Prepare for making SwitchInstProfUpdateWrapper strict

[yrouban]

Summary

This patch allows us to make the patch D64061 a one-liner that is need to revert it easily if any failure will arise.
Basically this patch removes the test part that relates to non-strict behavior and changes the assertion to llvm_unreachable() to allow the check in release builds.

[davidxl]

lgtm

[yrouban]

Closed by commit rL365439: Prepare for making SwitchInstProfUpdateWrapper strict (authored by yrouban).
yrouban committed rG592f44a7e75b: Prepare for making SwitchInstProfUpdateWrapper strict (authored by yrouban).
llvm-svn: 365439

llvm/lib/IR/Instructions.cpp

void SwitchInstProfUpdateWrapper::init() {
   if (!ProfileData) {
     State = Initialized;
     return;
   }
 
   if (ProfileData->getNumOperands() != SI.getNumSuccessors() + 1) {
     State = Invalid;
     if (SwitchInstProfUpdateWrapperStrict)
-      assert(false &&
-             "number of prof branch_weights metadata operands corresponds to"
-             " number of succesors");
+      llvm_unreachable("number of prof branch_weights metadata operands does "
+                       "not correspond to number of succesors");
     return;
   }
 
   SmallVector<uint32_t, 8> Weights;
   for (unsigned CI = 1, CE = SI.getNumSuccessors(); CI <= CE; ++CI) {
     ConstantInt *C = mdconst::extract<ConstantInt>(ProfileData->getOperand(CI));
     uint32_t CW = C->getValue().getZExtValue();
     Weights.push_back(CW);

llvm/unittests/IR/InstructionsTest.cpp

TEST(InstructionsTest, SwitchInstProfUpdateWrapper) {
   }
 
   { // Create another wrapper and check that the data persist.
     SwitchInstProfUpdateWrapper SIW(*SI);
     EXPECT_EQ(*SIW.getSuccessorWeight(0), 99u);
     EXPECT_EQ(*SIW.getSuccessorWeight(1), 11u);
     EXPECT_EQ(*SIW.getSuccessorWeight(2), 22u);
   }
-
-  // Make prof data invalid by adding one extra weight.
-  SI->setMetadata(LLVMContext::MD_prof, MDBuilder(C).createBranchWeights(
-                                            { 99, 11, 22, 33 })); // extra
-  { // Invalid prof data makes wrapper act as if there were no prof data.
-    SwitchInstProfUpdateWrapper SIW(*SI);
-    ASSERT_FALSE(SIW.getSuccessorWeight(0).hasValue());
-    ASSERT_FALSE(SIW.getSuccessorWeight(1).hasValue());
-    ASSERT_FALSE(SIW.getSuccessorWeight(2).hasValue());
-    SIW.addCase(ConstantInt::get(Int32Ty, 3), BB3.get(), 39);
-    ASSERT_FALSE(SIW.getSuccessorWeight(3).hasValue()); // did not add weight 39
-  }
-
-  { // With added 3rd case the prof data become consistent with num of cases.
-    SwitchInstProfUpdateWrapper SIW(*SI);
-    EXPECT_EQ(*SIW.getSuccessorWeight(0), 99u);
-    EXPECT_EQ(*SIW.getSuccessorWeight(1), 11u);
-    EXPECT_EQ(*SIW.getSuccessorWeight(2), 22u);
-    EXPECT_EQ(*SIW.getSuccessorWeight(3), 33u);
-  }
-
-  // Make prof data invalid by removing one extra weight.
-  SI->setMetadata(LLVMContext::MD_prof,
-                  MDBuilder(C).createBranchWeights({ 99, 11, 22 })); // shorter
-  { // Invalid prof data makes wrapper act as if there were no prof data.
-    SwitchInstProfUpdateWrapper SIW(*SI);
-    ASSERT_FALSE(SIW.getSuccessorWeight(0).hasValue());
-    ASSERT_FALSE(SIW.getSuccessorWeight(1).hasValue());
-    ASSERT_FALSE(SIW.getSuccessorWeight(2).hasValue());
-    SIW.removeCase(SwitchInst::CaseIt(SI, 2));
-  }
-
-  { // With removed 3rd case the prof data become consistent with num of cases.
-    SwitchInstProfUpdateWrapper SIW(*SI);
-    EXPECT_EQ(*SIW.getSuccessorWeight(0), 99u);
-    EXPECT_EQ(*SIW.getSuccessorWeight(1), 11u);
-    EXPECT_EQ(*SIW.getSuccessorWeight(2), 22u);
-  }
 }
 
 TEST(InstructionsTest, CommuteShuffleMask) {
   SmallVector<int, 16> Indices({-1, 0, 7});
   ShuffleVectorInst::commuteShuffleMask(Indices, 4);
   EXPECT_THAT(Indices, testing::ContainerEq(ArrayRef<int>({-1, 4, 3})));
 }