Grcov report - integer

1

use conjure_cp::ast::{Expression as Expr, GroundDomain};

2

use conjure_cp::ast::{SATIntEncoding, SymbolTable};

3

use conjure_cp::rule_engine::{

4

    ApplicationError, ApplicationError::RuleNotApplicable, ApplicationResult, Reduction,

5

    register_rule,

6

};

7

8

use conjure_cp::ast::Metadata;

9

use conjure_cp::ast::{Atom, Literal, Moo, Range};

10

use conjure_cp::into_matrix_expr;

11

12

use conjure_cp::{bug, essence_expr};

13

14

/// This function takes a target expression and a vector of ranges and creates an expression representing the ranges with the target expression as the subject

15

///

16

/// E.g. x : int(4), int(10..20), int(30..) ~~> Or(x=4, 10<=x<=20, x>=30)

17

1086

fn int_domain_to_expr(subject: Expr, ranges: &Vec<Range<i32>>) -> Expr {

18

1086

    let mut output = vec![];

19

20

1086

    let value = Moo::new(subject);

21

22

1206

    for range in ranges {

23

1206

        match range {

24

162

            Range::Single(x) => output.push(essence_expr!(&value = &x)),

25

1044

            Range::Bounded(x, y) => output.push(essence_expr!("&value >= &x /\\ &value <= &y")),

26

            _ => bug!("Unbounded domains not supported for SAT"),

27

28

29

30

1086

    Expr::Or(Metadata::new(), Moo::new(into_matrix_expr!(output)))

31

1086

32

33

/// This function confirms that all of the input expressions are log SATInts, and returns vectors for each input of their bits

34

/// This function also extends all vectors such that they have the same lengths

35

/// The vector lengths is either `n` for bit_count = Some(n), otherwise the length of the longest operand

36

1554

pub fn validate_log_int_operands(

37

1554

    exprs: Vec<Expr>,

38

1554

    bit_count: Option<u32>,

39

1554

) -> Result<Vec<Vec<Expr>>, ApplicationError> {

40

    // TODO: In the future it may be possible to optimize operations between integers with different bit sizes

41

    // Collect inner bit vectors from each SATInt

42

43

    // TODO: this file should be encoding agnostic so this needs to moved to the log_int_ops.rs file, do this once the direct ints have been merged to main though

44

1554

    let mut out: Vec<Vec<Expr>> = exprs

45

1554

        .into_iter()

46

2817

        .map(|expr| {

47

2394

            let Expr::SATInt(_, SATIntEncoding::Log, inner, _) = expr else {

48

423

                return Err(RuleNotApplicable);

49

};

50

2394

            let Some(bits) = inner.as_ref().clone().unwrap_list() else {

51

                return Err(RuleNotApplicable);

52

};

53

2394

            Ok(bits)

54

2817

})

55

1554

        .collect::<Result<_, _>>()?;

56

57

    // Determine target length

58

1131

    let max_len = bit_count

59

1131

        .map(|b| b as usize)

60

2169

        .unwrap_or_else(|| out.iter().map(|v| v.len()).max().unwrap_or(0));

61

62

    // Extend or crop each vector

63

2235

    for v in &mut out {

64

2235

        if v.len() < max_len {

65

            // pad with the last element

66

492

            if let Some(last) = v.last().cloned() {

67

492

                v.resize(max_len, last);

68

492

69

1743

        } else if v.len() > max_len {

70

            // crop extra elements

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            v.truncate(max_len);

72

1743

73

74

75

1131

    Ok(out)

76

1554

77

78

/// Converts an integer decision variable to SATInt form, creating a new representation of boolean variables if

79

/// one does not yet exist

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///

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/// ```text

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///  x

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///  ~~>

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///  SATInt([x#00, x#01, ...])

85

///

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///  new variables:

87

///  find x#00: bool

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///  find x#01: bool

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///  ...

90

///

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/// ```

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#[register_rule(("SAT_Direct", 9500))]

93

385146

fn integer_decision_representation_direct(expr: &Expr, symbols: &SymbolTable) -> ApplicationResult {

94

    // thing we are representing must be a reference

95

258168

    let Expr::Atomic(_, Atom::Reference(name)) = expr else {

96

139359

        return Err(RuleNotApplicable);

97

};

98

99

    // thing we are representing must be a variable

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    // symbols

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    //     .lookup(name)

102

    //     .ok_or(RuleNotApplicable)?

103

    //     .as_find()

104

    //     .ok_or(RuleNotApplicable)?;

105

106

    // thing we are representing must be an integer

107

245787

    let dom = name.resolved_domain().ok_or(RuleNotApplicable)?;

108

245787

    let GroundDomain::Int(ranges) = dom.as_ref() else {

109

244944

        return Err(RuleNotApplicable);

110

};

111

112

843

    let (min, max) = ranges

113

843

        .iter()

114

903

        .fold((i32::MAX, i32::MIN), |(min_a, max_b), range| {

115

903

116

903

                min_a.min(*range.low().unwrap()),

117

903

                max_b.max(*range.high().unwrap()),

118

903

119

903

});

120

121

843

    let mut symbols = symbols.clone();

122

123

843

    let new_name = &name.name().to_owned();

124

125

843

    let repr_exists = symbols

126

843

        .get_representation(new_name, &["sat_direct_int"])

127

843

        .is_some();

128

129

843

    let representation = symbols

130

843

        .get_or_add_representation(new_name, &["sat_direct_int"])

131

843

        .ok_or(RuleNotApplicable)?;

132

133

843

    let bits: Vec<Expr> = representation[0]

134

843

        .clone()

135

843

        .expression_down(&symbols)?

