xref: /llvm-project/llvm/unittests/Analysis/ValueTrackingTest.cpp (revision e13f88d1ff5234946af6349a9a7cf56fcb6c040e)
1 //===- ValueTrackingTest.cpp - ValueTracking 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 #include "llvm/Analysis/ValueTracking.h"
10 #include "llvm/Analysis/AssumptionCache.h"
11 #include "llvm/AsmParser/Parser.h"
12 #include "llvm/IR/ConstantRange.h"
13 #include "llvm/IR/Dominators.h"
14 #include "llvm/IR/Function.h"
15 #include "llvm/IR/IRBuilder.h"
16 #include "llvm/IR/InstIterator.h"
17 #include "llvm/IR/Instructions.h"
18 #include "llvm/IR/LLVMContext.h"
19 #include "llvm/IR/Module.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/KnownBits.h"
22 #include "llvm/Support/SourceMgr.h"
23 #include "llvm/Transforms/Utils/Local.h"
24 #include "gtest/gtest.h"
25 
26 using namespace llvm;
27 
28 namespace {
29 
30 static Instruction *findInstructionByNameOrNull(Function *F, StringRef Name) {
31   for (Instruction &I : instructions(F))
32     if (I.getName() == Name)
33       return &I;
34 
35   return nullptr;
36 }
37 
38 static Instruction &findInstructionByName(Function *F, StringRef Name) {
39   auto *I = findInstructionByNameOrNull(F, Name);
40   if (I)
41     return *I;
42 
43   llvm_unreachable("Expected value not found");
44 }
45 
46 class ValueTrackingTest : public testing::Test {
47 protected:
48   std::unique_ptr<Module> parseModule(StringRef Assembly) {
49     SMDiagnostic Error;
50     std::unique_ptr<Module> M = parseAssemblyString(Assembly, Error, Context);
51 
52     std::string errMsg;
53     raw_string_ostream os(errMsg);
54     Error.print("", os);
55     EXPECT_TRUE(M) << os.str();
56 
57     return M;
58   }
59 
60   void parseAssembly(StringRef Assembly) {
61     M = parseModule(Assembly);
62     ASSERT_TRUE(M);
63 
64     F = M->getFunction("test");
65     ASSERT_TRUE(F) << "Test must have a function @test";
66     if (!F)
67       return;
68 
69     A = findInstructionByNameOrNull(F, "A");
70     ASSERT_TRUE(A) << "@test must have an instruction %A";
71     A2 = findInstructionByNameOrNull(F, "A2");
72     A3 = findInstructionByNameOrNull(F, "A3");
73     A4 = findInstructionByNameOrNull(F, "A4");
74     A5 = findInstructionByNameOrNull(F, "A5");
75     A6 = findInstructionByNameOrNull(F, "A6");
76     A7 = findInstructionByNameOrNull(F, "A7");
77 
78     CxtI = findInstructionByNameOrNull(F, "CxtI");
79     CxtI2 = findInstructionByNameOrNull(F, "CxtI2");
80     CxtI3 = findInstructionByNameOrNull(F, "CxtI3");
81   }
82 
83   LLVMContext Context;
84   std::unique_ptr<Module> M;
85   Function *F = nullptr;
86   Instruction *A = nullptr;
87   // Instructions (optional)
88   Instruction *A2 = nullptr, *A3 = nullptr, *A4 = nullptr, *A5 = nullptr,
89               *A6 = nullptr, *A7 = nullptr;
90 
91   // Context instructions (optional)
92   Instruction *CxtI = nullptr, *CxtI2 = nullptr, *CxtI3 = nullptr;
93 };
94 
95 class MatchSelectPatternTest : public ValueTrackingTest {
96 protected:
97   void expectPattern(const SelectPatternResult &P) {
98     Value *LHS, *RHS;
99     Instruction::CastOps CastOp;
100     SelectPatternResult R = matchSelectPattern(A, LHS, RHS, &CastOp);
101     EXPECT_EQ(P.Flavor, R.Flavor);
102     EXPECT_EQ(P.NaNBehavior, R.NaNBehavior);
103     EXPECT_EQ(P.Ordered, R.Ordered);
104   }
105 };
106 
107 class ComputeKnownBitsTest : public ValueTrackingTest {
108 protected:
109   void expectKnownBits(uint64_t Zero, uint64_t One) {
110     auto Known = computeKnownBits(A, M->getDataLayout());
111     ASSERT_FALSE(Known.hasConflict());
112     EXPECT_EQ(Known.One.getZExtValue(), One);
113     EXPECT_EQ(Known.Zero.getZExtValue(), Zero);
114   }
115 };
116 
117 class ComputeKnownFPClassTest : public ValueTrackingTest {
118 protected:
119   void expectKnownFPClass(unsigned KnownTrue, std::optional<bool> SignBitKnown,
120                           Instruction *TestVal = nullptr) {
121     if (!TestVal)
122       TestVal = A;
123 
124     KnownFPClass Known = computeKnownFPClass(TestVal, M->getDataLayout());
125     EXPECT_EQ(KnownTrue, Known.KnownFPClasses);
126     EXPECT_EQ(SignBitKnown, Known.SignBit);
127   }
128 };
129 }
130 
131 TEST_F(MatchSelectPatternTest, SimpleFMin) {
132   parseAssembly(
133       "define float @test(float %a) {\n"
134       "  %1 = fcmp ult float %a, 5.0\n"
135       "  %A = select i1 %1, float %a, float 5.0\n"
136       "  ret float %A\n"
137       "}\n");
138   expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false});
139 }
140 
141 TEST_F(MatchSelectPatternTest, SimpleFMax) {
142   parseAssembly(
143       "define float @test(float %a) {\n"
144       "  %1 = fcmp ogt float %a, 5.0\n"
145       "  %A = select i1 %1, float %a, float 5.0\n"
146       "  ret float %A\n"
147       "}\n");
148   expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true});
149 }
150 
151 TEST_F(MatchSelectPatternTest, SwappedFMax) {
152   parseAssembly(
153       "define float @test(float %a) {\n"
154       "  %1 = fcmp olt float 5.0, %a\n"
155       "  %A = select i1 %1, float %a, float 5.0\n"
156       "  ret float %A\n"
157       "}\n");
158   expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, false});
159 }
160 
161 TEST_F(MatchSelectPatternTest, SwappedFMax2) {
162   parseAssembly(
163       "define float @test(float %a) {\n"
164       "  %1 = fcmp olt float %a, 5.0\n"
165       "  %A = select i1 %1, float 5.0, float %a\n"
166       "  ret float %A\n"
167       "}\n");
168   expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, false});
169 }
170 
171 TEST_F(MatchSelectPatternTest, SwappedFMax3) {
172   parseAssembly(
173       "define float @test(float %a) {\n"
174       "  %1 = fcmp ult float %a, 5.0\n"
175       "  %A = select i1 %1, float 5.0, float %a\n"
176       "  ret float %A\n"
177       "}\n");
178   expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true});
179 }
180 
181 TEST_F(MatchSelectPatternTest, FastFMin) {
182   parseAssembly(
183       "define float @test(float %a) {\n"
184       "  %1 = fcmp nnan olt float %a, 5.0\n"
185       "  %A = select i1 %1, float %a, float 5.0\n"
186       "  ret float %A\n"
187       "}\n");
188   expectPattern({SPF_FMINNUM, SPNB_RETURNS_ANY, false});
189 }
190 
191 TEST_F(MatchSelectPatternTest, FMinConstantZero) {
192   parseAssembly(
193       "define float @test(float %a) {\n"
194       "  %1 = fcmp ole float %a, 0.0\n"
195       "  %A = select i1 %1, float %a, float 0.0\n"
196       "  ret float %A\n"
197       "}\n");
198   // This shouldn't be matched, as %a could be -0.0.
199   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
200 }
201 
202 TEST_F(MatchSelectPatternTest, FMinConstantZeroNsz) {
203   parseAssembly(
204       "define float @test(float %a) {\n"
205       "  %1 = fcmp nsz ole float %a, 0.0\n"
206       "  %A = select i1 %1, float %a, float 0.0\n"
207       "  ret float %A\n"
208       "}\n");
209   // But this should be, because we've ignored signed zeroes.
210   expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true});
211 }
212 
213 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero1) {
214   parseAssembly(
215       "define float @test(float %a) {\n"
216       "  %1 = fcmp olt float -0.0, %a\n"
217       "  %A = select i1 %1, float 0.0, float %a\n"
218       "  ret float %A\n"
219       "}\n");
220   // The sign of zero doesn't matter in fcmp.
221   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
222 }
223 
224 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero2) {
225   parseAssembly(
226       "define float @test(float %a) {\n"
227       "  %1 = fcmp ogt float %a, -0.0\n"
228       "  %A = select i1 %1, float 0.0, float %a\n"
229       "  ret float %A\n"
230       "}\n");
231   // The sign of zero doesn't matter in fcmp.
232   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
233 }
234 
235 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero3) {
236   parseAssembly(
237       "define float @test(float %a) {\n"
238       "  %1 = fcmp olt float 0.0, %a\n"
239       "  %A = select i1 %1, float -0.0, float %a\n"
240       "  ret float %A\n"
241       "}\n");
242   // The sign of zero doesn't matter in fcmp.
243   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
244 }
245 
246 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero4) {
247   parseAssembly(
248       "define float @test(float %a) {\n"
249       "  %1 = fcmp ogt float %a, 0.0\n"
250       "  %A = select i1 %1, float -0.0, float %a\n"
251       "  ret float %A\n"
252       "}\n");
253   // The sign of zero doesn't matter in fcmp.
254   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
255 }
256 
257 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero5) {
258   parseAssembly(
259       "define float @test(float %a) {\n"
260       "  %1 = fcmp ogt float -0.0, %a\n"
261       "  %A = select i1 %1, float %a, float 0.0\n"
262       "  ret float %A\n"
263       "}\n");
264   // The sign of zero doesn't matter in fcmp.
265   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
266 }
267 
268 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero6) {
269   parseAssembly(
270       "define float @test(float %a) {\n"
271       "  %1 = fcmp olt float %a, -0.0\n"
272       "  %A = select i1 %1, float %a, float 0.0\n"
273       "  ret float %A\n"
274       "}\n");
275   // The sign of zero doesn't matter in fcmp.
276   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
277 }
278 
279 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero7) {
280   parseAssembly(
281       "define float @test(float %a) {\n"
282       "  %1 = fcmp ogt float 0.0, %a\n"
283       "  %A = select i1 %1, float %a, float -0.0\n"
284       "  ret float %A\n"
285       "}\n");
286   // The sign of zero doesn't matter in fcmp.
287   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
288 }
289 
290 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero8) {
291   parseAssembly(
292       "define float @test(float %a) {\n"
293       "  %1 = fcmp olt float %a, 0.0\n"
294       "  %A = select i1 %1, float %a, float -0.0\n"
295       "  ret float %A\n"
296       "}\n");
297   // The sign of zero doesn't matter in fcmp.
298   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
299 }
300 
301 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero1) {
302   parseAssembly(
303       "define float @test(float %a) {\n"
304       "  %1 = fcmp ogt float -0.0, %a\n"
305       "  %A = select i1 %1, float 0.0, float %a\n"
306       "  ret float %A\n"
307       "}\n");
308   // The sign of zero doesn't matter in fcmp.
309   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
310 }
311 
312 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero2) {
313   parseAssembly(
314       "define float @test(float %a) {\n"
315       "  %1 = fcmp olt float %a, -0.0\n"
316       "  %A = select i1 %1, float 0.0, float %a\n"
317       "  ret float %A\n"
318       "}\n");
319   // The sign of zero doesn't matter in fcmp.
320   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
321 }
322 
323 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero3) {
324   parseAssembly(
325       "define float @test(float %a) {\n"
326       "  %1 = fcmp ogt float 0.0, %a\n"
327       "  %A = select i1 %1, float -0.0, float %a\n"
328       "  ret float %A\n"
329       "}\n");
330   // The sign of zero doesn't matter in fcmp.
331   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
332 }
333 
334 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero4) {
335   parseAssembly(
336       "define float @test(float %a) {\n"
337       "  %1 = fcmp olt float %a, 0.0\n"
338       "  %A = select i1 %1, float -0.0, float %a\n"
339       "  ret float %A\n"
340       "}\n");
341   // The sign of zero doesn't matter in fcmp.
342   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
343 }
344 
345 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero5) {
346   parseAssembly(
347       "define float @test(float %a) {\n"
348       "  %1 = fcmp olt float -0.0, %a\n"
349       "  %A = select i1 %1, float %a, float 0.0\n"
350       "  ret float %A\n"
351       "}\n");
352   // The sign of zero doesn't matter in fcmp.
353   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
354 }
355 
356 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero6) {
357   parseAssembly(
358       "define float @test(float %a) {\n"
359       "  %1 = fcmp ogt float %a, -0.0\n"
360       "  %A = select i1 %1, float %a, float 0.0\n"
361       "  ret float %A\n"
362       "}\n");
363   // The sign of zero doesn't matter in fcmp.
364   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
365 }
366 
367 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero7) {
368   parseAssembly(
369       "define float @test(float %a) {\n"
370       "  %1 = fcmp olt float 0.0, %a\n"
371       "  %A = select i1 %1, float %a, float -0.0\n"
372       "  ret float %A\n"
373       "}\n");
374   // The sign of zero doesn't matter in fcmp.
375   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
376 }
377 
378 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero8) {
379   parseAssembly(
380       "define float @test(float %a) {\n"
381       "  %1 = fcmp ogt float %a, 0.0\n"
382       "  %A = select i1 %1, float %a, float -0.0\n"
383       "  ret float %A\n"
384       "}\n");
385   // The sign of zero doesn't matter in fcmp.
386   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
387 }
388 
389 TEST_F(MatchSelectPatternTest, FMinMismatchConstantZeroVecUndef) {
390   parseAssembly(
391       "define <2 x float> @test(<2 x float> %a) {\n"
392       "  %1 = fcmp ogt <2 x float> %a, <float -0.0, float -0.0>\n"
393       "  %A = select <2 x i1> %1, <2 x float> <float undef, float 0.0>, <2 x float> %a\n"
394       "  ret <2 x float> %A\n"
395       "}\n");
396   // An undef in a vector constant can not be back-propagated for this analysis.
397   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
398 }
399 
400 TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZeroVecUndef) {
401   parseAssembly(
402       "define <2 x float> @test(<2 x float> %a) {\n"
403       "  %1 = fcmp ogt <2 x float> %a, zeroinitializer\n"
404       "  %A = select <2 x i1> %1, <2 x float> %a, <2 x float> <float -0.0, float undef>\n"
405       "  ret <2 x float> %A\n"
406       "}\n");
407   // An undef in a vector constant can not be back-propagated for this analysis.
408   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
409 }
410 
411 TEST_F(MatchSelectPatternTest, VectorFMinimum) {
412   parseAssembly(
413       "define <4 x float> @test(<4 x float> %a) {\n"
414       "  %1 = fcmp ule <4 x float> %a, \n"
415       "    <float 5.0, float 5.0, float 5.0, float 5.0>\n"
416       "  %A = select <4 x i1> %1, <4 x float> %a,\n"
417       "     <4 x float> <float 5.0, float 5.0, float 5.0, float 5.0>\n"
418       "  ret <4 x float> %A\n"
419       "}\n");
420   // Check that pattern matching works on vectors where each lane has the same
421   // unordered pattern.
422   expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false});
423 }
424 
425 TEST_F(MatchSelectPatternTest, VectorFMinOtherOrdered) {
426   parseAssembly(
427       "define <4 x float> @test(<4 x float> %a) {\n"
428       "  %1 = fcmp ole <4 x float> %a, \n"
429       "    <float 5.0, float 5.0, float 5.0, float 5.0>\n"
430       "  %A = select <4 x i1> %1, <4 x float> %a,\n"
431       "     <4 x float> <float 5.0, float 5.0, float 5.0, float 5.0>\n"
432       "  ret <4 x float> %A\n"
433       "}\n");
434   // Check that pattern matching works on vectors where each lane has the same
435   // ordered pattern.
