Revert "[SCEVExpand] do not hoist divisions by zero (PR30935)"

Reverts r289412. It caused an OOB PHI operand access in instcombine when
ASan is enabled. Reduction in progress.

Also reverts "[SCEVExpander] Add a test case related to r289412"

llvm-svn: 289453

1 files changed, 4 insertions, 108 deletions

diff --git a/llvm/unittests/Analysis/ScalarEvolutionTest.cpp b/llvm/unittests/Analysis/ScalarEvolutionTest.cpp
index 2f509fd7e1b..752cc812824 100644
--- a/llvm/unittests/Analysis/ScalarEvolutionTest.cpp
+++ b/llvm/unittests/Analysis/ScalarEvolutionTest.cpp
@@ -51,21 +51,13 @@ protected:
     return ScalarEvolution(F, TLI, *AC, *DT, *LI);
   }
 
-  void runSCEVTest(Module &M, StringRef FuncName,
-                   function_ref<void(Function &F, DominatorTree &DT,
-                                     LoopInfo &LI, ScalarEvolution &SE)>
-                       Test) {
-    auto *F = M.getFunction(FuncName);
-    ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
-    ScalarEvolution SE = buildSE(*F);
-    Test(*F, *DT, *LI, SE);
-  }
-
   void runWithFunctionAndSE(
       Module &M, StringRef FuncName,
       function_ref<void(Function &F, ScalarEvolution &SE)> Test) {
-    runSCEVTest(M, FuncName, [&](Function &F, DominatorTree &DT, LoopInfo &LI,
-                                 ScalarEvolution &SE) { Test(F, SE); });
+    auto *F = M.getFunction(FuncName);
+    ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
+    ScalarEvolution SE = buildSE(*F);
+    Test(*F, SE);
   }
 };
 
@@ -357,13 +349,6 @@ static Instruction *getInstructionByName(Function &F, StringRef Name) {
   llvm_unreachable("Expected to find instruction!");
 }
 
-static Argument *getArgByName(Function &F, StringRef Name) {
-  for (auto &A : F.args())
-    if (A.getName() == Name)
-      return &A;
-  llvm_unreachable("Expected to find argument!");
-}
-
 TEST_F(ScalarEvolutionsTest, CommutativeExprOperandOrder) {
   LLVMContext C;
   SMDiagnostic Err;
@@ -547,94 +532,5 @@ TEST_F(ScalarEvolutionsTest, SCEVCompareComplexity) {
   EXPECT_NE(nullptr, SE.getSCEV(Acc[0]));
 }
 
-TEST_F(ScalarEvolutionsTest, BadHoistingSCEVExpander_PR30942) {
-  LLVMContext C;
-  SMDiagnostic Err;
-  std::unique_ptr<Module> M = parseAssemblyString(
-      "target datalayout = \"e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128\" "
-      " "
-      "define void @f_1(i32 %x, i32 %y, i32 %n, i1* %cond_buf) "
-      "    local_unnamed_addr { "
-      "entry: "
-      "  %entrycond = icmp sgt i32 %n, 0 "
-      "  br i1 %entrycond, label %loop.ph, label %for.end "
-      " "
-      "loop.ph: "
-      "  br label %loop "
-      " "
-      "loop: "
-      "  %iv1 = phi i32 [ %iv1.inc, %right ], [ 0, %loop.ph ] "
-      "  %iv1.inc = add nuw nsw i32 %iv1, 1 "
-      "  %cond = load volatile i1, i1* %cond_buf  "
-      "  br i1 %cond, label %left, label %right  "
-      "  "
-      "left: "
-      "  %div = udiv i32 %x, %y  "
-      "  br label %right  "
-      "  "
-      "right: "
-      "  %exitcond = icmp eq i32 %iv1.inc, %n "
-      "  br i1 %exitcond, label %for.end.loopexit, label %loop "
-      " "
-      "for.end.loopexit: "
-      "  br label %for.end "
-      " "
-      "for.end: "
-      "  ret void "
-      "} ",
-      Err, C);
-
-  assert(M && "Could not parse module?");
-  assert(!verifyModule(*M) && "Must have been well formed!");
-
-  runSCEVTest(*M, "f_1", [&](Function &F, DominatorTree &DT, LoopInfo &LI,
-                             ScalarEvolution &SE) {
-    SCEVExpander Expander(SE, M->getDataLayout(), "unittests");
-    auto *DivInst = getInstructionByName(F, "div");
-
-    {
-      auto *DivSCEV = SE.getSCEV(DivInst);
-      auto *DivExpansion = Expander.expandCodeFor(
-          DivSCEV, DivSCEV->getType(), DivInst->getParent()->getTerminator());
-      auto *DivExpansionInst = dyn_cast<Instruction>(DivExpansion);
-      ASSERT_NE(DivExpansionInst, nullptr);
-      EXPECT_EQ(DivInst->getParent(), DivExpansionInst->getParent());
-    }
-
-    {
-      auto *ArgY = getArgByName(F, "y");
-      auto *DivFromScratchSCEV =
-          SE.getUDivExpr(SE.getOne(ArgY->getType()), SE.getSCEV(ArgY));
-
-      auto *DivFromScratchExpansion = Expander.expandCodeFor(
-          DivFromScratchSCEV, DivFromScratchSCEV->getType(),
-          DivInst->getParent()->getTerminator());
-      auto *DivFromScratchExpansionInst =
-          dyn_cast<Instruction>(DivFromScratchExpansion);
-      ASSERT_NE(DivFromScratchExpansionInst, nullptr);
-      EXPECT_EQ(DivInst->getParent(), DivFromScratchExpansionInst->getParent());
-    }
-
-    {
-      auto *ArgY = getArgByName(F, "y");
-      auto *One = SE.getOne(ArgY->getType());
-      auto *DivFromScratchSCEV = SE.getUDivExpr(One, SE.getSCEV(ArgY));
-      auto *L = LI.getLoopFor(DivInst->getParent());
-      auto *ARFromScratchSCEV =
-          SE.getAddRecExpr(DivFromScratchSCEV, One, L, SCEV::FlagAnyWrap);
-
-      Expander.disableCanonicalMode();
-
-      auto *ARFromScratchExpansion = Expander.expandCodeFor(
-          ARFromScratchSCEV, ARFromScratchSCEV->getType(),
-          DivInst->getParent()->getTerminator());
-      auto *ARFromScratchExpansionInst =
-          dyn_cast<Instruction>(ARFromScratchExpansion);
-      ASSERT_NE(ARFromScratchExpansionInst, nullptr);
-      ASSERT_FALSE(verifyFunction(F));
-    }
-  });
-}
-
 }  // end anonymous namespace
 }  // end namespace llvm