[PATCH] D27857: [PATCH][DWARF] Don't propagate or set debug locations for PRE loads and associated address calculations

[Adrian Prantl via Phabricator via llvm-commits]

aprantl accepted this revision.
aprantl added a comment.
This revision is now accepted and ready to land.

I have two suggestions for further clarifying the comments. I'm somewhat concerned that this could regress profiling/instrumentation, but since this only affects singular load instructions it shouldn't be too bad.

thanks!



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Comment at: lib/Transforms/Scalar/GVN.cpp:1577
+    // the load address do not retain their original debug locations. Doing
+    // so could lead to erratic source attributions.
+    // FIXME: How do we retain source locations without causing poor debugging
----------------
... could lead to confusing (but correct) source attributions.


================
Comment at: lib/Transforms/Scalar/GVN.cpp:1612
+    // We do not propagate the old load's debug location, because the new
+    // load now lives in a different BB.
+    // FIXME: How do we retain source locations without causing poor debugging
----------------
, and we want to avoid a jumpy line table.


https://reviews.llvm.org/D27857