Summary:
Equality.classes was assuming a simpler representation, and was
incomplete as a result.
The 'representative' map is not kept in a normalized form, where
subterms are necessarily representatives. Therefore, applying the
representative map to subterms of terms in a class can reveal new
elements of the class. This mirrors how the `lookup` function in
`normalize` works.
Reviewed By: ngorogiannis
Differential Revision: D19221868
fbshipit-source-id: 4a2ed6d3f
Summary:
Reduce redundancy by printing adjacent segments as if they had been
concatenated together.
Reviewed By: ngorogiannis
Differential Revision: D19221881
fbshipit-source-id: 613105864
Summary:
Also, previous code was sometimes inconsistent regarding whether to
enumerate all subterms or only toplevel terms.
Reviewed By: ngorogiannis
Differential Revision: D19221873
fbshipit-source-id: e8644098b
Summary: It is easier to understand the order of args with diff_inter.
Reviewed By: ngorogiannis
Differential Revision: D19221869
fbshipit-source-id: b29ac83c8
Summary:
Add some test cases from Reuss and Shankar for equality that are
mishandled by Shostak's original algorithm.
Reviewed By: ngorogiannis
Differential Revision: D19221880
fbshipit-source-id: a6f9d51e3
Summary:
This diff enables parsing and auto-formatting documentation
comments (aka docstrings).
I have looked at this entire diff and manually made some changes to
improve the formatting. In some cases it looked like it would take too
much time, or benefit from someone more familiar with the code doing
it, and I instead disabled auto-formatting docstrings in those files.
Also, there are some source files where the docstrings are invalid,
and some where the structure detected by the parser appears not to
match what was intended. Auto-formatting has been disabled for these
files.
Reviewed By: ezgicicek
Differential Revision: D18755888
fbshipit-source-id: 68d72465d
Summary:
OCaml 4.08 supports a form of signature-local bindings, to that a type
can be defined in order to be used in other definitions, without
being part of the signature itself.
Reviewed By: ngorogiannis, jvillard
Differential Revision: D18736380
fbshipit-source-id: 0bb043de6
Summary:
Otherwise it is difficult to tell the difference between compilation
errors from previous versus current builds.
Reviewed By: ngorogiannis
Differential Revision: D18736376
fbshipit-source-id: 2e583f4ba
Summary:
OCaml 4.08 has a new warning (66) on unused `open!` statements. This
has a suboptimal interaction with `ppx_let`'s `let%map_open` which
leads to triggering the warning if any of a group of such let bindings
does not need the open.
In this case, the refactor is easy.
But, warning 66 is very dubious, so also just switch it off.
Reviewed By: jvillard
Differential Revision: D18708466
fbshipit-source-id: 77618ab6e
Summary:
It seems to be effectively unmaintained, as it still doesn't support
4.08.
Reviewed By: jvillard
Differential Revision: D18708467
fbshipit-source-id: dcb3361fc
Summary:
Term.solve makes the assumption that all distinct normalized constants
denote distinct values. This is fragile at best, and it is better to
enumerate the cases where solve discovers inconsistency.
Reviewed By: jvillard
Differential Revision: D18459619
fbshipit-source-id: 71f52557c
Summary:
Equality.or_ assumed a simpler representation of equality relations,
and was incomplete as a result.
Reviewed By: jvillard
Differential Revision: D18298138
fbshipit-source-id: cf91229f6
Summary:
The treatment of type conversions is too complicated, non-uniform,
etc. This diff attempts to simplify things by separating integer to
integer conversions, which are interpreted, from others, which are
essentially just uninterpreted functions. Integer conversions are now
handled using two expression and term forms: Signed and
Unsigned. These each interpret their argument as either a signed or
unsigned number of a given bitwidth:
```
| Signed of {bits: int}
(** [Ap1 (Signed {bits= n}, dst, arg)] is [arg] interpreted as an
[n]-bit signed integer and injected into the [dst] type. That is,
it two's-complement--decodes the low [n] bits of the infinite
two's-complement encoding of [arg]. The injection into [dst] is a
no-op, so [dst] must be an integer type with bitwidth at least
[n]. *)
| Unsigned of {bits: int}
(** [Ap1 (Unsigned {bits= n}, dst, arg)] is [arg] interpreted as an
[n]-bit unsigned integer and injected into the [dst] type. That
is, it unsigned-binary--decodes the low [n] bits of the infinite
two's-complement encoding of [arg]. The injection into [dst] is a
no-op, so [dst] must be an integer type with bitwidth greater than
[n]. *)
| Convert of {src: Typ.t}
(** [Ap1 (Convert {src}, dst, arg)] is [arg] converted from type [src]
to type [dst], possibly with loss of information. The [src] and
[dst] types must be [Typ.convertible] and must not both be
[Integer] types. *)
```
Reviewed By: ngorogiannis
Differential Revision: D18298140
fbshipit-source-id: 690f065b4
Summary:
LLAIR changed how it represents integer-to-integer conversions, and this
updates the semantics and proofs to show that the new way is correct.
