xref: /llvm-project/llvm/unittests/Support/KnownBitsTest.cpp (revision 4f111198d45481eb3b89d76f93d0bba6fe13f2b2)
1 //===- llvm/unittest/Support/KnownBitsTest.cpp - KnownBits tests ----------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements unit tests for KnownBits functions.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/Support/KnownBits.h"
14 #include "KnownBitsTest.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/ADT/Twine.h"
18 #include "gtest/gtest.h"
19 
20 using namespace llvm;
21 
22 using UnaryBitsFn = llvm::function_ref<KnownBits(const KnownBits &)>;
23 using UnaryIntFn = llvm::function_ref<std::optional<APInt>(const APInt &)>;
24 
25 using BinaryBitsFn =
26     llvm::function_ref<KnownBits(const KnownBits &, const KnownBits &)>;
27 using BinaryIntFn =
28     llvm::function_ref<std::optional<APInt>(const APInt &, const APInt &)>;
29 
30 static testing::AssertionResult checkResult(Twine Name, const KnownBits &Exact,
31                                             const KnownBits &Computed,
32                                             ArrayRef<KnownBits> Inputs,
33                                             bool CheckOptimality) {
34   if (CheckOptimality) {
35     // We generally don't want to return conflicting known bits, even if it is
36     // legal for always poison results.
37     if (Exact.hasConflict() || Computed == Exact)
38       return testing::AssertionSuccess();
39   } else {
40     if (Computed.Zero.isSubsetOf(Exact.Zero) &&
41         Computed.One.isSubsetOf(Exact.One))
42       return testing::AssertionSuccess();
43   }
44 
45   testing::AssertionResult Result = testing::AssertionFailure();
46   Result << Name << ": ";
47   Result << "Inputs = ";
48   for (const KnownBits &Input : Inputs)
49     Result << Input << ", ";
50   Result << "Computed = " << Computed << ", Exact = " << Exact;
51   return Result;
52 }
53 
54 static void testUnaryOpExhaustive(StringRef Name, UnaryBitsFn BitsFn,
55                                   UnaryIntFn IntFn,
56                                   bool CheckOptimality = true) {
57   for (unsigned Bits : {1, 4}) {
58     ForeachKnownBits(Bits, [&](const KnownBits &Known) {
59       KnownBits Computed = BitsFn(Known);
60       KnownBits Exact(Bits);
61       Exact.Zero.setAllBits();
62       Exact.One.setAllBits();
63 
64       ForeachNumInKnownBits(Known, [&](const APInt &N) {
65         if (std::optional<APInt> Res = IntFn(N)) {
66           Exact.One &= *Res;
67           Exact.Zero &= ~*Res;
68         }
69       });
70 
71       if (!Exact.hasConflict()) {
72         EXPECT_TRUE(checkResult(Name, Exact, Computed, Known, CheckOptimality));
73       }
74     });
75   }
76 }
77 
78 static void testBinaryOpExhaustive(StringRef Name, BinaryBitsFn BitsFn,
79                                    BinaryIntFn IntFn,
80                                    bool CheckOptimality = true,
81                                    bool RefinePoisonToZero = false) {
82   for (unsigned Bits : {1, 4}) {
83     ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
84       ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
85         KnownBits Computed = BitsFn(Known1, Known2);
86         KnownBits Exact(Bits);
87         Exact.Zero.setAllBits();
88         Exact.One.setAllBits();
89 
90         ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
91           ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
92             if (std::optional<APInt> Res = IntFn(N1, N2)) {
93               Exact.One &= *Res;
94               Exact.Zero &= ~*Res;
95             }
96           });
97         });
98 
99         if (!Exact.hasConflict()) {
100           EXPECT_TRUE(checkResult(Name, Exact, Computed, {Known1, Known2},
101                                   CheckOptimality));
102         }
103         // In some cases we choose to return zero if the result is always
104         // poison.
105         if (RefinePoisonToZero && Exact.hasConflict() &&
106             !Known1.hasConflict() && !Known2.hasConflict()) {
107           EXPECT_TRUE(Computed.isZero());
108         }
109       });
110     });
111   }
112 }
113 
114 namespace {
115 
116 TEST(KnownBitsTest, AddCarryExhaustive) {
117   unsigned Bits = 4;
118   ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
119     ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
120       ForeachKnownBits(1, [&](const KnownBits &KnownCarry) {
121         // Explicitly compute known bits of the addition by trying all
122         // possibilities.
