Teach lib/VMCore/ConstantFold.cpp how to set the inbounds keyword and
how to fold notionally-out-of-bounds array getelementptr indices instead
of just doing these in lib/Analysis/ConstantFolding.cpp, because it can
be done in a fairly general way without TargetData, and because not all
constants are visited by lib/Analysis/ConstantFolding.cpp. This enables
more constant folding.
Also, set the "inbounds" flag when the getelementptr indices are
one-past-the-end.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81483 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index f07d03a..c64b0ea 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -207,12 +207,8 @@
if (Offset != 0)
return 0;
- // If the base is the start of a GlobalVariable and all the array indices
- // remain in their static bounds, the GEP is inbounds. We can check that
- // all indices are in bounds by just checking the first index only
- // because we've just normalized all the indices.
- Constant *C = isa<GlobalVariable>(Ptr) && NewIdxs[0]->isNullValue() ?
- ConstantExpr::getInBoundsGetElementPtr(Ptr, &NewIdxs[0], NewIdxs.size()) :
+ // Create a GEP.
+ Constant *C =
ConstantExpr::getGetElementPtr(Ptr, &NewIdxs[0], NewIdxs.size());
assert(cast<PointerType>(C->getType())->getElementType() == Ty &&
"Computed GetElementPtr has unexpected type!");