q/src/asmc/jump.go

50 lines
1.0 KiB
Go

package asmc
import (
"fmt"
"git.urbach.dev/cli/q/src/asm"
"git.urbach.dev/cli/q/src/x86"
)
func (c *compiler) jump(x asm.Instruction) {
switch x.Mnemonic {
case asm.JE:
c.code = x86.Jump8IfEqual(c.code, 0x00)
case asm.JNE:
c.code = x86.Jump8IfNotEqual(c.code, 0x00)
case asm.JG:
c.code = x86.Jump8IfGreater(c.code, 0x00)
case asm.JGE:
c.code = x86.Jump8IfGreaterOrEqual(c.code, 0x00)
case asm.JL:
c.code = x86.Jump8IfLess(c.code, 0x00)
case asm.JLE:
c.code = x86.Jump8IfLessOrEqual(c.code, 0x00)
case asm.JUMP:
c.code = x86.Jump8(c.code, 0x00)
}
label := c.assembler.Param.Label[x.Index]
size := 1
pointer := &pointer{
Position: Address(len(c.code) - size),
OpSize: 1,
Size: uint8(size),
}
pointer.Resolve = func() Address {
destination, exists := c.codeLabels[label.Name]
if !exists {
panic(fmt.Sprintf("unknown jump label %s", label.Name))
}
distance := destination - (pointer.Position + Address(pointer.Size))
return distance
}
c.codePointers = append(c.codePointers, pointer)
}