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2019-04-27Merge branch 'sail2' into smt_experimentsAlasdair
2019-04-20Fix: Reduce constant-fold time for ARM from 20min+ to 10sAlasdair Armstrong
With the new interpreter changes computing the initial state for the interpreter does some significant work. The existing code was re-computing the initial state for every subexpression in the specification (not even just the ones due to be constant-folded away). Now we just compute the initial state once and use it for all constant folds. Also reduce the time taken for the simple_assignments rewrite from 20s to under 1s for ARMv8.5, by skipping l-expressions that are already in the simplest form.
2019-04-17Coq: support pure loops with termination measuresBrian Campbell
2019-04-15Merge branch 'sail2' of github.com:rems-project/sail into sail2Jon French
2019-04-15Merge branch 'sail2' into rmem_interpreterJon French
2019-04-15Basic loop termination measures for CoqBrian Campbell
Currently only supports pure termination measures for loops with effects. The user syntax uses separate termination measure declarations, as in the previous recursive termination measures, which are rewritten into the loop AST nodes before type checking (because it would be rather difficult to calculate the correct environment to type check the separate declaration in).
2019-04-13SMT: Add count_leading_zeros and more builtinsAlasdair
2019-04-11SMT: Add property and counterexample directiveAlasdair Armstrong
Rather than generating SMT from a function called check_sat, now find any function with a $property directive and generate SMT for it, e.g. $property function prop_cap_round_trip(cap: bits(128)) -> bool = { let cap_rt = capToBits(capBitsToCapability(true, cap)); cap == cap_rt } $property function prop_base_lteq_top(capbits: bits(128)) -> bool = { let c = capBitsToCapability(true, capbits); let (base, top) = getCapBounds(c); let e = unsigned(c.E); e >= 51 | base <= top } The file property.ml has a function for gathering all the properties in a file, as well as a rewrite-pass for properties with type quantifiers, which allows us to handle properties like function prop forall 'n, 'n <= 100. (bv: bits('n)) -> bool = exp by rewriting to (conceptually) function prop(bv: bits(MAX_BIT_WIDTH)) -> bool = if length(bv) > 100 then true else exp The function return is now automatically negated (i.e. always true = unsat, sometimes false = sat), which makes sense for quickcheck-type properties.
2019-04-10Coq: tweak measure rewrites slightlyBrian Campbell
Allows a quick hack where you can give a termination limit rather than a proper measure for functions with awkward termination properties.
2019-04-09SMT: Experimental Jib->SMT translationAlasdair Armstrong
Currently only works with CVC4, test cases are in test/smt. Can prove that RISC-V add instruction actually adds values in registers and that's about it for now.
2019-04-06Various bugfixes and improvementsAlasdair
- Rename DeIid to Operator. It corresponds to operator <string> in the syntax. The previous name is from when it was called deinfix in sail1. - Removed things that weren't actually common from pretty_print_common.ml, e.g. printing identifiers is backend specific. The doc_id function here was only used for a very specific use case in pretty_print_lem, so I simplified it and renamed it to doc_sia_id, as it is always used for a SIA.Id whatever that is. - There is some support for anonymous records in constructors, e.g. union Foo ('a : Type) = { MkFoo : { field1 : 'a, field2 : int } } somewhat similar to the enum syntax in Rust. I'm not sure when this was added, but there were a few odd things about it. It was desugared in the preprocessor, rather than initial_check, and the desugaring generated incorrect code for polymorphic anonymous records as above. I moved the code to initial_check, so the pre-processor now just deals with pre-processor things and not generating types, and I fixed the code to work with polymorphic types. This revealed some issues in the C backend w.r.t. polymorphic structs, which is the bulk of this commit. I also added some tests for this feature. - OCaml backend can now generate a valid string_of function for polymorphic structs, previously this would cause the ocaml to fail to compile. - Some cleanup in the Sail ott definition - Add support for E_var in interpreter previously this would just cause the interpreter to fail
2019-04-05Coq: termination measures for mutually recursive functionsBrian Campbell
2019-03-27Interactive: Refactor sail.ml some moreAlasdair Armstrong
Separate calling the rewriter from the backend-specific parts of sail.ml
2019-03-27Interactive: Refactor sail.mlAlasdair Armstrong
Rather than having a separate variable for each backend X, opt_print_X, just have a single variable opt_print_target, where target contains a string option, such as `Some "lem"` or `Some "ocaml"`, then we have a function target that takes that string and invokes the appropriate backend, so the main function in sail.ml goes from being a giant if-then-else block to a single call to target !opt_target ast env This allows us to implement a :compile <target> command in the interactive toplevel Also implement a :rewrites <target> command which performs all the rewrites for a specific target, so rather than doing e.g. > sail -c -O -o out $FILES one could instead interactively do > sail -i :option -undefined_gen :load $FILES :option -O :option -o out :rewrites c :compile c :quit for the same result. To support this the behavior of the interactive mode has changed slightly. It no longer performs any rewrites at all, so a :rewrites interpreter is currently needed to interpret functions in the interactive toplevel, nor does it automatically set any other flags, so -undefined_gen is needed in this case, which is usually implied by the -c flag.
