github.com/sean-/go@v0.0.0-20151219100004-97f854cd7bb6/src/cmd/compile/internal/amd64/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 amd64
    32  
    33  import (
    34  	"cmd/compile/internal/gc"
    35  	"cmd/internal/obj"
    36  	"cmd/internal/obj/x86"
    37  )
    38  
    39  const (
    40  	NREGVAR = 32
    41  )
    42  
    43  var regname = []string{
    44  	".AX",
    45  	".CX",
    46  	".DX",
    47  	".BX",
    48  	".SP",
    49  	".BP",
    50  	".SI",
    51  	".DI",
    52  	".R8",
    53  	".R9",
    54  	".R10",
    55  	".R11",
    56  	".R12",
    57  	".R13",
    58  	".R14",
    59  	".R15",
    60  	".X0",
    61  	".X1",
    62  	".X2",
    63  	".X3",
    64  	".X4",
    65  	".X5",
    66  	".X6",
    67  	".X7",
    68  	".X8",
    69  	".X9",
    70  	".X10",
    71  	".X11",
    72  	".X12",
    73  	".X13",
    74  	".X14",
    75  	".X15",
    76  }
    77  
    78  func regnames(n *int) []string {
    79  	*n = NREGVAR
    80  	return regname
    81  }
    82  
    83  func excludedregs() uint64 {
    84  	return RtoB(x86.REG_SP)
    85  }
    86  
    87  func doregbits(r int) uint64 {
    88  	b := uint64(0)
    89  	if r >= x86.REG_AX && r <= x86.REG_R15 {
    90  		b |= RtoB(r)
    91  	} else if r >= x86.REG_AL && r <= x86.REG_R15B {
    92  		b |= RtoB(r - x86.REG_AL + x86.REG_AX)
    93  	} else if r >= x86.REG_AH && r <= x86.REG_BH {
    94  		b |= RtoB(r - x86.REG_AH + x86.REG_AX)
    95  	} else if r >= x86.REG_X0 && r <= x86.REG_X0+15 {
    96  		b |= FtoB(r)
    97  	}
    98  	return b
    99  }
   100  
   101  // For ProgInfo.
   102  const (
   103  	AX  = 1 << (x86.REG_AX - x86.REG_AX)
   104  	BX  = 1 << (x86.REG_BX - x86.REG_AX)
   105  	CX  = 1 << (x86.REG_CX - x86.REG_AX)
   106  	DX  = 1 << (x86.REG_DX - x86.REG_AX)
   107  	DI  = 1 << (x86.REG_DI - x86.REG_AX)
   108  	SI  = 1 << (x86.REG_SI - x86.REG_AX)
   109  	R15 = 1 << (x86.REG_R15 - x86.REG_AX)
   110  	X0  = 1 << 16
   111  )
   112  
   113  func RtoB(r int) uint64 {
   114  	if r < x86.REG_AX || r > x86.REG_R15 {
   115  		return 0
   116  	}
   117  	return 1 << uint(r-x86.REG_AX)
   118  }
   119  
   120  func BtoR(b uint64) int {
   121  	b &= 0xffff
   122  	if gc.Nacl {
   123  		b &^= (1<<(x86.REG_BP-x86.REG_AX) | 1<<(x86.REG_R15-x86.REG_AX))
   124  	} else if obj.Framepointer_enabled != 0 {
   125  		// BP is part of the calling convention if framepointer_enabled.
   126  		b &^= (1 << (x86.REG_BP - x86.REG_AX))
   127  	}
   128  	if b == 0 {
   129  		return 0
   130  	}
   131  	return gc.Bitno(b) + x86.REG_AX
   132  }
   133  
   134  /*
   135   *	bit	reg
   136   *	16	X0
   137   *	...
   138   *	31	X15
   139   */
   140  func FtoB(f int) uint64 {
   141  	if f < x86.REG_X0 || f > x86.REG_X15 {
   142  		return 0
   143  	}
   144  	return 1 << uint(f-x86.REG_X0+16)
   145  }
   146  
   147  func BtoF(b uint64) int {
   148  	b &= 0xFFFF0000
   149  	if b == 0 {
   150  		return 0
   151  	}
   152  	return gc.Bitno(b) - 16 + x86.REG_X0
   153  }