Let targets adjust operand latency of bundles

This reverts the AMDGPU DAG mutation implemented in D72487 and gives
a more general way of adjusting BUNDLE operand latency.

It also replaces FixBundleLatencyMutation with adjustSchedDependency
callback in the AMDGPU, fixing not only successor latencies but
predecessors' as well.

Differential Revision: https://reviews.llvm.org/D72535

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
index 96a1f86c3e0..d11406cc330 100644
--- a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -270,8 +270,13 @@ void ScheduleDAGInstrs::addPhysRegDataDeps(SUnit *SU, unsigned OperIdx) {
         Dep.setLatency(SchedModel.computeOperandLatency(SU->getInstr(), OperIdx,
                                                         RegUse, UseOp));
         ST.adjustSchedDependency(SU, UseSU, Dep);
-      } else
+      } else {
         Dep.setLatency(0);
+        // FIXME: We could always let target to adjustSchedDependency(), and
+        // remove this condition, but that currently asserts in Hexagon BE.
+        if (SU->getInstr()->isBundle() || (RegUse && RegUse->isBundle()))
+          ST.adjustSchedDependency(SU, UseSU, Dep);
+      }
 
       UseSU->addPred(Dep);
     }