package codegen

import (
	"git.urbach.dev/cli/q/src/cpu"
	"git.urbach.dev/cli/q/src/set"
	"git.urbach.dev/cli/q/src/ssa"
)

// Step is created for every single SSA value and holds additional metadata.
type Step struct {
	Value    ssa.Value
	Block    *ssa.Block
	Phis     set.Ordered[*Step]
	Live     []*Step
	Hints    []cpu.Register
	Index    Index
	Register cpu.Register
}

// hint adds a register hint to the step.
func (s *Step) hint(reg cpu.Register) {
	if reg == -1 {
		panic("invalid register hint")
	}

	if len(s.Hints) == 0 {
		s.Register = reg
	}

	s.Hints = append(s.Hints, reg)
}

// String returns the underlying SSA value in human-readable form.
func (s *Step) String() string {
	return s.Value.String()
}