2019-03-27Rewriter: Finish refactoring rewrite sequencesAlasdair Armstrong
2019-03-26Rewriter: Expose rewrite passes to interactive modeAlasdair Armstrong
Rather than each rewrite being an opaque function, with separate lists of rewrites for each backend, instead put all the rewrites into a single list then have each backend define which of those rewrites it wants to use and in what order. For example, rather than having let rewrite_defs_ocaml = [ ... ("rewrite_undefined", rewrite_undefined_if_gen false); ... ] we would now have let all_rewrites = [ ... ("undefined", Bool_rewriter (fun b -> Basic_rewriter (rewrite_undefined_if_gen b))); ... ] let rewriters_ocaml = [ ... ("undefined", [Bool_arg false]); ... ] let rewrite_defs_ocaml = List.map (fun (name, args) -> (name, instantiate_rewrite (List.assoc name all_rewrites) args)) rewriters_ocaml This means we can introspect on the arguments required for each rewrite, allowing a :rewrite command in the interactive mode which can parse the arguments required for each rewrite, so we can invoke the above rewrite as sail> :rewrite undefined false with completion for the rewrite name based on all_rewrites, and hints for any arguments. The idea behind this is if we want to generate a very custom slice of a specification, we can set it up as a sequence of interpreter commands, e.g. ... :rewrite split execute :slice_roots execute_LOAD :slice_cuts rX wX :slice :rewrite tuple_assignments ... where we slice a spec just after splitting the execute function. This should help in avoiding an endless proliferation of additional options and flags on the command line.
2019-03-15Various monomorphisation tweaks and fixesThomas Bauereiss
2019-03-15Add a rewriting pass for constant propagation in mutrecsThomas Bauereiss
Propagating constants into mutually recursive calls and removing dead branches might break mutually recursive cycles. Also make constant propagation use the existing interpreter-based constant folding to evaluate function calls with only constant arguments (as opposed to a mixture of inlining and hard-coded rewrite rules).
2019-03-14Merge branch 'sail2' into rmem_interpreterJon French
2019-03-11Improve ocamldoc commentsAlasdair Armstrong
Check in a slightly nicer stylesheet for OCamldoc generated documentation in etc. Most just add a maximum width and increase the font size because the default looks absolutely terrible on high-DPI monitors. Move val_spec_ids out of initial_check and into ast_util where it probably belongs. Rename some functions in util.ml to better match the OCaml stdlib.
2019-03-08Rewriter: Cleanup old sizeof rewritesAlasdair Armstrong
Shouldn't affect anything as this is done by the typechecker now. Also remove some unfinished tracing code from c_backend.ml
2019-03-07Also remove impossible if-branchesThomas Bauereiss
2019-03-07Add a rewrite to remove impossible cases on integer literalsBrian Campbell
(e.g., for the dual 32/64 bit RISC-V model) Apply this rewrite in Coq backend.
2019-03-04Fix aarch64_small test XML for jenkinsAlasdair Armstrong
Rename rewrite_split_fun_constr_pats to rewrite_split_fun_ctor_pats as constr is commonly used as an abbreviation for constraint rather than constructor, and add a more descriptive comment.
2019-03-04Fix execute splitting to work when constructors have constraints.Alasdair Armstrong
Previously any constraints on constructors were just outright dropped when splitting the execute function in Lem generation. Now we get the constraints and type signature for each execute clause from the type given by Env.get_union_constructor, rather than by inferring the type of the pattern in each function clause. Currently this can still fail in the case where we have union U('x: Int), C1('x) = { ctor: {'y. C2('x, 'y), T('x, 'y)} } and val execute : forall 'z, C3('z). U('z) -> unit when C3 implies C1, and the body of an excute clause relies on the fact that C3 is stronger than C1, as each split function execute_ctor is only guaranteed to be constrained by some subset of C1. This seems unlikely to happen in practice though. Also fix a bug when binding P as int('T) against int('T) and similar cases, where the new type variable would cause the old type variable to become shadowed, but the constraint that the bound type variable and the old type variable are equal would not take this into account.
2019-03-04Merge branch 'sail2' into rmem_interpreterJon French
2019-02-27Tweaks to C compilation to make it more usable for embedding into other programsAlasdair Armstrong
Can now set a prefix for generated C functions with -c_prefix so -c_prefix sail_ would give sail_execute_CGetPerm over zexecute_CGetPerm. We still have to use our standard name-mangling scheme to avoid possible collisions within the name. Can build C that doesn't expect the standard runtime, which leaves operations like read_memory, write_memory etc to be stubbed in by another C program including the generated Sail. Things like letbindings are still an issue because we rely on a very small runtime to initialize global letbindings and similar. -c_separate_execute splits the execute function apart in the generated C
2019-02-25Merge branch 'sail2' into rmem_interpreterJon French
2019-02-21Allow monomorphisation with C generationAlasdair
Run C tests with -O -Oconstant_fold -auto_mono
2019-02-21Fix specialization bug involving function annotations not matching valspecsAlasdair
Perhaps suprisingly to some, this did not mean that Sail was unable to typecheck the identify function. While doing this rename Effect_opt_pure to Effect_opt_none - as Effect_opt_pure was the effect equivalent of Typ_annot_opt_none, and actually means that the function definition lacks an effect annnotation, not that the function is actually pure, so this was *extremely* misleading. The effect_opt that actually indicated a function is pure was (and still is) the succinct: Effect_opt_aux (Effect_opt_effect (Effect_aux (Effect_set [], _)), _) In fact because in the grammar we only specify effects on valspecs (they can always be inferred for fundefs in the absence of a valspec) effect_opts are basically vestigial and are always Effect_opt_none. What might actually be super nice would be to remove rec_opt, effect_opt and typ_annot_opt from fundefs in ast.ml altogether and if we want them in the syntax just have them in parse_ast.ml and pull them into a valspec during the initial check.
2019-02-18Make sure we remove bitvector patterns within guardsAlasdair Armstrong
Fixes #34
2019-02-15Tweak intermediate language names for loop combinators to allow reparsingBrian Campbell
This should produce identical Lem and Coq output, but allow dumped Sail ASTs from the final stages of rewriting to be reread with -dmagic_hash.
2019-02-14Don't do any rewrites when checking files for EmacsAlasdair Armstrong
This makes sure we don't do any kind of re-writing or de-scatter any definitions when loading files into emacs. The difference here is that normally all files are processed together, but the emacs mode loads each file one by one. This is probably what we want to be doing anyway, so location information stays accurate for scattered functions for things like type-at-cursor commands and similar. Also fix some warnings. Fixes #32
2019-02-13Merge branch 'sail2' into rmem_interpreterJon French
2019-02-08Add missing functions to HOL monad wrapperThomas Bauereiss
Also make the rewriter keep failed assertions in output when pruning blocks.
2019-02-08Rewrite type definitions in rewrite_nexp_idsThomas Bauereiss
For example, in type xlen : Int = 64 type xlenbits = bits(xlen) rewrite the 'xlen' in the definition of 'xlenbits' to the constant 64 in order to simplify Lem generation. In order to facilitate this, pass through the global typing environment to the rewriting steps (in the AST itself, type definitions don't carry annotations with environments).
2019-02-08Remove dead code from type-checkerAlasdair
add_num_def and get_num_def are no longer used. The rewrite pass that used them would fail on Nexp_ids because of this, but seeing as that never happened we can probably assume that particular line of code is simply never touched by any of our models or test suite?
2019-02-07Monomorphisation tweaks for v8.5Thomas Bauereiss
Various tweaks to the monomorphisation rewrites. Disable old sizeof rewriting for Lem backend and rely on the type checker rewriting implicit arguments. Also avoid unifying nexps with sums, as this can easily fail due to commutativity and associativity.
2019-02-06Fix some testsAlasdair Armstrong
2019-02-06Remove all sizeof rewriting from C compilationAlasdair
All sizeof expressions now removed by the type-checker, so it's now properly a type error if they cannot be removed rather than a bizarre re-write error. This also greatly improves compilation speed overall, at the expense of the first type-checking pass.
2019-02-05Use more general types for lexps in the internal lets rewriting passBrian Campbell
This reduces the amount of unnecessary complex existentials that appear during rewriting.
2019-02-03Merge branch 'sail2' into rmem_interpreterJon French
2019-02-02Merge remote-tracking branch 'origin/sail2' into asl_flow2Alasdair
2019-02-01Fix missing typedef cases in OCaml outputAlasdair
2019-01-31Turn on cast insertion for -lem_mwords and revert b826df25Brian Campbell
now that cast insertion can handle RISC-V Also inserts specs for casts in they're not present
2019-01-29Merge branch 'sail2' into asl_flow2Thomas Bauereiss
2019-01-24Make recheck_defs_without_effects restore old flag properlyBrian Campbell
2019-01-23Make rewriting of E_assign a bit more robustThomas Bauereiss
2019-01-22Add a pragma for unrolling recursive functionsAlasdair Armstrong
For example in RISC-V for the translation table walk: $optimize unroll 2 val walk32 ... function walk32 ... would create two extra copies of the walk_32 function, walk_32_unroll_1 and walk_32_unroll_2, with only walk_32_unroll_2 being recursive. Currently we only support the case where we have $optimize unroll, directly followed by a valspec, then a function, but this should be generalised in future. This optimization nearly doubles the performance of RISC-V It is implemented using a new Optimize.recheck rewrite that replaces the ordinary recheck_defs pass. It uses a new typechecker check_with_envs function that allows re-writes to utilise intermediate typechecking environments to minimize the amount of AST checking that occurs, for performance reasons. Note that older Sail versions including the current OPAM release will complain about the optimize pragma, so this cannot be used until they become up to date with this change.
2019-01-17Fix bug in letbind_effects rewriteThomas Bauereiss
Don't wrap effectful expressions in E_internal_return