Recommit "[SLP] Fix issues with debug output in the SLP vectorizer."

The primary issue here is that using NDEBUG alone isn't enough to guard
debug printing -- instead the DEBUG() macro needs to be used so that the
specific pass debug logging check is employed. Without this, every
asserts-enabled build was printing out information when it hit this.

I also fixed another place where we had multiple statements in a DEBUG
macro to use {}s to be a bit cleaner. And I fixed a place that used
errs() rather than dbgs().

llvm-svn: 329082

1 files changed, 4 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index b9b507d34d1..f6c5827ab93 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -2416,13 +2416,13 @@ int BoUpSLP::getSpillCost() {
         LiveValues.insert(cast<Instruction>(&*J));
     }
 
-    DEBUG(
+    DEBUG({
       dbgs() << "SLP: #LV: " << LiveValues.size();
       for (auto *X : LiveValues)
         dbgs() << " " << X->getName();
       dbgs() << ", Looking at ";
       Inst->dump();
-      );
+    });
 
     // Now find the sequence of instructions between PrevInst and Inst.
     BasicBlock::reverse_iterator InstIt = ++Inst->getIterator().getReverse(),
@@ -6079,7 +6079,8 @@ bool SLPVectorizerPass::vectorizeChainsInBlock(BasicBlock *BB, BoUpSLP &R) {
 
       // Try to vectorize them.
       unsigned NumElts = (SameTypeIt - IncIt);
-      DEBUG(errs() << "SLP: Trying to vectorize starting at PHIs (" << NumElts << ")\n");
+      DEBUG(dbgs() << "SLP: Trying to vectorize starting at PHIs (" << NumElts
+                   << ")\n");
       // The order in which the phi nodes appear in the program does not matter.
       // So allow tryToVectorizeList to reorder them if it is beneficial. This
       // is done when there are exactly two elements since tryToVectorizeList