanrodataL13<> + 16(SB)/8, $-.464359274328689195e+00
    11  DATA ·tanrodataL13<> + 24(SB)/8, $1.0
    12  DATA ·tanrodataL13<> + 32(SB)/8, $-.333333333333333464e+00
    13  DATA ·tanrodataL13<> + 40(SB)/8, $0.245751217306830032e-01
    14  DATA ·tanrodataL13<> + 48(SB)/8, $-.245391301343844510e-03
    15  DATA ·tanrodataL13<> + 56(SB)/8, $0.214530914428992319e-01
    16  DATA ·tanrodataL13<> + 64(SB)/8, $0.108285667160535624e-31
    17  DATA ·tanrodataL13<> + 72(SB)/8, $0.612323399573676480e-16
    18  DATA ·tanrodataL13<> + 80(SB)/8, $0.157079632679489656e+01
    19  DATA ·tanrodataL13<> + 88(SB)/8, $0.636619772367581341e+00
    20  GLOBL ·tanrodataL13<> + 0(SB), RODATA, $96
    21  
    22  // Constants
    23  DATA ·tanxnan<> + 0(SB)/8, $0x7ff8000000000000
    24  GLOBL ·tanxnan<> + 0(SB), RODATA, $8
    25  DATA ·tanxlim<> + 0(SB)/8, $0x432921fb54442d19
    26  GLOBL ·tanxlim<> + 0(SB), RODATA, $8
    27  DATA ·tanxadd<> + 0(SB)/8, $0xc338000000000000
    28  GLOBL ·tanxadd<> + 0(SB), RODATA, $8
    29  
    30  // Tan returns the tangent of the radian argument.
    31  //
    32  // Special cases are:
    33  //      Tan(±0) = ±0
    34  //      Tan(±Inf) = NaN
    35  //      Tan(NaN) = NaN
    36  // The algorithm used is minimax polynomial approximation using a table of
    37  // polynomial coefficients determined with a Remez exchange algorithm.
    38  
    39  TEXT	·tanAsm(SB), NOSPLIT, $0-16
    40  	FMOVD	x+0(FP), F0
    41  	//special case Tan(±0) = ±0
    42  	FMOVD   $(0.0), F1
    43  	FCMPU   F0, F1
    44  	BEQ     atanIsZero
    45  
    46  	MOVD	$·tanrodataL13<>+0(SB), R5
    47  	LTDBR	F0, F0
    48  	BLTU	L10
    49  	FMOVD	F0, F2
    50  L2:
    51  	MOVD	$·tanxlim<>+0(SB), R1
    52  	FMOVD	0(R1), F1
    53  	FCMPU	F2, F1
    54  	BGT	L9
    55  	BVS	L11
    56  	MOVD	$·tanxadd<>+0(SB), R1
    57  	FMOVD	88(R5), F6
    58  	FMOVD	0(R1), F4
    59  	WFMSDB	V0, V6, V4, V6
    60  	FMOVD	80(R5), F1
    61  	FADD	F6, F4
    62  	FMOVD	72(R5), F2
    63  	FMSUB	F1, F4, F0
    64  	FMOVD	64(R5), F3
    65  	WFMADB	V4, V2, V0, V2
    66  	FMOVD	56(R5), F1
    67  	WFMADB	V4, V3, V2, V4
    68  	FMUL	F2, F2
    69  	VLEG	$0, 48(R5), V18
    70  	LGDR	F6, R1
    71  	FMOVD	40(R5), F5
    72  	FMOVD	32(R5), F3
    73  	FMADD	F1, F2, F3
    74  	FMOVD	24(R5), F1
    75  	FMOVD	16(R5), F7
    76  	FMOVD	8(R5), F0
    77  	WFMADB	V2, V7, V1, V7
    78  	WFMADB	V2, V0, V5, V0
    79  	WFMDB	V2, V2, V1
    80  	FMOVD	0(R5), F5
    81  	WFLCDB	V4, V16
    82  	WFMADB	V2, V5, V18, V5
    83  	WFMADB	V1, V0, V7, V0
    84  	TMLL	R1, $1
    85  	WFMADB	V1, V5, V3, V1
    86  	BNE	L12
    87  	WFDDB	V0, V1, V0
    88  	WFMDB	V2, V16, V2
    89  	WFMADB	V2, V0, V4, V0
    90  	WORD	$0xB3130000	//lcdbr	%f0,%f0
    91  	FMOVD	F0, ret+8(FP)
    92  	RET
    93  L12:
    94  	WFMSDB	V2, V1, V0, V2
    95  	WFMDB	V16, V2, V2
    96  	FDIV	F2, F0
    97  	FMOVD	F0, ret+8(FP)
    98  	RET
    99  L11:
   100  	MOVD	$·tanxnan<>+0(SB), R1
   101  	FMOVD	0(R1), F0
   102  	FMOVD	F0, ret+8(FP)
   103  	RET
   104  L10:
   105  	WORD	$0xB3130020	//lcdbr	%f2,%f0
   106  	BR	L2
   107  L9:
   108  	BR	·tan(SB)
   109  atanIsZero:
   110  	FMOVD	F0, ret+8(FP)
   111  	RET
   112
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