Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Handle sqrt & Some Bodged Solution for computing through abs #1254

Merged
merged 19 commits into from
Nov 21, 2023
Merged
Show file tree
Hide file tree
Changes from 17 commits
Commits
Show all changes
19 commits
Select commit Hold shift + click to select a range
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 20 additions & 0 deletions src/analyses/base.ml
Original file line number Diff line number Diff line change
Expand Up @@ -2328,6 +2328,24 @@ struct
| _ -> failwith ("non-floating-point argument in call to function "^f.vname)
end
in
let apply_abs ik x =
let eval_x = eval_rv (Analyses.ask_of_ctx ctx) gs st x in
begin match eval_x with
| Int int_x ->
let xcast = ID.cast_to ik int_x in
(* the absolute value of the most-negative value is out of range for 2'complement types *)
(match (ID.minimal xcast), (ID.minimal (ID.top_of ik)) with
| _, None
| None, _ -> ID.top_of ik
| Some mx, Some mm when Z.equal mx mm -> ID.top_of ik
jerhard marked this conversation as resolved.
Show resolved Hide resolved
| _, _ ->
let x1 = ID.neg (ID.meet (ID.ending ik Z.zero) xcast) in
let x2 = ID.meet (ID.starting ik Z.zero) xcast in
ID.join x1 x2
)
| _ -> failwith ("non-integer argument in call to function "^f.vname)
end
in
let result:value =
begin match fun_args with
| Nan (fk, str) when Cil.isPointerType (Cilfacade.typeOf str) -> Float (FD.nan_of fk)
Expand Down Expand Up @@ -2356,6 +2374,8 @@ struct
| Isunordered (x,y) -> Int(ID.cast_to IInt (apply_binary FDouble FD.unordered x y))
| Fmax (fd, x ,y) -> Float (apply_binary fd FD.fmax x y)
| Fmin (fd, x ,y) -> Float (apply_binary fd FD.fmin x y)
| Sqrt (fk, x) -> Float (apply_unary fk FD.sqrt x)
| Abs (ik, x) -> Int (ID.cast_to ik (apply_abs ik x))
end
in
begin match lv with
Expand Down
27 changes: 27 additions & 0 deletions src/analyses/baseInvariant.ml
Original file line number Diff line number Diff line change
Expand Up @@ -821,4 +821,31 @@ struct
FD.top_of fk
in
inv_exp (Float ftv) exp st

let invariant ctx a gs st exp tv: D.t =
let refine0 = invariant ctx a gs st exp tv in
(* bodge for abs(...); To be removed once we have a clean solution *)
let refineAbs op absargexp valexp =
let flip op = match op with | Le -> Ge | Lt -> Gt | _ -> failwith "impossible" in
(* e.g. |arg| <= 40 *)
(* arg <= e (arg <= 40) *)
let le = BinOp (op, absargexp, valexp, intType) in
(* arg >= -e (arg >= -40) *)
let gt = BinOp(flip op, absargexp, UnOp (Neg, valexp, Cilfacade.typeOf valexp), intType) in
let one = invariant ctx (Analyses.ask_of_ctx ctx) ctx.global refine0 le tv in
invariant ctx (Analyses.ask_of_ctx ctx) ctx.global one gt tv
in
match exp with
| BinOp ((Lt|Le) as op, CastE(t, Lval (Var v, NoOffset)), e,_) when tv ->
begin match ctx.ask (Queries.TmpSpecial (v, Offset.Exp.of_cil NoOffset)) with
| `Lifted (Abs (ik, arg)) -> refineAbs op (CastE (t, arg)) e
| _ -> refine0
end
| BinOp ((Lt|Le) as op, Lval (Var v, NoOffset), e, _) when tv ->
begin match ctx.ask (Queries.TmpSpecial (v, Offset.Exp.of_cil NoOffset)) with
| `Lifted (Abs (ik, arg)) -> refineAbs op arg e
| _ -> refine0
end
| _ -> refine0

end
6 changes: 5 additions & 1 deletion src/analyses/libraryDesc.ml
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@ type math =
| Islessequal of (Basetype.CilExp.t * Basetype.CilExp.t)
| Islessgreater of (Basetype.CilExp.t * Basetype.CilExp.t)
| Isunordered of (Basetype.CilExp.t * Basetype.CilExp.t)
| Abs of (CilType.Ikind.t * Basetype.CilExp.t)
| Ceil of (CilType.Fkind.t * Basetype.CilExp.t)
| Floor of (CilType.Fkind.t * Basetype.CilExp.t)
| Fabs of (CilType.Fkind.t * Basetype.CilExp.t)
Expand All @@ -38,7 +39,8 @@ type math =
| Atan2 of (CilType.Fkind.t * Basetype.CilExp.t * Basetype.CilExp.t)
| Cos of (CilType.Fkind.t * Basetype.CilExp.t)
| Sin of (CilType.Fkind.t * Basetype.CilExp.t)
| Tan of (CilType.Fkind.t * Basetype.CilExp.t) [@@deriving eq, ord, hash]
| Tan of (CilType.Fkind.t * Basetype.CilExp.t)
| Sqrt of (CilType.Fkind.t * Basetype.CilExp.t) [@@deriving eq, ord, hash]

