llvm/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/AliasSetTracker.h"
  10 #include "llvm/Analysis/AliasAnalysis.h"
  11 #include "llvm/Analysis/TargetLibraryInfo.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 "llvm/TargetParser/Triple.h"
  18 #include "gtest/gtest.h"
  19
  20 using namespace llvm;
  21
  22 TEST(AliasSetTracker, AliasUnknownInst) {
  23   StringRef Assembly = R"(
  24     @a = common global i32 0, align 4
  25     @b = common global float 0.000000e+00, align 4
  26
  27     ; Function Attrs: nounwind ssp uwtable
  28     define i32 @read_a() #0 {
  29       %1 = load i32, i32* @a, align 4, !tbaa !3
  30       ret i32 %1
  31     }
  32
  33     ; Function Attrs: nounwind ssp uwtable
  34     define void @write_b() #0 {
  35       store float 1.000000e+01, float* @b, align 4, !tbaa !7
  36       ret void
  37     }
  38
  39     ; Function Attrs: nounwind ssp uwtable
  40     define void @test() #0 {
  41       %1 = call i32 @read_a(), !tbaa !3
  42       call void @write_b(), !tbaa !7
  43       ret void
  44     }
  45
  46     !3 = !{!4, !4, i64 0}
  47     !4 = !{!"int", !5, i64 0}
  48     !5 = !{!"omnipotent char", !6, i64 0}
  49     !6 = !{!"Simple C/C++ TBAA"}
  50     !7 = !{!8, !8, i64 0}
  51     !8 = !{!"float", !5, i64 0}
  52   )";
  53
  54   // Parse the IR. The two calls in @test can not access aliasing elements.
  55   LLVMContext Context;
  56   SMDiagnostic Error;
  57   auto M = parseAssemblyString(Assembly, Error, Context);
  58   ASSERT_TRUE(M) << "Bad assembly?";
  59
  60   // Initialize the alias result.
  61   Triple Trip(M->getTargetTriple());
  62   TargetLibraryInfoImpl TLII(Trip);
  63   TargetLibraryInfo TLI(TLII);
  64   AAResults AA(TLI);
  65   TypeBasedAAResult TBAAR;
  66   AA.addAAResult(TBAAR);
  67
  68   // Initialize the alias set tracker for the @test function.
  69   Function *Test = M->getFunction("test");
  70   ASSERT_NE(Test, nullptr);
  71   BatchAAResults BAA(AA);
  72   AliasSetTracker AST(BAA);
  73   for (auto &BB : *Test)
  74     AST.add(BB);
  75   // There should be 2 disjoint alias sets. 1 from each call.
  76   ASSERT_EQ((int)AST.getAliasSets().size(), 2);
  77
  78   // Directly test aliasesUnknownInst.
  79   // Now every call instruction should only alias one alias set.
  80   BatchAAResults BatchAA(AA);
  81   for (auto &Inst : *Test->begin()) {
  82     bool FoundAS = false;
  83     for (AliasSet &AS : AST) {
  84       if (!Inst.mayReadOrWriteMemory())
  85         continue;
  86       if (!isModOrRefSet(AS.aliasesUnknownInst(&Inst, BatchAA)))
  87         continue;
  88       ASSERT_NE(FoundAS, true);
  89       FoundAS = true;
  90     }
  91   }
  92 }