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 Max(x, y float64) float64 14 TEXT Max(SB),NOSPLIT,$0 15 // +Inf special cases 16 MOVD $PosInf, R4 17 MOVD x+0(FP), R8 18 CMPUBEQ R4, R8, isPosInf 19 MOVD y+8(FP), R9 20 CMPUBEQ R4, R9, isPosInf 21 // NaN special cases 22 MOVD $~(1<<63), R5 // bit mask 23 MOVD $PosInf, R4 24 MOVD R8, R2 25 AND R5, R2 // x = |x| 26 CMPUBLT R4, R2, isMaxNaN 27 MOVD R9, R3 28 AND R5, R3 // y = |y| 29 CMPUBLT R4, R3, isMaxNaN 30 // 0 special cases 31 OR R3, R2 32 BEQ isMaxZero 33 34 FMOVD x+0(FP), F1 35 FMOVD y+8(FP), F2 36 FCMPU F2, F1 37 BGT +3(PC) 38 FMOVD F1, ret+16(FP) 39 RET 40 FMOVD F2, ret+16(FP) 41 RET 42 isMaxNaN: // return NaN 43 MOVD $NaN, R4 44 isPosInf: // return +Inf 45 MOVD R4, ret+16(FP) 46 RET 47 isMaxZero: 48 MOVD $(1<<63), R4 // -0.0 49 CMPUBEQ R4, R8, +3(PC) 50 MOVD R8, ret+16(FP) // return 0 51 RET 52 MOVD R9, ret+16(FP) // return other 0 53 RET 54 55 // func Min(x, y float64) float64 56 TEXT Min(SB),NOSPLIT,$0 57 // -Inf special cases 58 MOVD $NegInf, R4 59 MOVD x+0(FP), R8 60 CMPUBEQ R4, R8, isNegInf 61 MOVD y+8(FP), R9 62 CMPUBEQ R4, R9, isNegInf 63 // NaN special cases 64 MOVD $~(1<<63), R5 65 MOVD $PosInf, R4 66 MOVD R8, R2 67 AND R5, R2 // x = |x| 68 CMPUBLT R4, R2, isMinNaN 69 MOVD R9, R3 70 AND R5, R3 // y = |y| 71 CMPUBLT R4, R3, isMinNaN 72 // 0 special cases 73 OR R3, R2 74 BEQ isMinZero 75 76 FMOVD x+0(FP), F1 77 FMOVD y+8(FP), F2 78 FCMPU F2, F1 79 BLT +3(PC) 80 FMOVD F1, ret+16(FP) 81 RET 82 FMOVD F2, ret+16(FP) 83 RET 84 isMinNaN: // return NaN 85 MOVD $NaN, R4 86 isNegInf: // return -Inf 87 MOVD R4, ret+16(FP) 88 RET 89 isMinZero: 90 MOVD $(1<<63), R4 // -0.0 91 CMPUBEQ R4, R8, +3(PC) 92 MOVD R9, ret+16(FP) // return other 0 93 RET 94 MOVD R8, ret+16(FP) // return -0 95 RET 96 97
