[llvm-commits] [llvm] r72003 - in /llvm/trunk: include/llvm/Analysis/ScalarEvolution.h lib/Analysis/ScalarEvolution.cpp

[Dan Gohman]

Author: djg
Date: Mon May 18 10:22:39 2009
New Revision: 72003

URL: http://llvm.org/viewvc/llvm-project?rev=72003&view=rev
Log:
Add an isOne() utility function to ScalarEvolution, similar to isZero()
and similar to ConstantInt's isOne().

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

Modified: llvm/trunk/include/llvm/Analysis/ScalarEvolution.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ScalarEvolution.h?rev=72003&r1=72002&r2=72003&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Analysis/ScalarEvolution.h (original)
+++ llvm/trunk/include/llvm/Analysis/ScalarEvolution.h Mon May 18 10:22:39 2009
@@ -77,6 +77,10 @@
     ///
     bool isZero() const;
 
+    /// isOne - Return true if the expression is a constant one.
+    ///
+    bool isOne() const;
+
     /// replaceSymbolicValuesWithConcrete - If this SCEV internally references
     /// the symbolic value "Sym", construct and return a new SCEV that produces
     /// the same value, but which uses the concrete value Conc instead of the

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=72003&r1=72002&r2=72003&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Mon May 18 10:22:39 2009
@@ -127,6 +127,11 @@
   return false;
 }
 
+bool SCEV::isOne() const {
+  if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(this))
+    return SC->getValue()->isOne();
+  return false;
+}
 
 SCEVCouldNotCompute::SCEVCouldNotCompute() : SCEV(scCouldNotCompute) {}
 SCEVCouldNotCompute::~SCEVCouldNotCompute() {}
@@ -3392,7 +3397,7 @@
     const SCEVConstant *CStep = dyn_cast<SCEVConstant>(Step);
     if (!CStep || CStep->isZero())
       return UnknownValue;
-    if (CStep->getValue()->getValue() == 1) {
+    if (CStep->isOne()) {
       // With unit stride, the iteration never steps past the limit value.
     } else if (CStep->getValue()->getValue().isStrictlyPositive()) {
       if (const SCEVConstant *CLimit = dyn_cast<SCEVConstant>(RHS)) {