From 12192f19ebb1ab1149720f3b1acf39510435ae01 Mon Sep 17 00:00:00 2001
From: Nadav Rotem <nrotem@apple.com>
Date: Sun, 25 Nov 2012 16:27:16 +0000
Subject: [PATCH] Refactor the ptr runtime check generation code. No
 functionality change.

llvm-svn: 168568
---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 116 ++++++++++++++----------
 1 file changed, 66 insertions(+), 50 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 8ed4caf..2ca5fea 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -128,6 +128,10 @@ public:
  }
 
 private:
+  /// Add code that checks at runtime if the accessed arrays overlap.
+  /// Returns the comperator value or NULL if no check is needed.
+  Value*  addRuntimeCheck(LoopVectorizationLegality *Legal,
+                          Instruction *Loc);
   /// Create an empty loop, based on the loop ranges of the old loop.
   void createEmptyLoop(LoopVectorizationLegality *Legal);
   /// Copy and widen the instructions from the old loop.
@@ -671,6 +675,67 @@ void SingleBlockLoopVectorizer::scalarizeInstruction(Instruction *Instr) {
     WidenMap[Instr] = VecResults;
 }
 
+Value*
+SingleBlockLoopVectorizer::addRuntimeCheck(LoopVectorizationLegality *Legal,
+                                           Instruction *Loc) {
+  LoopVectorizationLegality::RuntimePointerCheck *PtrRtCheck =
+    Legal->getRuntimePointerCheck();
+
+  if (!PtrRtCheck->Need)
+    return NULL;
+
+  Value *MemoryRuntimeCheck = 0;
+  unsigned NumPointers = PtrRtCheck->Pointers.size();
+  SmallVector<Value* , 2> Starts;
+  SmallVector<Value* , 2> Ends;
+
+  SCEVExpander Exp(*SE, "induction");
+
+  // Use this type for pointer arithmetic.
+  Type* PtrArithTy = PtrRtCheck->Pointers[0]->getType();
+
+  for (unsigned i=0; i < NumPointers; ++i) {
+    Value *Ptr = PtrRtCheck->Pointers[i];
+    const SCEV *Sc = SE->getSCEV(Ptr);
+
+    if (SE->isLoopInvariant(Sc, OrigLoop)) {
+      DEBUG(dbgs() << "LV1: Adding RT check for a loop invariant ptr:" <<
+            *Ptr <<"\n");
+      Starts.push_back(Ptr);
+      Ends.push_back(Ptr);
+    } else {
+      DEBUG(dbgs() << "LV: Adding RT check for range:" << *Ptr <<"\n");
+
+      Value *Start = Exp.expandCodeFor(PtrRtCheck->Starts[i],
+                                       PtrArithTy, Loc);
+      Value *End = Exp.expandCodeFor(PtrRtCheck->Ends[i], PtrArithTy, Loc);
+      Starts.push_back(Start);
+      Ends.push_back(End);
+    }
+  }
+
+  for (unsigned i = 0; i < NumPointers; ++i) {
+    for (unsigned j = i+1; j < NumPointers; ++j) {
+      Value *Cmp0 = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULE,
+                                    Starts[i], Ends[j], "bound0", Loc);
+      Value *Cmp1 = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULE,
+                                    Starts[j], Ends[i], "bound1", Loc);
+      Value *IsConflict = BinaryOperator::Create(Instruction::And, Cmp0, Cmp1,
+                                                 "found.conflict", Loc);
+      if (MemoryRuntimeCheck) {
+        MemoryRuntimeCheck = BinaryOperator::Create(Instruction::Or,
+                                                    MemoryRuntimeCheck,
+                                                    IsConflict,
+                                                    "conflict.rdx", Loc);
+      } else {
+        MemoryRuntimeCheck = IsConflict;
+      }
+    }
+  }
+
+  return MemoryRuntimeCheck;
+}
+
 void
 SingleBlockLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) {
   /*
@@ -791,56 +856,7 @@ SingleBlockLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) {
                                StartIdx,
                                "cmp.zero", Loc);
 
-  LoopVectorizationLegality::RuntimePointerCheck *PtrRtCheck =
-    Legal->getRuntimePointerCheck();
-  Value *MemoryRuntimeCheck = 0;
-  if (PtrRtCheck->Need) {
-    unsigned NumPointers = PtrRtCheck->Pointers.size();
-    SmallVector<Value* , 2> Starts;
-    SmallVector<Value* , 2> Ends;
-
-    // Use this type for pointer arithmetic.
-    Type* PtrArithTy = PtrRtCheck->Pointers[0]->getType();
-
-    for (unsigned i=0; i < NumPointers; ++i) {
-      Value *Ptr = PtrRtCheck->Pointers[i];
-      const SCEV *Sc = SE->getSCEV(Ptr);
-
-      if (SE->isLoopInvariant(Sc, OrigLoop)) {
-        DEBUG(dbgs() << "LV1: Adding RT check for a loop invariant ptr:" <<
-              *Ptr <<"\n");
-        Starts.push_back(Ptr);
-        Ends.push_back(Ptr);
-      } else {
-        DEBUG(dbgs() << "LV: Adding RT check for range:" << *Ptr <<"\n");
-
-        Value *Start = Exp.expandCodeFor(PtrRtCheck->Starts[i],
-                                         PtrArithTy, Loc);
-        Value *End = Exp.expandCodeFor(PtrRtCheck->Ends[i], PtrArithTy, Loc);
-        Starts.push_back(Start);
-        Ends.push_back(End);
-      }
-    }
-
-    for (unsigned i = 0; i < NumPointers; ++i) {
-      for (unsigned j = i+1; j < NumPointers; ++j) {
-        Value *Cmp0 = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULE,
-                                      Starts[i], Ends[j], "bound0", Loc);
-        Value *Cmp1 = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULE,
-                                      Starts[j], Ends[i], "bound1", Loc);
-        Value *IsConflict = BinaryOperator::Create(Instruction::And, Cmp0, Cmp1,
-                                                    "found.conflict", Loc);
-        if (MemoryRuntimeCheck) {
-          MemoryRuntimeCheck = BinaryOperator::Create(Instruction::Or,
-                                                      MemoryRuntimeCheck,
-                                                      IsConflict,
-                                                      "conflict.rdx", Loc);
-        } else {
-          MemoryRuntimeCheck = IsConflict;
-        }
-      }
-    }
-  }// end of need-runtime-check code.
+  Value *MemoryRuntimeCheck = addRuntimeCheck(Legal, Loc);  
 
   // If we are using memory runtime checks, include them in.
   if (MemoryRuntimeCheck) {
-- 
2.7.4