[PATCH] D38229: [DebugInfo] Insert DEBUG_VALUEs after each register redefinition

[Karl-Johan Karlsson via Phabricator via llvm-commits]

Ka-Ka added a comment.

> When I tried your test program above I found that faulty hoisting of a DBG_VALUE across the call to `usevals` seems to be done by the CodeGenPrepare pass (before instruction selection). This must be a bug. If you want I can convert code above into a testcase but it will contain this faulty hoisted DBG_VALUE from the CodeGenPrepare pass. This patch will not impact that testcase.

There already exist an old bug report regarding CodeGenPrepare moving llvm.dbg.value without proper analysis. I appended a new reproducer to pr31878.
https://bugs.llvm.org/show_bug.cgi?id=31878


https://reviews.llvm.org/D38229