[x64] Get rid of the stupid SmiConstantRegister.

src/x64/macro-assembler-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 1070 matching lines @@
   }
 }
 
 
 Register MacroAssembler::GetSmiConstant(Smi* source) {
   int value = source->value();
   if (value == 0) {
     xorl(kScratchRegister, kScratchRegister);
     return kScratchRegister;
   }
-  if (value == 1) {
-    return kSmiConstantRegister;
-  }
   LoadSmiConstant(kScratchRegister, source);
   return kScratchRegister;
 }
 
 
 void MacroAssembler::LoadSmiConstant(Register dst, Smi* source) {
-  if (emit_debug_code()) {
-    Move(dst, Smi::FromInt(kSmiConstantRegisterValue),
-         Assembler::RelocInfoNone());
-    cmpp(dst, kSmiConstantRegister);
-    Assert(equal, kUninitializedKSmiConstantRegister);
-  }
-  int value = source->value();
-  if (value == 0) {
-    xorl(dst, dst);
-    return;
-  }
-  bool negative = value < 0;
-  unsigned int uvalue = negative ? -value : value;
-
-  switch (uvalue) {
-    case 9:
-      leap(dst,
-           Operand(kSmiConstantRegister, kSmiConstantRegister, times_8, 0));
-      break;
-    case 8:
-      xorl(dst, dst);
-      leap(dst, Operand(dst, kSmiConstantRegister, times_8, 0));
-      break;
-    case 4:
-      xorl(dst, dst);
-      leap(dst, Operand(dst, kSmiConstantRegister, times_4, 0));
-      break;
-    case 5:
-      leap(dst,
-           Operand(kSmiConstantRegister, kSmiConstantRegister, times_4, 0));
-      break;
-    case 3:
-      leap(dst,
-           Operand(kSmiConstantRegister, kSmiConstantRegister, times_2, 0));
-      break;
-    case 2:
-      leap(dst,
-           Operand(kSmiConstantRegister, kSmiConstantRegister, times_1, 0));
-      break;
-    case 1:
-      movp(dst, kSmiConstantRegister);
-      break;
-    case 0:
-      UNREACHABLE();
-      return;
-    default:
-      Move(dst, source, Assembler::RelocInfoNone());
-      return;
-  }
-  if (negative) {
-    negp(dst);
-  }
+  Move(dst, source, Assembler::RelocInfoNone());
 }
 
 
 void MacroAssembler::Integer32ToSmi(Register dst, Register src) {
   STATIC_ASSERT(kSmiTag == 0);
   if (!dst.is(src)) {
     movl(dst, src);
   }
   shlp(dst, Immediate(kSmiShift));
 }
@@ skipping 272 matching lines @@
     if (!scratch.is(first)) {
       movl(scratch, first);
     }
     andl(scratch, second);
   }
   testb(scratch, Immediate(kSmiTagMask));
   return zero;
 }
 
 
-Condition MacroAssembler::CheckIsMinSmi(Register src) {
-  ASSERT(!src.is(kScratchRegister));
-  // If we overflow by subtracting one, it's the minimal smi value.
-  cmpp(src, kSmiConstantRegister);
-  return overflow;
-}
-
-
 Condition MacroAssembler::CheckInteger32ValidSmiValue(Register src) {
   if (SmiValuesAre32Bits()) {
     // A 32-bit integer value can always be converted to a smi.
     return always;
   } else {
     ASSERT(SmiValuesAre31Bits());
     cmpl(src, Immediate(0xc0000000));
     return positive;
   }
 }
@@ skipping 118 matching lines @@
 
 
 void MacroAssembler::SmiAddConstant(Register dst, Register src, Smi* constant) {
   if (constant->value() == 0) {
     if (!dst.is(src)) {
       movp(dst, src);
     }
     return;
   } else if (dst.is(src)) {
     ASSERT(!dst.is(kScratchRegister));
-    switch (constant->value()) {
-      case 1:
-        addp(dst, kSmiConstantRegister);
-        return;
-      case 2:
-        leap(dst, Operand(src, kSmiConstantRegister, times_2, 0));
-        return;
-      case 4:
-        leap(dst, Operand(src, kSmiConstantRegister, times_4, 0));
-        return;
-      case 8:
-        leap(dst, Operand(src, kSmiConstantRegister, times_8, 0));
-        return;
-      default:
-        Register constant_reg = GetSmiConstant(constant);
-        addp(dst, constant_reg);
-        return;
-    }
+    Register constant_reg = GetSmiConstant(constant);
+    addp(dst, constant_reg);
   } else {
-    switch (constant->value()) {
-      case 1:
-        leap(dst, Operand(src, kSmiConstantRegister, times_1, 0));
-        return;
-      case 2:
-        leap(dst, Operand(src, kSmiConstantRegister, times_2, 0));
-        return;
-      case 4:
-        leap(dst, Operand(src, kSmiConstantRegister, times_4, 0));
-        return;
-      case 8:
-        leap(dst, Operand(src, kSmiConstantRegister, times_8, 0));
-        return;
-      default:
-        LoadSmiConstant(dst, constant);
-        addp(dst, src);
-        return;
-    }
+    LoadSmiConstant(dst, constant);
+    addp(dst, src);
   }
 }
 
 
 void MacroAssembler::SmiAddConstant(const Operand& dst, Smi* constant) {
   if (constant->value() != 0) {
     if (SmiValuesAre32Bits()) {
       addl(Operand(dst, kSmiShift / kBitsPerByte),
            Immediate(constant->value()));
     } else {
@@ skipping 1256 matching lines @@
     leal(rsp, Operand(rsp, 4));
   }
 }
 
 
 void MacroAssembler::Pop(const Operand& dst) {
   if (kPointerSize == kInt64Size) {
     popq(dst);
   } else {
     Register scratch = dst.AddressUsesRegister(kScratchRegister)
-        ? kSmiConstantRegister : kScratchRegister;
+        ? kRootRegister : kScratchRegister;
     movp(scratch, Operand(rsp, 0));
     movp(dst, scratch);
     leal(rsp, Operand(rsp, 4));
-    if (scratch.is(kSmiConstantRegister)) {
-      // Restore kSmiConstantRegister.
-      movp(kSmiConstantRegister,
-           reinterpret_cast<void*>(Smi::FromInt(kSmiConstantRegisterValue)),
-           Assembler::RelocInfoNone());
+    if (scratch.is(kRootRegister)) {
+      // Restore kRootRegister.
+      InitializeRootRegister();
     }
   }
 }
 
 
 void MacroAssembler::PopQuad(const Operand& dst) {
   if (kPointerSize == kInt64Size) {
     popq(dst);
   } else {
     popq(kScratchRegister);
@@ skipping 122 matching lines @@
   Push(rcx);
   Push(rdx);
   Push(rbx);
   // Not pushing rsp or rbp.
   Push(rsi);
   Push(rdi);
   Push(r8);
   Push(r9);
   // r10 is kScratchRegister.
   Push(r11);
-  // r12 is kSmiConstantRegister.
+  // TODO(bmeurer): r12 is kSmiConstantRegister.

[rmcilroy, 2014/08/01 14:46:57]

nit - r12 is currently unused (will be kConstantPoolPointer)

   // r13 is kRootRegister.
   Push(r14);
   Push(r15);
   STATIC_ASSERT(11 == kNumSafepointSavedRegisters);
   // Use lea for symmetry with Popad.
   int sp_delta =
       (kNumSafepointRegisters - kNumSafepointSavedRegisters) * kPointerSize;
   leap(rsp, Operand(rsp, -sp_delta));
 }
 
@@ skipping 2311 matching lines @@
   if (ms.shift() > 0) sarl(rdx, Immediate(ms.shift()));
   movl(rax, dividend);
   shrl(rax, Immediate(31));
   addl(rdx, rax);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64