[SLP] fix verification check for valid IR

This is a fix for PR45965 - https://bugs.llvm.org/show_bug.cgi?id=45965 -
which was left out of D80106 because of a test failure.

SLP does its own mini-CSE after potentially creating redundant instructions,
so we need to wait for that to complete before running the verifier.
Otherwise, we will see a test failure for
test/Transforms/SLPVectorizer/X86/crash_vectorizeTree.ll (not changed here)
because a phi temporarily has identical but different incoming values for
the same incoming block.

A related, but independent, test that would have been altered here was
fixed with:
rG880df55

The test was escaping verification in SLP without this change because we
were not running verifyFunction() unless SLP actually changed the IR.

Differential Revision: https://reviews.llvm.org/D80401

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 26d9705..5627fa4 100644 (file)
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -2365,6 +2365,7 @@ BoUpSLP::~BoUpSLP() {
            "trying to erase instruction with users.");
     Pair.getFirst()->eraseFromParent();
   }
+  assert(!verifyFunction(*F, &dbgs()));
 }
 
 void BoUpSLP::eraseInstructions(ArrayRef<Value *> AV) {
@@ -5743,7 +5744,6 @@ bool SLPVectorizerPass::runImpl(Function &F, ScalarEvolution *SE_,
   if (Changed) {
     R.optimizeGatherSequence();
     LLVM_DEBUG(dbgs() << "SLP: vectorized \"" << F.getName() << "\"\n");
-    LLVM_DEBUG(verifyFunction(F));
   }
   return Changed;
 }