Add 'unstructured' template that tests random instruction bit patterns

This is intended to be used in single-implementation mode to check
that unknown bit patterns at least do not wedge the processor.

QCVEngine.cabal

@@ -52,6 +52,7 @@ executable QCVEngine
                        QuickCheckVEngine.Templates.GenCHERI,
                        QuickCheckVEngine.Templates.GenAll,
                        QuickCheckVEngine.Templates.GenTransExec,
+                       QuickCheckVEngine.Templates.GenUnstructured,
                        QuickCheckVEngine.Templates.RandomTest
   other-extensions:    FlexibleInstances, MultiParamTypeClasses,
                        FunctionalDependencies, OverloadedStrings,

src/QuickCheckVEngine/Main.hs

@@ -271,6 +271,7 @@ allTests = [
            , ("caprvcrandom", "Xcheri RVC Extension Random Template",                 andPs [has_cheri, has_c],                 randomCHERIRVCTest)
            , ("all",        "All Verification",                                       const True,                               genAll)
            , ("random",     "Random Template",                                        const True,                               randomTest)
+           , ("unstructured", "Unstructured random instruction bit Template",         const True,                               T.repeatTillEnd gen_unstructured)
            ]
   where andPs = foldl (\k p x -> p x && k x) (const True)
 

src/QuickCheckVEngine/Templates/GenUnstructured.hs

@@ -0,0 +1,45 @@
+--
+-- SPDX-License-Identifier: BSD-2-Clause
+--
+-- Copyright (c) 2025 Peter Rugg
+-- All rights reserved.
+--
+-- This software was developed by SRI International and the University of
+-- Cambridge Computer Laboratory (Department of Computer Science and
+-- Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
+-- DARPA SSITH research programme.
+--
+-- Redistribution and use in source and binary forms, with or without
+-- modification, are permitted provided that the following conditions
+-- are met:
+-- 1. Redistributions of source code must retain the above copyright
+--    notice, this list of conditions and the following disclaimer.
+-- 2. Redistributions in binary form must reproduce the above copyright
+--    notice, this list of conditions and the following disclaimer in the
+--    documentation and/or other materials provided with the distribution.
+--
+-- THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+-- ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+-- ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+-- FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+-- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+-- OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+-- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+-- LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+-- OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+-- SUCH DAMAGE.
+--
+
+module QuickCheckVEngine.Templates.GenUnstructured (
+  gen_unstructured
+) where
+
+import QuickCheckVEngine.Template
+import QuickCheckVEngine.Templates.Utils
+import InstrCodec
+
+gen_unstructured :: Template
+gen_unstructured = random $ do
+  instBits <- bits 32
+  return $ inst $ MkInstruction instBits