Long ago, the poll insertion code assumed that the insertion site was a terminator. As a result, the entry selection code would split a basic block to ensure it could pass a terminator. The insertion code was updated quite a while ago - possibly before it ever landed upstream - but the now redundant work was never removed.
While I'm at it, remove a comment which doesn't apply to the upstreamed code.
NFC intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238254
91177308-0d34-0410-b5e6-
96231b3b80d8
// that can grow the stack. This, combined with backedge polls,
// give us all the progress guarantees we need.
// that can grow the stack. This, combined with backedge polls,
// give us all the progress guarantees we need.
- // Due to the way the frontend generates IR, we may have a couple of initial
- // basic blocks before the first bytecode. These will be single-entry
- // single-exit blocks which conceptually are just part of the first 'real
- // basic block'. Since we don't have deopt state until the first bytecode,
- // walk forward until we've found the first unconditional branch or merge.
-
// hasNextInstruction and nextInstruction are used to iterate
// through a "straight line" execution sequence.
// hasNextInstruction and nextInstruction are used to iterate
// through a "straight line" execution sequence.
assert((hasNextInstruction(cursor) || cursor->isTerminator()) &&
"either we stopped because of a call, or because of terminator");
assert((hasNextInstruction(cursor) || cursor->isTerminator()) &&
"either we stopped because of a call, or because of terminator");
- if (cursor->isTerminator()) {
- return cursor;
- }
-
- BasicBlock *BB = cursor->getParent();
- SplitBlock(BB, cursor, &DT);
-
- // SplitBlock updates the DT
- DEBUG(DT.verifyDomTree());
-
- return BB->getTerminator();
}
/// Identify the list of call sites which need to be have parseable state
}
/// Identify the list of call sites which need to be have parseable state