func (fr *frame) createZExtOrTrunc(v llvm.Value, t llvm.Type, name string) llvm.Value {
switch n := v.Type().IntTypeWidth() - t.IntTypeWidth(); {
case n < 0:
v = fr.builder.CreateZExt(v, fr.target.IntPtrType(), name)
case n > 0:
v = fr.builder.CreateTrunc(v, fr.target.IntPtrType(), name)
}
return v
}
