From 7c88cdcc3ba49101fa119ec3b403e9980934384e Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Thu, 28 Oct 2010 01:46:29 +0000
Subject: [PATCH] Fix a major bug in operand latency computation. The use index
 must be adjusted by the number of defs first for it to match the instruction
 itinerary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117518 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 0ffb4da0f36..d34a52d8014 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -454,6 +454,9 @@ void ScheduleDAGSDNodes::ComputeOperandLatency(SDNode *Def, SDNode *Use,
     return;
 
   unsigned DefIdx = Use->getOperand(OpIdx).getResNo();
+  if (Use->isMachineOpcode())
+    // Adjust the use operand index by num of defs.
+    OpIdx += TII->get(Use->getMachineOpcode()).getNumDefs();
   int Latency = TII->getOperandLatency(InstrItins, Def, DefIdx, Use, OpIdx);
   if (Latency >= 0)
     dep.setLatency(Latency);
-- 
2.34.1