github.com/rakyll/go@v0.0.0-20170216000551-64c02460d703/src/cmd/compile/internal/ssa/gen/dec.rules (about)

     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  // This file contains rules to decompose builtin compound types
     6  // (complex,string,slice,interface) into their constituent
     7  // types.  These rules work together with the decomposeBuiltIn
     8  // pass which handles phis of these types.
     9  
    10  // complex ops
    11  (ComplexReal (ComplexMake real _  )) -> real
    12  (ComplexImag (ComplexMake _ imag )) -> imag
    13  
    14  (Load <t> ptr mem) && t.IsComplex() && t.Size() == 8 ->
    15    (ComplexMake
    16      (Load <config.fe.TypeFloat32()> ptr mem)
    17      (Load <config.fe.TypeFloat32()>
    18        (OffPtr <config.fe.TypeFloat32().PtrTo()> [4] ptr)
    19        mem)
    20      )
    21  (Store [8] dst (ComplexMake real imag) mem) ->
    22    (Store [4]
    23      (OffPtr <config.fe.TypeFloat32().PtrTo()> [4] dst)
    24      imag
    25      (Store [4] dst real mem))
    26  (Load <t> ptr mem) && t.IsComplex() && t.Size() == 16 ->
    27    (ComplexMake
    28      (Load <config.fe.TypeFloat64()> ptr mem)
    29      (Load <config.fe.TypeFloat64()>
    30        (OffPtr <config.fe.TypeFloat64().PtrTo()> [8] ptr)
    31        mem)
    32      )
    33  (Store [16] dst (ComplexMake real imag) mem) ->
    34    (Store [8]
    35      (OffPtr <config.fe.TypeFloat64().PtrTo()> [8] dst)
    36      imag
    37      (Store [8] dst real mem))
    38  
    39  // string ops
    40  (StringPtr (StringMake ptr _)) -> ptr
    41  (StringLen (StringMake _ len)) -> len
    42  
    43  (Load <t> ptr mem) && t.IsString() ->
    44    (StringMake
    45      (Load <config.fe.TypeBytePtr()> ptr mem)
    46      (Load <config.fe.TypeInt()>
    47        (OffPtr <config.fe.TypeInt().PtrTo()> [config.PtrSize] ptr)
    48        mem))
    49  (Store [2*config.PtrSize] dst (StringMake ptr len) mem) ->
    50    (Store [config.PtrSize]
    51      (OffPtr <config.fe.TypeInt().PtrTo()> [config.PtrSize] dst)
    52      len
    53      (Store [config.PtrSize] dst ptr mem))
    54  
    55  // slice ops
    56  (SlicePtr (SliceMake ptr _ _ )) -> ptr
    57  (SliceLen (SliceMake _ len _)) -> len
    58  (SliceCap (SliceMake _ _ cap)) -> cap
    59  
    60  (Load <t> ptr mem) && t.IsSlice() ->
    61    (SliceMake
    62      (Load <t.ElemType().PtrTo()> ptr mem)
    63      (Load <config.fe.TypeInt()>
    64        (OffPtr <config.fe.TypeInt().PtrTo()> [config.PtrSize] ptr)
    65        mem)
    66      (Load <config.fe.TypeInt()>
    67        (OffPtr <config.fe.TypeInt().PtrTo()> [2*config.PtrSize] ptr)
    68        mem))
    69  (Store [3*config.PtrSize] dst (SliceMake ptr len cap) mem) ->
    70    (Store [config.PtrSize]
    71      (OffPtr <config.fe.TypeInt().PtrTo()> [2*config.PtrSize] dst)
    72      cap
    73      (Store [config.PtrSize]
    74        (OffPtr <config.fe.TypeInt().PtrTo()> [config.PtrSize] dst)
    75        len
    76        (Store [config.PtrSize] dst ptr mem)))
    77  
    78  // interface ops
    79  (ITab (IMake itab _)) -> itab
    80  (IData (IMake _ data)) -> data
    81  
    82  (Load <t> ptr mem) && t.IsInterface() ->
    83    (IMake
    84      (Load <config.fe.TypeBytePtr()> ptr mem)
    85      (Load <config.fe.TypeBytePtr()>
    86        (OffPtr <config.fe.TypeBytePtr().PtrTo()> [config.PtrSize] ptr)
    87        mem))
    88  (Store [2*config.PtrSize] dst (IMake itab data) mem) ->
    89    (Store [config.PtrSize]
    90      (OffPtr <config.fe.TypeBytePtr().PtrTo()> [config.PtrSize] dst)
    91      data
    92      (Store [config.PtrSize] dst itab mem))