[PATCH] D78380: Let the target adjust physical output- and anti-deps

[Fraser Cormack via Phabricator via llvm-commits]

frasercrmck created this revision.
frasercrmck added reviewers: foad, MatzeB, rampitec.
frasercrmck added a project: LLVM.
Herald added subscribers: llvm-commits, hiraditya.

This is potentially required by targets for correctness, or at least for optimization purposes.

Let me know what you think. This is necessary for our downstream target as we have a complicated per-operand scheduling model. However, as I don't think it's too controversial I thought I would push it back upstream.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D78380

Files:
  llvm/lib/CodeGen/ScheduleDAGInstrs.cpp


Index: llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
===================================================================
--- llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -294,6 +294,8 @@
   if (MRI.isConstantPhysReg(Reg))
     return;
 
+  const TargetSubtargetInfo &ST = MF.getSubtarget();
+
   // Optionally add output and anti dependencies. For anti
   // dependencies we use a latency of 0 because for a multi-issue
   // target we want to allow the defining instruction to issue
@@ -311,14 +313,12 @@
       if (DefSU != SU &&
           (Kind != SDep::Output || !MO.isDead() ||
            !DefSU->getInstr()->registerDefIsDead(*Alias))) {
-        if (Kind == SDep::Anti)
-          DefSU->addPred(SDep(SU, Kind, /*Reg=*/*Alias));
-        else {
-          SDep Dep(SU, Kind, /*Reg=*/*Alias);
+        SDep Dep(SU, Kind, /*Reg=*/*Alias);
+        if (Kind != SDep::Anti)
           Dep.setLatency(
             SchedModel.computeOutputLatency(MI, OperIdx, DefSU->getInstr()));
-          DefSU->addPred(Dep);
-        }
+        ST.adjustSchedDependency(SU, OperIdx, DefSU, I->OpIdx, Dep);
+        DefSU->addPred(Dep);
       }
     }
   }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D78380.258349.patch
Type: text/x-patch
Size: 1182 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200417/4e9d3191/attachment.bin>