IR: Change the gep_type_iterator API to avoid always exposing the "current" type.
Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.
Differential Revision: https://reviews.llvm.org/D26594
llvm-svn: 288458
diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp
index 37bab3a..60f6fbb 100644
--- a/llvm/lib/IR/ConstantFold.cpp
+++ b/llvm/lib/IR/ConstantFold.cpp
@@ -2019,22 +2019,8 @@
}
/// Test whether a given ConstantInt is in-range for a SequentialType.
-static bool isIndexInRangeOfSequentialType(SequentialType *STy,
- const ConstantInt *CI) {
- // And indices are valid when indexing along a pointer
- if (isa<PointerType>(STy))
- return true;
-
- uint64_t NumElements = 0;
- // Determine the number of elements in our sequential type.
- if (auto *ATy = dyn_cast<ArrayType>(STy))
- NumElements = ATy->getNumElements();
- else if (auto *VTy = dyn_cast<VectorType>(STy))
- NumElements = VTy->getNumElements();
-
- assert((isa<ArrayType>(STy) || NumElements > 0) &&
- "didn't expect non-array type to have zero elements!");
-
+static bool isIndexInRangeOfArrayType(uint64_t NumElements,
+ const ConstantInt *CI) {
// We cannot bounds check the index if it doesn't fit in an int64_t.
if (CI->getValue().getActiveBits() > 64)
return false;
@@ -2089,10 +2075,10 @@
// getelementptr instructions into a single instruction.
//
if (CE->getOpcode() == Instruction::GetElementPtr) {
- Type *LastTy = nullptr;
+ gep_type_iterator LastI = gep_type_end(CE);
for (gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE);
I != E; ++I)
- LastTy = *I;
+ LastI = I;
// We cannot combine indices if doing so would take us outside of an
// array or vector. Doing otherwise could trick us if we evaluated such a
@@ -2115,9 +2101,11 @@
bool PerformFold = false;
if (Idx0->isNullValue())
PerformFold = true;
- else if (SequentialType *STy = dyn_cast_or_null<SequentialType>(LastTy))
+ else if (LastI.isSequential())
if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx0))
- PerformFold = isIndexInRangeOfSequentialType(STy, CI);
+ PerformFold =
+ !LastI.isBoundedSequential() ||
+ isIndexInRangeOfArrayType(LastI.getSequentialNumElements(), CI);
if (PerformFold) {
SmallVector<Value*, 16> NewIndices;
@@ -2228,7 +2216,10 @@
Unknown = true;
continue;
}
- if (isIndexInRangeOfSequentialType(STy, CI))
+ if (isIndexInRangeOfArrayType(isa<ArrayType>(STy)
+ ? cast<ArrayType>(STy)->getNumElements()
+ : cast<VectorType>(STy)->getNumElements(),
+ CI))
// It's in range, skip to the next index.
continue;
if (!isa<SequentialType>(Prev)) {