Make sure the selector emits register register copies with flag operands

linking them to calls when appropriate, this prevents the scheduler from
pulling these copies away from the call.

This fixes Ptrdist/yacr2

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23143 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index f2d65697da7a30b3b1ec32f1f6ceef9fba20cd86..06f363601a42efbb24db76a7e55e9ae35b8f66cf 100644 (file)
--- a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -1512,6 +1512,8 @@ SDOperand PPC32DAGToDAGISel::Select(SDOperand Op) {
       PPC::F8, PPC::F9, PPC::F10, PPC::F11, PPC::F12, PPC::F13
     };
     
+    SDOperand InFlag;  // Null incoming flag value.
+    
     for (unsigned i = 2, e = N->getNumOperands(); i != e; ++i) {
       unsigned DestReg = 0;
       MVT::ValueType RegTy;
@@ -1528,17 +1530,21 @@ SDOperand PPC32DAGToDAGISel::Select(SDOperand Op) {
       }
 
       if (N->getOperand(i).getOpcode() != ISD::UNDEF) {
-        SDOperand Reg = CurDAG->getRegister(DestReg, RegTy);
-        Chain = CurDAG->getNode(ISD::CopyToReg, MVT::Other, Chain, Reg,
-                                Select(N->getOperand(i)));
-        CallOperands.push_back(Reg);
+        Chain = CurDAG->getCopyToReg(Chain, DestReg,
+                                     Select(N->getOperand(i)), InFlag);
+        InFlag = Chain.getValue(1);
+        CallOperands.push_back(CurDAG->getRegister(DestReg, RegTy));
       }
     }
 
     // Finally, once everything is in registers to pass to the call, emit the
     // call itself.
-    CallOperands.push_back(Chain);
-    Chain = CurDAG->getTargetNode(CallOpcode, MVT::Other, CallOperands);
+    if (InFlag.Val)
+      CallOperands.push_back(InFlag);   // Strong dep on register copies.
+    else
+      CallOperands.push_back(Chain);    // Weak dep on whatever occurs before
+    Chain = CurDAG->getTargetNode(CallOpcode, MVT::Other, MVT::Flag,
+                                  CallOperands);
     
     std::vector<SDOperand> CallResults;
     
@@ -1548,18 +1554,22 @@ SDOperand PPC32DAGToDAGISel::Select(SDOperand Op) {
     case MVT::Other: break;
     case MVT::i32:
       if (N->getValueType(1) == MVT::i32) {
-        Chain = CurDAG->getCopyFromReg(Chain, PPC::R4, MVT::i32).getValue(1);
+        Chain = CurDAG->getCopyFromReg(Chain, PPC::R4, MVT::i32, 
+                                       Chain.getValue(1)).getValue(1);
         CallResults.push_back(Chain.getValue(0));
-        Chain = CurDAG->getCopyFromReg(Chain, PPC::R3, MVT::i32).getValue(1);
+        Chain = CurDAG->getCopyFromReg(Chain, PPC::R3, MVT::i32,
+                                       Chain.getValue(1)).getValue(1);
         CallResults.push_back(Chain.getValue(0));
       } else {
-        Chain = CurDAG->getCopyFromReg(Chain, PPC::R3, MVT::i32).getValue(1);
+        Chain = CurDAG->getCopyFromReg(Chain, PPC::R3, MVT::i32,
+                                       Chain.getValue(1)).getValue(1);
         CallResults.push_back(Chain.getValue(0));
       }
       break;
     case MVT::f32:
     case MVT::f64:
-      Chain = CurDAG->getCopyFromReg(Chain, PPC::F1, MVT::f64).getValue(1);
+      Chain = CurDAG->getCopyFromReg(Chain, PPC::F1, MVT::f64,
+                                     Chain.getValue(1)).getValue(1);
       if (N->getValueType(0) == MVT::f64)
         CallResults.push_back(Chain.getValue(0));
       else