ARM: Smi refactoring and improvements.

src/arm/macro-assembler-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 477 matching lines @@
 
   if (emit_debug_code()) {
     ldr(ip, MemOperand(address));
     cmp(ip, value);
     Check(eq, "Wrong address or value passed to RecordWrite");
   }
 
   Label done;
 
   if (smi_check == INLINE_SMI_CHECK) {
-    ASSERT_EQ(0, kSmiTag);
-    tst(value, Operand(kSmiTagMask));
-    b(eq, &done);
+    JumpIfSmi(value, &done);
   }
 
   CheckPageFlag(value,
                 value,  // Used as scratch.
                 MemoryChunk::kPointersToHereAreInterestingMask,
                 eq,
                 &done);
   CheckPageFlag(object,
                 value,  // Used as scratch.
                 MemoryChunk::kPointersFromHereAreInterestingMask,
@@ skipping 460 matching lines @@
   add(ip, sp, Operand(kPointerSize));
   str(ip, MemOperand(fp, ExitFrameConstants::kSPOffset));
 }
 
 
 void MacroAssembler::InitializeNewString(Register string,
                                          Register length,
                                          Heap::RootListIndex map_index,
                                          Register scratch1,
                                          Register scratch2) {
-  mov(scratch1, Operand(length, LSL, kSmiTagSize));
+  SmiTag(scratch1, length);
   LoadRoot(scratch2, map_index);
   str(scratch1, FieldMemOperand(string, String::kLengthOffset));
   mov(scratch1, Operand(String::kEmptyHashField));
   str(scratch2, FieldMemOperand(string, HeapObject::kMapOffset));
   str(scratch1, FieldMemOperand(string, String::kHashFieldOffset));
 }
 
 
 int MacroAssembler::ActivationFrameAlignment() {
 #if defined(V8_HOST_ARCH_ARM)
@@ skipping 222 matching lines @@
   ASSERT(fun.is(r1));
 
   Register expected_reg = r2;
   Register code_reg = r3;
 
   ldr(code_reg, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
   ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
   ldr(expected_reg,
       FieldMemOperand(code_reg,
                       SharedFunctionInfo::kFormalParameterCountOffset));
-  mov(expected_reg, Operand(expected_reg, ASR, kSmiTagSize));
+  SmiUntag(expected_reg);
   ldr(code_reg,
       FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
 
   ParameterCount expected(expected_reg);
   InvokeCode(code_reg, expected, actual, flag, call_wrapper, call_kind);
 }
 
 
 void MacroAssembler::InvokeFunction(Handle<JSFunction> function,
                                     const ParameterCount& expected,
@@ skipping 117 matching lines @@
 
 void MacroAssembler::JumpToHandlerEntry() {
   // Compute the handler entry address and jump to it.  The handler table is
   // a fixed array of (smi-tagged) code offsets.
   // r0 = exception, r1 = code object, r2 = state.
   ldr(r3, FieldMemOperand(r1, Code::kHandlerTableOffset));  // Handler table.
   add(r3, r3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   mov(r2, Operand(r2, LSR, StackHandler::kKindWidth));  // Handler index.
   ldr(r2, MemOperand(r3, r2, LSL, kPointerSizeLog2));  // Smi-tagged offset.
   add(r1, r1, Operand(Code::kHeaderSize - kHeapObjectTag));  // Code start.
-  add(pc, r1, Operand(r2, ASR, kSmiTagSize));  // Jump.
+  add(pc, r1, Operand::SmiUntag(r2));  // Jump
 }
 
 
 void MacroAssembler::Throw(Register value) {
   // Adjust this code if not the case.
   STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
   STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
@@ skipping 195 matching lines @@
   //
   // t1 - used to hold the capacity mask of the dictionary
   //
   // t2 - used for the index into the dictionary.
   Label done;
 
   GetNumberHash(t0, t1);
 
   // Compute the capacity mask.
   ldr(t1, FieldMemOperand(elements, SeededNumberDictionary::kCapacityOffset));
-  mov(t1, Operand(t1, ASR, kSmiTagSize));  // convert smi to int
+  SmiUntag(t1);
   sub(t1, t1, Operand(1));
 
