add GetElementPtrInst::hasAllZeroIndices, a long-overdue helper method.
Writing it twice in the same day was too much for me.
llvm-svn: 35978
diff --git a/llvm/lib/VMCore/Instructions.cpp b/llvm/lib/VMCore/Instructions.cpp
index f6abd85..bfda46d 100644
--- a/llvm/lib/VMCore/Instructions.cpp
+++ b/llvm/lib/VMCore/Instructions.cpp
@@ -966,6 +966,22 @@
return PTy->getElementType();
}
+
+/// hasAllZeroIndices - Return true if all of the indices of this GEP are
+/// zeros. If so, the result pointer and the first operand have the same
+/// value, just potentially different types.
+bool GetElementPtrInst::hasAllZeroIndices() const {
+ for (unsigned i = 1, e = getNumOperands(); i != e; ++i) {
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(getOperand(i))) {
+ if (!CI->isZero()) return false;
+ } else {
+ return false;
+ }
+ }
+ return true;
+}
+
+
//===----------------------------------------------------------------------===//
// ExtractElementInst Implementation
//===----------------------------------------------------------------------===//