xref: /llvm-project/llvm/unittests/Analysis/AliasSetTrackerTest.cpp (revision 2946cd701067404b99c39fb29dc9c74bd7193eb3)
1 //=======- AliasSetTrackerTest.cpp - Unit test for the Alias Set Tracker  -===//
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/AliasAnalysis.h"
10 #include "llvm/Analysis/AliasSetTracker.h"
11 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
12 #include "llvm/AsmParser/Parser.h"
13 #include "llvm/IR/LLVMContext.h"
14 #include "llvm/IR/Module.h"
15 #include "llvm/Support/SourceMgr.h"
16 #include "gtest/gtest.h"
17 
18 using namespace llvm;
19 
20 TEST(AliasSetTracker, AliasUnknownInst) {
21   StringRef Assembly = R"(
22     @a = common global i32 0, align 4
23     @b = common global float 0.000000e+00, align 4
24 
25     ; Function Attrs: nounwind ssp uwtable
26     define i32 @read_a() #0 {
27       %1 = load i32, i32* @a, align 4, !tbaa !3
28       ret i32 %1
29     }
30 
31     ; Function Attrs: nounwind ssp uwtable
32     define void @write_b() #0 {
33       store float 1.000000e+01, float* @b, align 4, !tbaa !7
34       ret void
35     }
36 
37     ; Function Attrs: nounwind ssp uwtable
38     define void @test() #0 {
39       %1 = call i32 @read_a(), !tbaa !3
40       call void @write_b(), !tbaa !7
41       ret void
42     }
43 
44     !3 = !{!4, !4, i64 0}
45     !4 = !{!"int", !5, i64 0}
46     !5 = !{!"omnipotent char", !6, i64 0}
47     !6 = !{!"Simple C/C++ TBAA"}
48     !7 = !{!8, !8, i64 0}
49     !8 = !{!"float", !5, i64 0}
50   )";
51 
52   // Parse the IR. The two calls in @test can not access aliasing elements.
53   LLVMContext Context;
54   SMDiagnostic Error;
55   auto M = parseAssemblyString(Assembly, Error, Context);
56   ASSERT_TRUE(M) << "Bad assembly?";
57 
58   // Initialize the alias result.
59   Triple Trip(M->getTargetTriple());
60   TargetLibraryInfoImpl TLII(Trip);
61   TargetLibraryInfo TLI(TLII);
62   AAResults AA(TLI);
63   TypeBasedAAResult TBAAR;
64   AA.addAAResult(TBAAR);
65 
66   // Initialize the alias set tracker for the @test function.
67   Function *Test = M->getFunction("test");
68   ASSERT_NE(Test, nullptr);
69   AliasSetTracker AST(AA);
70   for (auto &BB : *Test)
71     AST.add(BB);
72   // There should be 2 disjoint alias sets. 1 from each call.
73   ASSERT_EQ((int)AST.getAliasSets().size(), 2);
74 
75   // Directly test aliasesUnknownInst.
76   // Now every call instruction should only alias one alias set.
77   for (auto &Inst : *Test->begin()) {
78     bool FoundAS = false;
79     for (AliasSet &AS : AST) {
80       if (!Inst.mayReadOrWriteMemory())
81         continue;
82       if (!AS.aliasesUnknownInst(&Inst, AA))
83         continue;
84       ASSERT_NE(FoundAS, true);
85       FoundAS = true;
86     }
87   }
88 }
89