(** Type of special function, or {!Unknown}. *)
(* Use inline record if not single {!Cil.exp} argument. *)
Expand Down Expand Up @@ -158,6 +160,7 @@ module MathPrintable = struct
| Islessequal (exp1, exp2) -> Pretty.dprintf "isLessEqual(%a, %a)" d_exp exp1 d_exp exp2
| Islessgreater (exp1, exp2) -> Pretty.dprintf "isLessGreater(%a, %a)" d_exp exp1 d_exp exp2
| Isunordered (exp1, exp2) -> Pretty.dprintf "isUnordered(%a, %a)" d_exp exp1 d_exp exp2
| Abs (ik, exp) -> Pretty.dprintf "(%a )abs(%a)" d_ikind ik d_exp exp
| Ceil (fk, exp) -> Pretty.dprintf "(%a )ceil(%a)" d_fkind fk d_exp exp
| Floor (fk, exp) -> Pretty.dprintf "(%a )floor(%a)" d_fkind fk d_exp exp
| Fabs (fk, exp) -> Pretty.dprintf "(%a )fabs(%a)" d_fkind fk d_exp exp
Expand All @@ -170,6 +173,7 @@ module MathPrintable = struct
| Cos (fk, exp) -> Pretty.dprintf "(%a )cos(%a)" d_fkind fk d_exp exp
| Sin (fk, exp) -> Pretty.dprintf "(%a )sin(%a)" d_fkind fk d_exp exp
| Tan (fk, exp) -> Pretty.dprintf "(%a )tan(%a)" d_fkind fk d_exp exp
| Sqrt (fk, exp) -> Pretty.dprintf "(%a )sqrt(%a)" d_fkind fk d_exp exp

include Printable.SimplePretty (
struct
Expand Down
10 changes: 6 additions & 4 deletions src/analyses/libraryFunctions.ml
Original file line number Diff line number Diff line change
Expand Up @@ -130,7 +130,9 @@ let c_descs_list: (string * LibraryDesc.t) list = LibraryDsl.[
("wcstombs", unknown ~attrs:[ThreadUnsafe] [drop "dst" [w]; drop "src" [r]; drop "size" []]);
("wcsrtombs", unknown ~attrs:[ThreadUnsafe] [drop "dst" [w]; drop "src" [r_deep; w]; drop "size" []; drop "ps" [r_deep; w_deep]]);
("mbstowcs", unknown [drop "dest" [w]; drop "src" [r]; drop "n" []]);
("abs", unknown [drop "j" []]);
("abs", special [__ "j" []] @@ fun j -> Math { fun_args = (Abs (IInt, j)) });
("labs", special [__ "j" []] @@ fun j -> Math { fun_args = (Abs (ILong, j)) });
("llabs", special [__ "j" []] @@ fun j -> Math { fun_args = (Abs (ILongLong, j)) });
("localtime_r", unknown [drop "timep" [r]; drop "result" [w]]);
("strpbrk", unknown [drop "s" [r]; drop "accept" [r]]);
("_setjmp", special [__ "env" [w]] @@ fun env -> Setjmp { env }); (* only has one underscore *)
Expand Down Expand Up @@ -944,9 +946,9 @@ let math_descs_list: (string * LibraryDesc.t) list = LibraryDsl.[
("scalbln", unknown [drop "arg" []; drop "exp" []]);
("scalblnf", unknown [drop "arg" []; drop "exp" []]);
("scalblnl", unknown [drop "arg" []; drop "exp" []]);
("sqrt", unknown [drop "x" []]);
("sqrtf", unknown [drop "x" []]);
("sqrtl", unknown [drop "x" []]);
("sqrt", special [__ "x" []] @@ fun x -> Math { fun_args = (Sqrt (FDouble, x)) });
("sqrtf", special [__ "x" []] @@ fun x -> Math { fun_args = (Sqrt (FFloat, x)) });
("sqrtl", special [__ "x" []] @@ fun x -> Math { fun_args = (Sqrt (FLongDouble, x)) });
("tgamma", unknown [drop "x" []]);
("tgammaf", unknown [drop "x" []]);
("tgammal", unknown [drop "x" []]);
Expand Down
14 changes: 14 additions & 0 deletions src/autoTune.ml
Original file line number Diff line number Diff line change
Expand Up @@ -458,6 +458,17 @@ let wideningOption factors file =
print_endline "Enabled widening thresholds";
}

