func (mach X86) binaryShiftOp(code gen.RegCoder, index uint8, a, b values.Operand) values.Operand {
insn := binaryShiftInsns[index]
var targetReg regs.R
switch b.Storage {
case values.Imm:
targetReg, _ = mach.opMaybeResultReg(code, a, true)
insn.imm.op(code, b.Type, targetReg, uint8(b.ImmValue()))
default:
if b.Storage.IsReg() && b.Reg() == regShiftCount {
targetReg, _ = mach.opMaybeResultReg(code, a, false)
defer code.Discard(b)
} else {
if code.RegAllocated(types.I32, regShiftCount) {
targetReg, _ = mach.opMaybeResultReg(code, a, true)
if targetReg == regShiftCount {
Mov.opFromReg(code, a.Type, regResult, regShiftCount)
targetReg = regResult
defer code.FreeReg(types.I32, regShiftCount)
} else {
// unknown operand in regShiftCount
Mov.opFromReg(code, types.I64, regScratch, regShiftCount)
defer Mov.opFromReg(code, types.I64, regShiftCount, regScratch)
}
} else {
code.AllocSpecificReg(types.I32, regShiftCount)
defer code.FreeReg(types.I32, regShiftCount)
targetReg, _ = mach.opMaybeResultReg(code, a, true)
}
b.Type = types.I32 // TODO: 8-bit mov
mach.OpMove(code, regShiftCount, b, false)
}
insn.opReg(code, a.Type, targetReg)
}
return values.TempRegOperand(a.Type, targetReg, true)
}