123         KnownBits Exact(Bits);
124         Exact.Zero.setAllBits();
125         Exact.One.setAllBits();
126         ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
127           ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
128             ForeachNumInKnownBits(KnownCarry, [&](const APInt &Carry) {
129               APInt Add = N1 + N2;
130               if (Carry.getBoolValue())
131                 ++Add;
132 
133               Exact.One &= Add;
134               Exact.Zero &= ~Add;
135             });
136           });
137         });
138 
139         KnownBits Computed =
140             KnownBits::computeForAddCarry(Known1, Known2, KnownCarry);
141         if (!Exact.hasConflict()) {
142           EXPECT_EQ(Exact, Computed);
143         }
144       });
145     });
146   });
147 }
148 
149 static void TestAddSubExhaustive(bool IsAdd) {
150   Twine Name = IsAdd ? "add" : "sub";
151   unsigned Bits = 4;
152   ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
153     ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
154       KnownBits Exact(Bits), ExactNSW(Bits), ExactNUW(Bits),
155           ExactNSWAndNUW(Bits);
156       Exact.Zero.setAllBits();
157       Exact.One.setAllBits();
158       ExactNSW.Zero.setAllBits();
159       ExactNSW.One.setAllBits();
160       ExactNUW.Zero.setAllBits();
161       ExactNUW.One.setAllBits();
162       ExactNSWAndNUW.Zero.setAllBits();
163       ExactNSWAndNUW.One.setAllBits();
164 
165       ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
166         ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
167           bool SignedOverflow;
168           bool UnsignedOverflow;
169           APInt Res;
170           if (IsAdd) {
171             Res = N1.uadd_ov(N2, UnsignedOverflow);
172             Res = N1.sadd_ov(N2, SignedOverflow);
173           } else {
174             Res = N1.usub_ov(N2, UnsignedOverflow);
175             Res = N1.ssub_ov(N2, SignedOverflow);
176           }
177 
178           Exact.One &= Res;
179           Exact.Zero &= ~Res;
180 
181           if (!SignedOverflow) {
182             ExactNSW.One &= Res;
183             ExactNSW.Zero &= ~Res;
184           }
185 
186           if (!UnsignedOverflow) {
187             ExactNUW.One &= Res;
188             ExactNUW.Zero &= ~Res;
189           }
190 
191           if (!UnsignedOverflow && !SignedOverflow) {
192             ExactNSWAndNUW.One &= Res;
193             ExactNSWAndNUW.Zero &= ~Res;
194           }
195         });
196       });
197 
198       KnownBits Computed = KnownBits::computeForAddSub(
199           IsAdd, /*NSW=*/false, /*NUW=*/false, Known1, Known2);
200       EXPECT_TRUE(checkResult(Name, Exact, Computed, {Known1, Known2},
201                               /*CheckOptimality=*/true));
202 
203       KnownBits ComputedNSW = KnownBits::computeForAddSub(
204           IsAdd, /*NSW=*/true, /*NUW=*/false, Known1, Known2);
205       EXPECT_TRUE(checkResult(Name + " nsw", ExactNSW, ComputedNSW,
206                               {Known1, Known2},
207                               /*CheckOptimality=*/true));
208 
209       KnownBits ComputedNUW = KnownBits::computeForAddSub(
210           IsAdd, /*NSW=*/false, /*NUW=*/true, Known1, Known2);
211       EXPECT_TRUE(checkResult(Name + " nuw", ExactNUW, ComputedNUW,
212                               {Known1, Known2},
213                               /*CheckOptimality=*/true));
214 
215       KnownBits ComputedNSWAndNUW = KnownBits::computeForAddSub(
216           IsAdd, /*NSW=*/true, /*NUW=*/true, Known1, Known2);
217       EXPECT_TRUE(checkResult(Name + " nsw nuw", ExactNSWAndNUW,
218                               ComputedNSWAndNUW, {Known1, Known2},
219                               /*CheckOptimality=*/true));
220     });
221   });
222 }
223 
224 TEST(KnownBitsTest, AddSubExhaustive) {
225   TestAddSubExhaustive(true);
226   TestAddSubExhaustive(false);
227 }
228 
229 TEST(KnownBitsTest, SubBorrowExhaustive) {
230   unsigned Bits = 4;
231   ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
232     ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
233       ForeachKnownBits(1, [&](const KnownBits &KnownBorrow) {
234         // Explicitly compute known bits of the subtraction by trying all
235         // possibilities.
236         KnownBits Exact(Bits);
237         Exact.Zero.setAllBits();
238         Exact.One.setAllBits();
239         ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
240           ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
241             ForeachNumInKnownBits(KnownBorrow, [&](const APInt &Borrow) {
242               APInt Sub = N1 - N2;
243               if (Borrow.getBoolValue())
244                 --Sub;
245 
246               Exact.One &= Sub;
247               Exact.Zero &= ~Sub;
248             });
249           });
250         });
251 
252         KnownBits Computed =
253             KnownBits::computeForSubBorrow(Known1, Known2, KnownBorrow);
254         if (!Exact.hasConflict()) {
255           EXPECT_EQ(Exact, Computed);
256         }
257       });
258     });
259   });
260 }
261 
262 TEST(KnownBitsTest, SignBitUnknown) {
263   KnownBits Known(2);
264   EXPECT_TRUE(Known.isSignUnknown());
265   Known.Zero.setBit(0);
266   EXPECT_TRUE(Known.isSignUnknown());
267   Known.Zero.setBit(1);
268   EXPECT_FALSE(Known.isSignUnknown());
269   Known.Zero.clearBit(0);
270   EXPECT_FALSE(Known.isSignUnknown());
271   Known.Zero.clearBit(1);
272   EXPECT_TRUE(Known.isSignUnknown());
273 
274   Known.One.setBit(0);
275   EXPECT_TRUE(Known.isSignUnknown());
276   Known.One.setBit(1);
277   EXPECT_FALSE(Known.isSignUnknown());
278   Known.One.clearBit(0);
279   EXPECT_FALSE(Known.isSignUnknown());
280   Known.One.clearBit(1);
281   EXPECT_TRUE(Known.isSignUnknown());
282 }
283 
284 TEST(KnownBitsTest, BinaryExhaustive) {
285   testBinaryOpExhaustive(
286       "and",
287       [](const KnownBits &Known1, const KnownBits &Known2) {
288         return Known1 & Known2;
289       },
290       [](const APInt &N1, const APInt &N2) { return N1 & N2; });
291   testBinaryOpExhaustive(
292       "or",
293       [](const KnownBits &Known1, const KnownBits &Known2) {
294         return Known1 | Known2;
295       },
296       [](const APInt &N1, const APInt &N2) { return N1 | N2; });
297   testBinaryOpExhaustive(
298       "xor",
299       [](const KnownBits &Known1, const KnownBits &Known2) {
300         return Known1 ^ Known2;
301       },
302       [](const APInt &N1, const APInt &N2) { return N1 ^ N2; });
303   testBinaryOpExhaustive("umax", KnownBits::umax, APIntOps::umax);
304   testBinaryOpExhaustive("umin", KnownBits::umin, APIntOps::umin);
305   testBinaryOpExhaustive("smax", KnownBits::smax, APIntOps::smax);
306   testBinaryOpExhaustive("smin", KnownBits::smin, APIntOps::smin);
307   testBinaryOpExhaustive("abdu", KnownBits::abdu, APIntOps::abdu);
308   testBinaryOpExhaustive("abds", KnownBits::abds, APIntOps::abds);
309   testBinaryOpExhaustive(
310       "udiv",
311       [](const KnownBits &Known1, const KnownBits &Known2) {
312         return KnownBits::udiv(Known1, Known2);
313       },
314       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
315         if (N2.isZero())
316           return std::nullopt;
317         return N1.udiv(N2);
318       },
319       /*CheckOptimality=*/false);
320   testBinaryOpExhaustive(
321       "udiv exact",
322       [](const KnownBits &Known1, const KnownBits &Known2) {
323         return KnownBits::udiv(Known1, Known2, /*Exact=*/true);
324       },
325       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
326         if (N2.isZero() || !N1.urem(N2).isZero())
327           return std::nullopt;
328         return N1.udiv(N2);
329       },
330       /*CheckOptimality=*/false);
331   testBinaryOpExhaustive(
332       "sdiv",
333       [](const KnownBits &Known1, const KnownBits &Known2) {
334         return KnownBits::sdiv(Known1, Known2);
335       },
336       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
337         if (N2.isZero() || (N1.isMinSignedValue() && N2.isAllOnes()))
