func (f *Function) AllocInstr(instr *ssa.Alloc) (string, *Error) {
asm := ""
if instr == nil {
return ErrorMsg("AllocInstr: nil instr")
}
if instr.Heap {
msg := "Heap allocations are unsupported (are all print and log statements removed?), ssa variable: %v, type: %v"
msgstr := fmt.Sprintf(msg, instr.Name(), instr.Type())
return ErrorMsg(msgstr)
}
//Alloc values are always addresses, and have pointer types, so the type
//of the allocated variable is actually
//Type().Underlying().(*types.Pointer).Elem().
info := f.identifiers[instr.Name()]
if info.local == nil {
ice(fmt.Sprintf("expected %v to be a local variable", instr.Name()))
}
if _, ok := info.typ.(*types.Pointer); ok {
} else {
}
f.identifiers[instr.Name()] = info
return asm, nil
}
func visitAlloc(instr *ssa.Alloc, infer *TypeInfer, ctx *Context) {
allocType := instr.Type().(*types.Pointer).Elem()
switch t := allocType.Underlying().(type) {
case *types.Array: // Static size array
ctx.F.locals[instr] = &Value{instr, ctx.F.InstanceID(), ctx.L.Index}
if instr.Heap {
ctx.F.Prog.arrays[ctx.F.locals[instr]] = make(Elems, t.Len())
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc (array@heap) of type %s (%d elems)", ctx.F.locals[instr], instr.Type(), t.Len()))
} else {
ctx.F.arrays[ctx.F.locals[instr]] = make(Elems, t.Len())
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc (array@local) of type %s (%d elems)", ctx.F.locals[instr], instr.Type(), t.Len()))
}
case *types.Struct:
ctx.F.locals[instr] = &Value{instr, ctx.F.InstanceID(), ctx.L.Index}
if instr.Heap {
ctx.F.Prog.structs[ctx.F.locals[instr]] = make(Fields, t.NumFields())
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc (struct@heap) of type %s (%d fields)", ctx.F.locals[instr], instr.Type(), t.NumFields()))
} else {
ctx.F.structs[ctx.F.locals[instr]] = make(Fields, t.NumFields())
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc (struct@local) of type %s (%d fields)", ctx.F.locals[instr], instr.Type(), t.NumFields()))
}
case *types.Pointer:
switch pt := t.Elem().Underlying().(type) {
case *types.Array:
ctx.F.locals[instr] = &Value{instr, ctx.F.InstanceID(), ctx.L.Index}
if instr.Heap {
ctx.F.Prog.arrays[ctx.F.locals[instr]] = make(Elems, pt.Len())
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc/indirect (array@heap) of type %s (%d elems)", ctx.F.locals[instr], instr.Type(), pt.Len()))
} else {
ctx.F.locals[instr] = &Value{instr, ctx.F.InstanceID(), ctx.L.Index}
ctx.F.arrays[ctx.F.locals[instr]] = make(Elems, pt.Len())
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc/indirect (array@local) of type %s (%d elems)", ctx.F.locals[instr], instr.Type(), pt.Len()))
}
case *types.Struct:
ctx.F.locals[instr] = &Value{instr, ctx.F.InstanceID(), ctx.L.Index}
if instr.Heap {
ctx.F.Prog.structs[ctx.F.locals[instr]] = make(Fields, pt.NumFields())
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc/indirect (struct@heap) of type %s (%d fields)", ctx.F.locals[instr], instr.Type(), pt.NumFields()))
} else {
ctx.F.structs[ctx.F.locals[instr]] = make(Fields, pt.NumFields())
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc/indirect (struct@local) of type %s (%d fields)", ctx.F.locals[instr], instr.Type(), pt.NumFields()))
}
default:
ctx.F.locals[instr] = &Value{instr, ctx.F.InstanceID(), ctx.L.Index}
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc/indirect of type %s", ctx.F.locals[instr], instr.Type().Underlying()))
}
default:
ctx.F.locals[instr] = &Value{instr, ctx.F.InstanceID(), ctx.L.Index}
infer.Logger.Print(ctx.F.Sprintf(NewSymbol+"%s = alloc of type %s", ctx.F.locals[instr], instr.Type().Underlying()))
}
}
// Return true iff we think it might be beneficial to turn this alloc instruction
// into a statically allocated global.
// Precondition: we are compiling the init function.
func (fr *frame) shouldStaticallyAllocate(alloc *ssa.Alloc) bool {
// First, see if the allocated type is an array or struct, and if so determine
// the number of elements in the type. If the type is anything else, we
// statically allocate unconditionally.
var numElems int64
switch ty := deref(alloc.Type()).Underlying().(type) {
case *types.Array:
numElems = ty.Len()
case *types.Struct:
numElems = int64(ty.NumFields())
default:
return true
}
// We treat the number of referrers to the alloc instruction as a rough
// proxy for the number of elements initialized. If the data structure
// is densely initialized (> 1/4 elements initialized), enable the
// optimization.
return int64(len(*alloc.Referrers()))*4 > numElems
}
// visitAlloc is for variable allocation (usually by 'new')
// Everything allocated here are pointers
func visitAlloc(inst *ssa.Alloc, fr *frame) {
locn := loc(fr, inst.Pos())
allocType := inst.Type().(*types.Pointer).Elem()
if allocType == nil {
panic("Alloc: Cannot Alloc for non-pointer type")
}
var val ssa.Value = inst
switch t := allocType.Underlying().(type) {
case *types.Array:
vd := utils.NewDef(val)
fr.locals[val] = vd
if inst.Heap {
fr.env.arrays[vd] = make(Elems)
fmt.Fprintf(os.Stderr, " %s = Alloc (array@heap) of type %s (%d elems) at %s\n", cyan(reg(inst)), inst.Type().String(), t.Len(), locn)
} else {
fr.arrays[vd] = make(Elems)
fmt.Fprintf(os.Stderr, " %s = Alloc (array@local) of type %s (%d elems) at %s\n", cyan(reg(inst)), inst.Type().String(), t.Len(), locn)
}
case *types.Chan:
// VD will be created in MakeChan so no need to allocate here.
fmt.Fprintf(os.Stderr, " %s = Alloc (chan) of type %s at %s\n", cyan(reg(inst)), inst.Type().String(), locn)
case *types.Struct:
vd := utils.NewDef(val)
fr.locals[val] = vd
if inst.Heap {
fr.env.structs[vd] = make(Fields, t.NumFields())
fmt.Fprintf(os.Stderr, " %s = Alloc (struct@heap) of type %s (%d fields) at %s\n", cyan(reg(inst)), inst.Type().String(), t.NumFields(), locn)
} else {
fr.structs[vd] = make(Fields, t.NumFields())
fmt.Fprintf(os.Stderr, " %s = Alloc (struct@local) of type %s (%d fields) at %s\n", cyan(reg(inst)), inst.Type().String(), t.NumFields(), locn)
}
default:
fmt.Fprintf(os.Stderr, " # %s = "+red("Alloc %s")+" of type %s\n", inst.Name(), inst.String(), t.String())
}
}