unittests/Analysis/AliasSetTrackerTest.cpp

   1 //=======- AliasSetTrackerTest.cpp - Unit test for the Alias Set Tracker  -===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/Analysis/AliasAnalysis.h"
  11 #include "llvm/Analysis/AliasSetTracker.h"
  12 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
  13 #include "llvm/AsmParser/Parser.h"
  14 #include "llvm/IR/LLVMContext.h"
  15 #include "llvm/IR/Module.h"
  16 #include "llvm/Support/SourceMgr.h"
  17 #include "gtest/gtest.h"
  18
  19 using namespace llvm;
  20
  21 TEST(AliasSetTracker, AliasUnknownInst) {
  22   StringRef Assembly = R"(
  23     @a = common global i32 0, align 4
  24     @b = common global float 0.000000e+00, align 4
  25
  26     ; Function Attrs: nounwind ssp uwtable
  27     define i32 @read_a() #0 {
  28       %1 = load i32, i32* @a, align 4, !tbaa !3
  29       ret i32 %1
  30     }
  31
  32     ; Function Attrs: nounwind ssp uwtable
  33     define void @write_b() #0 {
  34       store float 1.000000e+01, float* @b, align 4, !tbaa !7
  35       ret void
  36     }
  37
  38     ; Function Attrs: nounwind ssp uwtable
  39     define void @test() #0 {
  40       %1 = call i32 @read_a(), !tbaa !3
  41       call void @write_b(), !tbaa !7
  42       ret void
  43     }
  44
  45     !3 = !{!4, !4, i64 0}
  46     !4 = !{!"int", !5, i64 0}
  47     !5 = !{!"omnipotent char", !6, i64 0}
  48     !6 = !{!"Simple C/C++ TBAA"}
  49     !7 = !{!8, !8, i64 0}
  50     !8 = !{!"float", !5, i64 0}
  51   )";
  52
  53   // Parse the IR. The two calls in @test can not access aliasing elements.
  54   LLVMContext Context;
  55   SMDiagnostic Error;
  56   auto M = parseAssemblyString(Assembly, Error, Context);
  57   ASSERT_TRUE(M) << "Bad assembly?";
  58
  59   // Initialize the alias result.
  60   Triple Trip(M->getTargetTriple());
  61   TargetLibraryInfoImpl TLII(Trip);
  62   TargetLibraryInfo TLI(TLII);
  63   AAResults AA(TLI);
  64   TypeBasedAAResult TBAAR;
  65   AA.addAAResult(TBAAR);
  66
  67   // Initialize the alias set tracker for the @test function.
  68   Function *Test = M->getFunction("test");
  69   ASSERT_NE(Test, nullptr);
  70   AliasSetTracker AST(AA);
  71   for (auto &BB : *Test)
  72     AST.add(BB);
  73   // There should be 2 disjoint alias sets. 1 from each call.
  74   ASSERT_EQ((int)AST.getAliasSets().size(), 2);
  75
  76   // Directly test aliasesUnknownInst.
  77   // Now every call instruction should only alias one alias set.
  78   for (auto &Inst : *Test->begin()) {
  79     bool FoundAS = false;
  80     for (AliasSet &AS : AST) {
  81       if (!AS.aliasesUnknownInst(&Inst, AA))
  82         continue;
  83       ASSERT_NE(FoundAS, true);
  84       FoundAS = true;
  85     }
  86   }
  87 }