338           return std::nullopt;
339         return N1.sdiv(N2);
340       },
341       /*CheckOptimality=*/false);
342   testBinaryOpExhaustive(
343       "sdiv exact",
344       [](const KnownBits &Known1, const KnownBits &Known2) {
345         return KnownBits::sdiv(Known1, Known2, /*Exact=*/true);
346       },
347       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
348         if (N2.isZero() || (N1.isMinSignedValue() && N2.isAllOnes()) ||
349             !N1.srem(N2).isZero())
350           return std::nullopt;
351         return N1.sdiv(N2);
352       },
353       /*CheckOptimality=*/false);
354   testBinaryOpExhaustive(
355       "urem", KnownBits::urem,
356       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
357         if (N2.isZero())
358           return std::nullopt;
359         return N1.urem(N2);
360       },
361       /*CheckOptimality=*/false);
362   testBinaryOpExhaustive(
363       "srem", KnownBits::srem,
364       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
365         if (N2.isZero())
366           return std::nullopt;
367         return N1.srem(N2);
368       },
369       /*CheckOptimality=*/false);
370   testBinaryOpExhaustive(
371       "sadd_sat", KnownBits::sadd_sat,
372       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
373         return N1.sadd_sat(N2);
374       },
375       /*CheckOptimality=*/false);
376   testBinaryOpExhaustive(
377       "uadd_sat", KnownBits::uadd_sat,
378       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
379         return N1.uadd_sat(N2);
380       },
381       /*CheckOptimality=*/false);
382   testBinaryOpExhaustive(
383       "ssub_sat", KnownBits::ssub_sat,
384       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
385         return N1.ssub_sat(N2);
386       },
387       /*CheckOptimality=*/false);
388   testBinaryOpExhaustive(
389       "usub_sat", KnownBits::usub_sat,
390       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
391         return N1.usub_sat(N2);
392       },
393       /*CheckOptimality=*/false);
394   testBinaryOpExhaustive(
395       "shl",
396       [](const KnownBits &Known1, const KnownBits &Known2) {
397         return KnownBits::shl(Known1, Known2);
398       },
399       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
400         if (N2.uge(N2.getBitWidth()))
401           return std::nullopt;
402         return N1.shl(N2);
403       },
404       /*CheckOptimality=*/true, /*RefinePoisonToZero=*/true);
405   testBinaryOpExhaustive(
406       "ushl_ov",
407       [](const KnownBits &Known1, const KnownBits &Known2) {
408         return KnownBits::shl(Known1, Known2, /*NUW=*/true);
409       },
410       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
411         bool Overflow;
412         APInt Res = N1.ushl_ov(N2, Overflow);
413         if (Overflow)
414           return std::nullopt;
415         return Res;
416       },
417       /*CheckOptimality=*/true, /*RefinePoisonToZero=*/true);
418   testBinaryOpExhaustive(
419       "shl nsw",
420       [](const KnownBits &Known1, const KnownBits &Known2) {
421         return KnownBits::shl(Known1, Known2, /*NUW=*/false, /*NSW=*/true);
422       },
423       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
424         bool Overflow;
425         APInt Res = N1.sshl_ov(N2, Overflow);
426         if (Overflow)
427           return std::nullopt;
428         return Res;
429       },
430       /*CheckOptimality=*/true, /*RefinePoisonToZero=*/true);
431   testBinaryOpExhaustive(
432       "shl nuw",
433       [](const KnownBits &Known1, const KnownBits &Known2) {
434         return KnownBits::shl(Known1, Known2, /*NUW=*/true, /*NSW=*/true);
435       },
436       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
