Reapply bottom-up fast-isel, with several fixes for x86-32:

 - Check getBytesToPopOnReturn().
 - Eschew ST0 and ST1 for return values.
 - Fix the PIC base register initialization so that it doesn't ever
   fail to end up the top of the entry block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108039 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 8 deletions

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 2d083105ea..2673eba3f3 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -519,13 +519,13 @@ static void ProcessSourceNode(SDNode *N, SelectionDAG *DAG,
     return;
 
   MachineBasicBlock *BB = Emitter.getBlock();
-  if (BB->empty() || BB->back().isPHI()) {
+  if (Emitter.getInsertPos() == BB->begin() || BB->back().isPHI()) {
     // Did not insert any instruction.
     Orders.push_back(std::make_pair(Order, (MachineInstr*)0));
     return;
   }
 
-  Orders.push_back(std::make_pair(Order, &BB->back()));
+  Orders.push_back(std::make_pair(Order, prior(Emitter.getInsertPos())));
   if (!N->getHasDebugValue())
     return;
   // Opportunistically insert immediate dbg_value uses, i.e. those with source
@@ -564,7 +564,7 @@ MachineBasicBlock *ScheduleDAGSDNodes::EmitSchedule() {
     for (; PDI != PDE; ++PDI) {
       MachineInstr *DbgMI= Emitter.EmitDbgValue(*PDI, VRBaseMap);
       if (DbgMI)
-        BB->push_back(DbgMI);
+        BB->insert(InsertPos, DbgMI);
     }
   }
 
@@ -608,9 +608,7 @@ MachineBasicBlock *ScheduleDAGSDNodes::EmitSchedule() {
   // Insert all the dbg_values which have not already been inserted in source
   // order sequence.
   if (HasDbg) {
-    MachineBasicBlock::iterator BBBegin = BB->empty() ? BB->end() : BB->begin();
-    while (BBBegin != BB->end() && BBBegin->isPHI())
-      ++BBBegin;
+    MachineBasicBlock::iterator BBBegin = BB->getFirstNonPHI();
 
     // Sort the source order instructions and use the order to insert debug
     // values.
@@ -626,7 +624,6 @@ MachineBasicBlock *ScheduleDAGSDNodes::EmitSchedule() {
       // Insert all SDDbgValue's whose order(s) are before "Order".
       if (!MI)
         continue;
-      MachineBasicBlock *MIBB = MI->getParent();
 #ifndef NDEBUG
       unsigned LastDIOrder = 0;
 #endif
@@ -646,7 +643,7 @@ MachineBasicBlock *ScheduleDAGSDNodes::EmitSchedule() {
             BB->insert(BBBegin, DbgMI);
           else {
             MachineBasicBlock::iterator Pos = MI;
-            MIBB->insert(llvm::next(Pos), DbgMI);
+            BB->insert(llvm::next(Pos), DbgMI);
           }
         }
       }