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      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 (a] 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 (a] 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 regname = []string{
     41 	".ax",
     42 	".cx",
     43 	".dx",
     44 	".bx",
     45 	".sp",
     46 	".bp",
     47 	".si",
     48 	".di",
     49 	".x0",
     50 	".x1",
     51 	".x2",
     52 	".x3",
     53 	".x4",
     54 	".x5",
     55 	".x6",
     56 	".x7",
     57 }
     58 
     59 func regnames(n *int) []string {
     60 	*n = NREGVAR
     61 	return regname
     62 }
     63 
     64 func excludedregs() uint64 {
     65 	return RtoB(x86.REG_SP)
     66 }
     67 
     68 func doregbits(r int) uint64 {
     69 	b := uint64(0)
     70 	if r >= x86.REG_AX && r <= x86.REG_DI {
     71 		b |= RtoB(r)
     72 	} else if r >= x86.REG_AL && r <= x86.REG_BL {
     73 		b |= RtoB(r - x86.REG_AL + x86.REG_AX)
     74 	} else if r >= x86.REG_AH && r <= x86.REG_BH {
     75 		b |= RtoB(r - x86.REG_AH + x86.REG_AX)
     76 	} else if r >= x86.REG_X0 && r <= x86.REG_X0+7 {
     77 		b |= FtoB(r)
     78 	}
     79 	return b
     80 }
     81 
     82 func RtoB(r int) uint64 {
     83 	if r < x86.REG_AX || r > x86.REG_DI {
     84 		return 0
     85 	}
     86 	return 1 << uint(r-x86.REG_AX)
     87 }
     88 
     89 func BtoR(b uint64) int {
     90 	b &= 0xff
     91 	if b == 0 {
     92 		return 0
     93 	}
     94 	return gc.Bitno(b) + x86.REG_AX
     95 }
     96 
     97 func FtoB(f int) uint64 {
     98 	if f < x86.REG_X0 || f > x86.REG_X7 {
     99 		return 0
    100 	}
    101 	return 1 << uint(f-x86.REG_X0+8)
    102 }
    103 
    104 func BtoF(b uint64) int {
    105 	b &= 0xFF00
    106 	if b == 0 {
    107 		return 0
    108 	}
    109 	return gc.Bitno(b) - 8 + x86.REG_X0
    110 }
    111