136

843

        .into_values()

137

843

        .collect();

138

139

843

    let cnf_int = Expr::SATInt(

140

843

        Metadata::new(),

141

843

        SATIntEncoding::Direct,

142

843

        Moo::new(into_matrix_expr!(bits.clone())),

143

843

        (min, max),

144

843

);

145

146

843

    if !repr_exists {

147

        // Domain constraint: the integer must take one of its valid values

148

513

        let constraints = vec![int_domain_to_expr(cnf_int.clone(), ranges)];

149

150

        // At-Most-One constraints: only one bit can be true.

151

513

        let mut clauses = vec![];

152

5193

        for i in 0..bits.len() {

153

157392

            for j in i + 1..bits.len() {

154

157392

                clauses.push(conjure_cp::ast::CnfClause::new(vec![

155

157392

                    Expr::Not(Metadata::new(), Moo::new(bits[i].clone())),

156

157392

                    Expr::Not(Metadata::new(), Moo::new(bits[j].clone())),

157

157392

                ]));

158

157392

159

160

161

513

        let mut reduction = Reduction::cnf(cnf_int, clauses, symbols);

162

513

        reduction.new_top = constraints;

163

513

        Ok(reduction)

164

    } else {

165

330

        Ok(Reduction::pure(cnf_int))

166

167

385146

168

169

#[register_rule(("SAT_Order", 9500))]

170

112632

fn integer_decision_representation_order(expr: &Expr, symbols: &SymbolTable) -> ApplicationResult {

171

    // thing we are representing must be a reference

172

59037

    let Expr::Atomic(_, Atom::Reference(name)) = expr else {

173

58695

        return Err(RuleNotApplicable);

174

};

175

176

    // thing we are representing must be an integer

177

53937

    let dom = name.resolved_domain().ok_or(RuleNotApplicable)?;

178

53937

    let GroundDomain::Int(ranges) = dom.as_ref() else {

179

53439

        return Err(RuleNotApplicable);

180

};

181

182

498

    let (min, max) = ranges

183

498

        .iter()

184

498

        .fold((i32::MAX, i32::MIN), |(min_a, max_b), range| {

185

498

186

498

                min_a.min(*range.low().unwrap()),

187

498

                max_b.max(*range.high().unwrap()),

188

498

189

498

});

190

191

498

    let mut symbols = symbols.clone();

192

193

498

    let new_name = &name.name().to_owned();

194

195

498

    let repr_exists = symbols

196

498

        .get_representation(new_name, &["sat_order_int"])

197

498

        .is_some();

198

199

498

    let representation = symbols

200

498

        .get_or_add_representation(new_name, &["sat_order_int"])

201

498

        .ok_or(RuleNotApplicable)?;

202

203

498

    let bits: Vec<Expr> = representation[0]

204

498

        .clone()

205

498

        .expression_down(&symbols)?

206

498

        .into_values()

207

498

        .collect();

208

209

498

    let cnf_int = Expr::SATInt(

210

498

        Metadata::new(),

211

498

        SATIntEncoding::Order,

212

498

        Moo::new(into_matrix_expr!(bits.clone())),

213

498

        (min, max),

214

498

);

215

216

498

    if !repr_exists {

217

        // Domain constraint: the integer must take one of its valid values

218

231

        let constraints = vec![int_domain_to_expr(cnf_int.clone(), ranges)];

219

220

        // Ordering constraints: b_i -> b_{i-1} which is !b_i or b_{i-1}

221

231

        let mut clauses = vec![];

222

912

        for i in 1..bits.len() {

223

912

            clauses.push(conjure_cp::ast::CnfClause::new(vec![

224

912

                Expr::Not(Metadata::new(), Moo::new(bits[i].clone())),

225

912

                bits[i - 1].clone(),

226

912

            ]));

227

912

228

229

231

        if !bits.is_empty() {

230

            // Domain constraint: a >= min, which is b_min.

231

            clauses.push(conjure_cp::ast::CnfClause::new(vec![bits[0].clone()]));

232

231

233

234

231

        let mut reduction = Reduction::cnf(cnf_int, clauses, symbols);

235

231

        reduction.new_top = constraints;

236

231

        Ok(reduction)

237

    } else {

238

267

        Ok(Reduction::pure(cnf_int))

239

240

112632

241

242

/// Converts an integer decision variable to SATInt form (Log encoding)

243

#[register_rule(("SAT_Log", 9500))]

244

247257

fn integer_decision_representation_log(expr: &Expr, symbols: &SymbolTable) -> ApplicationResult {

245

    // thing we are representing must be a reference

246

131361

    let Expr::Atomic(_, Atom::Reference(name)) = expr else {

247

144567

        return Err(RuleNotApplicable);

248

};

249

250

    // thing we are representing must be a variable

251

    // symbols

252

    //     .lookup(name)

253

    //     .ok_or(RuleNotApplicable)?

