[PATCH] D95480: [NFC] Fix bug with parsing hybrid sample trace line

[Lei Wang via Phabricator via llvm-commits]

wlei added inline comments.


================
Comment at: llvm/tools/llvm-profgen/PerfReader.cpp:414
       TraceIt.advance();
-      break;
+      return false;
     }
----------------
hoy wrote:
> A truncated context might still be helpful to the sample loader inliner. We saw this happened to some SPEC2006 benchmarks. What issue did it cause to you?
Sorry for the confusion. This line is for the non-address line like empty line.

This patch is for the issue like below
```
external address1
..
address2
address3
LBR entry
```
The first one is an `external address1`, so we need also skip the address2 and address3. otherwise, the missing part is the top frame, it will make the unwinder incorrect.

For the right truncated context, it's like below

``` 
address1
address2
external address3
..
LBR entry
```

Here the truncated part is at the bottom, then the compiler can use this for the inliner. The tool can handle this case.


 











Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D95480/new/

https://reviews.llvm.org/D95480