let activateTmpSpecialAnalysis () =
let isMathFun = function
| LibraryDesc.Math _ -> true
| _ -> false
in
let hasMathFunctions = hasFunction isMathFun in
if hasMathFunctions then (
print_endline @@ "math function -> enabling tmpSpecial analysis and floating-point domain";
enableAnalyses ["tmpSpecial"];
set_bool "ana.float.interval" true;
)

let estimateComplexity factors file =
let pathsEstimate = factors.loops + factors.controlFlowStatements / 90 in
Expand Down Expand Up @@ -518,6 +529,9 @@ let chooseConfig file =
if isActivated "arrayDomain" then
selectArrayDomains file;

if isActivated "tmpSpecialAnalysis" then
activateTmpSpecialAnalysis ();

let options = [] in
let options = if isActivated "congruence" then (congruenceOption factors file)::options else options in
let options = if isActivated "octagon" then (apronOctagonOption factors file)::options else options in
Expand Down
14 changes: 14 additions & 0 deletions src/cdomains/floatDomain.ml
Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,8 @@ module type FloatArith = sig
(** sin(x) *)
val tan : t -> t
(** tan(x) *)
val sqrt : t -> t
(** sqrt(x) *)

(** {inversions of unary functions}*)
val inv_ceil : ?asPreciseAsConcrete:bool -> t -> t
Expand Down Expand Up @@ -670,6 +672,14 @@ module FloatIntervalImpl(Float_t : CFloatType) = struct
| (l, h) when l = h && l = Float_t.zero -> of_const 0. (*tan(0) = 0*)
| _ -> top () (**could be exact for intervals where l=h, or even for some intervals *)

let eval_sqrt = function
| (l, h) when l = Float_t.zero && h = Float_t.zero -> of_const 0.
| (l, h) when l >= Float_t.zero ->
let low = Float_t.sqrt Down l in
let high = Float_t.sqrt Up h in
Interval (low, high)
| _ -> top ()

let eval_inv_ceil ?(asPreciseAsConcrete=false) = function
| (l, h) ->
if (Float_t.sub Up (Float_t.ceil l) (Float_t.sub Down (Float_t.ceil l) (Float_t.of_float Nearest 1.0)) = (Float_t.of_float Nearest 1.0)) then (
Expand Down Expand Up @@ -784,6 +794,7 @@ module FloatIntervalImpl(Float_t : CFloatType) = struct
let cos = eval_unop eval_cos
let sin = eval_unop eval_sin
let tan = eval_unop eval_tan
let sqrt = eval_unop eval_sqrt

let inv_ceil ?(asPreciseAsConcrete=false) = eval_unop ~warn:false (eval_inv_ceil ~asPreciseAsConcrete:asPreciseAsConcrete)
let inv_floor ?(asPreciseAsConcrete=false) = eval_unop ~warn:false (eval_inv_floor ~asPreciseAsConcrete:asPreciseAsConcrete)
Expand Down Expand Up @@ -899,6 +910,7 @@ module FloatIntervalImplLifted = struct
let cos = lift (F1.cos, F2.cos)
let sin = lift (F1.sin, F2.sin)
let tan = lift (F1.tan, F2.tan)
let sqrt = lift (F1.sqrt, F2.sqrt)

let inv_ceil ?(asPreciseAsConcrete=BoolDomain.MustBool.top ()) = function
| F32 a -> F32 (F1.inv_ceil ~asPreciseAsConcrete:true a)
Expand Down Expand Up @@ -1159,6 +1171,8 @@ module FloatDomTupleImpl = struct
map { f1= (fun (type a) (module F : FloatDomain with type t = a) -> F.sin); }
let tan =
map { f1= (fun (type a) (module F : FloatDomain with type t = a) -> F.tan); }
let sqrt =
map { f1= (fun (type a) (module F : FloatDomain with type t = a) -> F.sqrt); }

(*"asPreciseAsConcrete" has no meaning here*)
let inv_ceil ?(asPreciseAsConcrete=BoolDomain.MustBool.top ()) =
Expand Down
3 changes: 3 additions & 0 deletions src/cdomains/floatDomain.mli
Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,9 @@ module type FloatArith = sig
val tan : t -> t
(** tan(x) *)

val sqrt : t -> t
(** sqrt(x) *)

(** {inversions of unary functions}*)
val inv_ceil : ?asPreciseAsConcrete:bool -> t -> t
(** (inv_ceil z -> x) if (z = ceil(x)) *)
Expand Down
3 changes: 3 additions & 0 deletions src/cdomains/floatOps/floatOps.ml
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@ module type CFloatType = sig
val sub: round_mode -> t -> t -> t
val mul: round_mode -> t -> t -> t
val div: round_mode -> t -> t -> t
val sqrt: round_mode -> t -> t
val atof: round_mode -> string -> t
end

Expand Down Expand Up @@ -74,6 +75,7 @@ module CDouble = struct
external sub: round_mode -> t -> t -> t = "sub_double"
external mul: round_mode -> t -> t -> t = "mul_double"
external div: round_mode -> t -> t -> t = "div_double"
external sqrt: round_mode -> t -> t = "sqrt_double"

external atof: round_mode -> string -> t = "atof_double"
end
Expand Down Expand Up @@ -107,6 +109,7 @@ module CFloat = struct
external sub: round_mode -> t -> t -> t = "sub_float"
external mul: round_mode -> t -> t -> t = "mul_float"
external div: round_mode -> t -> t -> t = "div_float"
external sqrt: round_mode -> t -> t = "sqrt_float"

external atof: round_mode -> string -> t = "atof_float"

Expand Down
1 change: 1 addition & 0 deletions src/cdomains/floatOps/floatOps.mli
Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,7 @@ module type CFloatType = sig
val sub: round_mode -> t -> t -> t
val mul: round_mode -> t -> t -> t
val div: round_mode -> t -> t -> t
val sqrt: round_mode -> t -> t
val atof: round_mode -> string -> t
end

Expand Down
14 changes: 14 additions & 0 deletions src/cdomains/floatOps/stubs.c
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,20 @@ static void change_round_mode(int mode)
}
}

#define UNARY_OP(name, type, op) \
CAMLprim value name##_##type(value mode, value x) \
{ \
int old_roundingmode = fegetround(); \
change_round_mode(Int_val(mode)); \
volatile type r, x1 = Double_val(x); \
r = op(x1); \
fesetround(old_roundingmode); \
return caml_copy_double(r); \
}

UNARY_OP(sqrt, double, sqrt);
UNARY_OP(sqrt, float, sqrtf);

#define BINARY_OP(name, type, op) \
CAMLprim value name##_##type(value mode, value x, value y) \
{ \
Expand Down
2 changes: 1 addition & 1 deletion src/common/util/options.schema.json
Original file line number Diff line number Diff line change
Expand Up @@ -544,7 +544,7 @@
"type": "array",
"items": { "type": "string" },
"default": [
"congruence", "singleThreaded", "specification", "mallocWrappers", "noRecursiveIntervals", "enums", "loopUnrollHeuristic", "arrayDomain", "octagon", "wideningThresholds", "memsafetySpecification"
"congruence", "singleThreaded", "specification", "mallocWrappers", "noRecursiveIntervals", "enums", "loopUnrollHeuristic", "arrayDomain", "octagon", "wideningThresholds", "memsafetySpecification", "tmpSpecialAnalysis"
sim642 marked this conversation as resolved.
Show resolved Hide resolved
]
}
},
Expand Down
22 changes: 22 additions & 0 deletions tests/regression/39-signed-overflows/06-abs.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
//PARAM: --enable ana.int.interval --set ana.activated[+] tmpSpecial
jerhard marked this conversation as resolved.
Show resolved Hide resolved
#include<math.h>
int main() {
int data;
if (data > (-0x7fffffff - 1))
{
if (abs(data) < 100)
{
__goblint_check(data < 100);
__goblint_check(-100 < data);
int result = data * data; //NOWARN
}

if(abs(data) <= 100)
{
__goblint_check(data <= 100);
__goblint_check(-100 <= data);
int result = data * data; //NOWARN
}
}
return 8;
}
10 changes: 10 additions & 0 deletions tests/regression/39-signed-overflows/07-abs-sqrt.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
//PARAM: --enable ana.int.interval --enable ana.float.interval --set ana.activated[+] tmpSpecial
#include<math.h>
int main() {
int data;
if (data > (-0x7fffffff - 1) && abs(data) < (long)sqrt((double)0x7fffffff))
{
int result = data * data; //NOWARN
}
return 8;
}
22 changes: 22 additions & 0 deletions tests/regression/39-signed-overflows/08-labs.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
//PARAM: --enable ana.int.interval --set ana.activated[+] tmpSpecial
#include<stdlib.h>
int main() {
long data;
if (data > (-0xffffffff - 1))
{
if (labs(data) < 100)
{
__goblint_check(data < 100);
__goblint_check(-100 < data);
int result = data * data; //NOWARN
}

if(labs(data) <= 100)
{
__goblint_check(data <= 100);
__goblint_check(-100 <= data);
int result = data * data; //NOWARN
}
}
return 8;
}
10 changes: 10 additions & 0 deletions tests/regression/39-signed-overflows/09-labs-sqrt.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
//PARAM: --enable ana.int.interval --enable ana.float.interval --set ana.activated[+] tmpSpecial
#include<math.h>
int main() {
int data;
if (data > (-0x7fffffff - 1) && llabs(data) < (long)sqrt((double)0x7fffffff))
{
int result = data * data; //NOWARN
}
return 8;
}