Preserve NSW information in more places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91656 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index 4aa3dfa..6f57c74 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -243,7 +243,7 @@
/// createNodeForGEP - Provide the special handling we need to analyze GEP
/// SCEVs.
- const SCEV *createNodeForGEP(Operator *GEP);
+ const SCEV *createNodeForGEP(GEPOperator *GEP);
/// computeSCEVAtScope - Implementation code for getSCEVAtScope; called
/// at most once for each SCEV+Loop pair.
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index babfc85..551c25f 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1460,7 +1460,9 @@
AddRec->op_end());
AddRecOps[0] = getAddExpr(LIOps);
- const SCEV *NewRec = getAddRecExpr(AddRecOps, AddRec->getLoop());
+ const SCEV *NewRec = getAddRecExpr(AddRecOps, AddRec->getLoop(),
+ AddRec->hasNoUnsignedWrap() && HasNUW,
+ AddRec->hasNoSignedWrap() && HasNSW);
// If all of the other operands were loop invariant, we are done.
if (Ops.size() == 1) return NewRec;
@@ -1636,7 +1638,9 @@
}
}
- const SCEV *NewRec = getAddRecExpr(NewOps, AddRec->getLoop());
+ const SCEV *NewRec = getAddRecExpr(NewOps, AddRec->getLoop(),
+ AddRec->hasNoUnsignedWrap() && HasNUW,
+ AddRec->hasNoSignedWrap() && HasNSW);
// If all of the other operands were loop invariant, we are done.
if (Ops.size() == 1) return NewRec;
@@ -2592,8 +2596,9 @@
/// createNodeForGEP - Expand GEP instructions into add and multiply
/// operations. This allows them to be analyzed by regular SCEV code.
///
-const SCEV *ScalarEvolution::createNodeForGEP(Operator *GEP) {
+const SCEV *ScalarEvolution::createNodeForGEP(GEPOperator *GEP) {
+ bool InBounds = GEP->isInBounds();
const Type *IntPtrTy = getEffectiveSCEVType(GEP->getType());
Value *Base = GEP->getOperand(0);
// Don't attempt to analyze GEPs over unsized objects.
@@ -2610,18 +2615,24 @@
// For a struct, add the member offset.
unsigned FieldNo = cast<ConstantInt>(Index)->getZExtValue();
TotalOffset = getAddExpr(TotalOffset,
- getFieldOffsetExpr(STy, FieldNo));
+ getFieldOffsetExpr(STy, FieldNo),
+ /*HasNUW=*/false, /*HasNSW=*/InBounds);
} else {
// For an array, add the element offset, explicitly scaled.
const SCEV *LocalOffset = getSCEV(Index);
if (!isa<PointerType>(LocalOffset->getType()))
// Getelementptr indicies are signed.
LocalOffset = getTruncateOrSignExtend(LocalOffset, IntPtrTy);
- LocalOffset = getMulExpr(LocalOffset, getAllocSizeExpr(*GTI));
- TotalOffset = getAddExpr(TotalOffset, LocalOffset);
+ // Lower "inbounds" GEPs to NSW arithmetic.
+ bool HasNSW = GEP->isInBounds();
+ LocalOffset = getMulExpr(LocalOffset, getAllocSizeExpr(*GTI),
+ /*HasNUW=*/false, /*HasNSW=*/InBounds);
+ TotalOffset = getAddExpr(TotalOffset, LocalOffset,
+ /*HasNUW=*/false, /*HasNSW=*/InBounds);
}
}
- return getAddExpr(getSCEV(Base), TotalOffset);
+ return getAddExpr(getSCEV(Base), TotalOffset,
+ /*HasNUW=*/false, /*HasNSW=*/InBounds);
}
/// GetMinTrailingZeros - Determine the minimum number of zero bits that S is
@@ -3130,7 +3141,7 @@
// expressions we handle are GEPs and address literals.
case Instruction::GetElementPtr:
- return createNodeForGEP(U);
+ return createNodeForGEP(cast<GEPOperator>(U));
case Instruction::PHI:
return createNodeForPHI(cast<PHINode>(U));