Make a new reg class for 64 bit regs that aliases the 32 bit regs. This

will have to tide us over until we get real subreg support, but it prevents
the PrologEpilogInserter from spilling 8 byte GPRs on a G4 processor.

Add some initial support for TRUNCATE and ANY_EXTEND, but they don't
currently work due to issues with ScheduleDAG.  Something wll have to be
figured out.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23803 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/PPCISelDAGToDAG.cpp

@@ -219,6 +219,11 @@ static bool isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
 // and mask opcode and mask operation.
 static bool isRotateAndMask(SDNode *N, unsigned Mask, bool IsShiftMask,
                             unsigned &SH, unsigned &MB, unsigned &ME) {
+  // Don't even go down this path for i64, since different logic will be
+  // necessary for rldicl/rldicr/rldimi.
+  if (N->getValueType(0) != MVT::i32)
+    return false;
+
   unsigned Shift  = 32;
   unsigned Indeterminant = ~0;  // bit mask marking indeterminant results
   unsigned Opcode = N->getOpcode();
@@ -1206,14 +1211,27 @@ SDOperand PPCDAGToDAGISel::Select(SDOperand Op) {
       
     // Other cases are autogenerated.
     break;
+  case ISD::TRUNCATE: {
+    assert(N->getValueType(0) == MVT::i32 && 
+           N->getOperand(0).getValueType() == MVT::i64 &&
+           "TRUNCATE only supported for i64 -> i32");
+    // FIXME: this code breaks ScheduleDAG since Op0 is an i64 and OR4
+    // takes i32s.
+    SDOperand Op0 = Select(N->getOperand(0));
+    CurDAG->SelectNodeTo(N, PPC::OR4, MVT::i32, Op0, Op0);
+    break;
+  }
   case ISD::ANY_EXTEND:
     switch(N->getValueType(0)) {
     default: assert(0 && "Unhandled type in ANY_EXTEND");
-    case MVT::i64:
-      CurDAG->SelectNodeTo(N, PPC::OR8, MVT::i64, Select(N->getOperand(0)), 
-                           Select(N->getOperand(0)));
+    case MVT::i64: {
+      // FIXME: this code breaks ScheduleDAG since Op0 is an i32 and OR8
+      // takes i64s.
+      SDOperand Op0 = Select(N->getOperand(0));
+      CurDAG->SelectNodeTo(N, PPC::OR8, MVT::i64, Op0, Op0);
       break;
     }
+    }
     return SDOperand(N, 0);
   case ISD::ZERO_EXTEND:
     assert(N->getValueType(0) == MVT::i64 && 

lib/Target/PowerPC/PPCInstrInfo.td

@@ -703,7 +703,6 @@ def : Pat<(xor GPRC:$in, imm:$imm),
           (XORIS (XORI GPRC:$in, (LO16 imm:$imm)), (HI16 imm:$imm))>;
 
 
-
 // Same as above, but using a temporary. FIXME: implement temporaries :)
 /*
 def : Pattern<(xor GPRC:$in, imm:$imm),

lib/Target/PowerPC/PPCRegisterInfo.td

@@ -21,6 +21,12 @@ class GPR<bits<5> num, string n> : PPCReg<n> {
   field bits<5> Num = num;
 }
 
+// GP8 - One of the 32 64-bit general-purpose registers
+class GP8<bits<5> num, string n, Register Alias> : PPCReg<n> {
+  field bits<5> Num = num;
+  let Aliases = [Alias];
+}   
+
 // SPR - One of the 32-bit special-purpose registers
 class SPR<bits<5> num, string n> : PPCReg<n> {
   field bits<5> Num = num;
@@ -54,6 +60,24 @@ def R26 : GPR<26, "r26">;  def R27 : GPR<27, "r27">;
 def R28 : GPR<28, "r28">;  def R29 : GPR<29, "r29">;
 def R30 : GPR<30, "r30">;  def R31 : GPR<31, "r31">;
 
+// 64-bit General-purpose registers
+def X0  : GP8< 0,  "r0",  R0>;  def X1  : GP8< 1,  "r1",  R1>;
+def X2  : GP8< 2,  "r2",  R2>;  def X3  : GP8< 3,  "r3",  R3>;
+def X4  : GP8< 4,  "r4",  R4>;  def X5  : GP8< 5,  "r5",  R5>;
+def X6  : GP8< 6,  "r6",  R6>;  def X7  : GP8< 7,  "r7",  R7>;
+def X8  : GP8< 8,  "r8",  R8>;  def X9  : GP8< 9,  "r9",  R9>;
+def X10 : GP8<10, "r10", R10>;  def X11 : GP8<11, "r11", R11>;
+def X12 : GP8<12, "r12", R12>;  def X13 : GP8<13, "r13", R13>;
+def X14 : GP8<14, "r14", R14>;  def X15 : GP8<15, "r15", R15>;
+def X16 : GP8<16, "r16", R16>;  def X17 : GP8<17, "r17", R17>;
+def X18 : GP8<18, "r18", R18>;  def X19 : GP8<19, "r19", R19>;
+def X20 : GP8<20, "r20", R20>;  def X21 : GP8<21, "r21", R21>;
+def X22 : GP8<22, "r22", R22>;  def X23 : GP8<23, "r23", R23>;
+def X24 : GP8<24, "r24", R24>;  def X25 : GP8<25, "r25", R25>;
+def X26 : GP8<26, "r26", R26>;  def X27 : GP8<27, "r27", R27>;
+def X28 : GP8<28, "r28", R28>;  def X29 : GP8<29, "r29", R29>;
+def X30 : GP8<30, "r30", R30>;  def X31 : GP8<31, "r31", R31>;
+
 // Floating-point registers
 def F0  : FPR< 0,  "f0">;  def F1  : FPR< 1,  "f1">;
 def F2  : FPR< 2,  "f2">;  def F3  : FPR< 3,  "f3">;
@@ -111,9 +135,9 @@ def GPRC : RegisterClass<"PPC", i32, 32,
   }];
 }
 def G8RC : RegisterClass<"PPC", i64, 64,
-     [R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12,
-      R30, R29, R28, R27, R26, R25, R24, R23, R22, R21, R20, R19, R18, R17,
-      R16, R15, R14, R13, R31, R0, R1, LR]>
+     [X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12,
+      X30, X29, X28, X27, X26, X25, X24, X23, X22, X21, X20, X19, X18, X17,
+      X16, X15, X14, X13, X31, X0, X1]>
 {
   let MethodProtos = [{
     iterator allocation_order_begin(MachineFunction &MF) const;
@@ -127,9 +151,9 @@ def G8RC : RegisterClass<"PPC", i64, 64,
     G8RCClass::iterator
     G8RCClass::allocation_order_end(MachineFunction &MF) const {
       if (hasFP(MF))
-        return end()-4;
-      else
         return end()-3;
+      else
+        return end()-2;
     }
   }];
 }