For -O0 there might be unreachable BBs, which breaks the assumption that all the
BBs have an auxiliary data structure. In this patch, we add another interface
called findBBInfo() so that a nullptr can be returned for the unreachable BBs
(and the callers can ignore those BBs).
This fixes the bug reported
https://llvm.org/bugs/show_bug.cgi?id=31209
Differential Revision: https://reviews.llvm.org/D27280
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288528 91177308-0d34-0410-b5e6-96231b3b80d8
This new patch fixes a few bugs that exposed in last submit. It also improves
the test cases.
--Original Commit Message--
This patch implements a minimum spanning tree (MST) based instrumentation for
PGO. The use of MST guarantees minimum number of CFG edges getting
instrumented. An addition optimization is to instrument the less executed
edges to further reduce the instrumentation overhead. The patch contains both the
instrumentation and the use of the profile to set the branch weights.
Differential Revision: http://reviews.llvm.org/D12781
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255132 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements a minimum spanning tree (MST) based instrumentation for
PGO. The use of MST guarantees minimum number of CFG edges getting
instrumented. An addition optimization is to instrument the less executed
edges to further reduce the instrumentation overhead. The patch contains both the
instrumentation and the use of the profile to set the branch weights.
Differential Revision: http://reviews.llvm.org/D12781
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254021 91177308-0d34-0410-b5e6-96231b3b80d8
