From 597bfd84483fdb37d019dd7619dc984e841e6456 Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Tue, 3 Apr 2018 05:27:28 +0000
Subject: [PATCH] [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: 329046
---
 .../Transforms/Vectorize/SLPVectorizer.cpp    | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 735dfd4c79d4..f0ff12a668bb 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -1614,13 +1614,13 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         return;
       }
       if (!CurrentOrder.empty()) {
-#ifndef NDEBUG
-        dbgs() << "SLP: Reusing or shuffling of reordered extract sequence "
-                  "with order";
-        for (unsigned Idx : CurrentOrder)
-          dbgs() << " " << Idx;
-        dbgs() << "\n";
-#endif // NDEBUG
+        DEBUG({
+          dbgs() << "SLP: Reusing or shuffling of reordered extract sequence "
+                    "with order";
+          for (unsigned Idx : CurrentOrder)
+            dbgs() << " " << Idx;
+          dbgs() << "\n";
+        });
         // Insert new order with initial value 0, if it does not exist,
         // otherwise return the iterator to the existing one.
         auto StoredCurrentOrderAndNum =
@@ -2519,13 +2519,13 @@ 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(),
@@ -6214,7 +6214,7 @@ 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