[llvm-commits] [llvm] r147700 - in /llvm/trunk: include/llvm/Analysis/ScalarEvolution.h lib/Analysis/ScalarEvolution.cpp lib/Analysis/ScalarEvolutionExpander.cpp

[Andrew Trick]

Author: atrick
Date: Fri Jan  6 18:27:31 2012
New Revision: 147700

URL: http://llvm.org/viewvc/llvm-project?rev=147700&view=rev
Log:
Expose isNonConstantNegative to users of ScalarEvolution.

Modified:
    llvm/trunk/include/llvm/Analysis/ScalarEvolution.h
    llvm/trunk/lib/Analysis/ScalarEvolution.cpp
    llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp

Modified: llvm/trunk/include/llvm/Analysis/ScalarEvolution.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ScalarEvolution.h?rev=147700&r1=147699&r2=147700&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/ScalarEvolution.h (original)
+++ llvm/trunk/include/llvm/Analysis/ScalarEvolution.h Fri Jan  6 18:27:31 2012
@@ -119,6 +119,10 @@
     ///
     bool isAllOnesValue() const;
 
+    /// isNonConstantNegative - Return true if the specified scev is negated,
+    /// but not a constant.
+    bool isNonConstantNegative() const;
+
     /// print - Print out the internal representation of this scalar to the
     /// specified stream.  This should really only be used for debugging
     /// purposes.

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=147700&r1=147699&r2=147700&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Fri Jan  6 18:27:31 2012
@@ -284,6 +284,20 @@
   return false;
 }
 
+/// isNonConstantNegative - Return true if the specified scev is negated, but
+/// not a constant.
+bool SCEV::isNonConstantNegative() const {
+  const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(this);
+  if (!Mul) return false;
+
+  // If there is a constant factor, it will be first.
+  const SCEVConstant *SC = dyn_cast<SCEVConstant>(Mul->getOperand(0));
+  if (!SC) return false;
+
+  // Return true if the value is negative, this matches things like (-42 * V).
+  return SC->getValue()->getValue().isNegative();
+}
+
 SCEVCouldNotCompute::SCEVCouldNotCompute() :
   SCEV(FoldingSetNodeIDRef(), scCouldNotCompute) {}
 

Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=147700&r1=147699&r2=147700&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Fri Jan  6 18:27:31 2012
@@ -593,20 +593,6 @@
   return expand(SE.getAddExpr(Ops));
 }
 
-/// isNonConstantNegative - Return true if the specified scev is negated, but
-/// not a constant.
-static bool isNonConstantNegative(const SCEV *F) {
-  const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(F);
-  if (!Mul) return false;
-
-  // If there is a constant factor, it will be first.
-  const SCEVConstant *SC = dyn_cast<SCEVConstant>(Mul->getOperand(0));
-  if (!SC) return false;
-
-  // Return true if the value is negative, this matches things like (-42 * V).
-  return SC->getValue()->getValue().isNegative();
-}
-
 /// PickMostRelevantLoop - Given two loops pick the one that's most relevant for
 /// SCEV expansion. If they are nested, this is the most nested. If they are
 /// neighboring, pick the later.
@@ -685,10 +671,10 @@
     // If one operand is a non-constant negative and the other is not,
     // put the non-constant negative on the right so that a sub can
     // be used instead of a negate and add.
-    if (isNonConstantNegative(LHS.second)) {
-      if (!isNonConstantNegative(RHS.second))
+    if (LHS.second->isNonConstantNegative()) {
+      if (!RHS.second->isNonConstantNegative())
         return false;
-    } else if (isNonConstantNegative(RHS.second))
+    } else if (RHS.second->isNonConstantNegative())
       return true;
 
     // Otherwise they are equivalent according to this comparison.
@@ -749,7 +735,7 @@
       for (++I; I != E && I->first == CurLoop; ++I)
         NewOps.push_back(I->second);
       Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op));
-    } else if (isNonConstantNegative(Op)) {
+    } else if (Op->isNonConstantNegative()) {
       // Instead of doing a negate and add, just do a subtract.
       Value *W = expandCodeFor(SE.getNegativeSCEV(Op), Ty);
       Sum = InsertNoopCastOfTo(Sum, Ty);
@@ -1044,7 +1030,7 @@
   // If the stride is negative, insert a sub instead of an add for the increment
   // (unless it's a constant, because subtracts of constants are canonicalized
   // to adds).
-  bool useSubtract = !ExpandTy->isPointerTy() && isNonConstantNegative(Step);
+  bool useSubtract = !ExpandTy->isPointerTy() && Step->isNonConstantNegative();
   if (useSubtract)
     Step = SE.getNegativeSCEV(Step);
   // Expand the step somewhere that dominates the loop header.
@@ -1167,7 +1153,7 @@
       // inserting an extra IV increment. StepV might fold into PostLoopOffset,
       // but hopefully expandCodeFor handles that.
       bool useSubtract =
-        !ExpandTy->isPointerTy() && isNonConstantNegative(Step);
+        !ExpandTy->isPointerTy() && Step->isNonConstantNegative();
       if (useSubtract)
         Step = SE.getNegativeSCEV(Step);
       // Expand the step somewhere that dominates the loop header.