abi

Documentation

Index

• func RegisterTypes(apa []ABIParamAssignment) []*types.Type
• type ABIConfig
  • func NewABIConfig(iRegsCount, fRegsCount int, offsetForLocals int64) *ABIConfig
  • func (config *ABIConfig) ABIAnalyze(t *types.Type, setNname bool) *ABIParamResultInfo
  • func (config *ABIConfig) ABIAnalyzeFuncType(ft *types.Func) *ABIParamResultInfo
  • func (config *ABIConfig) ABIAnalyzeTypes(rcvr *types.Type, ins, outs []*types.Type) *ABIParamResultInfo
  • func (a *ABIConfig) Copy() *ABIConfig
  • func (a *ABIConfig) FloatIndexFor(r RegIndex) int64
  • func (a *ABIConfig) LocalsOffset() int64
  • func (a *ABIConfig) NumParamRegs(t *types.Type) int
• type ABIParamAssignment
  • func (pa *ABIParamAssignment) ComputePadding(storage []uint64) []uint64
  • func (a *ABIParamAssignment) FrameOffset(i *ABIParamResultInfo) int64
  • func (a *ABIParamAssignment) Offset() int32
  • func (pa *ABIParamAssignment) RegisterTypesAndOffsets() ([]*types.Type, []int64)
  • func (ri *ABIParamAssignment) ToString(config *ABIConfig, extra bool) string
• type ABIParamResultInfo
  • func (a *ABIParamResultInfo) ArgWidth() int64
  • func (a *ABIParamResultInfo) Config() *ABIConfig
  • func (a *ABIParamResultInfo) InParam(i int) *ABIParamAssignment
  • func (a *ABIParamResultInfo) InParams() []ABIParamAssignment
  • func (a *ABIParamResultInfo) InRegistersUsed() int
  • func (a *ABIParamResultInfo) OutParam(i int) *ABIParamAssignment
  • func (a *ABIParamResultInfo) OutParams() []ABIParamAssignment
  • func (a *ABIParamResultInfo) OutRegistersUsed() int
  • func (a *ABIParamResultInfo) SpillAreaOffset() int64
  • func (a *ABIParamResultInfo) SpillAreaSize() int64
  • func (ri *ABIParamResultInfo) String() string
• type RegAmounts
• type RegIndex

Functions

func RegisterTypes

func RegisterTypes(apa []ABIParamAssignment) []*types.Type

RegisterTypes returns a slice of the types of the registers corresponding to a slice of parameters. The returned slice has capacity for one more, likely a memory type.

Types

type ABIConfig

type ABIConfig struct {
	// contains filtered or unexported fields
}

ABIConfig captures the number of registers made available by the ABI rules for parameter passing and result returning.

func NewABIConfig

func NewABIConfig(iRegsCount, fRegsCount int, offsetForLocals int64) *ABIConfig

NewABIConfig returns a new ABI configuration for an architecture with iRegsCount integer/pointer registers and fRegsCount floating point registers.

func (*ABIConfig) ABIAnalyze

func (config *ABIConfig) ABIAnalyze(t *types.Type, setNname bool) *ABIParamResultInfo

ABIAnalyze returns the same result as ABIAnalyzeFuncType, but also updates the offsets of all the receiver, input, and output fields. If setNname is true, it also sets the FrameOffset of the Nname for the field(s); this is for use when compiling a function and figuring out spill locations. Doing this for callers can cause races for register outputs because their frame location transitions from BOGUS_FUNARG_OFFSET to zero to an as-if-AUTO offset that has no use for callers.

func (*ABIConfig) ABIAnalyzeFuncType

func (config *ABIConfig) ABIAnalyzeFuncType(ft *types.Func) *ABIParamResultInfo

ABIAnalyzeFuncType takes a function type 'ft' and an ABI rules description 'config' and analyzes the function to determine how its parameters and results will be passed (in registers or on the stack), returning an ABIParamResultInfo object that holds the results of the analysis.

func (*ABIConfig) ABIAnalyzeTypes

func (config *ABIConfig) ABIAnalyzeTypes(rcvr *types.Type, ins, outs []*types.Type) *ABIParamResultInfo

ABIAnalyzeTypes takes an optional receiver type, arrays of ins and outs, and returns an ABIParamResultInfo, based on the given configuration. This is the same result computed by config.ABIAnalyze applied to the corresponding method/function type, except that all the embedded parameter names are nil. This is intended for use by ssagen/ssa.go:(*state).rtcall, for runtime functions that lack a parsed function type.

func (*ABIConfig) Copy

func (a *ABIConfig) Copy() *ABIConfig

Copy returns a copy of an ABIConfig for use in a function's compilation so that access to the cache does not need to be protected with a mutex.

func (*ABIConfig) FloatIndexFor

func (a *ABIConfig) FloatIndexFor(r RegIndex) int64

FloatIndexFor translates r into an index in the floating point parameter registers. If the result is negative, the input index was actually for the integer parameter registers.

func (*ABIConfig) LocalsOffset

func (a *ABIConfig) LocalsOffset() int64

LocalsOffset returns the architecture-dependent offset from SP for args and results. In theory this is only used for debugging; it ought to already be incorporated into results from the ABI-related methods

func (*ABIConfig) NumParamRegs

func (a *ABIConfig) NumParamRegs(t *types.Type) int

NumParamRegs returns the number of parameter registers used for a given type, without regard for the number available.

