[llvm] r280405 - [LV] Use ScalarParts for ad-hoc pointer IV scalarization (NFCI)

[Matthew Simpson via llvm-commits]

Author: mssimpso
Date: Thu Sep  1 14:40:19 2016
New Revision: 280405

URL: http://llvm.org/viewvc/llvm-project?rev=280405&view=rev
Log:
[LV] Use ScalarParts for ad-hoc pointer IV scalarization (NFCI)

We can now maintain scalar values in VectorLoopValueMap. Thus, we no longer
have to create temporary vectors with insertelement instructions when handling
pointer induction variables. This case was mistakenly missed from r279649 when
refactoring the other scalarization code.

Modified:
    llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp

Modified: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp?rev=280405&r1=280404&r2=280405&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp Thu Sep  1 14:40:19 2016
@@ -4453,33 +4453,20 @@ void InnerLoopVectorizer::widenPHIInstru
     // This is the normalized GEP that starts counting at zero.
     Value *PtrInd = Induction;
     PtrInd = Builder.CreateSExtOrTrunc(PtrInd, II.getStep()->getType());
-    // This is the vector of results. Notice that we don't generate
-    // vector geps because scalar geps result in better code.
-    VectorParts Entry(UF);
-    for (unsigned part = 0; part < UF; ++part) {
-      if (VF == 1) {
-        int EltIndex = part;
-        Constant *Idx = ConstantInt::get(PtrInd->getType(), EltIndex);
+    // These are the scalar results. Notice that we don't generate vector GEPs
+    // because scalar GEPs result in better code.
+    ScalarParts Entry(UF);
+    for (unsigned Part = 0; Part < UF; ++Part) {
+      Entry[Part].resize(VF);
+      for (unsigned Lane = 0; Lane < VF; ++Lane) {
+        Constant *Idx = ConstantInt::get(PtrInd->getType(), Lane + Part * VF);
         Value *GlobalIdx = Builder.CreateAdd(PtrInd, Idx);
         Value *SclrGep = II.transform(Builder, GlobalIdx, PSE.getSE(), DL);
         SclrGep->setName("next.gep");
-        Entry[part] = SclrGep;
-        continue;
+        Entry[Part][Lane] = SclrGep;
       }
-
-      Value *VecVal = UndefValue::get(VectorType::get(P->getType(), VF));
-      for (unsigned int i = 0; i < VF; ++i) {
-        int EltIndex = i + part * VF;
-        Constant *Idx = ConstantInt::get(PtrInd->getType(), EltIndex);
-        Value *GlobalIdx = Builder.CreateAdd(PtrInd, Idx);
-        Value *SclrGep = II.transform(Builder, GlobalIdx, PSE.getSE(), DL);
-        SclrGep->setName("next.gep");
-        VecVal = Builder.CreateInsertElement(VecVal, SclrGep,
-                                             Builder.getInt32(i), "insert.gep");
-      }
-      Entry[part] = VecVal;
     }
-    VectorLoopValueMap.initVector(P, Entry);
+    VectorLoopValueMap.initScalar(P, Entry);
     return;
   }
   case InductionDescriptor::IK_FpInduction: {