github.com/panjjo/go@v0.0.0-20161104043856-d62b31386338/src/math/dim_s390x.s (about)

     1  // Copyright 2016 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  // Based on dim_amd64.s
     6  
     7  #include "textflag.h"
     8  
     9  #define PosInf 0x7FF0000000000000
    10  #define NaN    0x7FF8000000000001
    11  #define NegInf 0xFFF0000000000000
    12  
    13  // func Dim(x, y float64) float64
    14  TEXT ·Dim(SB),NOSPLIT,$0
    15  	// (+Inf, +Inf) special case
    16  	MOVD    x+0(FP), R2
    17  	MOVD    y+8(FP), R3
    18  	MOVD    $PosInf, R4
    19  	CMPUBNE R4, R2, dim2
    20  	CMPUBEQ R4, R3, bothInf
    21  dim2:	// (-Inf, -Inf) special case
    22  	MOVD    $NegInf, R4
    23  	CMPUBNE R4, R2, dim3
    24  	CMPUBEQ R4, R3, bothInf
    25  dim3:	// (NaN, x) or (x, NaN)
    26  	MOVD    $~(1<<63), R5
    27  	MOVD    $PosInf, R4
    28  	AND     R5, R2 // x = |x|
    29  	CMPUBLT R4, R2, isDimNaN
    30  	AND     R5, R3 // y = |y|
    31  	CMPUBLT R4, R3, isDimNaN
    32  
    33  	FMOVD   x+0(FP), F1
    34  	FMOVD   y+8(FP), F2
    35  	FSUB    F2, F1
    36  	FMOVD   $(0.0), F2
    37  	FCMPU   F2, F1
    38  	BGE     +3(PC)
    39  	FMOVD   F1, ret+16(FP)
    40  	RET
    41  	FMOVD   F2, ret+16(FP)
    42  	RET
    43  bothInf: // Dim(-Inf, -Inf) or Dim(+Inf, +Inf)
    44  isDimNaN:
    45  	MOVD    $NaN, R4
    46  	MOVD    R4, ret+16(FP)
    47  	RET
    48  
    49  // func ·Max(x, y float64) float64
    50  TEXT ·Max(SB),NOSPLIT,$0
    51  	// +Inf special cases
    52  	MOVD    $PosInf, R4
    53  	MOVD    x+0(FP), R8
    54  	CMPUBEQ R4, R8, isPosInf
    55  	MOVD    y+8(FP), R9
    56  	CMPUBEQ R4, R9, isPosInf
    57  	// NaN special cases
    58  	MOVD    $~(1<<63), R5 // bit mask
    59  	MOVD    $PosInf, R4
    60  	MOVD    R8, R2
    61  	AND     R5, R2 // x = |x|
    62  	CMPUBLT R4, R2, isMaxNaN
    63  	MOVD    R9, R3
    64  	AND     R5, R3 // y = |y|
    65  	CMPUBLT R4, R3, isMaxNaN
    66  	// ±0 special cases
    67  	OR      R3, R2
    68  	BEQ     isMaxZero
    69  
    70  	FMOVD   x+0(FP), F1
    71  	FMOVD   y+8(FP), F2
    72  	FCMPU   F2, F1
    73  	BGT     +3(PC)
    74  	FMOVD   F1, ret+16(FP)
    75  	RET
    76  	FMOVD   F2, ret+16(FP)
    77  	RET
    78  isMaxNaN: // return NaN
    79  	MOVD	$NaN, R4
    80  isPosInf: // return +Inf
    81  	MOVD    R4, ret+16(FP)
    82  	RET
    83  isMaxZero:
    84  	MOVD    $(1<<63), R4 // -0.0
    85  	CMPUBEQ R4, R8, +3(PC)
    86  	MOVD    R8, ret+16(FP) // return 0
    87  	RET
    88  	MOVD    R9, ret+16(FP) // return other 0
    89  	RET
    90  
    91  // func Min(x, y float64) float64
    92  TEXT ·Min(SB),NOSPLIT,$0
    93  	// -Inf special cases
    94  	MOVD    $NegInf, R4
    95  	MOVD    x+0(FP), R8
    96  	CMPUBEQ R4, R8, isNegInf
    97  	MOVD    y+8(FP), R9
    98  	CMPUBEQ R4, R9, isNegInf
    99  	// NaN special cases
   100  	MOVD    $~(1<<63), R5
   101  	MOVD    $PosInf, R4
   102  	MOVD    R8, R2
   103  	AND     R5, R2 // x = |x|
   104  	CMPUBLT R4, R2, isMinNaN
   105  	MOVD    R9, R3
   106  	AND     R5, R3 // y = |y|
   107  	CMPUBLT R4, R3, isMinNaN
   108  	// ±0 special cases
   109  	OR      R3, R2
   110  	BEQ     isMinZero
   111  
   112  	FMOVD   x+0(FP), F1
   113  	FMOVD   y+8(FP), F2
   114  	FCMPU   F2, F1
   115  	BLT     +3(PC)
   116  	FMOVD   F1, ret+16(FP)
   117  	RET
   118  	FMOVD   F2, ret+16(FP)
   119  	RET
   120  isMinNaN: // return NaN
   121  	MOVD	$NaN, R4
   122  isNegInf: // return -Inf
   123  	MOVD    R4, ret+16(FP)
   124  	RET
   125  isMinZero:
   126  	MOVD    $(1<<63), R4 // -0.0
   127  	CMPUBEQ R4, R8, +3(PC)
   128  	MOVD    R9, ret+16(FP) // return other 0
   129  	RET
   130  	MOVD    R8, ret+16(FP) // return -0
   131  	RET
   132