TiedTo flag can now be placed on implicit operands. isTwoAddrUse() should look

at all of the operands. Previously it was skipping over implicit operands which
cause infinite looping when the two-address pass try to reschedule a
two-address instruction below the kill of tied operand.

I'm unable to come up with a reasonably sized test case.
rdar://13747577

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180906 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index 3614bdb7bbd4463ac88699d0793390489c43c76f..7ca2beef65155989c437e0336d5cafae807580ef 100644 (file)
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -62,7 +62,8 @@ STATISTIC(NumReSchedDowns,     "Number of instructions re-scheduled down");
 // Temporary flag to disable rescheduling.
 static cl::opt<bool>
 EnableRescheduling("twoaddr-reschedule",
-                   cl::desc("Coalesce copies by rescheduling (default=true)"), cl::init(true), cl::Hidden);
+                   cl::desc("Coalesce copies by rescheduling (default=true)"),
+                   cl::init(true), cl::Hidden);
 
 namespace {
 class TwoAddressInstructionPass : public MachineFunctionPass {
@@ -432,10 +433,7 @@ static bool isKilled(MachineInstr &MI, unsigned Reg,
 /// isTwoAddrUse - Return true if the specified MI uses the specified register
 /// as a two-address use. If so, return the destination register by reference.
 static bool isTwoAddrUse(MachineInstr &MI, unsigned Reg, unsigned &DstReg) {
-  const MCInstrDesc &MCID = MI.getDesc();
-  unsigned NumOps = MI.isInlineAsm()
-    ? MI.getNumOperands() : MCID.getNumOperands();
-  for (unsigned i = 0; i != NumOps; ++i) {
+  for (unsigned i = 0, NumOps = MI.getNumOperands(); i != NumOps; ++i) {
     const MachineOperand &MO = MI.getOperand(i);
     if (!MO.isReg() || !MO.isUse() || MO.getReg() != Reg)
       continue;