src/cmd/compile/internal/ssa/gen/decArgs.rules

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Decompose compound argument values
// Do this early to simplify tracking names for debugging.

(Arg {n} [off]) && v.Type.IsString() ->
  (StringMake
    (Arg <typ.BytePtr> {n} [off])
    (Arg <typ.Int> {n} [off+config.PtrSize]))

(Arg {n} [off]) && v.Type.IsSlice() ->
  (SliceMake
    (Arg <v.Type.Elem().PtrTo()> {n} [off])
    (Arg <typ.Int> {n} [off+config.PtrSize])
    (Arg <typ.Int> {n} [off+2*config.PtrSize]))

(Arg {n} [off]) && v.Type.IsInterface() ->
  (IMake
    (Arg <typ.Uintptr> {n} [off])
    (Arg <typ.BytePtr> {n} [off+config.PtrSize]))

(Arg {n} [off]) && v.Type.IsComplex() && v.Type.Size() == 16 ->
  (ComplexMake
    (Arg <typ.Float64> {n} [off])
    (Arg <typ.Float64> {n} [off+8]))

(Arg {n} [off]) && v.Type.IsComplex() && v.Type.Size() == 8 ->
  (ComplexMake
    (Arg <typ.Float32> {n} [off])
    (Arg <typ.Float32> {n} [off+4]))

(Arg <t>) && t.IsStruct() && t.NumFields() == 0 && fe.CanSSA(t) ->
  (StructMake0)
(Arg <t> {n} [off]) && t.IsStruct() && t.NumFields() == 1 && fe.CanSSA(t) ->
  (StructMake1
    (Arg <t.FieldType(0)> {n} [off+t.FieldOff(0)]))
(Arg <t> {n} [off]) && t.IsStruct() && t.NumFields() == 2 && fe.CanSSA(t) ->
  (StructMake2
    (Arg <t.FieldType(0)> {n} [off+t.FieldOff(0)])
    (Arg <t.FieldType(1)> {n} [off+t.FieldOff(1)]))
(Arg <t> {n} [off]) && t.IsStruct() && t.NumFields() == 3 && fe.CanSSA(t) ->
  (StructMake3
    (Arg <t.FieldType(0)> {n} [off+t.FieldOff(0)])
    (Arg <t.FieldType(1)> {n} [off+t.FieldOff(1)])
    (Arg <t.FieldType(2)> {n} [off+t.FieldOff(2)]))
(Arg <t> {n} [off]) && t.IsStruct() && t.NumFields() == 4 && fe.CanSSA(t) ->
  (StructMake4
    (Arg <t.FieldType(0)> {n} [off+t.FieldOff(0)])
    (Arg <t.FieldType(1)> {n} [off+t.FieldOff(1)])
    (Arg <t.FieldType(2)> {n} [off+t.FieldOff(2)])
    (Arg <t.FieldType(3)> {n} [off+t.FieldOff(3)]))

(Arg <t>) && t.IsArray() && t.NumElem() == 0 ->
  (ArrayMake0)
(Arg <t> {n} [off]) && t.IsArray() && t.NumElem() == 1 && fe.CanSSA(t) ->
  (ArrayMake1 (Arg <t.Elem()> {n} [off]))