Introduce origin/kind for exit PHI node accesses

Previously, accesses that originate from PHI nodes in the exit block
were registered as SCALAR. In some context they are treated as scalars,
but it makes a difference in others. We used to check whether the
AccessInstruction is a terminator to differentiate the cases.

This patch introduces an MemoryAccess origin EXIT_PHI and a
ScopArrayInfo kind KIND_EXIT_PHI to make this case more explicit. No
behavioural change intended.

Differential Revision: http://reviews.llvm.org/D14688

llvm-svn: 254149

2 files changed, 5 insertions, 3 deletions

diff --git a/polly/lib/Analysis/ScopInfo.cpp b/polly/lib/Analysis/ScopInfo.cpp
index 33c5cdf165a..5f902029305 100644
--- a/polly/lib/Analysis/ScopInfo.cpp
+++ b/polly/lib/Analysis/ScopInfo.cpp
@@ -883,6 +883,8 @@ void ScopStmt::buildAccessRelations() {
     ScopArrayInfo::ARRAYKIND Ty;
     if (Access->isPHI())
       Ty = ScopArrayInfo::KIND_PHI;
+    else if (Access->isExitPHI())
+      Ty = ScopArrayInfo::KIND_EXIT_PHI;
     else if (Access->isImplicit())
       Ty = ScopArrayInfo::KIND_SCALAR;
     else
@@ -3932,7 +3934,7 @@ void ScopInfo::addPHIWriteAccess(PHINode *PHI, BasicBlock *IncomingBlock,
   addMemoryAccess(IncomingBlock, IncomingBlock->getTerminator(),
                   MemoryAccess::MUST_WRITE, PHI, 1, true, IncomingValue,
                   ArrayRef<const SCEV *>(), ArrayRef<const SCEV *>(),
-                  IsExitBlock ? MemoryAccess::SCALAR : MemoryAccess::PHI);
+                  IsExitBlock ? MemoryAccess::EXIT_PHI : MemoryAccess::PHI);
 }
 void ScopInfo::addPHIReadAccess(PHINode *PHI) {
   addMemoryAccess(PHI->getParent(), PHI, MemoryAccess::READ, PHI, 1, true, PHI,
diff --git a/polly/lib/CodeGen/BlockGenerators.cpp b/polly/lib/CodeGen/BlockGenerators.cpp
index 962cc380244..67d2e2260c9 100644
--- a/polly/lib/CodeGen/BlockGenerators.cpp
+++ b/polly/lib/CodeGen/BlockGenerators.cpp
@@ -1201,7 +1201,7 @@ void RegionGenerator::generateScalarStores(ScopStmt &Stmt, LoopToScevMapT &LTS,
     ValueMapT *LocalBBMap = &BBMap;
 
     // Implicit writes induced by PHIs must be written in the incoming blocks.
-    if (isa<TerminatorInst>(ScalarInst)) {
+    if (MA->isPHI() || MA->isExitPHI()) {
       BasicBlock *ExitingBB = ScalarInst->getParent();
       BasicBlock *ExitingBBCopy = BlockMap[ExitingBB];
       Builder.SetInsertPoint(ExitingBBCopy->getTerminator());
@@ -1217,7 +1217,7 @@ void RegionGenerator::generateScalarStores(ScopStmt &Stmt, LoopToScevMapT &LTS,
     Builder.CreateStore(Val, Address);
 
     // Restore the insertion point if necessary.
-    if (isa<TerminatorInst>(ScalarInst))
+    if (MA->isPHI() || MA->isExitPHI())
       Builder.SetInsertPoint(SavedInsertBB, SavedInsertionPoint);
   }
 }