437         bool OverflowUnsigned, OverflowSigned;
438         APInt Res = N1.ushl_ov(N2, OverflowUnsigned);
439         (void)N1.sshl_ov(N2, OverflowSigned);
440         if (OverflowUnsigned || OverflowSigned)
441           return std::nullopt;
442         return Res;
443       },
444       /*CheckOptimality=*/true, /*RefinePoisonToZero=*/true);
445 
446   testBinaryOpExhaustive(
447       "lshr",
448       [](const KnownBits &Known1, const KnownBits &Known2) {
449         return KnownBits::lshr(Known1, Known2);
450       },
451       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
452         if (N2.uge(N2.getBitWidth()))
453           return std::nullopt;
454         return N1.lshr(N2);
455       },
456       /*CheckOptimality=*/true, /*RefinePoisonToZero=*/true);
457   testBinaryOpExhaustive(
458       "lshr exact",
459       [](const KnownBits &Known1, const KnownBits &Known2) {
460         return KnownBits::lshr(Known1, Known2, /*ShAmtNonZero=*/false,
461                                /*Exact=*/true);
462       },
463       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
464         if (N2.uge(N2.getBitWidth()))
465           return std::nullopt;
466         if (!N1.extractBits(N2.getZExtValue(), 0).isZero())
467           return std::nullopt;
468         return N1.lshr(N2);
469       },
470       /*CheckOptimality=*/true, /*RefinePoisonToZero=*/true);
471   testBinaryOpExhaustive(
472       "ashr",
473       [](const KnownBits &Known1, const KnownBits &Known2) {
474         return KnownBits::ashr(Known1, Known2);
475       },
476       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
477         if (N2.uge(N2.getBitWidth()))
478           return std::nullopt;
479         return N1.ashr(N2);
480       },
481       /*CheckOptimality=*/true, /*RefinePoisonToZero=*/true);
482   testBinaryOpExhaustive(
483       "ashr exact",
484       [](const KnownBits &Known1, const KnownBits &Known2) {
485         return KnownBits::ashr(Known1, Known2, /*ShAmtNonZero=*/false,
486                                /*Exact=*/true);
487       },
488       [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
489         if (N2.uge(N2.getBitWidth()))
490           return std::nullopt;
491         if (!N1.extractBits(N2.getZExtValue(), 0).isZero())
492           return std::nullopt;
493         return N1.ashr(N2);
494       },
495       /*CheckOptimality=*/true, /*RefinePoisonToZero=*/true);
496   testBinaryOpExhaustive(
497       "mul",
498       [](const KnownBits &Known1, const KnownBits &Known2) {
499         return KnownBits::mul(Known1, Known2);
500       },
501       [](const APInt &N1, const APInt &N2) { return N1 * N2; },
502       /*CheckOptimality=*/false);
503   testBinaryOpExhaustive(
504       "mulhs", KnownBits::mulhs,
505       [](const APInt &N1, const APInt &N2) { return APIntOps::mulhs(N1, N2); },
506       /*CheckOptimality=*/false);
507   testBinaryOpExhaustive(
508       "mulhu", KnownBits::mulhu,
509       [](const APInt &N1, const APInt &N2) { return APIntOps::mulhu(N1, N2); },
510       /*CheckOptimality=*/false);
511 
512   testBinaryOpExhaustive("avgFloorS", KnownBits::avgFloorS, APIntOps::avgFloorS,
513                          false);
514 
515   testBinaryOpExhaustive("avgFloorU", KnownBits::avgFloorU, APIntOps::avgFloorU,
516                          false);
517 
518   testBinaryOpExhaustive("avgCeilU", KnownBits::avgCeilU, APIntOps::avgCeilU,
519                          false);
520 
521   testBinaryOpExhaustive("avgCeilS", KnownBits::avgCeilS, APIntOps::avgCeilS,
522                          false);
523 }
524 
525 TEST(KnownBitsTest, UnaryExhaustive) {
526   testUnaryOpExhaustive(
527       "abs", [](const KnownBits &Known) { return Known.abs(); },
528       [](const APInt &N) { return N.abs(); });
