[FuzzMutate] Correct type cast and add unit test for FCmp

This revision fixes an incorrect type cast from Instruction to ICmpInstr, which should have been to FCmpInstr instead. It turns out that StrategiesTest.cpp was missing a test case for InstModificationIRStrategy and FCmp, which is also now implemented in this revision. After this revision, [[ https://reviews.llvm.org/D148854 | llvm-stress in D148854 ]] no longer crashes randomly.

Reviewed By: Peter

Differential Revision: https://reviews.llvm.org/D148972

diff --git a/llvm/lib/FuzzMutate/IRMutator.cpp b/llvm/lib/FuzzMutate/IRMutator.cpp
index b896e3c..2d6c83e 100644 (file)
--- a/llvm/lib/FuzzMutate/IRMutator.cpp
+++ b/llvm/lib/FuzzMutate/IRMutator.cpp
@@ -243,7 +243,7 @@ void InstModificationIRStrategy::mutate(Instruction &Inst,
     break;
 
   case Instruction::FCmp:
-    CI = cast<ICmpInst>(&Inst);
+    CI = cast<FCmpInst>(&Inst);
     for (unsigned p = CmpInst::FIRST_FCMP_PREDICATE;
          p <= CmpInst::LAST_FCMP_PREDICATE; p++) {
       Modifications.push_back(

diff --git a/llvm/unittests/FuzzMutate/StrategiesTest.cpp b/llvm/unittests/FuzzMutate/StrategiesTest.cpp
index 5b87b9c..1de027c 100644 (file)
--- a/llvm/unittests/FuzzMutate/StrategiesTest.cpp
+++ b/llvm/unittests/FuzzMutate/StrategiesTest.cpp
@@ -245,6 +245,31 @@ TEST(InstModificationIRStrategyTest, ICmp) {
   EXPECT_TRUE(FoundNE);
 }
 
+TEST(InstModificationIRStrategyTest, FCmp) {
+  LLVMContext Ctx;
+  StringRef Source = "\n\
+      define i1 @test(float %x) {\n\
+        %a = fcmp oeq float %x, 10.0\n\
+        ret i1 %a\n\
+      }";
+
+  auto Mutator = createMutator<InstModificationIRStrategy>();
+  ASSERT_TRUE(Mutator);
+
+  auto M = parseAssembly(Source.data(), Ctx);
+  auto &F = *M->begin();
+  CmpInst *CI = cast<CmpInst>(&*F.begin()->begin());
+  ASSERT_TRUE(M && !verifyModule(*M, &errs()));
+  bool FoundONE = false;
+  for (int i = 0; i < 100; ++i) {
+    Mutator->mutateModule(*M, Seed + i, Source.size(), Source.size() + 100);
+    EXPECT_TRUE(!verifyModule(*M, &errs()));
+    FoundONE |= CI->getPredicate() == CmpInst::FCMP_ONE;
+  }
+
+  EXPECT_TRUE(FoundONE);
+}
+
 TEST(InstModificationIRStrategyTest, GEP) {
   LLVMContext Ctx;
   StringRef Source = "\n\