github.com/ltltlt/go-source-code@v0.0.0-20190830023027-95be009773aa/math/exp_s390x.s (about)

     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 approximation and other constants
     8  DATA ·exprodataL22<> + 0(SB)/8, $800.0E+00
     9  DATA ·exprodataL22<> + 8(SB)/8, $1.0000000000000022e+00
    10  DATA ·exprodataL22<> + 16(SB)/8, $0.500000000000004237e+00
    11  DATA ·exprodataL22<> + 24(SB)/8, $0.166666666630345592e+00
    12  DATA ·exprodataL22<> + 32(SB)/8, $0.138926439368309441e-02
    13  DATA ·exprodataL22<> + 40(SB)/8, $0.833349307718286047e-02
    14  DATA ·exprodataL22<> + 48(SB)/8, $0.416666664838056960e-01
    15  DATA ·exprodataL22<> + 56(SB)/8, $-.231904681384629956E-16
    16  DATA ·exprodataL22<> + 64(SB)/8, $-.693147180559945286E+00
    17  DATA ·exprodataL22<> + 72(SB)/8, $0.144269504088896339E+01
    18  DATA ·exprodataL22<> + 80(SB)/8, $704.0E+00
    19  GLOBL ·exprodataL22<> + 0(SB), RODATA, $88
    20  
    21  DATA ·expxinf<> + 0(SB)/8, $0x7ff0000000000000
    22  GLOBL ·expxinf<> + 0(SB), RODATA, $8
    23  DATA ·expx4ff<> + 0(SB)/8, $0x4ff0000000000000
    24  GLOBL ·expx4ff<> + 0(SB), RODATA, $8
    25  DATA ·expx2ff<> + 0(SB)/8, $0x2ff0000000000000
    26  GLOBL ·expx2ff<> + 0(SB), RODATA, $8
    27  DATA ·expxaddexp<> + 0(SB)/8, $0xc2f0000100003fef
    28  GLOBL ·expxaddexp<> + 0(SB), RODATA, $8
    29  
    30  // Log multipliers table
    31  DATA ·exptexp<> + 0(SB)/8, $0.442737824274138381E-01
    32  DATA ·exptexp<> + 8(SB)/8, $0.263602189790660309E-01
    33  DATA ·exptexp<> + 16(SB)/8, $0.122565642281703586E-01
    34  DATA ·exptexp<> + 24(SB)/8, $0.143757052860721398E-02
    35  DATA ·exptexp<> + 32(SB)/8, $-.651375034121276075E-02
    36  DATA ·exptexp<> + 40(SB)/8, $-.119317678849450159E-01
    37  DATA ·exptexp<> + 48(SB)/8, $-.150868749549871069E-01
    38  DATA ·exptexp<> + 56(SB)/8, $-.161992609578469234E-01
    39  DATA ·exptexp<> + 64(SB)/8, $-.154492360403337917E-01
    40  DATA ·exptexp<> + 72(SB)/8, $-.129850717389178721E-01
    41  DATA ·exptexp<> + 80(SB)/8, $-.892902649276657891E-02
    42  DATA ·exptexp<> + 88(SB)/8, $-.338202636596794887E-02
    43  DATA ·exptexp<> + 96(SB)/8, $0.357266307045684762E-02
    44  DATA ·exptexp<> + 104(SB)/8, $0.118665304327406698E-01
    45  DATA ·exptexp<> + 112(SB)/8, $0.214434994118118914E-01
    46  DATA ·exptexp<> + 120(SB)/8, $0.322580645161290314E-01
    47  GLOBL ·exptexp<> + 0(SB), RODATA, $128
    48  
    49  // Exp returns e**x, the base-e exponential of x.
    50  //
    51  // Special cases are:
    52  //      Exp(+Inf) = +Inf
    53  //      Exp(NaN) = NaN
    54  // Very large values overflow to 0 or +Inf.
    55  // Very small values underflow to 1.
    56  // The algorithm used is minimax polynomial approximation using a table of
    57  // polynomial coefficients determined with a Remez exchange algorithm.
