atan_s390x.s

Documentation: math

     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 coefficients and other constants
     8DATA ·atanrodataL8<> + 0(SB)/8, $0.199999999999554423E+00
     9DATA ·atanrodataL8<> + 8(SB)/8, $0.111111110136634272E+00
    10DATA ·atanrodataL8<> + 16(SB)/8, $-.142857142828026806E+00
    11DATA ·atanrodataL8<> + 24(SB)/8, $-.333333333333330928E+00
    12DATA ·atanrodataL8<> + 32(SB)/8, $0.769228118888682505E-01
    13DATA ·atanrodataL8<> + 40(SB)/8, $0.588059263575587687E-01
    14DATA ·atanrodataL8<> + 48(SB)/8, $-.666641501287528609E-01
    15DATA ·atanrodataL8<> + 56(SB)/8, $-.909090711945939878E-01
    16DATA ·atanrodataL8<> + 64(SB)/8, $0.472329433805024762E-01
    17DATA ·atanrodataL8<> + 72(SB)/8, $0.366935664549587481E-01
    18DATA ·atanrodataL8<> + 80(SB)/8, $-.422172007412067035E-01
    19DATA ·atanrodataL8<> + 88(SB)/8, $-.299856214685512712E-01
    20DATA ·atanrodataL8<> + 96(SB)/8, $0.220852012160300086E-01
    21DATA ·atanrodataL8<> + 104(SB)/8, $0.726338160757602439E-02
    22DATA ·atanrodataL8<> + 112(SB)/8, $0.843488472994227321E-03
    23DATA ·atanrodataL8<> + 120(SB)/8, $0.134893651284712515E-04
    24DATA ·atanrodataL8<> + 128(SB)/8, $-.525380587584426406E-01
    25DATA ·atanrodataL8<> + 136(SB)/8, $-.139950258898989925E-01
    26DATA ·atanrodataL8<> + 144(SB)/8, $-.291935324869629616E-02
    27DATA ·atanrodataL8<> + 152(SB)/8, $-.154797890856877418E-03
    28GLOBL ·atanrodataL8<> + 0(SB), RODATA, $160
    29
    30DATA ·atanxpi2h<> + 0(SB)/8, $0x3ff330e4e4fa7b1b
    31DATA ·atanxpi2h<> + 8(SB)/8, $0xbff330e4e4fa7b1b
    32DATA ·atanxpi2h<> + 16(SB)/8, $0x400330e4e4fa7b1b
    33DATA ·atanxpi2h<> + 24(SB)/4, $0xc00330e4e4fa7b1b
    34GLOBL ·atanxpi2h<> + 0(SB), RODATA, $32
    35DATA ·atanxpim<> + 0(SB)/8, $0x3ff4f42b00000000
    36GLOBL ·atanxpim<> + 0(SB), RODATA, $8
    37DATA ·atanxmone<> + 0(SB)/8, $-1.0
    38GLOBL ·atanxmone<> + 0(SB), RODATA, $8
    39
    40// Atan returns the arctangent, in radians, of the argument.
    41//
    42// Special cases are:
    43//      Atan(±0) = ±0
    44//      Atan(±Inf) = ±Pi/2Pi
    45// The algorithm used is minimax polynomial approximation
    46// with coefficients determined with a Remez exchange algorithm.
    47
    48TEXT	·atanAsm(SB), NOSPLIT, $0-16
    49	FMOVD	x+0(FP), F0
    50	//special case Atan(±0) = ±0
    51	FMOVD   $(0.0), F1
    52	FCMPU   F0, F1
    53	BEQ     atanIsZero
    54
    55	MOVD	$·atanrodataL8<>+0(SB), R5
    56	MOVH	$0x3FE0, R3
    57	LGDR	F0, R1
    58	RISBGNZ	$32, $63, $32, R1, R1
    59	RLL	$16, R1, R2
    60	ANDW	$0x7FF0, R2
    61	MOVW	R2, R6
    62	MOVW	R3, R7
    63	CMPUBLE	R6, R7, L6
    64	MOVD	$·atanxmone<>+0(SB), R3
    65	FMOVD	0(R3), F2
    66	WFDDB	V0, V2, V0
    67	RISBGZ	$63, $63, $33, R1, R1
    68	MOVD	$·atanxpi2h<>+0(SB), R3
    69	MOVWZ	R1, R1
    70	SLD	$3, R1, R1
    71	WORD	$0x68813000	//ld	%f8,0(%r1,%r3)
    72L6:
    73	WFMDB	V0, V0, V2
    74	FMOVD	152(R5), F6
    75	FMOVD	144(R5), F1
    76	FMOVD	136(R5), F7
    77	VLEG	$0, 128(R5), V16
    78	FMOVD	120(R5), F4
    79	FMOVD	112(R5), F5
    80	WFMADB	V2, V4, V6, V4
    81	WFMADB	V2, V5, V1, V5
    82	WFMDB	V2, V2, V6
    83	FMOVD	104(R5), F3
    84	FMOVD	96(R5), F1
    85	WFMADB	V2, V3, V7, V3
    86	MOVH	$0x3FE0, R1
    87	FMOVD	88(R5), F7
    88	WFMADB	V2, V1, V7, V1
    89	FMOVD	80(R5), F7
    90	WFMADB	V6, V3, V1, V3
    91	WFMADB	V6, V4, V5, V4
    92	WFMDB	V6, V6, V1
    93	FMOVD	72(R5), F5
    94	WFMADB	V2, V5, V7, V5
    95	FMOVD	64(R5), F7
    96	WFMADB	V2, V7, V16, V7
    97	VLEG	$0, 56(R5), V16
    98	WFMADB	V6, V5, V7, V5
    99	WFMADB	V1, V4, V3, V4
   100	FMOVD	48(R5), F7
   101	FMOVD	40(R5), F3
   102	WFMADB	V2, V3, V7, V3
   103	FMOVD	32(R5), F7
   104	WFMADB	V2, V7, V16, V7
   105	VLEG	$0, 24(R5), V16
   106	WFMADB	V1, V4, V5, V4
   107	FMOVD	16(R5), F5
   108	WFMADB	V6, V3, V7, V3
   109	FMOVD	8(R5), F7
   110	WFMADB	V2, V7, V5, V7
   111	FMOVD	0(R5), F5
   112	WFMADB	V2, V5, V16, V5
   113	WFMADB	V1, V4, V3, V4
   114	WFMADB	V6, V7, V5, V6
   115	FMUL	F0, F2
   116	FMADD	F4, F1, F6
   117	FMADD	F6, F2, F0
   118	MOVW	R2, R6
   119	MOVW	R1, R7
   120	CMPUBLE	R6, R7, L1
   121	MOVD	$·atanxpim<>+0(SB), R1
   122	WORD	$0xED801000	//madb	%f0,%f8,0(%r1)
   123	BYTE	$0x00
   124	BYTE	$0x1E
   125L1:
   126atanIsZero:
   127	FMOVD	F0, ret+8(FP)
   128	RET
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