[llvm-commits] CVS: llvm/lib/Target/PowerPC/PPC32ISelDAGToDAG.cpp

[Nate Begeman]

Changes in directory llvm/lib/Target/PowerPC:

PPC32ISelDAGToDAG.cpp updated: 1.1 -> 1.2
---
Log message:

Teach the DAG->DAG ISel about FNEG, and how it can be used to invert 
several of the PowerPC opcodes that come in both negated and non-negated
forms.


---
Diffs of the changes:  (+29 -2)

 PPC32ISelDAGToDAG.cpp |   31 +++++++++++++++++++++++++++++--
 1 files changed, 29 insertions(+), 2 deletions(-)


Index: llvm/lib/Target/PowerPC/PPC32ISelDAGToDAG.cpp
diff -u llvm/lib/Target/PowerPC/PPC32ISelDAGToDAG.cpp:1.1 llvm/lib/Target/PowerPC/PPC32ISelDAGToDAG.cpp:1.2
--- llvm/lib/Target/PowerPC/PPC32ISelDAGToDAG.cpp:1.1	Wed Aug 17 14:33:03 2005
+++ llvm/lib/Target/PowerPC/PPC32ISelDAGToDAG.cpp	Wed Aug 17 18:46:35 2005
@@ -199,7 +199,6 @@
       break;
     }
   }
-
   case ISD::ADD: {
     MVT::ValueType Ty = N->getValueType(0);
     if (Ty == MVT::i32) {
@@ -281,7 +280,35 @@
                          Select(N->getOperand(0)),
                          Select(N->getOperand(1)));
     break;
-  }    
+  }
+  case ISD::FNEG: {
+    SDOperand Val = Select(N->getOperand(0));
+    MVT::ValueType Ty = N->getValueType(0);
+    if (Val.Val->hasOneUse()) {
+      unsigned Opc;
+      switch (Val.getTargetOpcode()) {
+      default:          Opc = 0;            break;
+      case PPC::FABS:   Opc = PPC::FNABS;   break;
+      case PPC::FMADD:  Opc = PPC::FNMADD;  break;
+      case PPC::FMADDS: Opc = PPC::FNMADDS; break;
+      case PPC::FMSUB:  Opc = PPC::FNMSUB;  break;
+      case PPC::FMSUBS: Opc = PPC::FNMSUBS; break;
+      }
+      // If we inverted the opcode, then emit the new instruction with the
+      // inverted opcode and the original instruction's operands.  Otherwise, 
+      // fall through and generate a fneg instruction.
+      if (Opc) {
+        if (PPC::FNABS == Opc)
+          CurDAG->SelectNodeTo(N, Ty, Opc, Val.getOperand(0));
+        else
+          CurDAG->SelectNodeTo(N, Ty, Opc, Val.getOperand(0),
+                               Val.getOperand(1), Val.getOperand(2));
+        break;
+      }
+    }
+    CurDAG->SelectNodeTo(N, Ty, PPC::FNEG, Val);
+    break;
+  }
   case ISD::RET: {
     SDOperand Chain = Select(N->getOperand(0));     // Token chain.