    58  
    59  TEXT	·expAsm(SB), NOSPLIT, $0-16
    60  	FMOVD	x+0(FP), F0
    61  	MOVD	$·exprodataL22<>+0(SB), R5
    62  	WORD	$0xB3120000	//ltdbr	%f0,%f0
    63  	BLTU	L20
    64  	FMOVD	F0, F2
    65  L2:
    66  	WORD	$0xED205050	//cdb	%f2,.L23-.L22(%r5)
    67  	BYTE	$0x00
    68  	BYTE	$0x19
    69  	BGE	L16
    70  	BVS	L16
    71  	WFCEDBS	V2, V2, V2
    72  	BVS	LEXITTAGexp
    73  	MOVD	$·expxaddexp<>+0(SB), R1
    74  	FMOVD	72(R5), F6
    75  	FMOVD	0(R1), F2
    76  	WFMSDB	V0, V6, V2, V6
    77  	FMOVD	64(R5), F4
    78  	FADD	F6, F2
    79  	FMOVD	56(R5), F1
    80  	FMADD	F4, F2, F0
    81  	FMOVD	48(R5), F3
    82  	WFMADB	V2, V1, V0, V2
    83  	FMOVD	40(R5), F1
    84  	FMOVD	32(R5), F4
    85  	FMUL	F0, F0
    86  	WFMADB	V2, V4, V1, V4
    87  	WORD	$0xB3CD0016	//lgdr	%r1,%f6
    88  	FMOVD	24(R5), F1
    89  	WFMADB	V2, V3, V1, V3
    90  	FMOVD	16(R5), F1
    91  	WFMADB	V0, V4, V3, V4
    92  	FMOVD	8(R5), F3
    93  	WFMADB	V2, V1, V3, V1
    94  	WORD	$0xEC3139BC	//risbg	%r3,%r1,57,128+60,3
    95  	BYTE	$0x03
    96  	BYTE	$0x55
    97  	WFMADB	V0, V4, V1, V0
    98  	MOVD	$·exptexp<>+0(SB), R2
    99  	WORD	$0x68432000	//ld	%f4,0(%r3,%r2)
   100  	FMADD	F4, F2, F2
   101  	SLD	$48, R1, R2
   102  	WFMADB	V2, V0, V4, V2
   103  	WORD	$0xB3C10002	//ldgr	%f0,%r2
   104  	FMADD	F0, F2, F0
   105  	FMOVD	F0, ret+8(FP)
   106  	RET
   107  L16:
   108  	WFCEDBS	V2, V2, V4
   109  	BVS	LEXITTAGexp
   110  	WORD	$0xED205000	//cdb	%f2,.L33-.L22(%r5)
   111  	BYTE	$0x00
   112  	BYTE	$0x19
   113  	BLT	L6
   114  	WFCEDBS	V2, V0, V0
   115  	BVS	L13
   116  	MOVD	$·expxinf<>+0(SB), R1
   117  	FMOVD	0(R1), F0
   118  	FMOVD	F0, ret+8(FP)
   119  	RET
   120  L20:
   121  	WORD	$0xB3130020	//lcdbr	%f2,%f0
   122  	BR	L2
   123  L6:
   124  	MOVD	$·expxaddexp<>+0(SB), R1
   125  	FMOVD	72(R5), F3
   126  	FMOVD	0(R1), F4
   127  	WFMSDB	V0, V3, V4, V3
   128  	FMOVD	64(R5), F6
   129  	FADD	F3, F4
   130  	FMOVD	56(R5), F5
   131  	WFMADB	V4, V6, V0, V6
   132  	FMOVD	32(R5), F1
   133  	WFMADB	V4, V5, V6, V4
   134  	FMOVD	40(R5), F5
   135  	FMUL	F6, F6
   136  	WFMADB	V4, V1, V5, V1
   137  	FMOVD	48(R5), F7
   138  	WORD	$0xB3CD0013	//lgdr	%r1,%f3
   139  	FMOVD	24(R5), F5
   140  	WFMADB	V4, V7, V5, V7
   141  	FMOVD	16(R5), F5
   142  	WFMADB	V6, V1, V7, V1
   143  	FMOVD	8(R5), F7
   144  	WFMADB	V4, V5, V7, V5
   145  	WORD	$0xEC3139BC	//risbg	%r3,%r1,57,128+60,3
   146  	BYTE	$0x03
   147  	BYTE	$0x55
   148  	WFMADB	V6, V1, V5, V6
   149  	MOVD	$·exptexp<>+0(SB), R2
   150  	WFCHDBS	V2, V0, V0
   151  	WORD	$0x68132000	//ld	%f1,0(%r3,%r2)
   152  	FMADD	F1, F4, F4
   153  	MOVD	$0x4086000000000000, R2
   154  	WFMADB	V4, V6, V1, V4
   155  	BEQ	L21
   156  	ADDW	$0xF000, R1
   157  	WORD	$0xEC21000F	//risbgn	%r2,%r1,64-64+0,64-64+0+16-1,64-0-16
   158  	BYTE	$0x30
   159  	BYTE	$0x59
   160  	WORD	$0xB3C10002	//ldgr	%f0,%r2
   161  	FMADD	F0, F4, F0
   162  	MOVD	$·expx4ff<>+0(SB), R3
   163  	FMOVD	0(R3), F2
   164  	FMUL	F2, F0
   165  	FMOVD	F0, ret+8(FP)
   166  	RET
   167  L13:
   168  	FMOVD	$0, F0
   169  	FMOVD	F0, ret+8(FP)
   170  	RET
   171  L21:
   172  	ADDW	$0x1000, R1
   173  	WORD	$0xEC21000F	//risbgn	%r2,%r1,64-64+0,64-64+0+16-1,64-0-16
   174  	BYTE	$0x30
   175  	BYTE	$0x59
   176  	WORD	$0xB3C10002	//ldgr	%f0,%r2
   177  	FMADD	F0, F4, F0
   178  	MOVD	$·expx2ff<>+0(SB), R3
   179  	FMOVD	0(R3), F2
   180  	FMUL	F2, F0
   181  	FMOVD	F0, ret+8(FP)
   182  	RET
   183  LEXITTAGexp:
   184  	FMOVD	F0, ret+8(FP)
   185  	RET