From 8b0647f26bdcf53833f8e0de2e09fd1471be5349 Mon Sep 17 00:00:00 2001
From: Adam Nemet <anemet@apple.com>
Date: Wed, 18 Feb 2015 03:42:50 +0000
Subject: [PATCH] [LoopAccesses] Stash the report from the analysis rather than
 emitting it

The transformation passes will query this and then emit them as part of
their own report.  The currently only user LV is modified to do just
that.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229623 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Analysis/LoopAccessAnalysis.h | 20 ++++++++++++++------
 lib/Analysis/LoopAccessAnalysis.cpp        |  3 ++-
 lib/Transforms/Vectorize/LoopVectorize.cpp |  8 ++++++--
 3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/include/llvm/Analysis/LoopAccessAnalysis.h b/include/llvm/Analysis/LoopAccessAnalysis.h
index 9af3bf07065..93ee959bfa7 100644
--- a/include/llvm/Analysis/LoopAccessAnalysis.h
+++ b/include/llvm/Analysis/LoopAccessAnalysis.h
@@ -16,6 +16,7 @@
 #define LLVM_ANALYSIS_LOOPACCESSANALYSIS_H
 
 #include "llvm/ADT/EquivalenceClasses.h"
+#include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/AliasSetTracker.h"
@@ -129,11 +130,11 @@ public:
     SmallVector<unsigned, 2> AliasSetId;
   };
 
-  LoopAccessInfo(Function *F, Loop *L, ScalarEvolution *SE,
-                 const DataLayout *DL, const TargetLibraryInfo *TLI,
-                 AliasAnalysis *AA, DominatorTree *DT) :
-      TheFunction(F), TheLoop(L), SE(SE), DL(DL), TLI(TLI), AA(AA), DT(DT),
-      NumLoads(0), NumStores(0), MaxSafeDepDistBytes(-1U) {}
+  LoopAccessInfo(Loop *L, ScalarEvolution *SE, const DataLayout *DL,
+                 const TargetLibraryInfo *TLI, AliasAnalysis *AA,
+                 DominatorTree *DT) :
+      TheLoop(L), SE(SE), DL(DL), TLI(TLI), AA(AA), DT(DT), NumLoads(0),
+      NumStores(0), MaxSafeDepDistBytes(-1U) {}
 
   /// Return true we can analyze the memory accesses in the loop and there are
   /// no memory dependence cycles.  Replaces symbolic strides using Strides.
@@ -159,13 +160,16 @@ public:
   /// second value is the final comparator value or NULL if no check is needed.
   std::pair<Instruction *, Instruction *> addRuntimeCheck(Instruction *Loc);
 
+  /// \brief The diagnostics report generated for the analysis.  E.g. why we
+  /// couldn't analyze the loop.
+  Optional<VectorizationReport> &getReport() { return Report; }
+
 private:
   void emitAnalysis(VectorizationReport &Message);
 
   /// We need to check that all of the pointers in this list are disjoint
   /// at runtime.
   RuntimePointerCheck PtrRtCheck;
-  Function *TheFunction;
   Loop *TheLoop;
   ScalarEvolution *SE;
   const DataLayout *DL;
@@ -177,6 +181,10 @@ private:
   unsigned NumStores;
 
   unsigned MaxSafeDepDistBytes;
+
+  /// \brief The diagnostics report generated for the analysis.  E.g. why we
+  /// couldn't analyze the loop.
+  Optional<VectorizationReport> Report;
 };
 
 Value *stripIntegerCast(Value *V);
diff --git a/lib/Analysis/LoopAccessAnalysis.cpp b/lib/Analysis/LoopAccessAnalysis.cpp
index 9ac27ddb46f..927ae494548 100644
--- a/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/lib/Analysis/LoopAccessAnalysis.cpp
@@ -1077,7 +1077,8 @@ bool LoopAccessInfo::blockNeedsPredication(BasicBlock *BB)  {
 }
 
 void LoopAccessInfo::emitAnalysis(VectorizationReport &Message) {
-  VectorizationReport::emitAnalysis(Message, TheFunction, TheLoop);
+  assert(!Report && "Multiple report generated");
+  Report = Message;
 }
 
 bool LoopAccessInfo::isUniform(Value *V) {
diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp
index 3f6660203c0..abb38d19ea1 100644
--- a/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -556,7 +556,7 @@ public:
       : NumPredStores(0), TheLoop(L), SE(SE), DL(DL),
         TLI(TLI), TheFunction(F), TTI(TTI), Induction(nullptr),
         WidestIndTy(nullptr),
-        LAI(F, L, SE, DL, TLI, AA, DT),
+        LAI(L, SE, DL, TLI, AA, DT),
         HasFunNoNaNAttr(false) {}
 
   /// This enum represents the kinds of reductions that we support.
@@ -3825,7 +3825,11 @@ void LoopVectorizationLegality::collectLoopUniforms() {
 }
 
 bool LoopVectorizationLegality::canVectorizeMemory() {
-  return LAI.canVectorizeMemory(Strides);
+  bool Success = LAI.canVectorizeMemory(Strides);
+  auto &OptionalReport = LAI.getReport();
+  if (OptionalReport)
+    emitAnalysis(*OptionalReport);
+  return Success;
 }
 
 static bool hasMultipleUsesOf(Instruction *I,