436   expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true});
437 }
438 
439 TEST_F(MatchSelectPatternTest, VectorNotFMinimum) {
440   parseAssembly(
441       "define <4 x float> @test(<4 x float> %a) {\n"
442       "  %1 = fcmp ule <4 x float> %a, \n"
443       "    <float 5.0, float 0x7ff8000000000000, float 5.0, float 5.0>\n"
444       "  %A = select <4 x i1> %1, <4 x float> %a,\n"
445       "     <4 x float> <float 5.0, float 0x7ff8000000000000, float 5.0, float "
446       "5.0>\n"
447       "  ret <4 x float> %A\n"
448       "}\n");
449   // The lane that contains a NaN (0x7ff80...) behaves like a
450   // non-NaN-propagating min and the other lines behave like a NaN-propagating
451   // min, so check that neither is returned.
452   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
453 }
454 
455 TEST_F(MatchSelectPatternTest, VectorNotFMinZero) {
456   parseAssembly(
457       "define <4 x float> @test(<4 x float> %a) {\n"
458       "  %1 = fcmp ule <4 x float> %a, \n"
459       "    <float 5.0, float -0.0, float 5.0, float 5.0>\n"
460       "  %A = select <4 x i1> %1, <4 x float> %a,\n"
461       "     <4 x float> <float 5.0, float 0.0, float 5.0, float 5.0>\n"
462       "  ret <4 x float> %A\n"
463       "}\n");
464   // Always selects the second lane of %a if it is positive or negative zero, so
465   // this is stricter than a min.
466   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
467 }
468 
469 TEST_F(MatchSelectPatternTest, DoubleCastU) {
470   parseAssembly(
471       "define i32 @test(i8 %a, i8 %b) {\n"
472       "  %1 = icmp ult i8 %a, %b\n"
473       "  %2 = zext i8 %a to i32\n"
474       "  %3 = zext i8 %b to i32\n"
475       "  %A = select i1 %1, i32 %2, i32 %3\n"
476       "  ret i32 %A\n"
477       "}\n");
478   // We should be able to look through the situation where we cast both operands
479   // to the select.
480   expectPattern({SPF_UMIN, SPNB_NA, false});
481 }
482 
483 TEST_F(MatchSelectPatternTest, DoubleCastS) {
484   parseAssembly(
485       "define i32 @test(i8 %a, i8 %b) {\n"
486       "  %1 = icmp slt i8 %a, %b\n"
487       "  %2 = sext i8 %a to i32\n"
488       "  %3 = sext i8 %b to i32\n"
489       "  %A = select i1 %1, i32 %2, i32 %3\n"
490       "  ret i32 %A\n"
491       "}\n");
492   // We should be able to look through the situation where we cast both operands
493   // to the select.
494   expectPattern({SPF_SMIN, SPNB_NA, false});
495 }
496 
497 TEST_F(MatchSelectPatternTest, DoubleCastBad) {
498   parseAssembly(
499       "define i32 @test(i8 %a, i8 %b) {\n"
500       "  %1 = icmp ult i8 %a, %b\n"
501       "  %2 = zext i8 %a to i32\n"
502       "  %3 = sext i8 %b to i32\n"
503       "  %A = select i1 %1, i32 %2, i32 %3\n"
504       "  ret i32 %A\n"
505       "}\n");
506   // The cast types here aren't the same, so we cannot match an UMIN.
507   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
508 }
509 
510 TEST_F(MatchSelectPatternTest, NotNotSMin) {
511   parseAssembly(
512       "define i8 @test(i8 %a, i8 %b) {\n"
513       "  %cmp = icmp sgt i8 %a, %b\n"
514       "  %an = xor i8 %a, -1\n"
515       "  %bn = xor i8 %b, -1\n"
516       "  %A = select i1 %cmp, i8 %an, i8 %bn\n"
517       "  ret i8 %A\n"
518       "}\n");
519   expectPattern({SPF_SMIN, SPNB_NA, false});
520 }
521 
522 TEST_F(MatchSelectPatternTest, NotNotSMinSwap) {
523   parseAssembly(
524       "define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n"
525       "  %cmp = icmp slt <2 x i8> %a, %b\n"
526       "  %an = xor <2 x i8> %a, <i8 -1, i8-1>\n"
527       "  %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n"
528       "  %A = select <2 x i1> %cmp, <2 x i8> %bn, <2 x i8> %an\n"
529       "  ret <2 x i8> %A\n"
530       "}\n");
531   expectPattern({SPF_SMIN, SPNB_NA, false});
532 }
533 
534 TEST_F(MatchSelectPatternTest, NotNotSMax) {
535   parseAssembly(
536       "define i8 @test(i8 %a, i8 %b) {\n"
537       "  %cmp = icmp slt i8 %a, %b\n"
538       "  %an = xor i8 %a, -1\n"
539       "  %bn = xor i8 %b, -1\n"
540       "  %A = select i1 %cmp, i8 %an, i8 %bn\n"
541       "  ret i8 %A\n"
542       "}\n");
543   expectPattern({SPF_SMAX, SPNB_NA, false});
544 }
545 
546 TEST_F(MatchSelectPatternTest, NotNotSMaxSwap) {
547   parseAssembly(
548       "define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n"
549       "  %cmp = icmp sgt <2 x i8> %a, %b\n"
550       "  %an = xor <2 x i8> %a, <i8 -1, i8-1>\n"
551       "  %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n"
552       "  %A = select <2 x i1> %cmp, <2 x i8> %bn, <2 x i8> %an\n"
553       "  ret <2 x i8> %A\n"
554       "}\n");
555   expectPattern({SPF_SMAX, SPNB_NA, false});
556 }
557 
558 TEST_F(MatchSelectPatternTest, NotNotUMin) {
559   parseAssembly(
560       "define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n"
561       "  %cmp = icmp ugt <2 x i8> %a, %b\n"
562       "  %an = xor <2 x i8> %a, <i8 -1, i8-1>\n"
563       "  %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n"
564       "  %A = select <2 x i1> %cmp, <2 x i8> %an, <2 x i8> %bn\n"
565       "  ret <2 x i8> %A\n"
566       "}\n");
567   expectPattern({SPF_UMIN, SPNB_NA, false});
568 }
569 
570 TEST_F(MatchSelectPatternTest, NotNotUMinSwap) {
571   parseAssembly(
572       "define i8 @test(i8 %a, i8 %b) {\n"
573       "  %cmp = icmp ult i8 %a, %b\n"
574       "  %an = xor i8 %a, -1\n"
575       "  %bn = xor i8 %b, -1\n"
576       "  %A = select i1 %cmp, i8 %bn, i8 %an\n"
577       "  ret i8 %A\n"
578       "}\n");
579   expectPattern({SPF_UMIN, SPNB_NA, false});
580 }
581 
582 TEST_F(MatchSelectPatternTest, NotNotUMax) {
583   parseAssembly(
584       "define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n"
585       "  %cmp = icmp ult <2 x i8> %a, %b\n"
586       "  %an = xor <2 x i8> %a, <i8 -1, i8-1>\n"
587       "  %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n"
588       "  %A = select <2 x i1> %cmp, <2 x i8> %an, <2 x i8> %bn\n"
589       "  ret <2 x i8> %A\n"
590       "}\n");
591   expectPattern({SPF_UMAX, SPNB_NA, false});
592 }
593 
594 TEST_F(MatchSelectPatternTest, NotNotUMaxSwap) {
595   parseAssembly(
596       "define i8 @test(i8 %a, i8 %b) {\n"
597       "  %cmp = icmp ugt i8 %a, %b\n"
598       "  %an = xor i8 %a, -1\n"
599       "  %bn = xor i8 %b, -1\n"
600       "  %A = select i1 %cmp, i8 %bn, i8 %an\n"
601       "  ret i8 %A\n"
602       "}\n");
603   expectPattern({SPF_UMAX, SPNB_NA, false});
604 }
605 
606 TEST_F(MatchSelectPatternTest, NotNotEq) {
607   parseAssembly(
608       "define i8 @test(i8 %a, i8 %b) {\n"
609       "  %cmp = icmp eq i8 %a, %b\n"
610       "  %an = xor i8 %a, -1\n"
611       "  %bn = xor i8 %b, -1\n"
612       "  %A = select i1 %cmp, i8 %bn, i8 %an\n"
613       "  ret i8 %A\n"
614       "}\n");
615   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
616 }
617 
618 TEST_F(MatchSelectPatternTest, NotNotNe) {
619   parseAssembly(
620       "define i8 @test(i8 %a, i8 %b) {\n"
621       "  %cmp = icmp ne i8 %a, %b\n"
622       "  %an = xor i8 %a, -1\n"
623       "  %bn = xor i8 %b, -1\n"
624       "  %A = select i1 %cmp, i8 %bn, i8 %an\n"
625       "  ret i8 %A\n"
626       "}\n");
627   expectPattern({SPF_UNKNOWN, SPNB_NA, false});
628 }
629 
630 TEST(ValueTracking, GuaranteedToTransferExecutionToSuccessor) {
631   StringRef Assembly =
632       "declare void @nounwind_readonly(ptr) nounwind readonly "
633       "declare void @nounwind_argmemonly(ptr) nounwind argmemonly "
634       "declare void @nounwind_willreturn(ptr) nounwind willreturn "
635       "declare void @throws_but_readonly(ptr) readonly "
636       "declare void @throws_but_argmemonly(ptr) argmemonly "
637       "declare void @throws_but_willreturn(ptr) willreturn "
638       " "
639       "declare void @unknown(ptr) "
640       " "
641       "define void @f(ptr %p) { "
642       "  call void @nounwind_readonly(ptr %p) "
643       "  call void @nounwind_argmemonly(ptr %p) "
644       "  call void @nounwind_willreturn(ptr %p)"
645       "  call void @throws_but_readonly(ptr %p) "
646       "  call void @throws_but_argmemonly(ptr %p) "
647       "  call void @throws_but_willreturn(ptr %p) "
648       "  call void @unknown(ptr %p) nounwind readonly "
649       "  call void @unknown(ptr %p) nounwind argmemonly "
650       "  call void @unknown(ptr %p) nounwind willreturn "
651       "  call void @unknown(ptr %p) readonly "
652       "  call void @unknown(ptr %p) argmemonly "
653       "  call void @unknown(ptr %p) willreturn "
654       "  ret void "
655       "} ";
656 
657   LLVMContext Context;
658   SMDiagnostic Error;
659   auto M = parseAssemblyString(Assembly, Error, Context);
660   assert(M && "Bad assembly?");
661 
662   auto *F = M->getFunction("f");
663   assert(F && "Bad assembly?");
664 
665   auto &BB = F->getEntryBlock();
666   bool ExpectedAnswers[] = {
667       false, // call void @nounwind_readonly(ptr %p)
668       false, // call void @nounwind_argmemonly(ptr %p)
669       true,  // call void @nounwind_willreturn(ptr %p)
670       false, // call void @throws_but_readonly(ptr %p)
671       false, // call void @throws_but_argmemonly(ptr %p)
672       false, // call void @throws_but_willreturn(ptr %p)
673       false, // call void @unknown(ptr %p) nounwind readonly
674       false, // call void @unknown(ptr %p) nounwind argmemonly
675       true,  // call void @unknown(ptr %p) nounwind willreturn
676       false, // call void @unknown(ptr %p) readonly
677       false, // call void @unknown(ptr %p) argmemonly
678       false, // call void @unknown(ptr %p) willreturn
679       false, // ret void
680   };
681 
682   int Index = 0;
683   for (auto &I : BB) {
684     EXPECT_EQ(isGuaranteedToTransferExecutionToSuccessor(&I),
685               ExpectedAnswers[Index])
686         << "Incorrect answer at instruction " << Index << " = " << I;
687     Index++;
688   }
689 }
690 
691 TEST_F(ValueTrackingTest, ComputeNumSignBits_PR32045) {
692   parseAssembly(
693       "define i32 @test(i32 %a) {\n"
694       "  %A = ashr i32 %a, -1\n"
695       "  ret i32 %A\n"
696       "}\n");
697   EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u);
698 }
699 
700 // No guarantees for canonical IR in this analysis, so this just bails out.
701 TEST_F(ValueTrackingTest, ComputeNumSignBits_Shuffle) {
702   parseAssembly(
703       "define <2 x i32> @test() {\n"
704       "  %A = shufflevector <2 x i32> undef, <2 x i32> undef, <2 x i32> <i32 0, i32 0>\n"
705       "  ret <2 x i32> %A\n"
706       "}\n");
707   EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u);
708 }
709 
710 // No guarantees for canonical IR in this analysis, so a shuffle element that
711 // references an undef value means this can't return any extra information.
712 TEST_F(ValueTrackingTest, ComputeNumSignBits_Shuffle2) {
713   parseAssembly(
714       "define <2 x i32> @test(<2 x i1> %x) {\n"
715       "  %sext = sext <2 x i1> %x to <2 x i32>\n"
716       "  %A = shufflevector <2 x i32> %sext, <2 x i32> undef, <2 x i32> <i32 0, i32 2>\n"
717       "  ret <2 x i32> %A\n"
718       "}\n");
719   EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u);
720 }
721 
722 TEST_F(ValueTrackingTest, impliesPoisonTest_Identity) {
723   parseAssembly("define void @test(i32 %x, i32 %y) {\n"
724                 "  %A = add i32 %x, %y\n"
725                 "  ret void\n"
726                 "}");
727   EXPECT_TRUE(impliesPoison(A, A));
728 }
729 
730 TEST_F(ValueTrackingTest, impliesPoisonTest_ICmp) {
731   parseAssembly("define void @test(i32 %x) {\n"
732                 "  %A2 = icmp eq i32 %x, 0\n"
733                 "  %A = icmp eq i32 %x, 1\n"
734                 "  ret void\n"
735                 "}");
736   EXPECT_TRUE(impliesPoison(A2, A));
737 }
738 
739 TEST_F(ValueTrackingTest, impliesPoisonTest_ICmpUnknown) {
740   parseAssembly("define void @test(i32 %x, i32 %y) {\n"
741                 "  %A2 = icmp eq i32 %x, %y\n"
742                 "  %A = icmp eq i32 %x, 1\n"
743                 "  ret void\n"
744                 "}");
745   EXPECT_FALSE(impliesPoison(A2, A));
746 }
747 
748 TEST_F(ValueTrackingTest, impliesPoisonTest_AddNswOkay) {
749   parseAssembly("define void @test(i32 %x) {\n"
750                 "  %A2 = add nsw i32 %x, 1\n"
751                 "  %A = add i32 %A2, 1\n"
752                 "  ret void\n"
753                 "}");
754   EXPECT_TRUE(impliesPoison(A2, A));
755 }
756 
757 TEST_F(ValueTrackingTest, impliesPoisonTest_AddNswOkay2) {
758   parseAssembly("define void @test(i32 %x) {\n"
759                 "  %A2 = add i32 %x, 1\n"
760                 "  %A = add nsw i32 %A2, 1\n"
761                 "  ret void\n"
762                 "}");
763   EXPECT_TRUE(impliesPoison(A2, A));
764 }
765 
766 TEST_F(ValueTrackingTest, impliesPoisonTest_AddNsw) {
767   parseAssembly("define void @test(i32 %x) {\n"
768                 "  %A2 = add nsw i32 %x, 1\n"
769                 "  %A = add i32 %x, 1\n"
770                 "  ret void\n"
771                 "}");
772   EXPECT_FALSE(impliesPoison(A2, A));
773 }
774 
775 TEST_F(ValueTrackingTest, impliesPoisonTest_Cmp) {
776   parseAssembly("define void @test(i32 %x, i32 %y, i1 %c) {\n"
777                 "  %A2 = icmp eq i32 %x, %y\n"
778                 "  %A0 = icmp ult i32 %x, %y\n"
779                 "  %A = or i1 %A0, %c\n"
780                 "  ret void\n"
781                 "}");
782   EXPECT_TRUE(impliesPoison(A2, A));
783 }
784 
785 TEST_F(ValueTrackingTest, impliesPoisonTest_FCmpFMF) {
786   parseAssembly("define void @test(float %x, float %y, i1 %c) {\n"
787                 "  %A2 = fcmp nnan oeq float %x, %y\n"
788                 "  %A0 = fcmp olt float %x, %y\n"
789                 "  %A = or i1 %A0, %c\n"
790                 "  ret void\n"
791                 "}");
792   EXPECT_FALSE(impliesPoison(A2, A));
793 }
794 
795 TEST_F(ValueTrackingTest, impliesPoisonTest_AddSubSameOps) {
796   parseAssembly("define void @test(i32 %x, i32 %y, i1 %c) {\n"
797                 "  %A2 = add i32 %x, %y\n"
798                 "  %A = sub i32 %x, %y\n"
799                 "  ret void\n"
800                 "}");
801   EXPECT_TRUE(impliesPoison(A2, A));
802 }
803 
804 TEST_F(ValueTrackingTest, impliesPoisonTest_MaskCmp) {
805   parseAssembly("define void @test(i32 %x, i32 %y, i1 %c) {\n"
806                 "  %M2 = and i32 %x, 7\n"
807                 "  %A2 = icmp eq i32 %M2, 1\n"
808                 "  %M = and i32 %x, 15\n"
809                 "  %A = icmp eq i32 %M, 3\n"
810                 "  ret void\n"
811                 "}");
812   EXPECT_TRUE(impliesPoison(A2, A));
813 }
814 
815 TEST_F(ValueTrackingTest, ComputeNumSignBits_Shuffle_Pointers) {
816   parseAssembly(
817       "define <2 x ptr> @test(<2 x ptr> %x) {\n"
818       "  %A = shufflevector <2 x ptr> zeroinitializer, <2 x ptr> undef, <2 x i32> zeroinitializer\n"
819       "  ret <2 x ptr> %A\n"
820       "}\n");
821   EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 64u);
822 }
823 
824 TEST(ValueTracking, propagatesPoison) {
825   std::string AsmHead =
826       "declare i32 @g(i32)\n"
827       "declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)\n"
828       "declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)\n"
829       "declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)\n"
830       "declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)\n"
831       "declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)\n"
832       "declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)\n"
833       "declare float @llvm.sqrt.f32(float)\n"
834       "declare float @llvm.powi.f32.i32(float, i32)\n"
835       "declare float @llvm.sin.f32(float)\n"
836       "declare float @llvm.cos.f32(float)\n"
837       "declare float @llvm.pow.f32(float, float)\n"
838       "declare float @llvm.exp.f32(float)\n"
839       "declare float @llvm.exp2.f32(float)\n"
840       "declare float @llvm.log.f32(float)\n"
841       "declare float @llvm.log10.f32(float)\n"
842       "declare float @llvm.log2.f32(float)\n"
843       "declare float @llvm.fma.f32(float, float, float)\n"
844       "declare float @llvm.fabs.f32(float)\n"
845       "declare float @llvm.minnum.f32(float, float)\n"
846       "declare float @llvm.maxnum.f32(float, float)\n"
847       "declare float @llvm.minimum.f32(float, float)\n"
848       "declare float @llvm.maximum.f32(float, float)\n"
849       "declare float @llvm.copysign.f32(float, float)\n"
850       "declare float @llvm.floor.f32(float)\n"
851       "declare float @llvm.ceil.f32(float)\n"
852       "declare float @llvm.trunc.f32(float)\n"
853       "declare float @llvm.rint.f32(float)\n"
854       "declare float @llvm.nearbyint.f32(float)\n"
855       "declare float @llvm.round.f32(float)\n"
856       "declare float @llvm.roundeven.f32(float)\n"
857       "declare i32 @llvm.lround.f32(float)\n"
858       "declare i64 @llvm.llround.f32(float)\n"
859       "declare i32 @llvm.lrint.f32(float)\n"
860       "declare i64 @llvm.llrint.f32(float)\n"
861       "declare float @llvm.fmuladd.f32(float, float, float)\n"
862       "define void @f(i32 %x, i32 %y, float %fx, float %fy, "
863       "i1 %cond, ptr %p) {\n";
864   std::string AsmTail = "  ret void\n}";
865   // (propagates poison?, IR instruction)
866   SmallVector<std::tuple<bool, std::string, unsigned>, 32> Data = {
867       {true, "add i32 %x, %y", 0},
868       {true, "add i32 %x, %y", 1},
869       {true, "add nsw nuw i32 %x, %y", 0},
870       {true, "add nsw nuw i32 %x, %y", 1},
871       {true, "ashr i32 %x, %y", 0},
872       {true, "ashr i32 %x, %y", 1},
873       {true, "lshr exact i32 %x, 31", 0},
874       {true, "lshr exact i32 %x, 31", 1},
875       {true, "fadd float %fx, %fy", 0},
876       {true, "fadd float %fx, %fy", 1},
877       {true, "fsub float %fx, %fy", 0},
878       {true, "fsub float %fx, %fy", 1},
879       {true, "fmul float %fx, %fy", 0},
880       {true, "fmul float %fx, %fy", 1},
881       {true, "fdiv float %fx, %fy", 0},
882       {true, "fdiv float %fx, %fy", 1},
883       {true, "frem float %fx, %fy", 0},
884       {true, "frem float %fx, %fy", 1},
885       {true, "fneg float %fx", 0},
886       {true, "fcmp oeq float %fx, %fy", 0},
887       {true, "fcmp oeq float %fx, %fy", 1},
888       {true, "icmp eq i32 %x, %y", 0},
889       {true, "icmp eq i32 %x, %y", 1},
890       {true, "getelementptr i8, ptr %p, i32 %x", 0},
891       {true, "getelementptr i8, ptr %p, i32 %x", 1},
892       {true, "getelementptr inbounds i8, ptr %p, i32 %x", 0},
893       {true, "getelementptr inbounds i8, ptr %p, i32 %x", 1},
894       {true, "bitcast float %fx to i32", 0},
895       {true, "select i1 %cond, i32 %x, i32 %y", 0},
896       {false, "select i1 %cond, i32 %x, i32 %y", 1},
897       {false, "select i1 %cond, i32 %x, i32 %y", 2},
898       {false, "freeze i32 %x", 0},
899       {true, "udiv i32 %x, %y", 0},
900       {true, "udiv i32 %x, %y", 1},
901       {true, "urem i32 %x, %y", 0},
902       {true, "urem i32 %x, %y", 1},
903       {true, "sdiv exact i32 %x, %y", 0},
904       {true, "sdiv exact i32 %x, %y", 1},
905       {true, "srem i32 %x, %y", 0},
906       {true, "srem i32 %x, %y", 1},
907       {false, "call i32 @g(i32 %x)", 0},
908       {false, "call i32 @g(i32 %x)", 1},
909       {true, "call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %x, i32 %y)", 0},
910       {true, "call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %x, i32 %y)", 0},
911       {true, "call {i32, i1} @llvm.smul.with.overflow.i32(i32 %x, i32 %y)", 0},
912       {true, "call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %x, i32 %y)", 0},
913       {true, "call {i32, i1} @llvm.usub.with.overflow.i32(i32 %x, i32 %y)", 0},
914       {true, "call {i32, i1} @llvm.umul.with.overflow.i32(i32 %x, i32 %y)", 0},
915       {false, "call float @llvm.sqrt.f32(float %fx)", 0},
916       {false, "call float @llvm.powi.f32.i32(float %fx, i32 %x)", 0},
917       {false, "call float @llvm.sin.f32(float %fx)", 0},
918       {false, "call float @llvm.cos.f32(float %fx)", 0},
919       {false, "call float @llvm.pow.f32(float %fx, float %fy)", 0},
920       {false, "call float @llvm.exp.f32(float %fx)", 0},
921       {false, "call float @llvm.exp2.f32(float %fx)", 0},
922       {false, "call float @llvm.log.f32(float %fx)", 0},
923       {false, "call float @llvm.log10.f32(float %fx)", 0},
924       {false, "call float @llvm.log2.f32(float %fx)", 0},
925       {false, "call float @llvm.fma.f32(float %fx, float %fx, float %fy)", 0},
926       {false, "call float @llvm.fabs.f32(float %fx)", 0},
927       {false, "call float @llvm.minnum.f32(float %fx, float %fy)", 0},
928       {false, "call float @llvm.maxnum.f32(float %fx, float %fy)", 0},
929       {false, "call float @llvm.minimum.f32(float %fx, float %fy)", 0},
930       {false, "call float @llvm.maximum.f32(float %fx, float %fy)", 0},
931       {false, "call float @llvm.copysign.f32(float %fx, float %fy)", 0},
932       {false, "call float @llvm.floor.f32(float %fx)", 0},
933       {false, "call float @llvm.ceil.f32(float %fx)", 0},
934       {false, "call float @llvm.trunc.f32(float %fx)", 0},
935       {false, "call float @llvm.rint.f32(float %fx)", 0},
936       {false, "call float @llvm.nearbyint.f32(float %fx)", 0},
937       {false, "call float @llvm.round.f32(float %fx)", 0},
938       {false, "call float @llvm.roundeven.f32(float %fx)", 0},
939       {false, "call i32 @llvm.lround.f32(float %fx)", 0},
940       {false, "call i64 @llvm.llround.f32(float %fx)", 0},
941       {false, "call i32 @llvm.lrint.f32(float %fx)", 0},
942       {false, "call i64 @llvm.llrint.f32(float %fx)", 0},
943       {false, "call float @llvm.fmuladd.f32(float %fx, float %fx, float %fy)",
944        0}};
945 
946   std::string AssemblyStr = AsmHead;
947   for (auto &Itm : Data)
948     AssemblyStr += std::get<1>(Itm) + "\n";
949   AssemblyStr += AsmTail;
950 
951   LLVMContext Context;
952   SMDiagnostic Error;
953   auto M = parseAssemblyString(AssemblyStr, Error, Context);
954   assert(M && "Bad assembly?");
955 
956   auto *F = M->getFunction("f");
957   assert(F && "Bad assembly?");
958 
959   auto &BB = F->getEntryBlock();
960 
961   int Index = 0;
962   for (auto &I : BB) {
963     if (isa<ReturnInst>(&I))
964       break;
965     bool ExpectedVal = std::get<0>(Data[Index]);
966     unsigned OpIdx = std::get<2>(Data[Index]);
967     EXPECT_EQ(propagatesPoison(I.getOperandUse(OpIdx)), ExpectedVal)
968         << "Incorrect answer at instruction " << Index << " = " << I;
969     Index++;
970   }
971 }
972 
973 TEST_F(ValueTrackingTest, programUndefinedIfPoison) {
974   parseAssembly("declare i32 @any_num()"
975                 "define void @test(i32 %mask) {\n"
976                 "  %A = call i32 @any_num()\n"
977                 "  %B = or i32 %A, %mask\n"
978                 "  udiv i32 1, %B"
979                 "  ret void\n"
980                 "}\n");
981   // If %A was poison, udiv raises UB regardless of %mask's value
982   EXPECT_EQ(programUndefinedIfPoison(A), true);
983 }
984 
985 TEST_F(ValueTrackingTest, programUndefinedIfPoisonSelect) {
986   parseAssembly("declare i32 @any_num()"
987                 "define void @test(i1 %Cond) {\n"
988                 "  %A = call i32 @any_num()\n"
989                 "  %B = add i32 %A, 1\n"
990                 "  %C = select i1 %Cond, i32 %A, i32 %B\n"
991                 "  udiv i32 1, %C"
992                 "  ret void\n"
993                 "}\n");
994   // If A is poison, B is also poison, and therefore C is poison regardless of
995   // the value of %Cond.
996   EXPECT_EQ(programUndefinedIfPoison(A), true);
997 }
998 
999 TEST_F(ValueTrackingTest, programUndefinedIfUndefOrPoison) {
1000   parseAssembly("declare i32 @any_num()"
1001                 "define void @test(i32 %mask) {\n"
1002                 "  %A = call i32 @any_num()\n"
1003                 "  %B = or i32 %A, %mask\n"
1004                 "  udiv i32 1, %B"
1005                 "  ret void\n"
1006                 "}\n");
1007   // If %A was undef and %mask was 1, udiv does not raise UB
1008   EXPECT_EQ(programUndefinedIfUndefOrPoison(A), false);
1009 }
1010 
1011 TEST_F(ValueTrackingTest, isGuaranteedNotToBePoison_exploitBranchCond) {
1012   parseAssembly("declare i1 @any_bool()"
1013                 "define void @test(i1 %y) {\n"
1014                 "  %A = call i1 @any_bool()\n"
1015                 "  %cond = and i1 %A, %y\n"
1016                 "  br i1 %cond, label %BB1, label %BB2\n"
1017                 "BB1:\n"
1018                 "  ret void\n"
1019                 "BB2:\n"
1020                 "  ret void\n"
1021                 "}\n");
1022   DominatorTree DT(*F);
1023   for (auto &BB : *F) {
1024     if (&BB == &F->getEntryBlock())
1025       continue;
1026 
1027     EXPECT_EQ(isGuaranteedNotToBePoison(A, nullptr, BB.getTerminator(), &DT),
1028               true)
1029         << "isGuaranteedNotToBePoison does not hold at " << *BB.getTerminator();
1030   }
1031 }
1032 
1033 TEST_F(ValueTrackingTest, isGuaranteedNotToBePoison_phi) {
1034   parseAssembly("declare i32 @any_i32(i32)"
1035                 "define void @test() {\n"
1036                 "ENTRY:\n"
1037                 "  br label %LOOP\n"
1038                 "LOOP:\n"
1039                 "  %A = phi i32 [0, %ENTRY], [%A.next, %NEXT]\n"
1040                 "  %A.next = call i32 @any_i32(i32 %A)\n"
1041                 "  %cond = icmp eq i32 %A.next, 0\n"
1042                 "  br i1 %cond, label %NEXT, label %EXIT\n"
1043                 "NEXT:\n"
1044                 "  br label %LOOP\n"
1045                 "EXIT:\n"
1046                 "  ret void\n"
1047                 "}\n");
1048   DominatorTree DT(*F);
1049   for (auto &BB : *F) {
1050     if (BB.getName() == "LOOP") {
1051       EXPECT_EQ(isGuaranteedNotToBePoison(A, nullptr, A, &DT), true)
1052           << "isGuaranteedNotToBePoison does not hold";
1053     }
1054   }
1055 }
1056 
1057 TEST_F(ValueTrackingTest, isGuaranteedNotToBeUndefOrPoison) {
1058   parseAssembly("declare void @f(i32 noundef)"
1059                 "define void @test(i32 %x) {\n"
1060                 "  %A = bitcast i32 %x to i32\n"
1061                 "  call void @f(i32 noundef %x)\n"
1062                 "  ret void\n"
1063                 "}\n");
1064   EXPECT_EQ(isGuaranteedNotToBeUndefOrPoison(A), true);
1065   EXPECT_EQ(isGuaranteedNotToBeUndefOrPoison(UndefValue::get(IntegerType::get(Context, 8))), false);
1066   EXPECT_EQ(isGuaranteedNotToBeUndefOrPoison(PoisonValue::get(IntegerType::get(Context, 8))), false);
1067   EXPECT_EQ(isGuaranteedNotToBePoison(UndefValue::get(IntegerType::get(Context, 8))), true);
1068   EXPECT_EQ(isGuaranteedNotToBePoison(PoisonValue::get(IntegerType::get(Context, 8))), false);
1069 
1070   Type *Int32Ty = Type::getInt32Ty(Context);
1071   Constant *CU = UndefValue::get(Int32Ty);
1072   Constant *CP = PoisonValue::get(Int32Ty);
1073   Constant *C1 = ConstantInt::get(Int32Ty, 1);
1074   Constant *C2 = ConstantInt::get(Int32Ty, 2);
1075 
1076   {
1077     Constant *V1 = ConstantVector::get({C1, C2});
1078     EXPECT_TRUE(isGuaranteedNotToBeUndefOrPoison(V1));
1079     EXPECT_TRUE(isGuaranteedNotToBePoison(V1));
1080   }
1081 
1082   {
1083     Constant *V2 = ConstantVector::get({C1, CU});
1084     EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(V2));
1085     EXPECT_TRUE(isGuaranteedNotToBePoison(V2));
1086   }
1087 
1088   {
1089     Constant *V3 = ConstantVector::get({C1, CP});
1090     EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(V3));
1091     EXPECT_FALSE(isGuaranteedNotToBePoison(V3));
1092   }
1093 }
1094 
1095 TEST_F(ValueTrackingTest, isGuaranteedNotToBeUndefOrPoison_assume) {
1096   parseAssembly("declare i1 @f_i1()\n"
1097                 "declare i32 @f_i32()\n"
1098                 "declare void @llvm.assume(i1)\n"
1099                 "define void @test() {\n"
1100                 "  %A = call i32 @f_i32()\n"
1101                 "  %cond = call i1 @f_i1()\n"
1102                 "  %CxtI = add i32 0, 0\n"
1103                 "  br i1 %cond, label %BB1, label %EXIT\n"
1104                 "BB1:\n"
1105                 "  %CxtI2 = add i32 0, 0\n"
1106                 "  %cond2 = call i1 @f_i1()\n"
1107                 "  call void @llvm.assume(i1 true) [ \"noundef\"(i32 %A) ]\n"
1108                 "  br i1 %cond2, label %BB2, label %EXIT\n"
1109                 "BB2:\n"
1110                 "  %CxtI3 = add i32 0, 0\n"
1111                 "  ret void\n"
1112                 "EXIT:\n"
1113                 "  ret void\n"
1114                 "}");
1115   AssumptionCache AC(*F);
1116   DominatorTree DT(*F);
1117   EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI, &DT));
1118   EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI2, &DT));
1119   EXPECT_TRUE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI3, &DT));
1120 }
1121 
1122 TEST(ValueTracking, canCreatePoisonOrUndef) {
1123   std::string AsmHead =
1124       "@s = external dso_local global i32, align 1\n"
1125       "declare i32 @g(i32)\n"
1126       "declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)\n"
1127       "declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)\n"
1128       "declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)\n"
1129       "declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)\n"
1130       "declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)\n"
1131       "declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)\n"
1132       "define void @f(i32 %x, i32 %y, float %fx, float %fy, i1 %cond, "
1133       "<4 x i32> %vx, <4 x i32> %vx2, <vscale x 4 x i32> %svx, ptr %p) {\n";
1134   std::string AsmTail = "  ret void\n}";
1135   // (can create poison?, can create undef?, IR instruction)
1136   SmallVector<std::pair<std::pair<bool, bool>, std::string>, 32> Data = {
1137       {{false, false}, "add i32 %x, %y"},
1138       {{true, false}, "add nsw nuw i32 %x, %y"},
1139       {{true, false}, "shl i32 %x, %y"},
1140       {{true, false}, "shl <4 x i32> %vx, %vx2"},
1141       {{true, false}, "shl nsw i32 %x, %y"},
1142       {{true, false}, "shl nsw <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"},
1143       {{false, false}, "shl i32 %x, 31"},
1144       {{true, false}, "shl i32 %x, 32"},
1145       {{false, false}, "shl <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"},
1146       {{true, false}, "shl <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 32>"},
1147       {{true, false}, "ashr i32 %x, %y"},
1148       {{true, false}, "ashr exact i32 %x, %y"},
1149       {{false, false}, "ashr i32 %x, 31"},
1150       {{true, false}, "ashr exact i32 %x, 31"},
1151       {{false, false}, "ashr <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"},
1152       {{true, false}, "ashr <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 32>"},
1153       {{true, false}, "ashr exact <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"},
1154       {{true, false}, "lshr i32 %x, %y"},
1155       {{true, false}, "lshr exact i32 %x, 31"},
1156       {{false, false}, "udiv i32 %x, %y"},
1157       {{true, false}, "udiv exact i32 %x, %y"},
1158       {{false, false}, "getelementptr i8, ptr %p, i32 %x"},
1159       {{true, false}, "getelementptr inbounds i8, ptr %p, i32 %x"},
1160       {{true, false}, "fneg nnan float %fx"},
1161       {{false, false}, "fneg float %fx"},
1162       {{false, false}, "fadd float %fx, %fy"},
1163       {{true, false}, "fadd nnan float %fx, %fy"},
1164       {{false, false}, "urem i32 %x, %y"},
1165       {{true, false}, "fptoui float %fx to i32"},
1166       {{true, false}, "fptosi float %fx to i32"},
1167       {{false, false}, "bitcast float %fx to i32"},
1168       {{false, false}, "select i1 %cond, i32 %x, i32 %y"},
1169       {{true, false}, "select nnan i1 %cond, float %fx, float %fy"},
1170       {{true, false}, "extractelement <4 x i32> %vx, i32 %x"},
1171       {{false, false}, "extractelement <4 x i32> %vx, i32 3"},
1172       {{true, false}, "extractelement <vscale x 4 x i32> %svx, i32 4"},
1173       {{true, false}, "insertelement <4 x i32> %vx, i32 %x, i32 %y"},
1174       {{false, false}, "insertelement <4 x i32> %vx, i32 %x, i32 3"},
1175       {{true, false}, "insertelement <vscale x 4 x i32> %svx, i32 %x, i32 4"},
1176       {{false, false}, "freeze i32 %x"},
1177       {{false, false},
1178        "shufflevector <4 x i32> %vx, <4 x i32> %vx2, "
1179        "<4 x i32> <i32 0, i32 1, i32 2, i32 3>"},
1180       {{false, true},
1181        "shufflevector <4 x i32> %vx, <4 x i32> %vx2, "
1182        "<4 x i32> <i32 0, i32 1, i32 2, i32 undef>"},
1183       {{false, true},
1184        "shufflevector <vscale x 4 x i32> %svx, "
1185        "<vscale x 4 x i32> %svx, <vscale x 4 x i32> undef"},
1186       {{true, false}, "call i32 @g(i32 %x)"},
1187       {{false, false}, "call noundef i32 @g(i32 %x)"},
1188       {{true, false}, "fcmp nnan oeq float %fx, %fy"},
1189       {{false, false}, "fcmp oeq float %fx, %fy"},
1190       {{true, false}, "ashr i32 %x, ptrtoint (ptr @s to i32)"},
1191       {{false, false},
1192        "call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %x, i32 %y)"},
1193       {{false, false},
1194        "call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %x, i32 %y)"},
1195       {{false, false},
1196        "call {i32, i1} @llvm.smul.with.overflow.i32(i32 %x, i32 %y)"},
1197       {{false, false},
1198        "call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %x, i32 %y)"},
1199       {{false, false},
1200        "call {i32, i1} @llvm.usub.with.overflow.i32(i32 %x, i32 %y)"},
1201       {{false, false},
1202        "call {i32, i1} @llvm.umul.with.overflow.i32(i32 %x, i32 %y)"}};
1203 
1204   std::string AssemblyStr = AsmHead;
1205   for (auto &Itm : Data)
1206     AssemblyStr += Itm.second + "\n";
1207   AssemblyStr += AsmTail;
1208 
1209   LLVMContext Context;
1210   SMDiagnostic Error;
1211   auto M = parseAssemblyString(AssemblyStr, Error, Context);
1212   assert(M && "Bad assembly?");
1213 
1214   auto *F = M->getFunction("f");
1215   assert(F && "Bad assembly?");
1216 
1217   auto &BB = F->getEntryBlock();
1218 
1219   int Index = 0;
1220   for (auto &I : BB) {
1221     if (isa<ReturnInst>(&I))
1222       break;
1223     bool Poison = Data[Index].first.first;
1224     bool Undef = Data[Index].first.second;
1225     EXPECT_EQ(canCreatePoison(cast<Operator>(&I)), Poison)
1226         << "Incorrect answer of canCreatePoison at instruction " << Index
1227         << " = " << I;
1228     EXPECT_EQ(canCreateUndefOrPoison(cast<Operator>(&I)), Undef || Poison)
1229         << "Incorrect answer of canCreateUndef at instruction " << Index
1230         << " = " << I;
1231     Index++;
1232   }
1233 }
1234 
1235 TEST_F(ValueTrackingTest, computePtrAlignment) {
1236   parseAssembly("declare i1 @f_i1()\n"
1237                 "declare ptr @f_i8p()\n"
1238                 "declare void @llvm.assume(i1)\n"
1239                 "define void @test() {\n"
1240                 "  %A = call ptr @f_i8p()\n"
1241                 "  %cond = call i1 @f_i1()\n"
1242                 "  %CxtI = add i32 0, 0\n"
1243                 "  br i1 %cond, label %BB1, label %EXIT\n"
1244                 "BB1:\n"
1245                 "  %CxtI2 = add i32 0, 0\n"
1246                 "  %cond2 = call i1 @f_i1()\n"
1247                 "  call void @llvm.assume(i1 true) [ \"align\"(ptr %A, i64 16) ]\n"
1248                 "  br i1 %cond2, label %BB2, label %EXIT\n"
1249                 "BB2:\n"
1250                 "  %CxtI3 = add i32 0, 0\n"
1251                 "  ret void\n"
1252                 "EXIT:\n"
1253                 "  ret void\n"
1254                 "}");
1255   AssumptionCache AC(*F);
1256   DominatorTree DT(*F);
1257   const DataLayout &DL = M->getDataLayout();
1258   EXPECT_EQ(getKnownAlignment(A, DL, CxtI, &AC, &DT), Align(1));
1259   EXPECT_EQ(getKnownAlignment(A, DL, CxtI2, &AC, &DT), Align(1));
1260   EXPECT_EQ(getKnownAlignment(A, DL, CxtI3, &AC, &DT), Align(16));
1261 }
1262 
1263 TEST_F(ComputeKnownBitsTest, ComputeKnownBits) {
1264   parseAssembly(
1265       "define i32 @test(i32 %a, i32 %b) {\n"
1266       "  %ash = mul i32 %a, 8\n"
1267       "  %aad = add i32 %ash, 7\n"
1268       "  %aan = and i32 %aad, 4095\n"
1269       "  %bsh = shl i32 %b, 4\n"
1270       "  %bad = or i32 %bsh, 6\n"
1271       "  %ban = and i32 %bad, 4095\n"
1272       "  %A = mul i32 %aan, %ban\n"
1273       "  ret i32 %A\n"
1274       "}\n");
1275   expectKnownBits(/*zero*/ 4278190085u, /*one*/ 10u);
1276 }
1277 
1278 TEST_F(ComputeKnownBitsTest, ComputeKnownMulBits) {
1279   parseAssembly(
1280       "define i32 @test(i32 %a, i32 %b) {\n"
1281       "  %aa = shl i32 %a, 5\n"
1282       "  %bb = shl i32 %b, 5\n"
1283       "  %aaa = or i32 %aa, 24\n"
1284       "  %bbb = or i32 %bb, 28\n"
1285       "  %A = mul i32 %aaa, %bbb\n"
1286       "  ret i32 %A\n"
1287       "}\n");
1288   expectKnownBits(/*zero*/ 95u, /*one*/ 32u);
1289 }
1290 
1291 TEST_F(ComputeKnownFPClassTest, SelectPos0) {
1292   parseAssembly(
