[llvm] r266759 - [DependenceAnalysis] Refactor uses of getConstantPart. NFC.

[Brendon Cahoon via llvm-commits]

Author: bcahoon
Date: Tue Apr 19 11:46:57 2016
New Revision: 266759

URL: http://llvm.org/viewvc/llvm-project?rev=266759&view=rev
Log:
[DependenceAnalysis] Refactor uses of getConstantPart. NFC.

Rather than checking for the SCEV type prior to calling
getContantPart, perform the checks in the function. This reduces
the number of places where the checks are needed.

Differential Revision: http://reviews.llvm.org/D19241

Modified:
    llvm/trunk/lib/Analysis/DependenceAnalysis.cpp

Modified: llvm/trunk/lib/Analysis/DependenceAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/DependenceAnalysis.cpp?rev=266759&r1=266758&r2=266759&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/DependenceAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/DependenceAnalysis.cpp Tue Apr 19 11:46:57 2016
@@ -2256,11 +2256,12 @@ bool DependenceAnalysis::testMIV(const S
 // Given a product, e.g., 10*X*Y, returns the first constant operand,
 // in this case 10. If there is no constant part, returns NULL.
 static
-const SCEVConstant *getConstantPart(const SCEVMulExpr *Product) {
-  for (unsigned Op = 0, Ops = Product->getNumOperands(); Op < Ops; Op++) {
-    if (const SCEVConstant *Constant = dyn_cast<SCEVConstant>(Product->getOperand(Op)))
+const SCEVConstant *getConstantPart(const SCEV *Expr) {
+  if (const auto *Constant = dyn_cast<SCEVConstant>(Expr))
+    return Constant;
+  else if (const auto *Product = dyn_cast<SCEVMulExpr>(Expr))
+    if (const auto *Constant = dyn_cast<SCEVConstant>(Product->getOperand(0)))
       return Constant;
-  }
   return nullptr;
 }
 
@@ -2299,11 +2300,9 @@ bool DependenceAnalysis::gcdMIVtest(cons
   while (const SCEVAddRecExpr *AddRec =
          dyn_cast<SCEVAddRecExpr>(Coefficients)) {
     const SCEV *Coeff = AddRec->getStepRecurrence(*SE);
-    const SCEVConstant *Constant = dyn_cast<SCEVConstant>(Coeff);
-    if (const SCEVMulExpr *Product = dyn_cast<SCEVMulExpr>(Coeff))
-      // If the coefficient is the product of a constant and other stuff,
-      // we can use the constant in the GCD computation.
-      Constant = getConstantPart(Product);
+    // If the coefficient is the product of a constant and other stuff,
+    // we can use the constant in the GCD computation.
+    const auto *Constant = getConstantPart(Coeff);
     if (!Constant)
       return false;
     APInt ConstCoeff = Constant->getAPInt();
@@ -2320,11 +2319,9 @@ bool DependenceAnalysis::gcdMIVtest(cons
   while (const SCEVAddRecExpr *AddRec =
          dyn_cast<SCEVAddRecExpr>(Coefficients)) {
     const SCEV *Coeff = AddRec->getStepRecurrence(*SE);
-    const SCEVConstant *Constant = dyn_cast<SCEVConstant>(Coeff);
-    if (const SCEVMulExpr *Product = dyn_cast<SCEVMulExpr>(Coeff))
-      // If the coefficient is the product of a constant and other stuff,
-      // we can use the constant in the GCD computation.
-      Constant = getConstantPart(Product);
+    // If the coefficient is the product of a constant and other stuff,
+    // we can use the constant in the GCD computation.
+    const auto *Constant = getConstantPart(Coeff);
     if (!Constant)
       return false;
     APInt ConstCoeff = Constant->getAPInt();
@@ -2403,12 +2400,9 @@ bool DependenceAnalysis::gcdMIVtest(cons
       if (CurLoop == AddRec->getLoop())
         ; // SrcCoeff == Coeff
       else {
-        if (const SCEVMulExpr *Product = dyn_cast<SCEVMulExpr>(Coeff))
-          // If the coefficient is the product of a constant and other stuff,
-          // we can use the constant in the GCD computation.
-          Constant = getConstantPart(Product);
-        else
-          Constant = cast<SCEVConstant>(Coeff);
+        // If the coefficient is the product of a constant and other stuff,
+        // we can use the constant in the GCD computation.
+        Constant = getConstantPart(Coeff);
         if (!Constant)
           return false;
         APInt ConstCoeff = Constant->getAPInt();
@@ -2423,12 +2417,9 @@ bool DependenceAnalysis::gcdMIVtest(cons
       if (CurLoop == AddRec->getLoop())
         DstCoeff = Coeff;
       else {
-        if (const SCEVMulExpr *Product = dyn_cast<SCEVMulExpr>(Coeff))
-          // If the coefficient is the product of a constant and other stuff,
-          // we can use the constant in the GCD computation.
-          Constant = getConstantPart(Product);
-        else
-          Constant = cast<SCEVConstant>(Coeff);
+        // If the coefficient is the product of a constant and other stuff,
+        // we can use the constant in the GCD computation.
+        Constant = getConstantPart(Coeff);
         if (!Constant)
           return false;
         APInt ConstCoeff = Constant->getAPInt();
@@ -2437,19 +2428,13 @@ bool DependenceAnalysis::gcdMIVtest(cons
       Inner = AddRec->getStart();
     }
     Delta = SE->getMinusSCEV(SrcCoeff, DstCoeff);
-    if (const SCEVMulExpr *Product = dyn_cast<SCEVMulExpr>(Delta))
-      // If the coefficient is the product of a constant and other stuff,
-      // we can use the constant in the GCD computation.
-      Constant = getConstantPart(Product);
-    else if (isa<SCEVConstant>(Delta))
-      Constant = cast<SCEVConstant>(Delta);
-    else {
+    // If the coefficient is the product of a constant and other stuff,
+    // we can use the constant in the GCD computation.
+    Constant = getConstantPart(Delta);
+    if (!Constant)
       // The difference of the two coefficients might not be a product
       // or constant, in which case we give up on this direction.
       continue;
-    }
-    if (!Constant)
-      continue;
     APInt ConstCoeff = Constant->getAPInt();
     RunningGCD = APIntOps::GreatestCommonDivisor(RunningGCD, ConstCoeff.abs());
     DEBUG(dbgs() << "\tRunningGCD = " << RunningGCD << "\n");