[PATCH] D136497: [Clang] support for outputs along indirect edges of asm goto

[Bill Wendling via Phabricator via cfe-commits]

void added inline comments.


================
Comment at: clang/docs/ReleaseNotes.rst:199
+  guaranteed (and necessary to support outputs along indirect edges, which is
+  now supported as of this release).
+
----------------
Is it worth it to mention that this change makes Clang's behavior with regards to your example here consistent with GCC's behavior?


================
Comment at: clang/lib/CodeGen/CGStmt.cpp:2814
+  // A 2D vector, indexed by indirect destination, then ResultReg.
+  std::vector<std::vector<llvm::Value *>> CBRRegResults;
   if (IsGCCAsmGoto) {
----------------
It seems as if you really want a map indexed by the `BasicBlock*`. So something like this:

```
DenseMap<BasicBlock *, SmallVector<Value *, 4>> // 4 should be enough for anyone.
```

That way you can iterate over `CBR->getIndirectDests()` instead of having to use an iterator.


================
Comment at: clang/lib/CodeGen/CGStmt.cpp:2868
+  // CBRRegResults rather than RegResults.
+  if (IsGCCAsmGoto && CBRRegResults.size()) {
+    for (unsigned i = 0, e = CBR->getNumIndirectDests(); i != e; ++i) {
----------------
Could probably use `!CBRRegResults.empty()` instead of `.size()`. The first should be `O(1)` (granted `.size()` probably should be too, but `.empty()` is more explicit anyway).


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D136497/new/

https://reviews.llvm.org/D136497