[ScopBuilder] Split statements on encountering store instructions.

Introduce -polly-stmt-granularity=store option.

Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D37337

llvm-svn: 320360

1 files changed, 10 insertions, 4 deletions

diff --git a/polly/lib/Analysis/ScopBuilder.cpp b/polly/lib/Analysis/ScopBuilder.cpp
index 44aec902c41..3c7f67be0ec 100644
--- a/polly/lib/Analysis/ScopBuilder.cpp
+++ b/polly/lib/Analysis/ScopBuilder.cpp
@@ -103,7 +103,7 @@ static cl::opt<bool> DisableMultiplicativeReductions(
     cl::desc("Disable multiplicative reductions"), cl::Hidden, cl::ZeroOrMore,
     cl::init(false), cl::cat(PollyCategory));
 
-enum class GranularityChoice { BasicBlocks, ScalarIndependence };
+enum class GranularityChoice { BasicBlocks, ScalarIndependence, Stores };
 
 static cl::opt<GranularityChoice> StmtGranularity(
     "polly-stmt-granularity",
@@ -112,7 +112,9 @@ static cl::opt<GranularityChoice> StmtGranularity(
     cl::values(clEnumValN(GranularityChoice::BasicBlocks, "bb",
                           "One statement per basic block"),
                clEnumValN(GranularityChoice::ScalarIndependence, "scalar-indep",
-                          "Scalar independence heuristic")),
+                          "Scalar independence heuristic"),
+               clEnumValN(GranularityChoice::Stores, "store",
+                          "Store-level granularity")),
     cl::init(GranularityChoice::BasicBlocks), cl::cat(PollyCategory));
 
 void ScopBuilder::buildPHIAccesses(ScopStmt *PHIStmt, PHINode *PHI,
@@ -686,7 +688,7 @@ bool ScopBuilder::shouldModelInst(Instruction *Inst, Loop *L) {
          !canSynthesize(Inst, *scop, &SE, L);
 }
 
-void ScopBuilder::buildSequentialBlockStmts(BasicBlock *BB) {
+void ScopBuilder::buildSequentialBlockStmts(BasicBlock *BB, bool SplitOnStore) {
   Loop *SurroundingLoop = LI.getLoopFor(BB);
 
   int Count = 0;
@@ -694,7 +696,8 @@ void ScopBuilder::buildSequentialBlockStmts(BasicBlock *BB) {
   for (Instruction &Inst : *BB) {
     if (shouldModelInst(&Inst, SurroundingLoop))
       Instructions.push_back(&Inst);
-    if (Inst.getMetadata("polly_split_after")) {
+    if (Inst.getMetadata("polly_split_after") ||
+        (SplitOnStore && isa<StoreInst>(Inst))) {
       scop->addScopStmt(BB, SurroundingLoop, Instructions, Count);
       Count++;
       Instructions.clear();
@@ -900,6 +903,9 @@ void ScopBuilder::buildStmts(Region &SR) {
       case GranularityChoice::ScalarIndependence:
         buildEqivClassBlockStmts(BB);
         break;
+      case GranularityChoice::Stores:
+        buildSequentialBlockStmts(BB, true);
+        break;
       }
     }
 }