[PATCH] D140168: Do not mark non-phi loop var def as loop-carried dep

[Thomas Preud'homme via Phabricator via llvm-commits]

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As spotted by Sumanth Gundapaneni, commit
c8be35293c82f216e975c56f62ddf9199a22f2e2 <https://reviews.llvm.org/rGc8be35293c82f216e975c56f62ddf9199a22f2e2> incorrectly marked loop
variable not defined by a PHI as loop-carried dependencies. This commit
fixes that.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D140168

Files:
  llvm/lib/CodeGen/MachinePipeliner.cpp


Index: llvm/lib/CodeGen/MachinePipeliner.cpp
===================================================================
--- llvm/lib/CodeGen/MachinePipeliner.cpp
+++ llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -2280,7 +2280,7 @@
   MachineInstr *DefS = MRI.getVRegDef(BaseOpS->getReg());
   MachineInstr *DefD = MRI.getVRegDef(BaseOpD->getReg());
   if (!DefS || !DefD || !DefS->isPHI() || !DefD->isPHI())
-    return true;
+    return false;
 
   unsigned InitValS = 0;
   unsigned LoopValS = 0;


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