Custom primitives to disable binary ops across int/float sizes

[ysbaddaden]

The current primitives.cr in crystal always define cross integer and float sizes binary operations. I'd like to disable that in nano, and only have binary operations across same type & sizes, only keeping the checked & unchecked conversions. We could then bring them back on demand.

Note: I wonder why cross type operations are primitives, they could be handled in stdlib only:

struct Int32
  @[AlwaysInline]
  def +(other : Int8) : Int32
    self + other.to_i32!
  end
end

[straight-shoota]

I wonder why cross type operations are primitives, they could be handled in stdlib only.

LLVM exposes cross-size operations directly, so it's quite easily available. Maybe there's some efficiency benefit? Although I would expect the optimizer to handle this as well. But maybe primitives are more performant without optimizations?

[ysbaddaden]

The LLVM IR looks identical to the above crystal code (cast then add), optimized or not (using unchecked math for brevity):

@[NoInline]
def add(a : Int32, other : Int8) : Int32
  a &+ other
end

define i32 @"*add<Int32, Int8>:Int32"(i32 %a, i8 %other) #3 {
entry:
  %0 = sext i8 %other to i32
  %1 = add i32 %a, %0
  ret i32 %1
}

Maybe it's more efficient compile-time wise to always generate the LLVM code in place (inlined), than creating lots of methods to be typed, then inlined :thinking: