tan_s390x.s raw

   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  	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  	LCDBR	F0, F2
 106  	BR	L2
 107  L9:
 108  	BR	·tan(SB)
 109  atanIsZero:
 110  	FMOVD	F0, ret+8(FP)
 111  	RET
 112