Pass an explicit operand number to addLiveIns.

Not all instructions define a virtual register in their first operand.
Specifically, INLINEASM has a different format.

<rdar://problem/12472811>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165721 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 40 insertions, 8 deletions

diff --git a/lib/CodeGen/MachineTraceMetrics.cpp b/lib/CodeGen/MachineTraceMetrics.cpp
index b3abec76bc..9686b04132 100644
--- a/lib/CodeGen/MachineTraceMetrics.cpp
+++ b/lib/CodeGen/MachineTraceMetrics.cpp
@@ -850,14 +850,14 @@ static bool pushDepHeight(const DataDep &Dep,
   return false;
 }
 
-/// Assuming that DefMI was used by Trace.back(), add it to the live-in lists
-/// of all the blocks in Trace. Stop when reaching the block that contains
-/// DefMI.
+/// Assuming that the virtual register defined by DefMI:DefOp was used by
+/// Trace.back(), add it to the live-in lists of all the blocks in Trace. Stop
+/// when reaching the block that contains DefMI.
 void MachineTraceMetrics::Ensemble::
-addLiveIns(const MachineInstr *DefMI,
+addLiveIns(const MachineInstr *DefMI, unsigned DefOp,
            ArrayRef<const MachineBasicBlock*> Trace) {
   assert(!Trace.empty() && "Trace should contain at least one block");
-  unsigned Reg = DefMI->getOperand(0).getReg();
+  unsigned Reg = DefMI->getOperand(DefOp).getReg();
   assert(TargetRegisterInfo::isVirtualRegister(Reg));
   const MachineBasicBlock *DefMBB = DefMI->getParent();
 
@@ -950,7 +950,7 @@ computeInstrHeights(const MachineBasicBlock *MBB) {
           DEBUG(dbgs() << "pred\t" << Height << '\t' << *PHI);
           if (pushDepHeight(Deps.front(), PHI, Height,
                             Heights, MTM.SchedModel, MTM.TII))
-            addLiveIns(Deps.front().DefMI, Stack);
+            addLiveIns(Deps.front().DefMI, Deps.front().DefOp, Stack);
         }
       }
     }
@@ -983,7 +983,7 @@ computeInstrHeights(const MachineBasicBlock *MBB) {
       // Update the required height of any virtual registers read by MI.
       for (unsigned i = 0, e = Deps.size(); i != e; ++i)
         if (pushDepHeight(Deps[i], MI, Cycle, Heights, MTM.SchedModel, MTM.TII))
-          addLiveIns(Deps[i].DefMI, Stack);
+          addLiveIns(Deps[i].DefMI, Deps[i].DefOp, Stack);
 
       InstrCycles &MICycles = Cycles[MI];
       MICycles.Height = Cycle;
diff --git a/lib/CodeGen/MachineTraceMetrics.h b/lib/CodeGen/MachineTraceMetrics.h
index 5f3b1d23e4..460730b040 100644
--- a/lib/CodeGen/MachineTraceMetrics.h
+++ b/lib/CodeGen/MachineTraceMetrics.h
@@ -279,7 +279,7 @@ public:
     unsigned computeCrossBlockCriticalPath(const TraceBlockInfo&);
     void computeInstrDepths(const MachineBasicBlock*);
     void computeInstrHeights(const MachineBasicBlock*);
-    void addLiveIns(const MachineInstr *DefMI,
+    void addLiveIns(const MachineInstr *DefMI, unsigned DefOp,
                     ArrayRef<const MachineBasicBlock*> Trace);
 
   protected:
diff --git a/test/CodeGen/X86/early-ifcvt-crash.ll b/test/CodeGen/X86/early-ifcvt-crash.ll
new file mode 100644
index 0000000000..c828026968
--- /dev/null
+++ b/test/CodeGen/X86/early-ifcvt-crash.ll
@@ -0,0 +1,32 @@
+; RUN: llc < %s -x86-early-ifcvt -verify-machineinstrs
+; RUN: llc < %s -x86-early-ifcvt -stress-early-ifcvt -verify-machineinstrs
+;
+; Run these tests with and without -stress-early-ifcvt to exercise heuristics.
+;
+target triple = "x86_64-apple-macosx10.8.0"
+
+; MachineTraceMetrics::Ensemble::addLiveIns crashes because the first operand
+; on an inline asm instruction is not a vreg def.
+; <rdar://problem/12472811>
+define void @f1() nounwind {
+entry:
+  br i1 undef, label %if.then6.i, label %if.end.i
+
+if.then6.i:
+  br label %if.end.i
+
+if.end.i:
+  br i1 undef, label %if.end25.i, label %if.else17.i
+
+if.else17.i:
+  %shl24.i = shl i32 undef, undef
+  br label %if.end25.i
+
+if.end25.i:
+  %storemerge31.i = phi i32 [ %shl24.i, %if.else17.i ], [ 0, %if.end.i ]
+  store i32 %storemerge31.i, i32* undef, align 4
+  %0 = tail call i32 asm sideeffect "", "=r,r,i,i"(i32 undef, i32 15, i32 1) nounwind
+  %conv = trunc i32 %0 to i8
+  store i8 %conv, i8* undef, align 1
+  unreachable
+}