   // Generate an unrolled loop that performs a few probes before giving up.
   static const int kProbes = 4;
   for (int i = 0; i < kProbes; i++) {
     // Use t2 for index calculations and keep the hash intact in t0.
     mov(t2, t0);
     // Compute the masked index: (hash + i + i * i) & mask.
     if (i > 0) {
       add(t2, t2, Operand(SeededNumberDictionary::GetProbeOffset(i)));
@@ skipping 499 matching lines @@
   // Force a canonical NaN.
   if (emit_debug_code()) {
     vmrs(ip);
     tst(ip, Operand(kVFPDefaultNaNModeControlBit));
     Assert(ne, "Default NaN mode not set");
   }
   VFPCanonicalizeNaN(d0);
   b(&store);
 
   bind(&smi_value);
-  Register untagged_value = scratch1;
-  SmiUntag(untagged_value, value_reg);
-  vmov(s2, untagged_value);
-  vcvt_f64_s32(d0, s2);
+  SmiToDouble(d0, value_reg);
 
   bind(&store);
-  add(scratch1, elements_reg,
-      Operand(key_reg, LSL, kDoubleSizeLog2 - kSmiTagSize));
+  add(scratch1, elements_reg, Operand::DoubleOffsetFromSmiKey(key_reg));
   vstr(d0, FieldMemOperand(scratch1,
                            FixedDoubleArray::kHeaderSize - elements_offset));
 }
 
 
 void MacroAssembler::CompareMap(Register obj,
                                 Register scratch,
                                 Handle<Map> map,
                                 Label* early_success,
                                 CompareMapMode mode) {
@@ skipping 267 matching lines @@
 
 void MacroAssembler::IndexFromHash(Register hash, Register index) {
   // If the hash field contains an array index pick it out. The assert checks
   // that the constants for the maximum number of digits for an array index
   // cached in the hash field and the number of bits reserved for it does not
   // conflict.
   ASSERT(TenToThe(String::kMaxCachedArrayIndexLength) <
          (1 << String::kArrayIndexValueBits));
   // We want the smi-tagged index in key.  kArrayIndexValueMask has zeros in
   // the low kHashShift bits.
-  STATIC_ASSERT(kSmiTag == 0);
   Ubfx(hash, hash, String::kHashShift, String::kArrayIndexValueBits);
-  mov(index, Operand(hash, LSL, kSmiTagSize));
+  SmiTag(index, hash);
 }
 
 
-void MacroAssembler::IntegerToDoubleConversionWithVFP3(Register inReg,
-                                                       Register outHighReg,
-                                                       Register outLowReg) {
-  // ARMv7 VFP3 instructions to implement integer to double conversion.
-  mov(r7, Operand(inReg, ASR, kSmiTagSize));
-  vmov(s15, r7);
-  vcvt_f64_s32(d7, s15);
-  vmov(outLowReg, outHighReg, d7);
+void MacroAssembler::SmiToDouble(DwVfpRegister value, Register smi) {
+  ASSERT(value.code() < 16);
+  if (CpuFeatures::IsSupported(VFP3)) {
+    vmov(value.low(), smi);
+    vcvt_f64_s32(value, 1);
+  } else {
+    SmiUntag(ip, smi);
+    vmov(value.low(), ip);
+    vcvt_f64_s32(value, value.low());
+  }
 }
 
