unittests/Analysis/AliasSetTrackerTest.cpp

   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 }