Make constant arrays that are passed to functions as const.

[oota-llvm.git] / lib / Target / PowerPC / PPCLoopPreIncPrep.cpp

diff --git a/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp b/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
index 76dbebc47bce8bb471851b6e94ec0a1a2e774c00..388effd2f8be792f7e9d8165a0c0ecad800fca7f 100644 (file)
--- a/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
+++ b/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
@@ -22,10 +22,9 @@
 #define DEBUG_TYPE "ppc-loop-preinc-prep"
 #include "PPC.h"
 #include "PPCTargetMachine.h"
-#include "llvm/Transforms/Scalar.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/Analysis/CodeMetrics.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/LoopInfo.h"
@@ -37,10 +36,13 @@
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/LoopUtils.h"
 #include "llvm/Transforms/Utils/ValueMapper.h"
 using namespace llvm;
 
@@ -83,7 +85,6 @@ namespace {
     PPCTargetMachine *TM;
     LoopInfo *LI;
     ScalarEvolution *SE;
-    const DataLayout *DL;
   };
 }
 
@@ -140,9 +141,6 @@ bool PPCLoopPreIncPrep::runOnFunction(Function &F) {
   LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
   SE = &getAnalysis<ScalarEvolution>();
 
-  DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
-  DL = DLP ? &DLP->getDataLayout() : 0;
-
   bool MadeChange = false;
 
   for (LoopInfo::iterator I = LI->begin(), E = LI->end();
@@ -157,17 +155,11 @@ bool PPCLoopPreIncPrep::runOnFunction(Function &F) {
 bool PPCLoopPreIncPrep::runOnLoop(Loop *L) {
   bool MadeChange = false;
 
-  if (!DL)
-    return MadeChange;
-
   // Only prep. the inner-most loop
   if (!L->empty())
     return MadeChange;
 
   BasicBlock *Header = L->getHeader();
-  BasicBlock *LoopPredecessor = L->getLoopPredecessor();
-  if (!LoopPredecessor)
-    return MadeChange;
 
   const PPCSubtarget *ST =
     TM ? TM->getSubtargetImpl(*Header->getParent()) : nullptr;
@@ -236,7 +228,17 @@ bool PPCLoopPreIncPrep::runOnLoop(Loop *L) {
     }
   }
 
-  if (Buckets.size() > MaxVars)
+  if (Buckets.empty() || Buckets.size() > MaxVars)
+    return MadeChange;
+
+  BasicBlock *LoopPredecessor = L->getLoopPredecessor();
+  // If there is no loop predecessor, or the loop predecessor's terminator
+  // returns a value (which might contribute to determining the loop's
+  // iteration space), insert a new preheader for the loop.
+  if (!LoopPredecessor ||
+      !LoopPredecessor->getTerminator()->getType()->isVoidTy())
+    LoopPredecessor = InsertPreheaderForLoop(L, this);
+  if (!LoopPredecessor)
     return MadeChange;
 
   SmallSet<BasicBlock *, 16> BBChanged;