529 
530   testUnaryOpExhaustive(
531       "abs(true)", [](const KnownBits &Known) { return Known.abs(true); },
532       [](const APInt &N) -> std::optional<APInt> {
533         if (N.isMinSignedValue())
534           return std::nullopt;
535         return N.abs();
536       });
537 
538   testUnaryOpExhaustive(
539       "blsi", [](const KnownBits &Known) { return Known.blsi(); },
540       [](const APInt &N) { return N & -N; });
541   testUnaryOpExhaustive(
542       "blsmsk", [](const KnownBits &Known) { return Known.blsmsk(); },
543       [](const APInt &N) { return N ^ (N - 1); });
544 
545   testUnaryOpExhaustive(
546       "mul self",
547       [](const KnownBits &Known) {
548         return KnownBits::mul(Known, Known, /*SelfMultiply=*/true);
549       },
550       [](const APInt &N) { return N * N; }, /*CheckOptimality=*/false);
551 }
552 
553 TEST(KnownBitsTest, WideShifts) {
554   unsigned BitWidth = 128;
555   KnownBits Unknown(BitWidth);
556   KnownBits AllOnes = KnownBits::makeConstant(APInt::getAllOnes(BitWidth));
557 
558   KnownBits ShlResult(BitWidth);
559   ShlResult.makeNegative();
560   EXPECT_EQ(KnownBits::shl(AllOnes, Unknown), ShlResult);
561   KnownBits LShrResult(BitWidth);
562   LShrResult.One.setBit(0);
563   EXPECT_EQ(KnownBits::lshr(AllOnes, Unknown), LShrResult);
564   EXPECT_EQ(KnownBits::ashr(AllOnes, Unknown), AllOnes);
565 }
566 
567 TEST(KnownBitsTest, ICmpExhaustive) {
568   unsigned Bits = 4;
569   ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
570     ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
571       bool AllEQ = true, NoneEQ = true;
572       bool AllNE = true, NoneNE = true;
573       bool AllUGT = true, NoneUGT = true;
574       bool AllUGE = true, NoneUGE = true;
575       bool AllULT = true, NoneULT = true;
576       bool AllULE = true, NoneULE = true;
577       bool AllSGT = true, NoneSGT = true;
578       bool AllSGE = true, NoneSGE = true;
579       bool AllSLT = true, NoneSLT = true;
580       bool AllSLE = true, NoneSLE = true;
581 
582       ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
583         ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
584           AllEQ &= N1.eq(N2);
585           AllNE &= N1.ne(N2);
586           AllUGT &= N1.ugt(N2);
587           AllUGE &= N1.uge(N2);
588           AllULT &= N1.ult(N2);
589           AllULE &= N1.ule(N2);
590           AllSGT &= N1.sgt(N2);
591           AllSGE &= N1.sge(N2);
592           AllSLT &= N1.slt(N2);
593           AllSLE &= N1.sle(N2);
594           NoneEQ &= !N1.eq(N2);
595           NoneNE &= !N1.ne(N2);
596           NoneUGT &= !N1.ugt(N2);
597           NoneUGE &= !N1.uge(N2);
598           NoneULT &= !N1.ult(N2);
599           NoneULE &= !N1.ule(N2);
600           NoneSGT &= !N1.sgt(N2);
601           NoneSGE &= !N1.sge(N2);
602           NoneSLT &= !N1.slt(N2);
603           NoneSLE &= !N1.sle(N2);
604         });
605       });
606 
607       std::optional<bool> KnownEQ = KnownBits::eq(Known1, Known2);
608       std::optional<bool> KnownNE = KnownBits::ne(Known1, Known2);
609       std::optional<bool> KnownUGT = KnownBits::ugt(Known1, Known2);
610       std::optional<bool> KnownUGE = KnownBits::uge(Known1, Known2);
611       std::optional<bool> KnownULT = KnownBits::ult(Known1, Known2);
612       std::optional<bool> KnownULE = KnownBits::ule(Known1, Known2);
613       std::optional<bool> KnownSGT = KnownBits::sgt(Known1, Known2);
614       std::optional<bool> KnownSGE = KnownBits::sge(Known1, Known2);
615       std::optional<bool> KnownSLT = KnownBits::slt(Known1, Known2);
616       std::optional<bool> KnownSLE = KnownBits::sle(Known1, Known2);
617 
618       if (Known1.hasConflict() || Known2.hasConflict())
619         return;
620 
