Added SCEV::NoWrapFlags to manage unsigned, signed, and self wrap

[oota-llvm.git] / lib / Transforms / Scalar / LoopStrengthReduce.cpp

diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index ac4aea2e404eed5adb5b8c4f55f454c473575f4c..1bc6f5259d2dc15351d0dffc543ad2ce1224fc1a 100644 (file)
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -253,7 +253,8 @@ static void DoInitialMatch(const SCEV *S, Loop *L,
       DoInitialMatch(AR->getStart(), L, Good, Bad, SE);
       DoInitialMatch(SE.getAddRecExpr(SE.getConstant(AR->getType(), 0),
                                       AR->getStepRecurrence(SE),
-                                      AR->getLoop()),
+                                      // FIXME: AR->getNoWrapFlags()
+                                      AR->getLoop(), SCEV::FlagAnyWrap),
                      L, Good, Bad, SE);
       return;
     }
@@ -455,7 +456,10 @@ static const SCEV *getExactSDiv(const SCEV *LHS, const SCEV *RHS,
       const SCEV *Start = getExactSDiv(AR->getStart(), RHS, SE,
                                        IgnoreSignificantBits);
       if (!Start) return 0;
-      return SE.getAddRecExpr(Start, Step, AR->getLoop());
+      // FlagNW is independent of the start value, step direction, and is
+      // preserved with smaller magnitude steps.
+      // FIXME: AR->getNoWrapFlags(SCEV::FlagNW)
+      return SE.getAddRecExpr(Start, Step, AR->getLoop(), SCEV::FlagAnyWrap);
     }
     return 0;
   }
@@ -520,7 +524,9 @@ static int64_t ExtractImmediate(const SCEV *&S, ScalarEvolution &SE) {
     SmallVector<const SCEV *, 8> NewOps(AR->op_begin(), AR->op_end());
     int64_t Result = ExtractImmediate(NewOps.front(), SE);
     if (Result != 0)
-      S = SE.getAddRecExpr(NewOps, AR->getLoop());
+      S = SE.getAddRecExpr(NewOps, AR->getLoop(),
+                           // FIXME: AR->getNoWrapFlags(SCEV::FlagNW)
+                           SCEV::FlagAnyWrap);
     return Result;
   }
   return 0;
@@ -545,7 +551,9 @@ static GlobalValue *ExtractSymbol(const SCEV *&S, ScalarEvolution &SE) {
     SmallVector<const SCEV *, 8> NewOps(AR->op_begin(), AR->op_end());
     GlobalValue *Result = ExtractSymbol(NewOps.front(), SE);
     if (Result)
-      S = SE.getAddRecExpr(NewOps, AR->getLoop());
+      S = SE.getAddRecExpr(NewOps, AR->getLoop(),
+                           // FIXME: AR->getNoWrapFlags(SCEV::FlagNW)
+                           SCEV::FlagAnyWrap);
     return Result;
   }
   return 0;
@@ -2236,7 +2244,9 @@ static void CollectSubexprs(const SCEV *S, const SCEVConstant *C,
     if (!AR->getStart()->isZero()) {
       CollectSubexprs(SE.getAddRecExpr(SE.getConstant(AR->getType(), 0),
                                        AR->getStepRecurrence(SE),
-                                       AR->getLoop()),
+                                       AR->getLoop(),
+                                       //FIXME: AR->getNoWrapFlags(SCEV::FlagNW)
+                                       SCEV::FlagAnyWrap),
                       C, Ops, L, SE);
       CollectSubexprs(AR->getStart(), C, Ops, L, SE);
       return;
@@ -3047,7 +3057,7 @@ void LSRInstance::NarrowSearchSpaceByCollapsingUnrolledCode() {
   }
 }
 
-/// NarrowSearchSpaceByRefilteringUndesirableDedicatedRegisters - Call 
+/// NarrowSearchSpaceByRefilteringUndesirableDedicatedRegisters - Call
 /// FilterOutUndesirableDedicatedRegisters again, if necessary, now that
 /// we've done more filtering, as it may be able to find more formulae to
 /// eliminate.