search for: machinebranchprobability

Hello LLVM-Dev, The other day as I was digging through lldb’s test suite I noticed they support something kinda neat. In their python test harness, the attribute they use to denote expected failures supports a parameter for specifying the bug number. This got me thinking. I believe that any test that is marked XFAIL is a bug, and we can use LIT to enforce that. So I wrote a patch

This may be an unpopular opinion (and I don’t have the full context on those specific issues), but I believe that these are an abuse of XFAIL, and should probably be written in terms of REQUIRES instead of XFAIL. I believe XFAIL tests actually execute, and are just marked as expected failure. If a test is not expected to ever succeed, we shouldn’t bother running it, which is what the REQUIRES

...lt MBB, one edge for the jumptable, and another one for the jump handling the case when the index is not in the jumptable. For some reason, our backend assigns those edges different weights (let's say 24 for the default edge and 16 for the others). In LLVM 3.1, getSumForBlock in lib/CodeGen/MachineBranchProbability.cpp used getEdgeWeight(MBB*, MBB*), which always return the weight of the first edge to the default block, i.e., it calculated the sum of the weights as 24+16+24+16+16 = 96. In LLVM 3.2 getSumForBlock was changed to use getEdgeWeight(MBB*, MBB::succ_iterator), causing it to calculate the sum of...