PPC: Clean up register save/restore logic.

src/ppc/macro-assembler-ppc.cc

Index: src/ppc/macro-assembler-ppc.cc
diff --git a/src/ppc/macro-assembler-ppc.cc b/src/ppc/macro-assembler-ppc.cc
index 1598f8fee763d28659dc734deb0571360607754d..4ee6323e6616d2384f9c065020c56fe71b23f96c 100644
--- a/src/ppc/macro-assembler-ppc.cc
+++ b/src/ppc/macro-assembler-ppc.cc
@@ -224,30 +224,59 @@ void MacroAssembler::Move(DoubleRegister dst, DoubleRegister src) {
 }
 
 
-void MacroAssembler::MultiPush(RegList regs) {
+void MacroAssembler::MultiPush(RegList regs, Register location) {
   int16_t num_to_push = NumberOfBitsSet(regs);
   int16_t stack_offset = num_to_push * kPointerSize;
 
-  subi(sp, sp, Operand(stack_offset));
-  for (int16_t i = kNumRegisters - 1; i >= 0; i--) {
+  subi(location, location, Operand(stack_offset));
+  for (int16_t i = Register::kNumRegisters - 1; i >= 0; i--) {
     if ((regs & (1 << i)) != 0) {
       stack_offset -= kPointerSize;
-      StoreP(ToRegister(i), MemOperand(sp, stack_offset));
+      StoreP(ToRegister(i), MemOperand(location, stack_offset));
     }
   }
 }
 
 
-void MacroAssembler::MultiPop(RegList regs) {
+void MacroAssembler::MultiPop(RegList regs, Register location) {
   int16_t stack_offset = 0;
 
-  for (int16_t i = 0; i < kNumRegisters; i++) {
+  for (int16_t i = 0; i < Register::kNumRegisters; i++) {
     if ((regs & (1 << i)) != 0) {
-      LoadP(ToRegister(i), MemOperand(sp, stack_offset));
+      LoadP(ToRegister(i), MemOperand(location, stack_offset));
       stack_offset += kPointerSize;
     }
   }
-  addi(sp, sp, Operand(stack_offset));
+  addi(location, location, Operand(stack_offset));
+}
+
+
+void MacroAssembler::MultiPushDoubles(RegList dregs, Register location) {
+  int16_t num_to_push = NumberOfBitsSet(dregs);
+  int16_t stack_offset = num_to_push * kDoubleSize;
+
+  subi(location, location, Operand(stack_offset));
+  for (int16_t i = DoubleRegister::kNumRegisters - 1; i >= 0; i--) {
+    if ((dregs & (1 << i)) != 0) {
+      DoubleRegister dreg = DoubleRegister::from_code(i);
+      stack_offset -= kDoubleSize;
+      stfd(dreg, MemOperand(location, stack_offset));
+    }
+  }
+}
+
+
+void MacroAssembler::MultiPopDoubles(RegList dregs, Register location) {
+  int16_t stack_offset = 0;
+
+  for (int16_t i = 0; i < DoubleRegister::kNumRegisters; i++) {
+    if ((dregs & (1 << i)) != 0) {
+      DoubleRegister dreg = DoubleRegister::from_code(i);
+      lfd(dreg, MemOperand(location, stack_offset));
+      stack_offset += kDoubleSize;
+    }
+  }
+  addi(location, location, Operand(stack_offset));
 }
 
 
@@ -825,7 +854,7 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space) {
 
   // Optionally save all volatile double registers.
   if (save_doubles) {
-    SaveFPRegs(sp, 0, DoubleRegister::kNumVolatileRegisters);
+    MultiPushDoubles(kCallerSavedDoubles);
     // Note that d0 will be accessible at
     //   fp - ExitFrameConstants::kFrameSize -
     //   kNumVolatileRegisters * kDoubleSize,
@@ -891,7 +920,7 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles, Register argument_count,
     const int offset =
         (ExitFrameConstants::kFrameSize + kNumRegs * kDoubleSize);
     addi(r6, fp, Operand(-offset));
-    RestoreFPRegs(r6, 0, kNumRegs);
+    MultiPopDoubles(kCallerSavedDoubles, r6);
   }
 
   // Clear top frame.
@@ -2955,28 +2984,6 @@ void MacroAssembler::InitializeFieldsWithFiller(Register start_offset,
 }
 
 
-void MacroAssembler::SaveFPRegs(Register location, int first, int count) {
-  DCHECK(count > 0);
-  int cur = first;
-  subi(location, location, Operand(count * kDoubleSize));
-  for (int i = 0; i < count; i++) {
-    DoubleRegister reg = DoubleRegister::from_code(cur++);
-    stfd(reg, MemOperand(location, i * kDoubleSize));
-  }
-}
-
-
-void MacroAssembler::RestoreFPRegs(Register location, int first, int count) {
-  DCHECK(count > 0);
-  int cur = first + count - 1;
-  for (int i = count - 1; i >= 0; i--) {
-    DoubleRegister reg = DoubleRegister::from_code(cur--);
-    lfd(reg, MemOperand(location, i * kDoubleSize));
-  }
-  addi(location, location, Operand(count * kDoubleSize));
-}
-
-
 void MacroAssembler::JumpIfBothInstanceTypesAreNotSequentialOneByte(
     Register first, Register second, Register scratch1, Register scratch2,
     Label* failure) {