1293       "define float @test(i1 %cond) {\n"
1294       "  %A = select i1 %cond, float 0.0, float 0.0"
1295       "  ret float %A\n"
1296       "}\n");
1297   expectKnownFPClass(fcPosZero, false);
1298 }
1299 
1300 TEST_F(ComputeKnownFPClassTest, SelectNeg0) {
1301   parseAssembly(
1302       "define float @test(i1 %cond) {\n"
1303       "  %A = select i1 %cond, float -0.0, float -0.0"
1304       "  ret float %A\n"
1305       "}\n");
1306   expectKnownFPClass(fcNegZero, true);
1307 }
1308 
1309 TEST_F(ComputeKnownFPClassTest, SelectPosOrNeg0) {
1310   parseAssembly(
1311       "define float @test(i1 %cond) {\n"
1312       "  %A = select i1 %cond, float 0.0, float -0.0"
1313       "  ret float %A\n"
1314       "}\n");
1315   expectKnownFPClass(fcZero, std::nullopt);
1316 }
1317 
1318 TEST_F(ComputeKnownFPClassTest, SelectPosInf) {
1319   parseAssembly(
1320       "define float @test(i1 %cond) {\n"
1321       "  %A = select i1 %cond, float 0x7FF0000000000000, float 0x7FF0000000000000"
1322       "  ret float %A\n"
1323       "}\n");
1324   expectKnownFPClass(fcPosInf, false);
1325 }
1326 
1327 TEST_F(ComputeKnownFPClassTest, SelectNegInf) {
1328   parseAssembly(
1329       "define float @test(i1 %cond) {\n"
1330       "  %A = select i1 %cond, float 0xFFF0000000000000, float 0xFFF0000000000000"
1331       "  ret float %A\n"
1332       "}\n");
1333   expectKnownFPClass(fcNegInf, true);
1334 }
1335 
1336 TEST_F(ComputeKnownFPClassTest, SelectPosOrNegInf) {
1337   parseAssembly(
1338       "define float @test(i1 %cond) {\n"
1339       "  %A = select i1 %cond, float 0x7FF0000000000000, float 0xFFF0000000000000"
1340       "  ret float %A\n"
1341       "}\n");
1342   expectKnownFPClass(fcInf, std::nullopt);
1343 }
1344 
1345 TEST_F(ComputeKnownFPClassTest, SelectNNaN) {
1346   parseAssembly(
1347       "define float @test(i1 %cond, float %arg0, float %arg1) {\n"
1348       "  %A = select nnan i1 %cond, float %arg0, float %arg1"
1349       "  ret float %A\n"
1350       "}\n");
1351   expectKnownFPClass(~fcNan, std::nullopt);
1352 }
1353 
1354 TEST_F(ComputeKnownFPClassTest, SelectNInf) {
1355   parseAssembly(
1356       "define float @test(i1 %cond, float %arg0, float %arg1) {\n"
1357       "  %A = select ninf i1 %cond, float %arg0, float %arg1"
1358       "  ret float %A\n"
1359       "}\n");
1360   expectKnownFPClass(~fcInf, std::nullopt);
1361 }
1362 
1363 TEST_F(ComputeKnownFPClassTest, SelectNNaNNInf) {
1364   parseAssembly(
1365       "define float @test(i1 %cond, float %arg0, float %arg1) {\n"
1366       "  %A = select nnan ninf i1 %cond, float %arg0, float %arg1"
1367       "  ret float %A\n"
1368       "}\n");
1369   expectKnownFPClass(~(fcNan | fcInf), std::nullopt);
1370 }
1371 
1372 TEST_F(ComputeKnownFPClassTest, SelectNoFPClassArgUnionAll) {
1373   parseAssembly(
1374       "define float @test(i1 %cond, float nofpclass(snan ninf nsub pzero pnorm) %arg0, float nofpclass(qnan nnorm nzero psub pinf) %arg1) {\n"
1375       "  %A = select i1 %cond, float %arg0, float %arg1"
1376       "  ret float %A\n"
1377       "}\n");
1378   expectKnownFPClass(fcAllFlags, std::nullopt);
1379 }
1380 
1381 TEST_F(ComputeKnownFPClassTest, SelectNoFPClassArgNoNan) {
1382   parseAssembly(
1383       "define float @test(i1 %cond, float nofpclass(nan) %arg0, float nofpclass(nan) %arg1) {\n"
1384       "  %A = select i1 %cond, float %arg0, float %arg1"
1385       "  ret float %A\n"
1386       "}\n");
1387   expectKnownFPClass(~fcNan, std::nullopt);
1388 }
1389 
1390 TEST_F(ComputeKnownFPClassTest, SelectNoFPClassArgNoPInf) {
1391   parseAssembly(
1392       "define float @test(i1 %cond, float nofpclass(inf) %arg0, float nofpclass(pinf) %arg1) {\n"
1393       "  %A = select i1 %cond, float %arg0, float %arg1"
1394       "  ret float %A\n"
1395       "}\n");
1396   expectKnownFPClass(~fcPosInf, std::nullopt);
1397 }
1398 
1399 TEST_F(ComputeKnownFPClassTest, SelectNoFPClassArgNoNInf) {
1400   parseAssembly(
1401       "define float @test(i1 %cond, float nofpclass(ninf) %arg0, float nofpclass(inf) %arg1) {\n"
1402       "  %A = select i1 %cond, float %arg0, float %arg1"
1403       "  ret float %A\n"
1404       "}\n");
1405   expectKnownFPClass(~fcNegInf, std::nullopt);
1406 }
1407 
1408 TEST_F(ComputeKnownFPClassTest, SelectNoFPClassCallSiteNoNan) {
1409   parseAssembly(
1410       "declare float @func()\n"
1411       "define float @test() {\n"
1412       "  %A = call nofpclass(nan) float @func()\n"
1413       "  ret float %A\n"
1414       "}\n");
1415   expectKnownFPClass(~fcNan, std::nullopt);
1416 }
1417 
1418 TEST_F(ComputeKnownFPClassTest, SelectNoFPClassCallSiteNoZeros) {
1419   parseAssembly(
1420       "declare float @func()\n"
1421       "define float @test() {\n"
1422       "  %A = call nofpclass(zero) float @func()\n"
1423       "  ret float %A\n"
1424       "}\n");
1425   expectKnownFPClass(~fcZero, std::nullopt);
1426 }
1427 
1428 TEST_F(ComputeKnownFPClassTest, SelectNoFPClassDeclarationNoNan) {
1429   parseAssembly(
1430       "declare nofpclass(nan) float @no_nans()\n"
1431       "define float @test() {\n"
1432       "  %A = call float @no_nans()\n"
1433       "  ret float %A\n"
1434       "}\n");
1435   expectKnownFPClass(~fcNan, std::nullopt);
1436 }
1437 
1438 // Check nofpclass + ninf works on a callsite
1439 TEST_F(ComputeKnownFPClassTest, SelectNoFPClassCallSiteNoZerosNInfFlags) {
1440   parseAssembly(
1441       "declare float @func()\n"
1442       "define float @test() {\n"
1443       "  %A = call ninf nofpclass(zero) float @func()\n"
1444       "  ret float %A\n"
1445       "}\n");
1446   expectKnownFPClass(~(fcZero | fcInf), std::nullopt);
1447 }
1448 
1449 TEST_F(ComputeKnownFPClassTest, FNegNInf) {
1450   parseAssembly(
1451       "define float @test(float %arg) {\n"
1452       "  %A = fneg ninf float %arg"
1453       "  ret float %A\n"
1454       "}\n");
1455   expectKnownFPClass(~fcInf, std::nullopt);
1456 }
1457 
1458 TEST_F(ComputeKnownFPClassTest, FabsUnknown) {
1459   parseAssembly(
1460       "declare float @llvm.fabs.f32(float)"
1461       "define float @test(float %arg) {\n"
1462       "  %A = call float @llvm.fabs.f32(float %arg)"
1463       "  ret float %A\n"
1464       "}\n");
1465   expectKnownFPClass(fcPositive | fcNan, false);
1466 }
1467 
1468 TEST_F(ComputeKnownFPClassTest, FNegFabsUnknown) {
1469   parseAssembly(
1470       "declare float @llvm.fabs.f32(float)"
1471       "define float @test(float %arg) {\n"
1472       "  %fabs = call float @llvm.fabs.f32(float %arg)"
1473       "  %A = fneg float %fabs"
1474       "  ret float %A\n"
1475       "}\n");
1476   expectKnownFPClass(fcNegative | fcNan, true);
1477 }
1478 
1479 TEST_F(ComputeKnownFPClassTest, NegFabsNInf) {
1480   parseAssembly(
1481       "declare float @llvm.fabs.f32(float)"
1482       "define float @test(float %arg) {\n"
1483       "  %fabs = call ninf float @llvm.fabs.f32(float %arg)"
1484       "  %A = fneg float %fabs"
1485       "  ret float %A\n"
1486       "}\n");
1487   expectKnownFPClass((fcNegative & ~fcNegInf) | fcNan, true);
1488 }
1489 
1490 TEST_F(ComputeKnownFPClassTest, FNegFabsNNaN) {
1491   parseAssembly(
1492       "declare float @llvm.fabs.f32(float)"
1493       "define float @test(float %arg) {\n"
1494       "  %fabs = call nnan float @llvm.fabs.f32(float %arg)"
1495       "  %A = fneg float %fabs"
1496       "  ret float %A\n"
1497       "}\n");
1498   expectKnownFPClass(fcNegative, true);
1499 }
1500 
1501 TEST_F(ComputeKnownFPClassTest, CopySignNNanSrc0) {
1502   parseAssembly(
1503       "declare float @llvm.fabs.f32(float)\n"
1504       "declare float @llvm.copysign.f32(float, float)\n"
1505       "define float @test(float %arg0, float %arg1) {\n"
1506       "  %fabs = call nnan float @llvm.fabs.f32(float %arg0)"
1507       "  %A = call float @llvm.copysign.f32(float %fabs, float %arg1)"
1508       "  ret float %A\n"
1509       "}\n");
1510   expectKnownFPClass(~fcNan, std::nullopt);
1511 }
1512 
1513 TEST_F(ComputeKnownFPClassTest, CopySignNInfSrc0_NegSign) {
1514   parseAssembly(
1515       "declare float @llvm.log.f32(float)\n"
1516       "declare float @llvm.copysign.f32(float, float)\n"
1517       "define float @test(float %arg0, float %arg1) {\n"
1518       "  %ninf = call ninf float @llvm.log.f32(float %arg0)"
1519       "  %A = call float @llvm.copysign.f32(float %ninf, float -1.0)"
1520       "  ret float %A\n"
1521       "}\n");
1522   expectKnownFPClass(fcNegFinite | fcNan, true);
1523 }
1524 
1525 TEST_F(ComputeKnownFPClassTest, CopySignNInfSrc0_PosSign) {
1526   parseAssembly(
1527       "declare float @llvm.sqrt.f32(float)\n"
1528       "declare float @llvm.copysign.f32(float, float)\n"
1529       "define float @test(float %arg0, float %arg1) {\n"
1530       "  %ninf = call ninf float @llvm.sqrt.f32(float %arg0)"
1531       "  %A = call float @llvm.copysign.f32(float %ninf, float 1.0)"
1532       "  ret float %A\n"
1533       "}\n");
1534   expectKnownFPClass(fcPosFinite | fcNan, false);
1535 }
1536 
1537 TEST_F(ComputeKnownFPClassTest, UIToFP) {
1538   parseAssembly(
1539       "define float @test(i32 %arg0, i16 %arg1) {\n"
1540       "  %A = uitofp i32 %arg0 to float"
1541       "  %A2 = uitofp i16 %arg1 to half"
1542       "  ret float %A\n"
1543       "}\n");
1544   expectKnownFPClass(fcPosFinite & ~fcSubnormal, false, A);
1545   expectKnownFPClass(fcPositive & ~fcSubnormal, false, A2);
1546 }
1547 
1548 TEST_F(ComputeKnownFPClassTest, SIToFP) {
1549   parseAssembly(
1550       "define float @test(i32 %arg0, i16 %arg1, i17 %arg2) {\n"
1551       "  %A = sitofp i32 %arg0 to float"
1552       "  %A2 = sitofp i16 %arg1 to half"
1553       "  %A3 = sitofp i17 %arg2 to half"
1554       "  ret float %A\n"
1555       "}\n");
1556   expectKnownFPClass(fcFinite & ~fcNegZero & ~fcSubnormal, std::nullopt, A);
1557   expectKnownFPClass(fcFinite & ~fcNegZero & ~fcSubnormal, std::nullopt, A2);
1558   expectKnownFPClass(~(fcNan | fcNegZero | fcSubnormal), std::nullopt, A3);
1559 }
1560 
1561 TEST_F(ComputeKnownFPClassTest, FAdd) {
1562   parseAssembly(
1563       "define float @test(float nofpclass(nan inf) %nnan.ninf, float nofpclass(nan) %nnan, float nofpclass(qnan) %no.qnan, float %unknown) {\n"
1564       "  %A = fadd float %nnan, %nnan.ninf"
1565       "  %A2 = fadd float %nnan.ninf, %nnan"
1566       "  %A3 = fadd float %nnan.ninf, %unknown"
1567       "  %A4 = fadd float %nnan.ninf, %no.qnan"
1568       "  %A5 = fadd float %nnan, %nnan"
1569       "  ret float %A\n"
1570       "}\n");
1571   expectKnownFPClass(fcFinite | fcInf, std::nullopt, A);
1572   expectKnownFPClass(fcFinite | fcInf, std::nullopt, A2);
1573   expectKnownFPClass(fcAllFlags, std::nullopt, A3);
1574   expectKnownFPClass(fcAllFlags, std::nullopt, A4);
1575   expectKnownFPClass(fcAllFlags, std::nullopt, A5);
1576 }
1577 
1578 TEST_F(ComputeKnownFPClassTest, FSub) {
1579   parseAssembly(
1580       "define float @test(float nofpclass(nan inf) %nnan.ninf, float nofpclass(nan) %nnan, float nofpclass(qnan) %no.qnan, float %unknown) {\n"
1581       "  %A = fsub float %nnan, %nnan.ninf"
1582       "  %A2 = fsub float %nnan.ninf, %nnan"
1583       "  %A3 = fsub float %nnan.ninf, %unknown"
1584       "  %A4 = fsub float %nnan.ninf, %no.qnan"
1585       "  %A5 = fsub float %nnan, %nnan"
1586       "  ret float %A\n"
1587       "}\n");
1588   expectKnownFPClass(fcFinite | fcInf, std::nullopt, A);
1589   expectKnownFPClass(fcFinite | fcInf, std::nullopt, A2);
1590   expectKnownFPClass(fcAllFlags, std::nullopt, A3);
1591   expectKnownFPClass(fcAllFlags, std::nullopt, A4);
1592   expectKnownFPClass(fcAllFlags, std::nullopt, A5);
1593 }
1594 
1595 TEST_F(ComputeKnownFPClassTest, FMul) {
1596   parseAssembly(
1597       "define float @test(float nofpclass(nan inf) %nnan.ninf0, float nofpclass(nan inf) %nnan.ninf1, float nofpclass(nan) %nnan, float nofpclass(qnan) %no.qnan, float %unknown) {\n"
1598       "  %A = fmul float %nnan.ninf0, %nnan.ninf1"
1599       "  %A2 = fmul float %nnan.ninf0, %nnan"
1600       "  %A3 = fmul float %nnan, %nnan.ninf0"
1601       "  %A4 = fmul float %nnan.ninf0, %no.qnan"
1602       "  %A5 = fmul float %nnan, %nnan"
1603       "  ret float %A\n"
1604       "}\n");
1605   expectKnownFPClass(fcFinite | fcInf, std::nullopt, A);
1606   expectKnownFPClass(fcAllFlags, std::nullopt, A2);
1607   expectKnownFPClass(fcAllFlags, std::nullopt, A3);
1608   expectKnownFPClass(fcAllFlags, std::nullopt, A4);
1609   expectKnownFPClass(fcPositive | fcNan, std::nullopt, A5);
1610 }
1611 
1612 TEST_F(ComputeKnownFPClassTest, FMulNoZero) {
1613   parseAssembly(
1614       "define float @test(float nofpclass(zero) %no.zero, float nofpclass(zero nan) %no.zero.nan0, float nofpclass(zero nan) %no.zero.nan1, float nofpclass(nzero nan) %no.negzero.nan, float nofpclass(pzero nan) %no.poszero.nan, float nofpclass(inf nan) %no.inf.nan, float nofpclass(inf) %no.inf, float nofpclass(nan) %no.nan) {\n"
1615       "  %A = fmul float %no.zero.nan0, %no.zero.nan1"
1616       "  %A2 = fmul float %no.zero, %no.zero"
1617       "  %A3 = fmul float %no.poszero.nan, %no.zero.nan0"
1618       "  %A4 = fmul float %no.nan, %no.zero"
1619       "  %A5 = fmul float %no.zero, %no.inf"
1620       "  %A6 = fmul float %no.zero.nan0, %no.nan"
1621       "  %A7 = fmul float %no.nan, %no.zero.nan0"
1622       "  ret float %A\n"
1623       "}\n");
1624   expectKnownFPClass(fcFinite | fcInf, std::nullopt, A);
1625   expectKnownFPClass(fcPositive | fcNan, std::nullopt, A2);
1626   expectKnownFPClass(fcAllFlags, std::nullopt, A3);
1627   expectKnownFPClass(fcAllFlags, std::nullopt, A4);
1628   expectKnownFPClass(fcAllFlags, std::nullopt, A5);
1629   expectKnownFPClass(fcAllFlags, std::nullopt, A6);
1630   expectKnownFPClass(fcAllFlags, std::nullopt, A7);
1631 }
1632 
1633 TEST_F(ComputeKnownFPClassTest, CannotBeOrderedLessThanZero) {
1634   parseAssembly("define float @test(float %arg) {\n"
1635                 "  %A = fmul float %arg, %arg"
1636                 "  ret float %A\n"
1637                 "}\n");
1638 
1639   Type *FPTy = Type::getDoubleTy(M->getContext());
1640   const DataLayout &DL = M->getDataLayout();
1641 
1642   EXPECT_TRUE(
1643       computeKnownFPClass(ConstantFP::getZero(FPTy, /*Negative=*/false), DL)
1644           .cannotBeOrderedLessThanZero());
1645   EXPECT_TRUE(
1646       computeKnownFPClass(ConstantFP::getZero(FPTy, /*Negative=*/true), DL)
1647           .cannotBeOrderedLessThanZero());
1648 
1649   EXPECT_TRUE(computeKnownFPClass(ConstantFP::getInfinity(FPTy, false), DL)
1650                   .cannotBeOrderedLessThanZero());
1651   EXPECT_FALSE(computeKnownFPClass(ConstantFP::getInfinity(FPTy, true), DL)
1652                    .cannotBeOrderedLessThanZero());
1653 
1654   EXPECT_TRUE(computeKnownFPClass(ConstantFP::get(FPTy, 1.0), DL)
1655                   .cannotBeOrderedLessThanZero());
1656   EXPECT_FALSE(computeKnownFPClass(ConstantFP::get(FPTy, -1.0), DL)
1657                    .cannotBeOrderedLessThanZero());
1658 
1659   EXPECT_TRUE(
1660       computeKnownFPClass(
1661           ConstantFP::get(FPTy, APFloat::getSmallest(FPTy->getFltSemantics(),
1662                                                      /*Negative=*/false)),
1663           DL)
1664           .cannotBeOrderedLessThanZero());
1665   EXPECT_FALSE(
1666       computeKnownFPClass(
1667           ConstantFP::get(FPTy, APFloat::getSmallest(FPTy->getFltSemantics(),
1668                                                      /*Negative=*/true)),
1669           DL)
1670           .cannotBeOrderedLessThanZero());
1671 
1672   EXPECT_TRUE(
1673       computeKnownFPClass(ConstantFP::getQNaN(FPTy, /*Negative=*/false), DL)
1674           .cannotBeOrderedLessThanZero());
1675   EXPECT_TRUE(
1676       computeKnownFPClass(ConstantFP::getQNaN(FPTy, /*Negative=*/true), DL)
1677           .cannotBeOrderedLessThanZero());
1678   EXPECT_TRUE(
1679       computeKnownFPClass(ConstantFP::getSNaN(FPTy, /*Negative=*/false), DL)
1680           .cannotBeOrderedLessThanZero());
1681   EXPECT_TRUE(
1682       computeKnownFPClass(ConstantFP::getSNaN(FPTy, /*Negative=*/true), DL)
1683           .cannotBeOrderedLessThanZero());
1684 }
1685 
1686 TEST_F(ValueTrackingTest, isNonZeroRecurrence) {
1687   parseAssembly(R"(
1688     define i1 @test(i8 %n, i8 %r) {
1689     entry:
1690       br label %loop
1691     loop:
1692       %p = phi i8 [ -1, %entry ], [ %next, %loop ]
1693       %next = add nsw i8 %p, -1
1694       %cmp1 = icmp eq i8 %p, %n
1695       br i1 %cmp1, label %exit, label %loop
1696     exit:
1697       %A = or i8 %p, %r
1698       %CxtI = icmp eq i8 %A, 0
1699       ret i1 %CxtI
1700     }
1701   )");
1702   const DataLayout &DL = M->getDataLayout();
1703   AssumptionCache AC(*F);
1704   EXPECT_TRUE(isKnownNonZero(A, DL, 0, &AC, CxtI));
1705 }
1706 
1707 TEST_F(ValueTrackingTest, KnownNonZeroFromDomCond) {
1708   parseAssembly(R"(
1709     declare ptr @f_i8()
1710     define void @test(i1 %c) {
1711       %A = call ptr @f_i8()
1712       %B = call ptr @f_i8()
1713       %c1 = icmp ne ptr %A, null
1714       %cond = and i1 %c1, %c
1715       br i1 %cond, label %T, label %Q
1716     T:
1717       %CxtI = add i32 0, 0
1718       ret void
1719     Q:
1720       %CxtI2 = add i32 0, 0
1721       ret void
1722     }
1723   )");
1724   AssumptionCache AC(*F);
1725   DominatorTree DT(*F);
1726   const DataLayout &DL = M->getDataLayout();
1727   EXPECT_EQ(isKnownNonZero(A, DL, 0, &AC, CxtI, &DT), true);
1728   EXPECT_EQ(isKnownNonZero(A, DL, 0, &AC, CxtI2, &DT), false);
1729 }
1730 
1731 TEST_F(ValueTrackingTest, KnownNonZeroFromDomCond2) {
1732   parseAssembly(R"(
1733     declare ptr @f_i8()
1734     define void @test(i1 %c) {
1735       %A = call ptr @f_i8()
1736       %B = call ptr @f_i8()
1737       %c1 = icmp ne ptr %A, null
1738       %cond = select i1 %c, i1 %c1, i1 false
1739       br i1 %cond, label %T, label %Q
1740     T:
1741       %CxtI = add i32 0, 0
1742       ret void
1743     Q:
1744       %CxtI2 = add i32 0, 0
1745       ret void
1746     }
1747   )");
1748   AssumptionCache AC(*F);
1749   DominatorTree DT(*F);
1750   const DataLayout &DL = M->getDataLayout();
1751   EXPECT_EQ(isKnownNonZero(A, DL, 0, &AC, CxtI, &DT), true);
1752   EXPECT_EQ(isKnownNonZero(A, DL, 0, &AC, CxtI2, &DT), false);
1753 }
1754 
1755 TEST_F(ValueTrackingTest, IsImpliedConditionAnd) {
1756   parseAssembly(R"(
1757     define void @test(i32 %x, i32 %y) {
1758       %c1 = icmp ult i32 %x, 10
1759       %c2 = icmp ult i32 %y, 15
1760       %A = and i1 %c1, %c2
1761       ; x < 10 /\ y < 15
1762       %A2 = icmp ult i32 %x, 20
1763       %A3 = icmp uge i32 %y, 20
1764       %A4 = icmp ult i32 %x, 5
1765       ret void
1766     }
1767   )");
1768   const DataLayout &DL = M->getDataLayout();
1769   EXPECT_EQ(isImpliedCondition(A, A2, DL), true);
1770   EXPECT_EQ(isImpliedCondition(A, A3, DL), false);
1771   EXPECT_EQ(isImpliedCondition(A, A4, DL), std::nullopt);
1772 }
1773 
1774 TEST_F(ValueTrackingTest, IsImpliedConditionAnd2) {
1775   parseAssembly(R"(
1776     define void @test(i32 %x, i32 %y) {
1777       %c1 = icmp ult i32 %x, 10
1778       %c2 = icmp ult i32 %y, 15
1779       %A = select i1 %c1, i1 %c2, i1 false
1780       ; x < 10 /\ y < 15
1781       %A2 = icmp ult i32 %x, 20
1782       %A3 = icmp uge i32 %y, 20
1783       %A4 = icmp ult i32 %x, 5
1784       ret void
1785     }
1786   )");
1787   const DataLayout &DL = M->getDataLayout();
1788   EXPECT_EQ(isImpliedCondition(A, A2, DL), true);
1789   EXPECT_EQ(isImpliedCondition(A, A3, DL), false);
1790   EXPECT_EQ(isImpliedCondition(A, A4, DL), std::nullopt);
1791 }
1792 
1793 TEST_F(ValueTrackingTest, IsImpliedConditionAndVec) {
1794   parseAssembly(R"(
1795     define void @test(<2 x i8> %x, <2 x i8> %y) {
1796       %A = icmp ult <2 x i8> %x, %y
1797       %A2 = icmp ule <2 x i8> %x, %y
1798       ret void
1799     }
1800   )");
1801   const DataLayout &DL = M->getDataLayout();
1802   EXPECT_EQ(isImpliedCondition(A, A2, DL), true);
1803 }
1804 
1805 TEST_F(ValueTrackingTest, IsImpliedConditionOr) {
1806   parseAssembly(R"(
1807     define void @test(i32 %x, i32 %y) {
1808       %c1 = icmp ult i32 %x, 10
1809       %c2 = icmp ult i32 %y, 15
1810       %A = or i1 %c1, %c2 ; negated
1811       ; x >= 10 /\ y >= 15
1812       %A2 = icmp ult i32 %x, 5
1813       %A3 = icmp uge i32 %y, 10
1814       %A4 = icmp ult i32 %x, 15
1815       ret void
1816     }
1817   )");
1818   const DataLayout &DL = M->getDataLayout();
1819   EXPECT_EQ(isImpliedCondition(A, A2, DL, false), false);
1820   EXPECT_EQ(isImpliedCondition(A, A3, DL, false), true);
1821   EXPECT_EQ(isImpliedCondition(A, A4, DL, false), std::nullopt);
1822 }
1823 
1824 TEST_F(ValueTrackingTest, IsImpliedConditionOr2) {
1825   parseAssembly(R"(
1826     define void @test(i32 %x, i32 %y) {
1827       %c1 = icmp ult i32 %x, 10
1828       %c2 = icmp ult i32 %y, 15
1829       %A = select i1 %c1, i1 true, i1 %c2 ; negated
1830       ; x >= 10 /\ y >= 15
1831       %A2 = icmp ult i32 %x, 5
1832       %A3 = icmp uge i32 %y, 10
1833       %A4 = icmp ult i32 %x, 15
1834       ret void
1835     }
1836   )");
1837   const DataLayout &DL = M->getDataLayout();
1838   EXPECT_EQ(isImpliedCondition(A, A2, DL, false), false);
1839   EXPECT_EQ(isImpliedCondition(A, A3, DL, false), true);
1840   EXPECT_EQ(isImpliedCondition(A, A4, DL, false), std::nullopt);
1841 }
1842 
1843 TEST_F(ComputeKnownBitsTest, KnownNonZeroShift) {
1844   // %q is known nonzero without known bits.
1845   // Because %q is nonzero, %A[0] is known to be zero.
1846   parseAssembly(
1847       "define i8 @test(i8 %p, ptr %pq) {\n"
1848       "  %q = load i8, ptr %pq, !range !0\n"
1849       "  %A = shl i8 %p, %q\n"
1850       "  ret i8 %A\n"
1851       "}\n"
1852       "!0 = !{ i8 1, i8 5 }\n");
1853   expectKnownBits(/*zero*/ 1u, /*one*/ 0u);
1854 }
1855 
1856 TEST_F(ComputeKnownBitsTest, ComputeKnownFshl) {
1857   // fshl(....1111....0000, 00..1111........, 6)
1858   // = 11....000000..11
1859   parseAssembly(
1860       "define i16 @test(i16 %a, i16 %b) {\n"
1861       "  %aa = shl i16 %a, 4\n"
1862       "  %bb = lshr i16 %b, 2\n"
1863       "  %aaa = or i16 %aa, 3840\n"
1864       "  %bbb = or i16 %bb, 3840\n"
1865       "  %A = call i16 @llvm.fshl.i16(i16 %aaa, i16 %bbb, i16 6)\n"
1866       "  ret i16 %A\n"
1867       "}\n"
1868       "declare i16 @llvm.fshl.i16(i16, i16, i16)\n");
1869   expectKnownBits(/*zero*/ 1008u, /*one*/ 49155u);
1870 }
1871 
1872 TEST_F(ComputeKnownBitsTest, ComputeKnownFshr) {
1873   // fshr(....1111....0000, 00..1111........, 26)
1874   // = 11....000000..11
1875   parseAssembly(
1876       "define i16 @test(i16 %a, i16 %b) {\n"
1877       "  %aa = shl i16 %a, 4\n"
1878       "  %bb = lshr i16 %b, 2\n"
1879       "  %aaa = or i16 %aa, 3840\n"
1880       "  %bbb = or i16 %bb, 3840\n"
1881       "  %A = call i16 @llvm.fshr.i16(i16 %aaa, i16 %bbb, i16 26)\n"
1882       "  ret i16 %A\n"
1883       "}\n"
1884       "declare i16 @llvm.fshr.i16(i16, i16, i16)\n");
1885   expectKnownBits(/*zero*/ 1008u, /*one*/ 49155u);
1886 }
1887 
1888 TEST_F(ComputeKnownBitsTest, ComputeKnownFshlZero) {
1889   // fshl(....1111....0000, 00..1111........, 0)
1890   // = ....1111....0000
1891   parseAssembly(
1892       "define i16 @test(i16 %a, i16 %b) {\n"
1893       "  %aa = shl i16 %a, 4\n"
1894       "  %bb = lshr i16 %b, 2\n"
1895       "  %aaa = or i16 %aa, 3840\n"
1896       "  %bbb = or i16 %bb, 3840\n"
1897       "  %A = call i16 @llvm.fshl.i16(i16 %aaa, i16 %bbb, i16 0)\n"
1898       "  ret i16 %A\n"
1899       "}\n"
1900       "declare i16 @llvm.fshl.i16(i16, i16, i16)\n");
1901   expectKnownBits(/*zero*/ 15u, /*one*/ 3840u);
1902 }
1903 
1904 TEST_F(ComputeKnownBitsTest, ComputeKnownUAddSatLeadingOnes) {
1905   // uadd.sat(1111...1, ........)
1906   // = 1111....
1907   parseAssembly(
1908       "define i8 @test(i8 %a, i8 %b) {\n"
1909       "  %aa = or i8 %a, 241\n"
1910       "  %A = call i8 @llvm.uadd.sat.i8(i8 %aa, i8 %b)\n"
1911       "  ret i8 %A\n"
1912       "}\n"
1913       "declare i8 @llvm.uadd.sat.i8(i8, i8)\n");
1914   expectKnownBits(/*zero*/ 0u, /*one*/ 240u);
1915 }
1916 
1917 TEST_F(ComputeKnownBitsTest, ComputeKnownUAddSatOnesPreserved) {
1918   // uadd.sat(00...011, .1...110)
1919   // = .......1
1920   parseAssembly(
1921       "define i8 @test(i8 %a, i8 %b) {\n"
1922       "  %aa = or i8 %a, 3\n"
1923       "  %aaa = and i8 %aa, 59\n"
1924       "  %bb = or i8 %b, 70\n"
1925       "  %bbb = and i8 %bb, 254\n"
1926       "  %A = call i8 @llvm.uadd.sat.i8(i8 %aaa, i8 %bbb)\n"
1927       "  ret i8 %A\n"
1928       "}\n"
1929       "declare i8 @llvm.uadd.sat.i8(i8, i8)\n");
1930   expectKnownBits(/*zero*/ 0u, /*one*/ 1u);
1931 }
1932 
1933 TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatLHSLeadingZeros) {
1934   // usub.sat(0000...0, ........)
1935   // = 0000....
1936   parseAssembly(
1937       "define i8 @test(i8 %a, i8 %b) {\n"
1938       "  %aa = and i8 %a, 14\n"
1939       "  %A = call i8 @llvm.usub.sat.i8(i8 %aa, i8 %b)\n"
1940       "  ret i8 %A\n"
1941       "}\n"
1942       "declare i8 @llvm.usub.sat.i8(i8, i8)\n");
1943   expectKnownBits(/*zero*/ 240u, /*one*/ 0u);
1944 }
1945 
1946 TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatRHSLeadingOnes) {
1947   // usub.sat(........, 1111...1)
1948   // = 0000....
1949   parseAssembly(
1950       "define i8 @test(i8 %a, i8 %b) {\n"
1951       "  %bb = or i8 %a, 241\n"
1952       "  %A = call i8 @llvm.usub.sat.i8(i8 %a, i8 %bb)\n"
1953       "  ret i8 %A\n"
1954       "}\n"
1955       "declare i8 @llvm.usub.sat.i8(i8, i8)\n");
1956   expectKnownBits(/*zero*/ 240u, /*one*/ 0u);
1957 }
1958 
1959 TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatZerosPreserved) {
1960   // usub.sat(11...011, .1...110)
1961   // = ......0.
1962   parseAssembly(
1963       "define i8 @test(i8 %a, i8 %b) {\n"
1964       "  %aa = or i8 %a, 195\n"
1965       "  %aaa = and i8 %aa, 251\n"
1966       "  %bb = or i8 %b, 70\n"
1967       "  %bbb = and i8 %bb, 254\n"
1968       "  %A = call i8 @llvm.usub.sat.i8(i8 %aaa, i8 %bbb)\n"
1969       "  ret i8 %A\n"
1970       "}\n"
1971       "declare i8 @llvm.usub.sat.i8(i8, i8)\n");
1972   expectKnownBits(/*zero*/ 2u, /*one*/ 0u);
1973 }
1974 
1975 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsPtrToIntTrunc) {
1976   // ptrtoint truncates the pointer type.
1977   parseAssembly(
1978       "define void @test(ptr %p) {\n"
1979       "  %A = load ptr, ptr %p\n"
1980       "  %i = ptrtoint ptr %A to i32\n"
1981       "  %m = and i32 %i, 31\n"
1982       "  %c = icmp eq i32 %m, 0\n"
1983       "  call void @llvm.assume(i1 %c)\n"
1984       "  ret void\n"
1985       "}\n"
1986       "declare void @llvm.assume(i1)\n");
1987   AssumptionCache AC(*F);
1988   KnownBits Known = computeKnownBits(
1989       A, M->getDataLayout(), /* Depth */ 0, &AC, F->front().getTerminator());
1990   EXPECT_EQ(Known.Zero.getZExtValue(), 31u);
1991   EXPECT_EQ(Known.One.getZExtValue(), 0u);
1992 }
1993 
1994 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsPtrToIntZext) {
1995   // ptrtoint zero extends the pointer type.
1996   parseAssembly(
1997       "define void @test(ptr %p) {\n"
1998       "  %A = load ptr, ptr %p\n"
1999       "  %i = ptrtoint ptr %A to i128\n"
2000       "  %m = and i128 %i, 31\n"
2001       "  %c = icmp eq i128 %m, 0\n"
2002       "  call void @llvm.assume(i1 %c)\n"
2003       "  ret void\n"
2004       "}\n"
2005       "declare void @llvm.assume(i1)\n");
2006   AssumptionCache AC(*F);
2007   KnownBits Known = computeKnownBits(
2008       A, M->getDataLayout(), /* Depth */ 0, &AC, F->front().getTerminator());
2009   EXPECT_EQ(Known.Zero.getZExtValue(), 31u);
2010   EXPECT_EQ(Known.One.getZExtValue(), 0u);
2011 }
2012 
2013 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsFreeze) {
2014   parseAssembly("define void @test() {\n"
2015                 "  %m = call i32 @any_num()\n"
2016                 "  %A = freeze i32 %m\n"
2017                 "  %n = and i32 %m, 31\n"
2018                 "  %c = icmp eq i32 %n, 0\n"
2019                 "  call void @llvm.assume(i1 %c)\n"
2020                 "  ret void\n"
2021                 "}\n"
2022                 "declare void @llvm.assume(i1)\n"
2023                 "declare i32 @any_num()\n");
2024   AssumptionCache AC(*F);
2025   KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
2026                                      F->front().getTerminator());
2027   EXPECT_EQ(Known.Zero.getZExtValue(), 31u);
2028   EXPECT_EQ(Known.One.getZExtValue(), 0u);
2029 }
2030 
2031 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsAddWithRange) {
2032   parseAssembly("define void @test(ptr %p) {\n"
2033                 "  %A = load i64, ptr %p, !range !{i64 64, i64 65536}\n"
2034                 "  %APlus512 = add i64 %A, 512\n"
2035                 "  %c = icmp ugt i64 %APlus512, 523\n"
2036                 "  call void @llvm.assume(i1 %c)\n"
2037                 "  ret void\n"
2038                 "}\n"
2039                 "declare void @llvm.assume(i1)\n");
2040   AssumptionCache AC(*F);
2041   KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
2042                                      F->front().getTerminator());
2043   EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1));
2044   EXPECT_EQ(Known.One.getZExtValue(), 0u);
2045   Instruction &APlus512 = findInstructionByName(F, "APlus512");
2046   Known = computeKnownBits(&APlus512, M->getDataLayout(), /* Depth */ 0, &AC,
2047                            F->front().getTerminator());
2048   // We know of one less zero because 512 may have produced a 1 that
2049   // got carried all the way to the first trailing zero.
2050   EXPECT_EQ(Known.Zero.getZExtValue(), (~(65536llu - 1)) << 1);
2051   EXPECT_EQ(Known.One.getZExtValue(), 0u);
2052   // The known range is not precise given computeKnownBits works
2053   // with the masks of zeros and ones, not the ranges.
2054   EXPECT_EQ(Known.getMinValue(), 0u);
2055   EXPECT_EQ(Known.getMaxValue(), 131071);
2056 }
2057 
2058 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsUnknownVScale) {
2059   Module M("", Context);
2060   IRBuilder<> Builder(Context);
2061   Function *TheFn =
2062       Intrinsic::getDeclaration(&M, Intrinsic::vscale, {Builder.getInt32Ty()});
2063   CallInst *CI = Builder.CreateCall(TheFn, {}, {}, "");
2064 
2065   KnownBits Known = computeKnownBits(CI, M.getDataLayout(), /* Depth */ 0);
2066   // There is no parent function so we cannot look up the vscale_range
2067   // attribute to determine the number of bits.
2068   EXPECT_EQ(Known.One.getZExtValue(), 0u);
2069   EXPECT_EQ(Known.Zero.getZExtValue(), 0u);
2070 
2071   BasicBlock *BB = BasicBlock::Create(Context);
2072   CI->insertInto(BB, BB->end());
2073   Known = computeKnownBits(CI, M.getDataLayout(), /* Depth */ 0);
2074   // There is no parent function so we cannot look up the vscale_range
2075   // attribute to determine the number of bits.
2076   EXPECT_EQ(Known.One.getZExtValue(), 0u);
2077   EXPECT_EQ(Known.Zero.getZExtValue(), 0u);
2078 
2079   CI->removeFromParent();
2080   delete CI;
2081   delete BB;
2082 }
2083 
2084 // 512 + [32, 64) doesn't produce overlapping bits.
2085 // Make sure we get all the individual bits properly.
2086 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsAddWithRangeNoOverlap) {
2087   parseAssembly("define void @test(ptr %p) {\n"
2088                 "  %A = load i64, ptr %p, !range !{i64 32, i64 64}\n"
2089                 "  %APlus512 = add i64 %A, 512\n"
2090                 "  %c = icmp ugt i64 %APlus512, 523\n"
2091                 "  call void @llvm.assume(i1 %c)\n"
2092                 "  ret void\n"
2093                 "}\n"
2094                 "declare void @llvm.assume(i1)\n");
2095   AssumptionCache AC(*F);
2096   KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
2097                                      F->front().getTerminator());
2098   EXPECT_EQ(Known.Zero.getZExtValue(), ~(64llu - 1));
2099   EXPECT_EQ(Known.One.getZExtValue(), 32u);
2100   Instruction &APlus512 = findInstructionByName(F, "APlus512");
2101   Known = computeKnownBits(&APlus512, M->getDataLayout(), /* Depth */ 0, &AC,
2102                            F->front().getTerminator());
2103   EXPECT_EQ(Known.Zero.getZExtValue(), ~512llu & ~(64llu - 1));
2104   EXPECT_EQ(Known.One.getZExtValue(), 512u | 32u);
2105   // The known range is not precise given computeKnownBits works
2106   // with the masks of zeros and ones, not the ranges.
2107   EXPECT_EQ(Known.getMinValue(), 544);
2108   EXPECT_EQ(Known.getMaxValue(), 575);
2109 }
2110 
2111 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsGEPWithRange) {
2112   parseAssembly(
2113       "define void @test(ptr %p) {\n"
2114       "  %A = load i64, ptr %p, !range !{i64 64, i64 65536}\n"
2115       "  %APtr = inttoptr i64 %A to float*"
2116       "  %APtrPlus512 = getelementptr float, float* %APtr, i32 128\n"
2117       "  %c = icmp ugt float* %APtrPlus512, inttoptr (i32 523 to float*)\n"
2118       "  call void @llvm.assume(i1 %c)\n"
2119       "  ret void\n"
2120       "}\n"
2121       "declare void @llvm.assume(i1)\n");
2122   AssumptionCache AC(*F);
2123   KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
2124                                      F->front().getTerminator());
2125   EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1));
2126   EXPECT_EQ(Known.One.getZExtValue(), 0u);
2127   Instruction &APtrPlus512 = findInstructionByName(F, "APtrPlus512");
2128   Known = computeKnownBits(&APtrPlus512, M->getDataLayout(), /* Depth */ 0, &AC,
2129                            F->front().getTerminator());
2130   // We know of one less zero because 512 may have produced a 1 that
2131   // got carried all the way to the first trailing zero.
2132   EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1) << 1);
2133   EXPECT_EQ(Known.One.getZExtValue(), 0u);
2134   // The known range is not precise given computeKnownBits works
2135   // with the masks of zeros and ones, not the ranges.
2136   EXPECT_EQ(Known.getMinValue(), 0u);
2137   EXPECT_EQ(Known.getMaxValue(), 131071);
2138 }
2139 
2140 // 4*128 + [32, 64) doesn't produce overlapping bits.
2141 // Make sure we get all the individual bits properly.
2142 // This test is useful to check that we account for the scaling factor
2143 // in the gep. Indeed, gep float, [32,64), 128 is not 128 + [32,64).
2144 TEST_F(ComputeKnownBitsTest, ComputeKnownBitsGEPWithRangeNoOverlap) {
2145   parseAssembly(
2146       "define void @test(ptr %p) {\n"
2147       "  %A = load i64, ptr %p, !range !{i64 32, i64 64}\n"
2148       "  %APtr = inttoptr i64 %A to float*"
2149       "  %APtrPlus512 = getelementptr float, float* %APtr, i32 128\n"
2150       "  %c = icmp ugt float* %APtrPlus512, inttoptr (i32 523 to float*)\n"
2151       "  call void @llvm.assume(i1 %c)\n"
2152       "  ret void\n"
2153       "}\n"
2154       "declare void @llvm.assume(i1)\n");
2155   AssumptionCache AC(*F);
2156   KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
2157                                      F->front().getTerminator());
2158   EXPECT_EQ(Known.Zero.getZExtValue(), ~(64llu - 1));
2159   EXPECT_EQ(Known.One.getZExtValue(), 32u);
2160   Instruction &APtrPlus512 = findInstructionByName(F, "APtrPlus512");
2161   Known = computeKnownBits(&APtrPlus512, M->getDataLayout(), /* Depth */ 0, &AC,
2162                            F->front().getTerminator());
2163   EXPECT_EQ(Known.Zero.getZExtValue(), ~512llu & ~(64llu - 1));
2164   EXPECT_EQ(Known.One.getZExtValue(), 512u | 32u);
2165   // The known range is not precise given computeKnownBits works
2166   // with the masks of zeros and ones, not the ranges.
2167   EXPECT_EQ(Known.getMinValue(), 544);
2168   EXPECT_EQ(Known.getMaxValue(), 575);
2169 }
2170 
2171 TEST_F(ValueTrackingTest, HaveNoCommonBitsSet) {
2172   {
2173     // Check for an inverted mask: (X & ~M) op (Y & M).
2174     auto M = parseModule(R"(
2175   define i32 @test(i32 %X, i32 %Y, i32 %M) {
2176     %1 = xor i32 %M, -1
2177     %LHS = and i32 %1, %X
2178     %RHS = and i32 %Y, %M
2179     %Ret = add i32 %LHS, %RHS
2180     ret i32 %Ret
2181   })");
2182 
2183     auto *F = M->getFunction("test");
2184     auto *LHS = findInstructionByNameOrNull(F, "LHS");
2185     auto *RHS = findInstructionByNameOrNull(F, "RHS");
2186 
2187     const DataLayout &DL = M->getDataLayout();
2188     EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL));
2189     EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL));
2190   }
2191   {
2192     // Check for (A & B) and ~(A | B)
2193     auto M = parseModule(R"(
2194   define void @test(i32 %A, i32 %B) {
2195     %LHS = and i32 %A, %B
2196     %or = or i32 %A, %B
2197     %RHS = xor i32 %or, -1
2198 
2199     %LHS2 = and i32 %B, %A
2200     %or2 = or i32 %A, %B
2201     %RHS2 = xor i32 %or2, -1
2202 
2203     ret void
2204   })");
2205 
2206     auto *F = M->getFunction("test");
2207     const DataLayout &DL = M->getDataLayout();
2208 
2209     auto *LHS = findInstructionByNameOrNull(F, "LHS");
2210     auto *RHS = findInstructionByNameOrNull(F, "RHS");
2211     EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL));
2212     EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL));
2213 
2214     auto *LHS2 = findInstructionByNameOrNull(F, "LHS2");
2215     auto *RHS2 = findInstructionByNameOrNull(F, "RHS2");
2216     EXPECT_TRUE(haveNoCommonBitsSet(LHS2, RHS2, DL));
2217     EXPECT_TRUE(haveNoCommonBitsSet(RHS2, LHS2, DL));
2218   }
2219   {
2220     // Check for (A & B) and ~(A | B) in vector version
2221     auto M = parseModule(R"(
2222   define void @test(<2 x i32> %A, <2 x i32> %B) {
2223     %LHS = and <2 x i32> %A, %B
2224     %or = or <2 x i32> %A, %B
2225     %RHS = xor <2 x i32> %or, <i32 -1, i32 -1>
2226 
2227     %LHS2 = and <2 x i32> %B, %A
2228     %or2 = or <2 x i32> %A, %B
2229     %RHS2 = xor <2 x i32> %or2, <i32 -1, i32 -1>
2230 
2231     ret void
2232   })");
2233 
2234     auto *F = M->getFunction("test");
2235     const DataLayout &DL = M->getDataLayout();
2236 
2237     auto *LHS = findInstructionByNameOrNull(F, "LHS");
2238     auto *RHS = findInstructionByNameOrNull(F, "RHS");
2239     EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL));
2240     EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL));
2241 
2242     auto *LHS2 = findInstructionByNameOrNull(F, "LHS2");
2243     auto *RHS2 = findInstructionByNameOrNull(F, "RHS2");
2244     EXPECT_TRUE(haveNoCommonBitsSet(LHS2, RHS2, DL));
2245     EXPECT_TRUE(haveNoCommonBitsSet(RHS2, LHS2, DL));
2246   }
2247 }
2248 
2249 class IsBytewiseValueTest : public ValueTrackingTest,
2250                             public ::testing::WithParamInterface<
2251                                 std::pair<const char *, const char *>> {
2252 protected:
2253 };
2254 
2255 const std::pair<const char *, const char *> IsBytewiseValueTests[] = {
2256     {
2257         "i8 0",
2258         "i48* null",
2259     },
2260     {
2261         "i8 undef",
2262         "i48* undef",
2263     },
2264     {
2265         "i8 0",
2266         "i8 zeroinitializer",
2267     },
2268     {
2269         "i8 0",
2270         "i8 0",
2271     },
2272     {
2273         "i8 -86",
2274         "i8 -86",
2275     },
2276     {
2277         "i8 -1",
2278         "i8 -1",
2279     },
2280     {
2281         "i8 undef",
2282         "i16 undef",
2283     },
2284     {
2285         "i8 0",
2286         "i16 0",
2287     },
2288     {
2289         "",
2290         "i16 7",
2291     },
2292     {
2293         "i8 -86",
2294         "i16 -21846",
2295     },
2296     {
2297         "i8 -1",
2298         "i16 -1",
2299     },
2300     {
2301         "i8 0",
2302         "i48 0",
2303     },
2304     {
2305         "i8 -1",
2306         "i48 -1",
2307     },
2308     {
2309         "i8 0",
2310         "i49 0",
2311     },
2312     {
2313         "",
2314         "i49 -1",
2315     },
2316     {
2317         "i8 0",
2318         "half 0xH0000",
2319     },
2320     {
2321         "i8 -85",
2322         "half 0xHABAB",
2323     },
2324     {
2325         "i8 0",
2326         "float 0.0",
2327     },
2328     {
2329         "i8 -1",
2330         "float 0xFFFFFFFFE0000000",
2331     },
2332     {
2333         "i8 0",
2334         "double 0.0",
2335     },
2336     {
2337         "i8 -15",
2338         "double 0xF1F1F1F1F1F1F1F1",
2339     },
2340     {
2341         "i8 undef",
2342         "i16* undef",
2343     },
2344     {
2345         "i8 0",
2346         "i16* inttoptr (i64 0 to i16*)",
2347     },
2348     {
2349         "i8 -1",
2350         "i16* inttoptr (i64 -1 to i16*)",
2351     },
2352     {
2353         "i8 -86",
2354         "i16* inttoptr (i64 -6148914691236517206 to i16*)",
2355     },
2356     {
2357         "",
2358         "i16* inttoptr (i48 -1 to i16*)",
2359     },
2360     {
2361         "i8 -1",
2362         "i16* inttoptr (i96 -1 to i16*)",
2363     },
2364     {
2365         "i8 undef",
2366         "[0 x i8] zeroinitializer",
2367     },
2368     {
2369         "i8 undef",
2370         "[0 x i8] undef",
2371     },
2372     {
2373         "i8 undef",
2374         "[5 x [0 x i8]] zeroinitializer",
2375     },
2376     {
2377         "i8 undef",
2378         "[5 x [0 x i8]] undef",
2379     },
2380     {
