github.com/q45/go@v0.0.0-20151101211701-a4fb8c13db3f/src/cmd/compile/internal/arm/reg.go (about)

     1  // Inferno utils/5c/reg.c
     2  // http://code.google.com/p/inferno-os/source/browse/utils/5c/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 arm
    32  
    33  import "cmd/internal/obj/arm"
    34  import "cmd/compile/internal/gc"
    35  
    36  const (
    37  	NREGVAR = 32
    38  )
    39  
    40  var regname = []string{
    41  	".R0",
    42  	".R1",
    43  	".R2",
    44  	".R3",
    45  	".R4",
    46  	".R5",
    47  	".R6",
    48  	".R7",
    49  	".R8",
    50  	".R9",
    51  	".R10",
    52  	".R11",
    53  	".R12",
    54  	".R13",
    55  	".R14",
    56  	".R15",
    57  	".F0",
    58  	".F1",
    59  	".F2",
    60  	".F3",
    61  	".F4",
    62  	".F5",
    63  	".F6",
    64  	".F7",
    65  	".F8",
    66  	".F9",
    67  	".F10",
    68  	".F11",
    69  	".F12",
    70  	".F13",
    71  	".F14",
    72  	".F15",
    73  }
    74  
    75  func regnames(n *int) []string {
    76  	*n = NREGVAR
    77  	return regname
    78  }
    79  
    80  func excludedregs() uint64 {
    81  	return RtoB(arm.REGSP) | RtoB(arm.REGLINK) | RtoB(arm.REGPC)
    82  }
    83  
    84  func doregbits(r int) uint64 {
    85  	return 0
    86  }
    87  
    88  /*
    89   *	bit	reg
    90   *	0	R0
    91   *	1	R1
    92   *	...	...
    93   *	10	R10
    94   *	12  R12
    95   *
    96   *	bit	reg
    97   *	18	F2
    98   *	19	F3
    99   *	...	...
   100   *	31	F15
   101   */
   102  func RtoB(r int) uint64 {
   103  	if arm.REG_R0 <= r && r <= arm.REG_R15 {
   104  		if r >= arm.REGTMP-2 && r != arm.REG_R12 { // excluded R9 and R10 for m and g, but not R12
   105  			return 0
   106  		}
   107  		return 1 << uint(r-arm.REG_R0)
   108  	}
   109  
   110  	if arm.REG_F0 <= r && r <= arm.REG_F15 {
   111  		if r < arm.REG_F2 || r > arm.REG_F0+arm.NFREG-1 {
   112  			return 0
   113  		}
   114  		return 1 << uint((r-arm.REG_F0)+16)
   115  	}
   116  
   117  	return 0
   118  }
   119  
   120  func BtoR(b uint64) int {
   121  	// TODO Allow R0 and R1, but be careful with a 0 return
   122  	// TODO Allow R9. Only R10 is reserved now (just g, not m).
   123  	b &= 0x11fc // excluded R9 and R10 for m and g, but not R12
   124  	if b == 0 {
   125  		return 0
   126  	}
   127  	return gc.Bitno(b) + arm.REG_R0
   128  }
   129  
   130  func BtoF(b uint64) int {
   131  	b &= 0xfffc0000
   132  	if b == 0 {
   133  		return 0
   134  	}
   135  	return gc.Bitno(b) - 16 + arm.REG_F0
   136  }