Cast error ?

[hutou]

Given the following code :

alias CellType = Bool | Char | Int::Signed | Int::Unsigned | Float32 | Float64 | String | Symbol
x = 7.as(CellType)
y = x.as(Number)
puts typeof(y)
puts y * 2

displayed results are :

(Float32 | Float64 | Int128 | Int16 | Int32 | Int64 | Int8 | UInt128 | UInt16 | UInt32 | UInt64 | UInt8)
14

But if I try to multiply y with any other value than 2, for example
puts y * 3
I get :

/usr/bin/ld: _main.o: in function `__crystal_main':
./eval:4: undefined reference to `__muloti4'
collect2: error: ld returned 1 exit status
Error: execution of command failed with code: 1: `cc "${@}" -o '/home/crystal/.cache/crystal/crystal-run-eval.tmp'  -rdynamic  -lpcre -lm -lgc -lpthread /usr/lib/crystal/ext/libcrystal.a -levent -lrt -ldl -L/usr/lib -L/usr/local/lib`

This error appears from the 0.31 release

[oprypin]

Yep, this is real
https://carc.in/#/r/7ozm

[bcardiff]

@hutou can you describe your environment? arch/distro

The issue is related to the partial Int128 bits support?

As a workaround, you should be able to

alias CellType = Float32 | Float64 | Int16 | Int32 | Int64 | Int8 | UInt16 | UInt32 | UInt64 | UInt8
x = 7.as(CellType)
y = x.as(Number)
puts typeof(y)
puts y * 2
puts y * 3

Might be fixed after #7093

[oprypin]

@bcardiff it also happens on carc.in!
That's probably Arch Linux

[hutou]

@bcardiff Environment is : Gnome 3.34.0 on Archlinux (5.3.1-arch1-1-ARCH - x86_64)
As you suggest, removing UInt128 and Int128 from CellType solves the problem

[RX14]

y * 2 will be optimized to a shift, avoiding the muloti4 call. This is just about compiler-rt.

[jhass]

So is this something we need to fix in Archlinux packaging or in the compiler?

[straight-shoota]

The reproduction is trivial: 1.to_i128 * 3. The missing symbol muloti4 is supposed to implement multiplication of 128-bit integers in compiler-rt.

We're just missing support for 128-bit arithmetics and the Int::Signed and Int::Unsigned unions include Int128 and UInt128 types. This is just a duplicate of #8373.