search for: symbolrefattr

...e minimal step forward: 1. Build a mechanism to break the use dependencies for GlobalValue and BasicBlock, i.e. allow immortal BlockAddress and ConstantGlobalValue values while _also_ allowing us to delete GlobalValues and BasicBlocks. For this mechanism, we can let ourselves be inspired by mlir::SymbolRefAttr, which uses strings for the linkage. Alternatively (and perhaps preferably), we could use a weak_ptr-like mechanism. This can be very efficient, since each GlobalValue and BasicBlock only ever needs to have a single instance of ConstantGlobalValue and BlockAddress referring to it, respectively, so...

> On Mar 20, 2020, at 12:34 PM, Nicholas Krause <xerofoify at gmail.com> wrote: > >> >> The problem isn’t constants or functions themselves, it is that they are instances of llvm::Value. Everything that walks a use/def list would have to run code that checks for this, and every call to inst->setOperand() would have to do locking or conditional locking. This would be