1 // Copyright 2010 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 #define PosInf 0x7FF0000000000000 8 #define NaN 0x7FF8000000000001 9 #define NegInf 0xFFF0000000000000 10 11 // func Dim(x, y float64) float64 12 TEXT Dim(SB),NOSPLIT,$0 13 // (+Inf, +Inf) special case 14 MOVQ x+0(FP), BX 15 MOVQ y+8(FP), CX 16 MOVQ $PosInf, AX 17 CMPQ AX, BX 18 JNE dim2 19 CMPQ AX, CX 20 JEQ bothInf 21 dim2: // (-Inf, -Inf) special case 22 MOVQ $NegInf, AX 23 CMPQ AX, BX 24 JNE dim3 25 CMPQ AX, CX 26 JEQ bothInf 27 dim3: // (NaN, x) or (x, NaN) 28 MOVQ $~(1<<63), DX 29 MOVQ $PosInf, AX 30 ANDQ DX, BX // x = |x| 31 CMPQ AX, BX 32 JLT isDimNaN 33 ANDQ DX, CX // y = |y| 34 CMPQ AX, CX 35 JLT isDimNaN 36 37 MOVSD x+0(FP), X0 38 SUBSD y+8(FP), X0 39 MOVSD $(0.0), X1 40 MAXSD X1, X0 41 MOVSD X0, ret+16(FP) 42 RET 43 bothInf: // Dim(-Inf, -Inf) or Dim(+Inf, +Inf) 44 isDimNaN: 45 MOVQ $NaN, AX 46 MOVQ AX, ret+16(FP) 47 RET 48 49 // func Max(x, y float64) float64 50 TEXT Max(SB),NOSPLIT,$0 51 // +Inf special cases 52 MOVQ $PosInf, AX 53 MOVQ x+0(FP), R8 54 CMPQ AX, R8 55 JEQ isPosInf 56 MOVQ y+8(FP), R9 57 CMPQ AX, R9 58 JEQ isPosInf 59 // NaN special cases 60 MOVQ $~(1<<63), DX // bit mask 61 MOVQ $PosInf, AX 62 MOVQ R8, BX 63 ANDQ DX, BX // x = |x| 64 CMPQ AX, BX 65 JLT isMaxNaN 66 MOVQ R9, CX 67 ANDQ DX, CX // y = |y| 68 CMPQ AX, CX 69 JLT isMaxNaN 70 // 0 special cases 71 ORQ CX, BX 72 JEQ isMaxZero 73 74 MOVQ R8, X0 75 MOVQ R9, X1 76 MAXSD X1, X0 77 MOVSD X0, ret+16(FP) 78 RET 79 isMaxNaN: // return NaN 80 MOVQ $NaN, AX 81 isPosInf: // return +Inf 82 MOVQ AX, ret+16(FP) 83 RET 84 isMaxZero: 85 MOVQ $(1<<63), AX // -0.0 86 CMPQ AX, R8 87 JEQ +3(PC) 88 MOVQ R8, ret+16(FP) // return 0 89 RET 90 MOVQ R9, ret+16(FP) // return other 0 91 RET 92 93 // func Min(x, y float64) float64 94 TEXT Min(SB),NOSPLIT,$0 95 // -Inf special cases 96 MOVQ $NegInf, AX 97 MOVQ x+0(FP), R8 98 CMPQ AX, R8 99 JEQ isNegInf 100 MOVQ y+8(FP), R9 101 CMPQ AX, R9 102 JEQ isNegInf 103 // NaN special cases 104 MOVQ $~(1<<63), DX 105 MOVQ $PosInf, AX 106 MOVQ R8, BX 107 ANDQ DX, BX // x = |x| 108 CMPQ AX, BX 109 JLT isMinNaN 110 MOVQ R9, CX 111 ANDQ DX, CX // y = |y| 112 CMPQ AX, CX 113 JLT isMinNaN 114 // 0 special cases 115 ORQ CX, BX 116 JEQ isMinZero 117 118 MOVQ R8, X0 119 MOVQ R9, X1 120 MINSD X1, X0 121 MOVSD X0, ret+16(FP) 122 RET 123 isMinNaN: // return NaN 124 MOVQ $NaN, AX 125 isNegInf: // return -Inf 126 MOVQ AX, ret+16(FP) 127 RET 128 isMinZero: 129 MOVQ $(1<<63), AX // -0.0 130 CMPQ AX, R8 131 JEQ +3(PC) 132 MOVQ R9, ret+16(FP) // return other 0 133 RET 134 MOVQ R8, ret+16(FP) // return -0 135 RET 136 137
