[PATCH] D58453: [DebugInfo][CGP] Limit placeDbgValues movement of dbg.value intrinsics

[Adrian Prantl via Phabricator via llvm-commits]

aprantl added a comment.

In D58453#1409964 <https://reviews.llvm.org/D58453#1409964>, @probinson wrote:

> In D58453#1409691 <https://reviews.llvm.org/D58453#1409691>, @jmorse wrote:
>
> >
>




> https://llvm.org/docs/SourceLevelDebugging.html#format-common-intrinsics
>  "This intrinsic provides information when a user source variable is set to a new value."  Naively I read this "when" as meaning, the position of the intrinsic in the instruction stream indicates the starting point where the variable takes on the new value.  But making that clearer would be a Good Thing.

That is indeed the intended reading of that sentence. Perhaps we should include an example here that uses a dbg.value with a constant to start a new range and an undef to end it to really drive the point home.

> And as various reviews and whatnot fly by, I'm inclined to think it's at least a common misperception that the dbg.value has to be adjacent to the instruction that produces the value operand.  Stating that it's not required would surely help.

Agreed!


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https://reviews.llvm.org/D58453