q/src/build/SaveRegister.go

43 lines
893 B
Go

package build
import (
"git.akyoto.dev/cli/q/src/build/asm"
"git.akyoto.dev/cli/q/src/build/config"
"git.akyoto.dev/cli/q/src/build/cpu"
)
// SaveRegister attempts to move a variable occupying this register to another register.
func (f *Function) SaveRegister(register cpu.Register) {
if f.cpu.IsFree(register) {
return
}
var variable *Variable
for _, v := range f.variables {
if v.Register == register {
variable = v
break
}
}
if variable == nil || variable.Alive == 0 {
return
}
newRegister, exists := f.cpu.FindFree(f.cpu.General)
if !exists {
panic("no free registers")
}
if config.Verbose {
f.Logf("moving %s from %s to %s (alive: %d)", variable.Name, variable.Register, newRegister, variable.Alive)
}
f.assembler.RegisterRegister(asm.MOVE, newRegister, register)
f.cpu.Free(register)
f.cpu.Use(newRegister)
variable.Register = newRegister
}