621       EXPECT_EQ(AllEQ || NoneEQ, KnownEQ.has_value());
622       EXPECT_EQ(AllNE || NoneNE, KnownNE.has_value());
623       EXPECT_EQ(AllUGT || NoneUGT, KnownUGT.has_value());
624       EXPECT_EQ(AllUGE || NoneUGE, KnownUGE.has_value());
625       EXPECT_EQ(AllULT || NoneULT, KnownULT.has_value());
626       EXPECT_EQ(AllULE || NoneULE, KnownULE.has_value());
627       EXPECT_EQ(AllSGT || NoneSGT, KnownSGT.has_value());
628       EXPECT_EQ(AllSGE || NoneSGE, KnownSGE.has_value());
629       EXPECT_EQ(AllSLT || NoneSLT, KnownSLT.has_value());
630       EXPECT_EQ(AllSLE || NoneSLE, KnownSLE.has_value());
631 
632       EXPECT_EQ(AllEQ, KnownEQ.has_value() && *KnownEQ);
633       EXPECT_EQ(AllNE, KnownNE.has_value() && *KnownNE);
634       EXPECT_EQ(AllUGT, KnownUGT.has_value() && *KnownUGT);
635       EXPECT_EQ(AllUGE, KnownUGE.has_value() && *KnownUGE);
636       EXPECT_EQ(AllULT, KnownULT.has_value() && *KnownULT);
637       EXPECT_EQ(AllULE, KnownULE.has_value() && *KnownULE);
638       EXPECT_EQ(AllSGT, KnownSGT.has_value() && *KnownSGT);
639       EXPECT_EQ(AllSGE, KnownSGE.has_value() && *KnownSGE);
640       EXPECT_EQ(AllSLT, KnownSLT.has_value() && *KnownSLT);
641       EXPECT_EQ(AllSLE, KnownSLE.has_value() && *KnownSLE);
642 
643       EXPECT_EQ(NoneEQ, KnownEQ.has_value() && !*KnownEQ);
644       EXPECT_EQ(NoneNE, KnownNE.has_value() && !*KnownNE);
645       EXPECT_EQ(NoneUGT, KnownUGT.has_value() && !*KnownUGT);
646       EXPECT_EQ(NoneUGE, KnownUGE.has_value() && !*KnownUGE);
647       EXPECT_EQ(NoneULT, KnownULT.has_value() && !*KnownULT);
648       EXPECT_EQ(NoneULE, KnownULE.has_value() && !*KnownULE);
649       EXPECT_EQ(NoneSGT, KnownSGT.has_value() && !*KnownSGT);
650       EXPECT_EQ(NoneSGE, KnownSGE.has_value() && !*KnownSGE);
651       EXPECT_EQ(NoneSLT, KnownSLT.has_value() && !*KnownSLT);
652       EXPECT_EQ(NoneSLE, KnownSLE.has_value() && !*KnownSLE);
653     });
654   });
655 }
656 
657 TEST(KnownBitsTest, GetMinMaxVal) {
658   unsigned Bits = 4;
659   ForeachKnownBits(Bits, [&](const KnownBits &Known) {
660     APInt Min = APInt::getMaxValue(Bits);
661     APInt Max = APInt::getMinValue(Bits);
662     ForeachNumInKnownBits(Known, [&](const APInt &N) {
663       Min = APIntOps::umin(Min, N);
664       Max = APIntOps::umax(Max, N);
665     });
666     if (!Known.hasConflict()) {
667       EXPECT_EQ(Min, Known.getMinValue());
668       EXPECT_EQ(Max, Known.getMaxValue());
669     }
670   });
671 }
672 
673 TEST(KnownBitsTest, GetSignedMinMaxVal) {
674   unsigned Bits = 4;
675   ForeachKnownBits(Bits, [&](const KnownBits &Known) {
676     APInt Min = APInt::getSignedMaxValue(Bits);
677     APInt Max = APInt::getSignedMinValue(Bits);
678     ForeachNumInKnownBits(Known, [&](const APInt &N) {
679       Min = APIntOps::smin(Min, N);
680       Max = APIntOps::smax(Max, N);
681     });
682     if (!Known.hasConflict()) {
683       EXPECT_EQ(Min, Known.getSignedMinValue());
684       EXPECT_EQ(Max, Known.getSignedMaxValue());
685     }
686   });
687 }
688 
689 TEST(KnownBitsTest, CountMaxActiveBits) {
690   unsigned Bits = 4;
691   ForeachKnownBits(Bits, [&](const KnownBits &Known) {
692     unsigned Expected = 0;
693     ForeachNumInKnownBits(Known, [&](const APInt &N) {
694       Expected = std::max(Expected, N.getActiveBits());
695     });
696     if (!Known.hasConflict()) {
697       EXPECT_EQ(Expected, Known.countMaxActiveBits());
698     }
699   });
700 }
701 
702 TEST(KnownBitsTest, CountMaxSignificantBits) {
703   unsigned Bits = 4;
704   ForeachKnownBits(Bits, [&](const KnownBits &Known) {
705     unsigned Expected = 0;
706     ForeachNumInKnownBits(Known, [&](const APInt &N) {
707       Expected = std::max(Expected, N.getSignificantBits());
708     });
709     if (!Known.hasConflict()) {