 
-void MacroAssembler::ObjectToDoubleVFPRegister(Register object,
-                                               DwVfpRegister result,
-                                               Register scratch1,
-                                               Register scratch2,
-                                               Register heap_number_map,
-                                               SwVfpRegister scratch3,
-                                               Label* not_number,
-                                               ObjectToDoubleFlags flags) {
-  Label done;
-  if ((flags & OBJECT_NOT_SMI) == 0) {
-    Label not_smi;
-    JumpIfNotSmi(object, &not_smi);
-    // Remove smi tag and convert to double.
-    mov(scratch1, Operand(object, ASR, kSmiTagSize));
-    vmov(scratch3, scratch1);
-    vcvt_f64_s32(result, scratch3);
-    b(&done);
-    bind(&not_smi);
-  }
-  // Check for heap number and load double value from it.
-  ldr(scratch1, FieldMemOperand(object, HeapObject::kMapOffset));
-  sub(scratch2, object, Operand(kHeapObjectTag));
-  cmp(scratch1, heap_number_map);
-  b(ne, not_number);
-  if ((flags & AVOID_NANS_AND_INFINITIES) != 0) {
-    // If exponent is all ones the number is either a NaN or +/-Infinity.
-    ldr(scratch1, FieldMemOperand(object, HeapNumber::kExponentOffset));
-    Sbfx(scratch1,
-         scratch1,
-         HeapNumber::kExponentShift,
-         HeapNumber::kExponentBits);
-    // All-one value sign extend to -1.
-    cmp(scratch1, Operand(-1));
-    b(eq, not_number);
-  }
-  vldr(result, scratch2, HeapNumber::kValueOffset);
-  bind(&done);
-}
-
-
-void MacroAssembler::SmiToDoubleVFPRegister(Register smi,
-                                            DwVfpRegister value,
-                                            Register scratch1,
-                                            SwVfpRegister scratch2) {
-  mov(scratch1, Operand(smi, ASR, kSmiTagSize));
-  vmov(scratch2, scratch1);
-  vcvt_f64_s32(value, scratch2);
-}
-
-
 void MacroAssembler::TestDoubleIsInt32(DwVfpRegister double_input,
                                        DwVfpRegister double_scratch) {
   ASSERT(!double_input.is(double_scratch));
   vcvt_s32_f64(double_scratch.low(), double_input);
   vcvt_f64_s32(double_scratch, double_scratch.low());
   VFPCompareAndSetFlags(double_input, double_scratch);
 }
 
 
 void MacroAssembler::TryDoubleToInt32Exact(Register result,
@@ skipping 133 matching lines @@
   bind(&done);
 }
 
 
 void MacroAssembler::GetLeastBitsFromSmi(Register dst,
                                          Register src,
                                          int num_least_bits) {
   if (CpuFeatures::IsSupported(ARMv7) && !predictable_code_size()) {
     ubfx(dst, src, kSmiTagSize, num_least_bits);
   } else {
-    mov(dst, Operand(src, ASR, kSmiTagSize));
+    SmiUntag(dst, src);
     and_(dst, dst, Operand((1 << num_least_bits) - 1));
   }
 }
 
 
 void MacroAssembler::GetLeastBitsFromInt32(Register dst,
                                            Register src,
                                            int num_least_bits) {
   and_(dst, src, Operand((1 << num_least_bits) - 1));
 }
@@ skipping 374 matching lines @@
   STATIC_ASSERT(kSmiTag == 0);
   tst(reg1, Operand(kSmiTagMask));
   tst(reg2, Operand(kSmiTagMask), eq);
   b(ne, on_not_both_smi);
 }
 
 
 void MacroAssembler::UntagAndJumpIfSmi(
     Register dst, Register src, Label* smi_case) {
   STATIC_ASSERT(kSmiTag == 0);
-  mov(dst, Operand(src, ASR, kSmiTagSize), SetCC);
+  SmiUntag(dst, src, SetCC);
   b(cc, smi_case);  // Shifter carry is not set for a smi.
 }
 
 
 void MacroAssembler::UntagAndJumpIfNotSmi(
     Register dst, Register src, Label* non_smi_case) {
   STATIC_ASSERT(kSmiTag == 0);
-  mov(dst, Operand(src, ASR, kSmiTagSize), SetCC);
+  SmiUntag(dst, src, SetCC);
   b(cs, non_smi_case);  // Shifter carry is set for a non-smi.
 }
 
 
 void MacroAssembler::JumpIfEitherSmi(Register reg1,
                                      Register reg2,
                                      Label* on_either_smi) {
   STATIC_ASSERT(kSmiTag == 0);
   tst(reg1, Operand(kSmiTagMask));
   tst(reg2, Operand(kSmiTagMask), ne);
@@ skipping 86 matching lines @@
                                                scratch2,
                                                failure);
 }
 
 void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(Register first,
                                                          Register second,
                                                          Register scratch1,
                                                          Register scratch2,
                                                          Label* failure) {
   // Check that neither is a smi.
-  STATIC_ASSERT(kSmiTag == 0);
   and_(scratch1, first, Operand(second));
   JumpIfSmi(scratch1, failure);
   JumpIfNonSmisNotBothSequentialAsciiStrings(first,
                                              second,
                                              scratch1,
                                              scratch2,
                                              failure);
 }
 
 
@@ skipping 724 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM