This reapplies revision 285093. Original commit message:
The branch folding pass tail merges blocks into a common-tail. However, the
tail retains the debug information from one of the original inputs to the
merge (chosen randomly). This is a problem for sampled-based PGO, as hits
on the common-tail will be attributed to whichever block was chosen,
irrespective of which path was actually taken to the common-tail.
This patch fixes the issue by nulling the debug location for the common-tail.
Differential Revision: https://reviews.llvm.org/D25742
llvm-svn: 285212
This reverts r285093, as it caused unexpected buildbot failures on
clang-ppc64le-linux, clang-ppc64be-linux, clang-ppc64be-linux-multistage
and clang-ppc64be-linux-lnt. Failing test ubsan/TestCases/TypeCheck/vptr.cpp.
llvm-svn: 285110
The branch folding pass tail merges blocks into a common-tail. However, the
tail retains the debug information from one of the original inputs to the
merge (chosen randomly). This is a problem for sampled-based PGO, as hits
on the common-tail will be attributed to whichever block was chosen,
irrespective of which path was actually taken to the common-tail.
This patch fixes the issue by nulling the debug location for the common-tail.
Differential Revision: https://reviews.llvm.org/D25742
llvm-svn: 285093
Robert Lougher