2381         "i8 0",
2382         "[6 x i8] zeroinitializer",
2383     },
2384     {
2385         "i8 undef",
2386         "[6 x i8] undef",
2387     },
2388     {
2389         "i8 1",
2390         "[5 x i8] [i8 1, i8 1, i8 1, i8 1, i8 1]",
2391     },
2392     {
2393         "",
2394         "[5 x i64] [i64 1, i64 1, i64 1, i64 1, i64 1]",
2395     },
2396     {
2397         "i8 -1",
2398         "[5 x i64] [i64 -1, i64 -1, i64 -1, i64 -1, i64 -1]",
2399     },
2400     {
2401         "",
2402         "[4 x i8] [i8 1, i8 2, i8 1, i8 1]",
2403     },
2404     {
2405         "i8 1",
2406         "[4 x i8] [i8 1, i8 undef, i8 1, i8 1]",
2407     },
2408     {
2409         "i8 0",
2410         "<6 x i8> zeroinitializer",
2411     },
2412     {
2413         "i8 undef",
2414         "<6 x i8> undef",
2415     },
2416     {
2417         "i8 1",
2418         "<5 x i8> <i8 1, i8 1, i8 1, i8 1, i8 1>",
2419     },
2420     {
2421         "",
2422         "<5 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1>",
2423     },
2424     {
2425         "i8 -1",
2426         "<5 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>",
2427     },
2428     {
2429         "",
2430         "<4 x i8> <i8 1, i8 1, i8 2, i8 1>",
2431     },
2432     {
2433         "i8 5",
2434         "<2 x i8> < i8 5, i8 undef >",
2435     },
2436     {
2437         "i8 0",
2438         "[2 x [2 x i16]] zeroinitializer",
2439     },
2440     {
2441         "i8 undef",
2442         "[2 x [2 x i16]] undef",
2443     },
2444     {
2445         "i8 -86",
2446         "[2 x [2 x i16]] [[2 x i16] [i16 -21846, i16 -21846], "
2447         "[2 x i16] [i16 -21846, i16 -21846]]",
2448     },
2449     {
2450         "",
2451         "[2 x [2 x i16]] [[2 x i16] [i16 -21846, i16 -21846], "
2452         "[2 x i16] [i16 -21836, i16 -21846]]",
2453     },
2454     {
2455         "i8 undef",
2456         "{ } zeroinitializer",
2457     },
2458     {
2459         "i8 undef",
2460         "{ } undef",
2461     },
2462     {
2463         "i8 undef",
2464         "{ {}, {} } zeroinitializer",
2465     },
2466     {
2467         "i8 undef",
2468         "{ {}, {} } undef",
2469     },
2470     {
2471         "i8 0",
2472         "{i8, i64, i16*} zeroinitializer",
2473     },
2474     {
2475         "i8 undef",
2476         "{i8, i64, i16*} undef",
2477     },
2478     {
2479         "i8 -86",
2480         "{i8, i64, i16*} {i8 -86, i64 -6148914691236517206, i16* undef}",
2481     },
2482     {
2483         "",
2484         "{i8, i64, i16*} {i8 86, i64 -6148914691236517206, i16* undef}",
2485     },
2486 };
2487 
2488 INSTANTIATE_TEST_SUITE_P(IsBytewiseValueParamTests, IsBytewiseValueTest,
2489                          ::testing::ValuesIn(IsBytewiseValueTests));
2490 
2491 TEST_P(IsBytewiseValueTest, IsBytewiseValue) {
2492   auto M = parseModule(std::string("@test = global ") + GetParam().second);
2493   GlobalVariable *GV = dyn_cast<GlobalVariable>(M->getNamedValue("test"));
2494   Value *Actual = isBytewiseValue(GV->getInitializer(), M->getDataLayout());
2495   std::string Buff;
2496   raw_string_ostream S(Buff);
2497   if (Actual)
2498     S << *Actual;
2499   EXPECT_EQ(GetParam().first, S.str());
2500 }
2501 
2502 TEST_F(ValueTrackingTest, ComputeConstantRange) {
2503   {
2504     // Assumptions:
2505     //  * stride >= 5
2506     //  * stride < 10
2507     //
2508     // stride = [5, 10)
2509     auto M = parseModule(R"(
2510   declare void @llvm.assume(i1)
2511 
2512   define i32 @test(i32 %stride) {
2513     %gt = icmp uge i32 %stride, 5
2514     call void @llvm.assume(i1 %gt)
2515     %lt = icmp ult i32 %stride, 10
2516     call void @llvm.assume(i1 %lt)
2517     %stride.plus.one = add nsw nuw i32 %stride, 1
2518     ret i32 %stride.plus.one
2519   })");
2520     Function *F = M->getFunction("test");
2521 
2522     AssumptionCache AC(*F);
2523     Value *Stride = &*F->arg_begin();
2524     ConstantRange CR1 = computeConstantRange(Stride, false, true, &AC, nullptr);
2525     EXPECT_TRUE(CR1.isFullSet());
2526 
2527     Instruction *I = &findInstructionByName(F, "stride.plus.one");
2528     ConstantRange CR2 = computeConstantRange(Stride, false, true, &AC, I);
2529     EXPECT_EQ(5, CR2.getLower());
2530     EXPECT_EQ(10, CR2.getUpper());
2531   }
2532 
2533   {
2534     // Assumptions:
2535     //  * stride >= 5
2536     //  * stride < 200
2537     //  * stride == 99
2538     //
2539     // stride = [99, 100)
2540     auto M = parseModule(R"(
2541   declare void @llvm.assume(i1)
2542 
2543   define i32 @test(i32 %stride) {
2544     %gt = icmp uge i32 %stride, 5
2545     call void @llvm.assume(i1 %gt)
2546     %lt = icmp ult i32 %stride, 200
2547     call void @llvm.assume(i1 %lt)
2548     %eq = icmp eq i32 %stride, 99
2549     call void @llvm.assume(i1 %eq)
2550     %stride.plus.one = add nsw nuw i32 %stride, 1
2551     ret i32 %stride.plus.one
2552   })");
2553     Function *F = M->getFunction("test");
2554 
2555     AssumptionCache AC(*F);
2556     Value *Stride = &*F->arg_begin();
2557     Instruction *I = &findInstructionByName(F, "stride.plus.one");
2558     ConstantRange CR = computeConstantRange(Stride, false, true, &AC, I);
2559     EXPECT_EQ(99, *CR.getSingleElement());
2560   }
2561 
2562   {
2563     // Assumptions:
2564     //  * stride >= 5
2565     //  * stride >= 50
2566     //  * stride < 100
2567     //  * stride < 200
2568     //
2569     // stride = [50, 100)
2570     auto M = parseModule(R"(
2571   declare void @llvm.assume(i1)
2572 
2573   define i32 @test(i32 %stride, i1 %cond) {
2574     %gt = icmp uge i32 %stride, 5
2575     call void @llvm.assume(i1 %gt)
2576     %gt.2 = icmp uge i32 %stride, 50
2577     call void @llvm.assume(i1 %gt.2)
2578     br i1 %cond, label %bb1, label %bb2
2579 
2580   bb1:
2581     %lt = icmp ult i32 %stride, 200
2582     call void @llvm.assume(i1 %lt)
2583     %lt.2 = icmp ult i32 %stride, 100
2584     call void @llvm.assume(i1 %lt.2)
2585     %stride.plus.one = add nsw nuw i32 %stride, 1
2586     ret i32 %stride.plus.one
2587 
2588   bb2:
2589     ret i32 0
2590   })");
2591     Function *F = M->getFunction("test");
2592 
2593     AssumptionCache AC(*F);
2594     Value *Stride = &*F->arg_begin();
2595     Instruction *GT2 = &findInstructionByName(F, "gt.2");
2596     ConstantRange CR = computeConstantRange(Stride, false, true, &AC, GT2);
2597     EXPECT_EQ(5, CR.getLower());
2598     EXPECT_EQ(0, CR.getUpper());
2599 
2600     Instruction *I = &findInstructionByName(F, "stride.plus.one");
2601     ConstantRange CR2 = computeConstantRange(Stride, false, true, &AC, I);
2602     EXPECT_EQ(50, CR2.getLower());
2603     EXPECT_EQ(100, CR2.getUpper());
2604   }
2605 
2606   {
2607     // Assumptions:
2608     //  * stride > 5
2609     //  * stride < 5
2610     //
2611     // stride = empty range, as the assumptions contradict each other.
2612     auto M = parseModule(R"(
2613   declare void @llvm.assume(i1)
2614 
2615   define i32 @test(i32 %stride, i1 %cond) {
2616     %gt = icmp ugt i32 %stride, 5
2617     call void @llvm.assume(i1 %gt)
2618     %lt = icmp ult i32 %stride, 5
2619     call void @llvm.assume(i1 %lt)
2620     %stride.plus.one = add nsw nuw i32 %stride, 1
2621     ret i32 %stride.plus.one
2622   })");
2623     Function *F = M->getFunction("test");
2624 
2625     AssumptionCache AC(*F);
2626     Value *Stride = &*F->arg_begin();
2627 
2628     Instruction *I = &findInstructionByName(F, "stride.plus.one");
2629     ConstantRange CR = computeConstantRange(Stride, false, true, &AC, I);
2630     EXPECT_TRUE(CR.isEmptySet());
2631   }
2632 
2633   {
2634     // Assumptions:
2635     //  * x.1 >= 5
2636     //  * x.2 < x.1
2637     //
2638     // stride = [0, -1)
2639     auto M = parseModule(R"(
2640   declare void @llvm.assume(i1)
2641 
2642   define i32 @test(i32 %x.1, i32 %x.2) {
2643     %gt = icmp uge i32 %x.1, 5
2644     call void @llvm.assume(i1 %gt)
2645     %lt = icmp ult i32 %x.2, %x.1
2646     call void @llvm.assume(i1 %lt)
2647     %stride.plus.one = add nsw nuw i32 %x.1, 1
2648     ret i32 %stride.plus.one
2649   })");
2650     Function *F = M->getFunction("test");
2651 
2652     AssumptionCache AC(*F);
2653     Value *X1 = &*(F->arg_begin());
2654     Value *X2 = &*std::next(F->arg_begin());
2655 
2656     Instruction *I = &findInstructionByName(F, "stride.plus.one");
2657     ConstantRange CR1 = computeConstantRange(X1, false, true, &AC, I);
2658     ConstantRange CR2 = computeConstantRange(X2, false, true, &AC, I);
2659 
2660     EXPECT_EQ(5, CR1.getLower());
2661     EXPECT_EQ(0, CR1.getUpper());
2662 
2663     EXPECT_EQ(0, CR2.getLower());
2664     EXPECT_EQ(0xffffffff, CR2.getUpper());
2665 
2666     // Check the depth cutoff results in a conservative result (full set) by
2667     // passing Depth == MaxDepth == 6.
2668     ConstantRange CR3 = computeConstantRange(X2, false, true, &AC, I, nullptr, 6);
2669     EXPECT_TRUE(CR3.isFullSet());
2670   }
2671   {
2672     // Assumptions:
2673     //  * x.2 <= x.1
2674     auto M = parseModule(R"(
2675   declare void @llvm.assume(i1)
2676 
2677   define i32 @test(i32 %x.1, i32 %x.2) {
2678     %lt = icmp ule i32 %x.2, %x.1
2679     call void @llvm.assume(i1 %lt)
2680     %stride.plus.one = add nsw nuw i32 %x.1, 1
2681     ret i32 %stride.plus.one
2682   })");
2683     Function *F = M->getFunction("test");
2684 
2685     AssumptionCache AC(*F);
2686     Value *X2 = &*std::next(F->arg_begin());
2687 
2688     Instruction *I = &findInstructionByName(F, "stride.plus.one");
2689     ConstantRange CR1 = computeConstantRange(X2, false, true, &AC, I);
2690     // If we don't know the value of x.2, we don't know the value of x.1.
2691     EXPECT_TRUE(CR1.isFullSet());
2692   }
2693 }
2694 
2695 struct FindAllocaForValueTestParams {
2696   const char *IR;
2697   bool AnyOffsetResult;
2698   bool ZeroOffsetResult;
2699 };
2700 
2701 class FindAllocaForValueTest
2702     : public ValueTrackingTest,
2703       public ::testing::WithParamInterface<FindAllocaForValueTestParams> {
2704 protected:
2705 };
2706 
2707 const FindAllocaForValueTestParams FindAllocaForValueTests[] = {
2708     {R"(
2709       define void @test() {
2710         %a = alloca i64
2711         %r = bitcast ptr %a to ptr
2712         ret void
2713       })",
2714      true, true},
2715 
2716     {R"(
2717       define void @test() {
2718         %a = alloca i32
2719         %r = getelementptr i32, ptr %a, i32 1
2720         ret void
2721       })",
2722      true, false},
2723 
2724     {R"(
2725       define void @test() {
2726         %a = alloca i32
2727         %r = getelementptr i32, ptr %a, i32 0
2728         ret void
2729       })",
2730      true, true},
2731 
2732     {R"(
2733       define void @test(i1 %cond) {
2734       entry:
2735         %a = alloca i32
2736         br label %bb1
2737 
2738       bb1:
2739         %r = phi ptr [ %a, %entry ], [ %r, %bb1 ]
2740         br i1 %cond, label %bb1, label %exit
2741 
2742       exit:
2743         ret void
2744       })",
2745      true, true},
2746 
2747     {R"(
2748       define void @test(i1 %cond) {
2749         %a = alloca i32
2750         %r = select i1 %cond, ptr %a, ptr %a
2751         ret void
2752       })",
2753      true, true},
2754 
2755     {R"(
2756       define void @test(i1 %cond) {
2757         %a = alloca i32
2758         %b = alloca i32
2759         %r = select i1 %cond, ptr %a, ptr %b
2760         ret void
2761       })",
2762      false, false},
2763 
2764     {R"(
2765       define void @test(i1 %cond) {
2766       entry:
2767         %a = alloca i64
2768         %a32 = bitcast ptr %a to ptr
2769         br label %bb1
2770 
2771       bb1:
2772         %x = phi ptr [ %a32, %entry ], [ %x, %bb1 ]
2773         %r = getelementptr i32, ptr %x, i32 1
2774         br i1 %cond, label %bb1, label %exit
2775 
2776       exit:
2777         ret void
2778       })",
2779      true, false},
2780 
2781     {R"(
2782       define void @test(i1 %cond) {
2783       entry:
2784         %a = alloca i64
2785         %a32 = bitcast ptr %a to ptr
2786         br label %bb1
2787 
2788       bb1:
2789         %x = phi ptr [ %a32, %entry ], [ %r, %bb1 ]
2790         %r = getelementptr i32, ptr %x, i32 1
2791         br i1 %cond, label %bb1, label %exit
2792 
2793       exit:
2794         ret void
2795       })",
2796      true, false},
2797 
2798     {R"(
2799       define void @test(i1 %cond, ptr %a) {
2800       entry:
2801         %r = bitcast ptr %a to ptr
2802         ret void
2803       })",
2804      false, false},
2805 
2806     {R"(
2807       define void @test(i1 %cond) {
2808       entry:
2809         %a = alloca i32
2810         %b = alloca i32
2811         br label %bb1
2812 
2813       bb1:
2814         %r = phi ptr [ %a, %entry ], [ %b, %bb1 ]
2815         br i1 %cond, label %bb1, label %exit
2816 
2817       exit:
2818         ret void
2819       })",
2820      false, false},
2821     {R"(
2822       declare ptr @retptr(ptr returned)
2823       define void @test(i1 %cond) {
2824         %a = alloca i32
2825         %r = call ptr @retptr(ptr %a)
2826         ret void
2827       })",
2828      true, true},
2829     {R"(
2830       declare ptr @fun(ptr)
2831       define void @test(i1 %cond) {
2832         %a = alloca i32
2833         %r = call ptr @fun(ptr %a)
2834         ret void
2835       })",
2836      false, false},
2837 };
2838 
2839 TEST_P(FindAllocaForValueTest, findAllocaForValue) {
2840   auto M = parseModule(GetParam().IR);
2841   Function *F = M->getFunction("test");
2842   Instruction *I = &findInstructionByName(F, "r");
2843   const AllocaInst *AI = findAllocaForValue(I);
2844   EXPECT_EQ(!!AI, GetParam().AnyOffsetResult);
2845 }
2846 
2847 TEST_P(FindAllocaForValueTest, findAllocaForValueZeroOffset) {
2848   auto M = parseModule(GetParam().IR);
2849   Function *F = M->getFunction("test");
2850   Instruction *I = &findInstructionByName(F, "r");
2851   const AllocaInst *AI = findAllocaForValue(I, true);
2852   EXPECT_EQ(!!AI, GetParam().ZeroOffsetResult);
2853 }
2854 
2855 INSTANTIATE_TEST_SUITE_P(FindAllocaForValueTest, FindAllocaForValueTest,
2856                          ::testing::ValuesIn(FindAllocaForValueTests));
2857