254

    //     .as_find()

255

    //     .ok_or(RuleNotApplicable)?;

256

257

    // thing we are representing must be an integer

258

102690

    let dom = name.resolved_domain().ok_or(RuleNotApplicable)?;

259

102690

    let GroundDomain::Int(ranges) = dom.as_ref() else {

260

102198

        return Err(RuleNotApplicable);

261

};

262

263

492

    let (min, max) = ranges

264

492

        .iter()

265

552

        .fold((i32::MAX, i32::MIN), |(min_a, max_b), range| {

266

552

267

552

                min_a.min(*range.low().unwrap()),

268

552

                max_b.max(*range.high().unwrap()),

269

552

270

552

});

271

272

492

    let mut symbols = symbols.clone();

273

274

492

    let new_name = &name.name().to_owned();

275

276

492

    let repr_exists = symbols

277

492

        .get_representation(new_name, &["sat_log_int"])

278

492

        .is_some();

279

280

492

    let representation = symbols

281

492

        .get_or_add_representation(new_name, &["sat_log_int"])

282

492

        .ok_or(RuleNotApplicable)?;

283

284

492

    let bits = representation[0]

285

492

        .clone()

286

492

        .expression_down(&symbols)?

287

492

        .into_values()

288

492

        .collect();

289

290

492

    let cnf_int = Expr::SATInt(

291

492

        Metadata::new(),

292

492

        SATIntEncoding::Log,

293

492

        Moo::new(into_matrix_expr!(bits)),

294

492

        (min, max),

295

492

);

296

297

492

    if !repr_exists {

298

        // add domain ranges as constraints if this is the first time the representation is added

299

342

        Ok(Reduction::new(

300

342

            cnf_int.clone(),

301

342

            vec![int_domain_to_expr(cnf_int, ranges)], // contains domain rules

302

342

            symbols,

303

342

))

304

    } else {

305

150

        Ok(Reduction::pure(cnf_int))

306

307

247257

308

309

/// Converts an integer literal to SATInt form

310

///

311

/// ```text

312

///  3

313

///  ~~>

314

///  SATInt([true,true,false,false,false,false,false,false;int(1..)])

315

///

316

/// ```

317

#[register_rule(("SAT_Log", 9500))]

318

247257

fn literal_cnf_int(expr: &Expr, _: &SymbolTable) -> ApplicationResult {

319

900

    let value = {

320

28671

        if let Expr::Atomic(_, Atom::Literal(Literal::Int(v))) = expr {

321

900

*v

322

        } else {

323

246357

            return Err(RuleNotApplicable);

324

325

};

326

    //TODO: Adding constant optimization to all int operations should hopefully make this rule redundant

327

328

900

    let mut binary_encoding = vec![];

329

330

900

    let bit_count = bit_magnitude(value);

331

332

900

    let mut value_mut = value as u32;

333

334

3309

    for _ in 0..bit_count {

335

3309

        binary_encoding.push(Expr::Atomic(

336

3309

            Metadata::new(),

337

3309

            Atom::Literal(Literal::Bool((value_mut & 1) != 0)),

338

3309

));

339

3309

        value_mut >>= 1;

340

3309

341

342

900

    Ok(Reduction::pure(Expr::SATInt(

343

900

        Metadata::new(),

344

900

        SATIntEncoding::Log,

345

900

        Moo::new(into_matrix_expr!(binary_encoding)),

346

900

        (value, value),

347

900

)))

348

247257

349

350

/// Determine the number of bits required to encode an i32 in 2s complement

351

972

pub fn bit_magnitude(x: i32) -> usize {

352

972

    if x >= 0 {

353

        // positive: bits = highest set bit + 1 sign bit

354

861

        (1 + (32 - x.leading_zeros())).try_into().unwrap()

355

    } else {

356

        // negative: bits = highest set bit in magnitude

357

111

        (33 - (!x).leading_zeros()).try_into().unwrap()

358

359

972

360

361

/// Given two vectors of expressions, extend the shorter one by repeating its last element until both are the same length

362

6

pub fn match_bits_length(a: Vec<Expr>, b: Vec<Expr>) -> (Vec<Expr>, Vec<Expr>) {

363

6

    let len_a = a.len();

364

6

    let len_b = b.len();

365

366

6

    if len_a < len_b {

367

        let last_a = a.last().cloned().unwrap();

368

        let mut a_extended = a;

369

        a_extended.resize(len_b, last_a);

370

        (a_extended, b)

371

6

    } else if len_b < len_a {

372

        let last_b = b.last().cloned().unwrap();

373

        let mut b_extended = b;

374

        b_extended.resize(len_a, last_b);

375

        (a, b_extended)

376

    } else {

377

6

        (a, b)

378

379

6