[IR] Add BasicBlock::isEntryBlock() (NFC)

This is a recurring and somewhat awkward pattern. Add a helper
method for it.

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
index 48227d8..d14abaf 100644
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -372,6 +372,12 @@ bool BasicBlock::isLegalToHoistInto() const {
   return !Term->isExceptionalTerminator();
 }
 
+bool BasicBlock::isEntryBlock() const {
+  const Function *F = getParent();
+  assert(F && "Block must have a parent function to use this API");
+  return this == &F->getEntryBlock();
+}
+
 BasicBlock *BasicBlock::splitBasicBlock(iterator I, const Twine &BBName,
                                         bool Before) {
   if (Before)