Move a few containers out of ScheduleDAGInstrs::BuildSchedGraph
and into the ScheduleDAGInstrs class, so that they don't get
destructed and re-constructed for each block. This fixes a
compile-time hot spot in the post-pass scheduler.

To help facilitate this, tidy and do some minor reorganization
in the scheduler constructor functions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62275 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
index e93d4a6..282b533 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
@@ -381,7 +381,7 @@
     unsigned SubIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
 
     // Create the extract_subreg machine instruction.
-    MachineInstr *MI = BuildMI(*MF, TII->get(TargetInstrInfo::EXTRACT_SUBREG));
+    MachineInstr *MI = BuildMI(MF, TII->get(TargetInstrInfo::EXTRACT_SUBREG));
 
     // Figure out the register class to create for the destreg.
     unsigned VReg = getVR(Node->getOperand(0), VRBaseMap);
@@ -427,7 +427,7 @@
     }
     
     // Create the insert_subreg or subreg_to_reg machine instruction.
-    MachineInstr *MI = BuildMI(*MF, TII->get(Opc));
+    MachineInstr *MI = BuildMI(MF, TII->get(Opc));
     MI->addOperand(MachineOperand::CreateReg(VRBase, true));
     
     // If creating a subreg_to_reg, then the first input operand
@@ -484,7 +484,7 @@
 #endif
 
     // Create the new machine instruction.
-    MachineInstr *MI = BuildMI(*MF, II);
+    MachineInstr *MI = BuildMI(MF, II);
     
     // Add result register values for things that are defined by this
     // instruction.
@@ -568,7 +568,7 @@
       --NumOps;  // Ignore the flag operand.
       
     // Create the inline asm machine instruction.
-    MachineInstr *MI = BuildMI(*MF, TII->get(TargetInstrInfo::INLINEASM));
+    MachineInstr *MI = BuildMI(MF, TII->get(TargetInstrInfo::INLINEASM));
 
     // Add the asm string as an external symbol operand.
     const char *AsmStr =