Reviewed By: jberdine
Differential Revision: D18448616
fbshipit-source-id: b657fcd20
Summary:
The old version of simp_convert in LLAIR had a bug, but the sanity
theorem didn't catch it because it didn't enforce that the result fit
into the size it should have. This updates to newer version of
simp_convert and adds a theorem that the result fits.
Reviewed By: jberdine
Differential Revision: D18346833
fbshipit-source-id: 533c836bf
Summary:
Extend the APRON-backed interval analysis to handle a wider range
of LLAIR expressions.
Reviewed By: jvillard
Differential Revision: D17858072
fbshipit-source-id: c50f5bf20
Summary:
In some cases the result of an integer conversion needs to be
truncated by a bit.
Differential Revision: D18271179
fbshipit-source-id: e80740045
Summary:
Improve the invariants to show that phi instructions are correctly
translated. It remains to show that the invariants can be established
when jumping to the start of a block
Reviewed By: jberdine
Differential Revision: D18228272
fbshipit-source-id: 4330b4781
Summary:
Add a new interval abstract domain. This domain uses the APRON
numerical analysis library to keep track of the range of values held
by llair variables where possible. This works by translating LLAIR
expressions into APRON tree expressions, so only handles the
subset of the LLAIR expression language that can be embedded.
Note also that function summarization is not yet implemented.
Future commits will add summarization and improve coverage of
LLAIR's expression language.
Reviewed By: jberdine
Differential Revision: D17763517
fbshipit-source-id: 826ce4cc5
Summary:
Add some theorems establishing the correspondence between the
implementation of the Convert operation in OCaml and the definition of
Convert in the semantics. Essentially, the OCaml version is in terms of
extracting certain ranges of bits, whereas the semantics is in terms of
integer arithmetic (addition, modulus, and exponentiation)
Reviewed By: jberdine
Differential Revision: D18113878
fbshipit-source-id: c318596d0
Summary:
This commit adds truncation, sign extension and zero extension to LLVM
and the Convert instruction to LLAIR.
The LLVM instructions use HOL's build-in word/int and word/num
conversions. Sanity-checking theorems prove that zero-extending leaves
the value of the word unchanged when considered as an unsigned value,
and that sign-extending leaves the value unchanged when considered as a
signed value.
The llair semantics for Convert uses the truncate_2comp function which
converts an integer to another integer as though they were represented
in 2's complement. e.g. truncate_2comp 255 16 = 255, truncate_2comp
255 8 = -1, truncate_2comp -3 2 = 1
Reviewed By: jberdine
Differential Revision: D18058833
fbshipit-source-id: df9de480c
Summary:
The old syntactic invariant in prog_ok was in the wrong direction,
saying that all labels in a phi instruction have to exist, rather than
saying that when we jump to a new block, the label of the block we came
from must be in all of the phi instructions.
Reviewed By: jberdine
Differential Revision: D18058832
fbshipit-source-id: d2ad33b04
Summary:
This required some minor tweaks to how the semantics encode values into
and out of byte lists. The remaining problems have to do with how LLVM
globals are translated into llair. At the moment, llair semantic's state
keeps a mapping for globals to their addresses, following the LLVM
semantics. However, it is not used because the translation (following
the code in frontend.ml) translates LLVM globals into llair locals,
which the llair semantics isn't set up to handle.
Reviewed By: jberdine
Differential Revision: D17930787
fbshipit-source-id: 06c6368e0
Summary:
The Used globals (pre-)analysis produces results queried by
Control. This diff adds a type definition for these and moves the
query into the Used_globals module.
Reviewed By: bennostein
Differential Revision: D17856879
fbshipit-source-id: 0211b82d7
Summary:
To avoid code explosion, the frontend emits move instructions for
expressions with more than one use. This diff relaxes this slightly by
allowing duplication of casts.
Reviewed By: bennostein
Differential Revision: D17856384
fbshipit-source-id: 6f6c496ef
Josh Berdine
Scott Owens
Benno Stein