Add an isOne() utility function to ScalarEvolution, similar to isZero()
and similar to ConstantInt's isOne().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72003 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index 76e23b1..a5534e8 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -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
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 77a8070..4b99a86 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -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)) {