[GuardWidening] Widen guards with conditions of frequently taken dominated branches
If there is a frequently taken branch dominated by a guard, and its condition is available
at the point of the guard, we can widen guard with condition of this branch and convert
the branch into unconditional:
guard(cond1)
if (cond2) {
// taken in 99.9% cases
// do something
} else {
// do something else
}
Converts to
guard(cond1 && cond2)
// do something
Differential Revision: https://reviews.llvm.org/D49974
Reviewed By: reames
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338988 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed