frontend: crash in mostly constant function

[AndreasKrall]

The following program:

  constant VL    = 128                // vector length, number of bits in a vector register

  using Bits5    = Bits< 5>           //  5 bit type
  using Bits2    = Bits< 2>           //  2 bit type
  using BitsX    = Bits<64>           // 64 bit type

  function DecodePredCount(pattern: Bits5, size: Bits2) -> BitsX =
    let elements = VL >> (3+size) in
      match pattern with
        { '00000' => elements as BitsX                      // elements is always a power of 2
        , '00001' => if elements >=   1 then   1 else 0
        , '00010' => if elements >=   2 then   2 else 0
        , '00011' => if elements >=   3 then   3 else 0
        , '00100' => if elements >=   4 then   4 else 0
        , '00101' => if elements >=   5 then   5 else 0
        , '00110' => if elements >=   6 then   6 else 0
        , '00111' => if elements >=   7 then   7 else 0
        , '01000' => if elements >=   8 then   8 else 0
        , '01001' => if elements >=  16 then  16 else 0
        , '01010' => if elements >=  32 then  32 else 0
        , '01011' => if elements >=  64 then  64 else 0
        , '01100' => if elements >= 128 then 128 else 0
        , '01101' => if elements >= 256 then 256 else 0
        , '11101' => elements - elements % 4
        , '11110' => elements - elements % 3
        , '11111' => elements
        , _       => 0
        }

leads to the following crash:

                             ___ ___    _   ___ _  _
                            / __| _ \  /_\ / __| || |
                           | (__|   / / _ \\__ \ __ |
                            \___|_|_\/_/ \_\___/_||_|

                       🔥 The OpenVADL compiler crashed 🔥

This shouldn't have happened, please open an issue with the stacktrace below at:
https://github.com/OpenVADL/open-vadl/issues/new


vadl.ast.EvaluationError: Cannot evaluate identifier with origin of vadl.ast.Parameter
	at vadl.ast.ConstantEvaluator.visitIdentifiable(ConstantEvaluator.java:112)
	at vadl.ast.ConstantEvaluator.visit(ConstantEvaluator.java:158)
	at vadl.ast.ConstantEvaluator.visit(ConstantEvaluator.java:47)
	at vadl.ast.Identifier.accept(Expr.java:219)
	at vadl.ast.ConstantEvaluator.eval(ConstantEvaluator.java:70)
	at vadl.ast.ConstantEvaluator.visit(ConstantEvaluator.java:201)
	at vadl.ast.ConstantEvaluator.visit(ConstantEvaluator.java:47)
	at vadl.ast.BinaryExpr.accept(Expr.java:454)
	at vadl.ast.ConstantEvaluator.visit(ConstantEvaluator.java:404)
	at vadl.ast.ConstantEvaluator.visit(ConstantEvaluator.java:47)
	at vadl.ast.CastExpr.accept(Expr.java:2217)
	at vadl.ast.ConstantEvaluator.eval(ConstantEvaluator.java:70)
	at vadl.ast.ConstantEvaluator.visit(ConstantEvaluator.java:201)
	at vadl.ast.ConstantEvaluator.visit(ConstantEvaluator.java:47)
	at vadl.ast.BinaryExpr.accept(Expr.java:454)
	at vadl.ast.ConstantEvaluator.eval(ConstantEvaluator.java:70)
	at vadl.ast.TypeChecker.visit(TypeChecker.java:2596)
	at vadl.ast.TypeChecker.visit(TypeChecker.java:74)
	at vadl.ast.BinaryExpr.accept(Expr.java:454)
	at vadl.ast.TypeChecker.check(TypeChecker.java:161)
	at vadl.ast.TypeChecker.visit(TypeChecker.java:3638)
	at vadl.ast.TypeChecker.visit(TypeChecker.java:74)
	at vadl.ast.LetExpr.accept(Expr.java:2143)
	at vadl.ast.TypeChecker.check(TypeChecker.java:161)
	at vadl.ast.TypeChecker.visit(TypeChecker.java:1085)
	at vadl.ast.TypeChecker.visit(TypeChecker.java:74)
	at vadl.ast.FunctionDefinition.accept(Definition.java:1977)
	at vadl.ast.TypeChecker.check(TypeChecker.java:261)
	at java.base@25.0.1/java.util.ArrayList.forEach(ArrayList.java:1604)
	at vadl.ast.TypeChecker.verify(TypeChecker.java:284)
	at vadl.cli.BaseCommand.parseToVIAM(BaseCommand.java:255)
	at vadl.cli.BaseCommand.call(BaseCommand.java:329)
	at vadl.cli.BaseCommand.call(BaseCommand.java:66)
	at picocli.CommandLine.executeUserObject(CommandLine.java:2045)
	at picocli.CommandLine.access$1500(CommandLine.java:148)
	at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2465)
	at picocli.CommandLine$RunLast.handle(CommandLine.java:2457)
	at picocli.CommandLine$RunLast.handle(CommandLine.java:2419)
	at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2277)
	at picocli.CommandLine$RunLast.execute(CommandLine.java:2421)
	at picocli.CommandLine.execute(CommandLine.java:2174)
	at vadl.cli.Main.main(Main.java:44)
	at java.base@25.0.1/java.lang.invoke.LambdaForm$DMH/sa346b79c.invokeStaticInit(LambdaForm$DMH)

[flofriday]

The interpreter doesn't have the concept of function frames and therefore can only interpret the most simple functions (the ones that don't read any parameters).

This will need some restructuring to implement. How soon do you need it?

[AndreasKrall]

This one is not so important now, but the next one I would need soon

[AndreasKrall]

I just noticed, this is also only the shift problem. It works fine if I change the program to

  constant VL    = 128                // vector length, number of bits in a vector register

  using Bits5    = Bits< 5>           //  5 bit type
  using Bits2    = Bits< 2>           //  2 bit type
  using BitsX    = Bits<64>           // 64 bit type

  function DecodePredCount(pattern: Bits5, size: Bits2) -> BitsX =
    let elements = VL as BitsX >> (3+size) in
      match pattern with
        { 0b00000 => elements as BitsX                      // elements is always a power of 2
        , 0b00001 => if elements >=   1 then   1 as BitsX else 0
        , 0b00010 => if elements >=   2 then   2 as BitsX else 0
        , 0b00011 => if elements >=   3 then   3 as BitsX else 0
        , 0b00100 => if elements >=   4 then   4 as BitsX else 0
        , 0b00101 => if elements >=   5 then   5 as BitsX else 0
        , 0b00110 => if elements >=   6 then   6 as BitsX else 0
        , 0b00111 => if elements >=   7 then   7 as BitsX else 0
        , 0b01000 => if elements >=   8 then   8 as BitsX else 0
        , 0b01001 => if elements >=  16 then  16 as BitsX else 0
        , 0b01010 => if elements >=  32 then  32 as BitsX else 0
        , 0b01011 => if elements >=  64 then  64 as BitsX else 0
        , 0b01100 => if elements >= 128 then 128 as BitsX else 0
        , 0b01101 => if elements >= 256 then 256 as BitsX else 0
        , 0b11101 => elements - elements % 4
        , 0b11110 => elements - elements % 3
        , 0b11111 => elements
        , _       => 0
        }

[flofriday]

Oh I was confused by the title then.
So I guess that's the same issue like the #654 then, let me check and close this too if so.

[flofriday]

I verified that it was the same issue as #654 so closing this.