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

[Nick Desaulniers via Phabricator via cfe-commits]

nickdesaulniers added inline comments.


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Comment at: clang/lib/CodeGen/CGStmt.cpp:2868-2873
+      // If we happen to share the same indirect and default dest, don't re-add
+      // stores. That was done for the default destination in the above call to
+      // EmitAsmStores.
+      llvm::BasicBlock *Succ = CBR->getIndirectDest(i);
+      if (Succ == CBR->getDefaultDest())
+        continue;
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nickdesaulniers wrote:
> I'm not sure that I need to handle this case (of a callbr with the same indirect destination as the default destination).  That might result from optimizations, but I don't think clang can or will generate such IR.  Maybe I should turn this into an: `assert(CBR->getIndirectDest(i) != CBR->getDefaultDest(i) && "We already emitted asm stores in the default dest");`?
Yeah, it's impossible. While a CallBrInst can have a same indirect destination as the default destination as a result of optimizations, above we always create an `"asm.fallthrough"` block that is distinct from any of the named labels from the `asm goto`.


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https://reviews.llvm.org/D136497