github.com/c0deoo1/golang1.5@v0.0.0-20220525150107-c87c805d4593/src/cmd/compile/internal/x86/reg.go (about) 1 // Derived from Inferno utils/6c/reg.c 2 // http://code.google.com/p/inferno-os/source/browse/utils/6c/reg.c 3 // 4 // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. 5 // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) 6 // Portions Copyright © 1997-1999 Vita Nuova Limited 7 // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) 8 // Portions Copyright © 2004,2006 Bruce Ellis 9 // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) 10 // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others 11 // Portions Copyright © 2009 The Go Authors. All rights reserved. 12 // 13 // Permission is hereby granted, free of charge, to any person obtaining a copy 14 // of this software and associated documentation files (the "Software"), to deal 15 // in the Software without restriction, including without limitation the rights 16 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 17 // copies of the Software, and to permit persons to whom the Software is 18 // furnished to do so, subject to the following conditions: 19 // 20 // The above copyright notice and this permission notice shall be included in 21 // all copies or substantial portions of the Software. 22 // 23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 24 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 25 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 26 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 27 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 28 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 29 // THE SOFTWARE. 30 31 package x86 32 33 import "cmd/internal/obj/x86" 34 import "cmd/compile/internal/gc" 35 36 const ( 37 NREGVAR = 16 /* 8 integer + 8 floating */ 38 ) 39 40 var reg [x86.MAXREG]uint8 41 42 var regname = []string{ 43 ".ax", 44 ".cx", 45 ".dx", 46 ".bx", 47 ".sp", 48 ".bp", 49 ".si", 50 ".di", 51 ".x0", 52 ".x1", 53 ".x2", 54 ".x3", 55 ".x4", 56 ".x5", 57 ".x6", 58 ".x7", 59 } 60 61 func regnames(n *int) []string { 62 *n = NREGVAR 63 return regname 64 } 65 66 func excludedregs() uint64 { 67 return RtoB(x86.REG_SP) 68 } 69 70 func doregbits(r int) uint64 { 71 b := uint64(0) 72 if r >= x86.REG_AX && r <= x86.REG_DI { 73 b |= RtoB(r) 74 } else if r >= x86.REG_AL && r <= x86.REG_BL { 75 b |= RtoB(r - x86.REG_AL + x86.REG_AX) 76 } else if r >= x86.REG_AH && r <= x86.REG_BH { 77 b |= RtoB(r - x86.REG_AH + x86.REG_AX) 78 } else if r >= x86.REG_X0 && r <= x86.REG_X0+7 { 79 b |= FtoB(r) 80 } 81 return b 82 } 83 84 func RtoB(r int) uint64 { 85 if r < x86.REG_AX || r > x86.REG_DI { 86 return 0 87 } 88 return 1 << uint(r-x86.REG_AX) 89 } 90 91 func BtoR(b uint64) int { 92 b &= 0xff 93 if b == 0 { 94 return 0 95 } 96 return gc.Bitno(b) + x86.REG_AX 97 } 98 99 func FtoB(f int) uint64 { 100 if f < x86.REG_X0 || f > x86.REG_X7 { 101 return 0 102 } 103 return 1 << uint(f-x86.REG_X0+8) 104 } 105 106 func BtoF(b uint64) int { 107 b &= 0xFF00 108 if b == 0 { 109 return 0 110 } 111 return gc.Bitno(b) - 8 + x86.REG_X0 112 }