type ABIParamAssignment

type ABIParamAssignment struct {
	Type      *types.Type
	Name      types.Object // should always be *ir.Name, used to match with a particular ssa.OpArg.
	Registers []RegIndex
	// contains filtered or unexported fields
}

ABIParamAssignment holds information about how a specific param or result will be passed: in registers (in which case 'Registers' is populated) or on the stack (in which case 'Offset' is set to a non-negative stack offset. The values in 'Registers' are indices (as described above), not architected registers.

func (*ABIParamAssignment) ComputePadding

func (pa *ABIParamAssignment) ComputePadding(storage []uint64) []uint64

ComputePadding returns a list of "post element" padding values in the case where we have a structure being passed in registers. Given a param assignment corresponding to a struct, it returns a list containing padding values for each field, e.g. the Kth element in the list is the amount of padding between field K and the following field. For things that are not structs (or structs without padding) it returns a list of zeros. Example:

type small struct {
  x uint16
  y uint8
  z int32
  w int32
}

For this struct we would return a list [0, 1, 0, 0], meaning that we have one byte of padding after the second field, and no bytes of padding after any of the other fields. Input parameter "storage" is a slice with enough capacity to accommodate padding elements for the architected register set in question.

func (*ABIParamAssignment) FrameOffset

func (a *ABIParamAssignment) FrameOffset(i *ABIParamResultInfo) int64

FrameOffset returns the frame-pointer-relative location that a function would spill its input or output parameter to, if such a spill slot exists. If there is none defined (e.g., register-allocated outputs) it panics. For register-allocated inputs that is their spill offset reserved for morestack; for stack-allocated inputs and outputs, that is their location on the stack. (In a future version of the ABI, register-resident inputs may lose their defined spill area to help reduce stack sizes.)

func (*ABIParamAssignment) Offset

func (a *ABIParamAssignment) Offset() int32

Offset returns the stack offset for addressing the parameter that "a" describes. This will panic if "a" describes a register-allocated parameter.

func (*ABIParamAssignment) RegisterTypesAndOffsets

func (pa *ABIParamAssignment) RegisterTypesAndOffsets() ([]*types.Type, []int64)

func (*ABIParamAssignment) ToString

func (ri *ABIParamAssignment) ToString(config *ABIConfig, extra bool) string

ToString method renders an ABIParamAssignment in human-readable form, suitable for debugging or unit testing.

type ABIParamResultInfo

type ABIParamResultInfo struct {
	// contains filtered or unexported fields
}

ABIParamResultInfo stores the results of processing a given function type to compute stack layout and register assignments. For each input and output parameter we capture whether the param was register-assigned (and to which register(s)) or the stack offset for the param if is not going to be passed in registers according to the rules in the Go internal ABI specification (1.17).

func (*ABIParamResultInfo) ArgWidth

func (a *ABIParamResultInfo) ArgWidth() int64

ArgWidth returns the amount of stack needed for all the inputs and outputs of a function or method, including ABI-defined parameter slots and ABI-defined spill slots for register-resident parameters. The name is inherited from (*Type).ArgWidth(), which it replaces.

func (*ABIParamResultInfo) Config

func (a *ABIParamResultInfo) Config() *ABIConfig

func (*ABIParamResultInfo) InParam

func (a *ABIParamResultInfo) InParam(i int) *ABIParamAssignment

func (*ABIParamResultInfo) InParams

func (a *ABIParamResultInfo) InParams() []ABIParamAssignment

func (*ABIParamResultInfo) InRegistersUsed

func (a *ABIParamResultInfo) InRegistersUsed() int

func (*ABIParamResultInfo) OutParam

func (a *ABIParamResultInfo) OutParam(i int) *ABIParamAssignment

func (*ABIParamResultInfo) OutParams

func (a *ABIParamResultInfo) OutParams() []ABIParamAssignment

func (*ABIParamResultInfo) OutRegistersUsed

func (a *ABIParamResultInfo) OutRegistersUsed() int

func (*ABIParamResultInfo) SpillAreaOffset

func (a *ABIParamResultInfo) SpillAreaOffset() int64

func (*ABIParamResultInfo) SpillAreaSize

func (a *ABIParamResultInfo) SpillAreaSize() int64

func (*ABIParamResultInfo) String

func (ri *ABIParamResultInfo) String() string

String method renders an ABIParamResultInfo in human-readable form, suitable for debugging or unit testing.

type RegAmounts

type RegAmounts struct {
	// contains filtered or unexported fields
}

RegAmounts holds a specified number of integer/float registers.

type RegIndex

type RegIndex uint8

RegIndex stores the index into the set of machine registers used by the ABI on a specific architecture for parameter passing. RegIndex values 0 through N-1 (where N is the number of integer registers used for param passing according to the ABI rules) describe integer registers; values N through M (where M is the number of floating point registers used). Thus if the ABI says there are 5 integer registers and 7 floating point registers, then RegIndex value of 4 indicates the 5th integer register, and a RegIndex value of 11 indicates the 7th floating point register.