[PATCH] D112980: [LoopInfo] Fix a bug in the function getInductionVariable

[duanbo via Phabricator via llvm-commits]

duan.db updated this revision to Diff 385494.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D112980/new/

https://reviews.llvm.org/D112980

Files:
  llvm/lib/Analysis/LoopInfo.cpp
  llvm/unittests/Analysis/LoopInfoTest.cpp


Index: llvm/unittests/Analysis/LoopInfoTest.cpp
===================================================================
--- llvm/unittests/Analysis/LoopInfoTest.cpp
+++ llvm/unittests/Analysis/LoopInfoTest.cpp
@@ -1547,3 +1547,39 @@
     EXPECT_EQ(L->getLoopGuardBranch(), nullptr);
   });
 }
+
+TEST(LoopInfoTest, LoopInductionVariable) {
+  const char *ModuleStr =
+      "define i32 @foo(i32* %addr) {\n"
+      "entry:\n"
+      "  br label %for.body\n"
+      "for.body:\n"
+      "  %sum.08 = phi i32 [ 0, %entry ], [ %add, %for.body ]\n"
+      "  %addr.addr.06 = phi i32* [ %addr, %entry ], [ %incdec.ptr, %for.body "
+      "]\n"
+      "  %count.07 = phi i32 [ 6000, %entry ], [ %dec, %for.body ]\n"
+      "  %0 = load i32, i32* %addr.addr.06, align 4\n"
+      "  %add = add nsw i32 %0, %sum.08\n"
+      "  %dec = add nsw i32 %count.07, -1\n"
+      "  %incdec.ptr = getelementptr inbounds i32, i32* %addr.addr.06, i64 1\n"
+      "  %cmp = icmp ugt i32 %count.07, 1\n"
+      "  br i1 %cmp, label %for.body, label %for.end\n"
+      "for.end:\n"
+      "  %cmp1 = icmp eq i32 %add, -1\n"
+      "  %conv = zext i1 %cmp1 to i32\n"
+      "  ret i32 %conv\n"
+      "}\n";
+
+  // Parse the module.
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
+
+  runWithLoopInfoPlus(
+      *M, "foo", [&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
+        Function::iterator FI = F.begin();
+        BasicBlock *Header = &*(++FI);
+        Loop *L = LI.getLoopFor(Header);
+        EXPECT_NE(L, nullptr);
+        EXPECT_EQ(L->getInductionVariable(SE)->getName(), "count.07");
+      });
+}
Index: llvm/lib/Analysis/LoopInfo.cpp
===================================================================
--- llvm/lib/Analysis/LoopInfo.cpp
+++ llvm/lib/Analysis/LoopInfo.cpp
@@ -301,15 +301,16 @@
   if (!CmpInst)
     return nullptr;
 
-  Instruction *LatchCmpOp0 = dyn_cast<Instruction>(CmpInst->getOperand(0));
-  Instruction *LatchCmpOp1 = dyn_cast<Instruction>(CmpInst->getOperand(1));
+  Value *LatchCmpOp0 = CmpInst->getOperand(0);
+  Value *LatchCmpOp1 = CmpInst->getOperand(1);
 
   for (PHINode &IndVar : Header->phis()) {
     InductionDescriptor IndDesc;
     if (!InductionDescriptor::isInductionPHI(&IndVar, this, &SE, IndDesc))
       continue;
 
-    Instruction *StepInst = IndDesc.getInductionBinOp();
+    BasicBlock *Latch = getLoopLatch();
+    Value *StepInst = IndVar.getIncomingValueForBlock(Latch);
 
     // case 1:
     // IndVar = phi[{InitialValue, preheader}, {StepInst, latch}]


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