710       EXPECT_EQ(Expected, Known.countMaxSignificantBits());
711     }
712   });
713 }
714 
715 TEST(KnownBitsTest, SExtOrTrunc) {
716   const unsigned NarrowerSize = 4;
717   const unsigned BaseSize = 6;
718   const unsigned WiderSize = 8;
719   APInt NegativeFitsNarrower(BaseSize, -4, /*isSigned=*/true);
720   APInt NegativeDoesntFitNarrower(BaseSize, -28, /*isSigned=*/true);
721   APInt PositiveFitsNarrower(BaseSize, 14);
722   APInt PositiveDoesntFitNarrower(BaseSize, 36);
723   auto InitKnownBits = [&](KnownBits &Res, const APInt &Input) {
724     Res = KnownBits(Input.getBitWidth());
725     Res.One = Input;
726     Res.Zero = ~Input;
727   };
728 
729   for (unsigned Size : {NarrowerSize, BaseSize, WiderSize}) {
730     for (const APInt &Input :
731          {NegativeFitsNarrower, NegativeDoesntFitNarrower, PositiveFitsNarrower,
732           PositiveDoesntFitNarrower}) {
733       KnownBits Test;
734       InitKnownBits(Test, Input);
735       KnownBits Baseline;
736       InitKnownBits(Baseline, Input.sextOrTrunc(Size));
737       Test = Test.sextOrTrunc(Size);
738       EXPECT_EQ(Test, Baseline);
739     }
740   }
741 }
742 
743 TEST(KnownBitsTest, SExtInReg) {
744   unsigned Bits = 4;
745   for (unsigned FromBits = 1; FromBits <= Bits; ++FromBits) {
746     ForeachKnownBits(Bits, [&](const KnownBits &Known) {
747       APInt CommonOne = APInt::getAllOnes(Bits);
748       APInt CommonZero = APInt::getAllOnes(Bits);
749       unsigned ExtBits = Bits - FromBits;
750       ForeachNumInKnownBits(Known, [&](const APInt &N) {
751         APInt Ext = N << ExtBits;
752         Ext.ashrInPlace(ExtBits);
753         CommonOne &= Ext;
754         CommonZero &= ~Ext;
755       });
756       KnownBits KnownSExtInReg = Known.sextInReg(FromBits);
757       if (!Known.hasConflict()) {
758         EXPECT_EQ(CommonOne, KnownSExtInReg.One);
759         EXPECT_EQ(CommonZero, KnownSExtInReg.Zero);
760       }
761     });
762   }
763 }
764 
765 TEST(KnownBitsTest, CommonBitsSet) {
766   unsigned Bits = 4;
767   ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
768     ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
769       bool HasCommonBitsSet = false;
770       ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
771         ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
772           HasCommonBitsSet |= N1.intersects(N2);
773         });
774       });
775       if (!Known1.hasConflict() && !Known2.hasConflict()) {
776         EXPECT_EQ(!HasCommonBitsSet,
777                   KnownBits::haveNoCommonBitsSet(Known1, Known2));
778       }
779     });
780   });
781 }
782 
783 TEST(KnownBitsTest, ConcatBits) {
784   unsigned Bits = 4;
785   for (unsigned LoBits = 1; LoBits < Bits; ++LoBits) {
786     unsigned HiBits = Bits - LoBits;
787     ForeachKnownBits(LoBits, [&](const KnownBits &KnownLo) {
788       ForeachKnownBits(HiBits, [&](const KnownBits &KnownHi) {
789         KnownBits KnownAll = KnownHi.concat(KnownLo);
790 
791         EXPECT_EQ(KnownLo.countMinPopulation() + KnownHi.countMinPopulation(),
792                   KnownAll.countMinPopulation());
793         EXPECT_EQ(KnownLo.countMaxPopulation() + KnownHi.countMaxPopulation(),
794                   KnownAll.countMaxPopulation());
795 
796         KnownBits ExtractLo = KnownAll.extractBits(LoBits, 0);
797         KnownBits ExtractHi = KnownAll.extractBits(HiBits, LoBits);
798 
799         EXPECT_EQ(KnownLo.One.getZExtValue(), ExtractLo.One.getZExtValue());
800         EXPECT_EQ(KnownHi.One.getZExtValue(), ExtractHi.One.getZExtValue());
801         EXPECT_EQ(KnownLo.Zero.getZExtValue(), ExtractLo.Zero.getZExtValue());
802         EXPECT_EQ(KnownHi.Zero.getZExtValue(), ExtractHi.Zero.getZExtValue());
803       });
804     });
805   }
806 }
807 
808 } // end anonymous namespace
809