MemCpyOptimizer: Use max legal int size instead of pointer size

If there are no legal integers, assume 1 byte.

This makes more sense than using the pointer size as
a guess for the maximum GPR width.

It is conceivable to want to use some 64-bit pointers
on a target where 64-bit integers aren't legal.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190817 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 0 deletions

diff --git a/include/llvm/IR/DataLayout.h b/include/llvm/IR/DataLayout.h
index 25f7569e24..10630a2620 100644
--- a/include/llvm/IR/DataLayout.h
+++ b/include/llvm/IR/DataLayout.h
@@ -369,6 +369,17 @@ public:
   /// least as big as Width bits.
   Type *getSmallestLegalIntType(LLVMContext &C, unsigned Width = 0) const;
 
+  /// getLargestLegalIntType - Return the largest legal integer type, or null if
+  /// none are set.
+  Type *getLargestLegalIntType(LLVMContext &C) const {
+    unsigned LargestSize = getLargestLegalIntTypeSize();
+    return (LargestSize == 0) ? 0 : Type::getIntNTy(C, LargestSize);
+  }
+
+  /// getLargestLegalIntType - Return the size of largest legal integer type
+  /// size, or 0 if none are set.
+  unsigned getLargestLegalIntTypeSize() const;
+
   /// getIndexedOffset - return the offset from the beginning of the type for
   /// the specified indices.  This is used to implement getelementptr.
   uint64_t getIndexedOffset(Type *Ty, ArrayRef<Value *> Indices) const;