Implement the getRegForInlineAsmConstraint method for PPC. With recent

sdisel changes, this eliminates a ton of copies around common inline asms.
For example:

int test2(int Y, int X) {
  asm("foo %0, %1" : "=r"(X): "r"(X));
  return X;
}

now compiles to:

_test2:
        foo r3, r4
        blr

instead of:

_test2:
        mr r2, r4
        foo r2, r2
        mr r3, r2
        blr

GCC produces:

_test2:
        foo r4, r4
        mr r3,r4
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31367 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 4 deletions

diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 06a51ae5eb..2d4ec1d3d7 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -18,6 +18,7 @@
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/CodeGen/SelectionDAG.h"
 #include "PPC.h"
+#include "PPCSubtarget.h"
 
 namespace llvm {
   namespace PPCISD {
@@ -168,8 +169,9 @@ namespace llvm {
   class PPCTargetLowering : public TargetLowering {
     int VarArgsFrameIndex;            // FrameIndex for start of varargs area.
     int ReturnAddrIndex;              // FrameIndex for return slot.
+    const PPCSubtarget &PPCSubTarget;
   public:
-    PPCTargetLowering(TargetMachine &TM);
+    PPCTargetLowering(PPCTargetMachine &TM);
     
     /// getTargetNodeName() - This method returns the name of a target specific
     /// DAG node.
@@ -191,9 +193,9 @@ namespace llvm {
                                                        MachineBasicBlock *MBB);
     
     ConstraintType getConstraintType(char ConstraintLetter) const;
-    std::vector<unsigned> 
-      getRegClassForInlineAsmConstraint(const std::string &Constraint,
-                                        MVT::ValueType VT) const;
+    std::pair<unsigned, const TargetRegisterClass*> 
+      getRegForInlineAsmConstraint(const std::string &Constraint,
+                                   MVT::ValueType VT) const;
     SDOperand isOperandValidForConstraint(SDOperand Op, char ConstraintLetter,
                                           SelectionDAG &DAG);