Move the special cases for constants out of getUnknown and into
createSCEV. Also, recognize UndefValue in createSCEV.
Change getIntegerSCEV's comment to avoid mentioning FP types,
and re-implement it in terms of getConstant instead of getUnknown.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74041 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 50137fa..7abd0a5 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1867,10 +1867,11 @@
}
const SCEV* ScalarEvolution::getUnknown(Value *V) {
- if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
- return getConstant(CI);
- if (isa<ConstantPointerNull>(V))
- return getIntegerSCEV(0, V->getType());
+ // Don't attempt to do anything other than create a SCEVUnknown object
+ // here. createSCEV only calls getUnknown after checking for all other
+ // interesting possibilities, and any other code that calls getUnknown
+ // is doing so in order to hide a value from SCEV canonicalization.
+
SCEVUnknown *&Result = SCEVUnknowns[V];
if (Result == 0) Result = new SCEVUnknown(V);
return Result;
@@ -1948,19 +1949,11 @@
return S;
}
-/// getIntegerSCEV - Given an integer or FP type, create a constant for the
+/// getIntegerSCEV - Given a SCEVable type, create a constant for the
/// specified signed integer value and return a SCEV for the constant.
const SCEV* ScalarEvolution::getIntegerSCEV(int Val, const Type *Ty) {
- Ty = getEffectiveSCEVType(Ty);
- Constant *C;
- if (Val == 0)
- C = Constant::getNullValue(Ty);
- else if (Ty->isFloatingPoint())
- C = ConstantFP::get(APFloat(Ty==Type::FloatTy ? APFloat::IEEEsingle :
- APFloat::IEEEdouble, Val));
- else
- C = ConstantInt::get(Ty, Val);
- return getUnknown(C);
+ const IntegerType *ITy = cast<IntegerType>(getEffectiveSCEVType(Ty));
+ return getConstant(ConstantInt::get(ITy, Val));
}
/// getNegativeSCEV - Return a SCEV corresponding to -V = -1*V
@@ -2429,6 +2422,12 @@
Opcode = I->getOpcode();
else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
Opcode = CE->getOpcode();
+ else if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
+ return getConstant(CI);
+ else if (isa<ConstantPointerNull>(V))
+ return getIntegerSCEV(0, V->getType());
+ else if (isa<UndefValue>(V))
+ return getIntegerSCEV(0, V->getType());
else
return getUnknown(V);