Reland r22247 "ARM64: Use UntagSmi helpers and clean up assertions."

src/arm64/code-stubs-arm64.cc

 // Copyright 2013 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_ARM64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 1970 matching lines @@
   // Stack layout on entry.
   //  jssp[0]:  number of parameters (tagged)
   //  jssp[8]:  address of receiver argument
   //  jssp[16]: function
 
   // Check if the calling frame is an arguments adaptor frame.
   Label runtime;
   Register caller_fp = x10;
   __ Ldr(caller_fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   // Load and untag the context.
-  STATIC_ASSERT((kSmiShift / kBitsPerByte) == 4);
-  __ Ldr(w11, MemOperand(caller_fp, StandardFrameConstants::kContextOffset +
-                         (kSmiShift / kBitsPerByte)));
+  __ Ldr(w11, UntagSmiMemOperand(caller_fp,
+                                 StandardFrameConstants::kContextOffset));
   __ Cmp(w11, StackFrame::ARGUMENTS_ADAPTOR);
   __ B(ne, &runtime);
 
   // Patch the arguments.length and parameters pointer in the current frame.
   __ Ldr(x11, MemOperand(caller_fp,
                          ArgumentsAdaptorFrameConstants::kLengthOffset));
   __ Poke(x11, 0 * kXRegSize);
   __ Add(x10, caller_fp, Operand::UntagSmiAndScale(x11, kPointerSizeLog2));
   __ Add(x10, x10, StandardFrameConstants::kCallerSPOffset);
   __ Poke(x10, 1 * kXRegSize);
@@ skipping 827 matching lines @@
   __ Bind(&next_capture);
   __ Subs(number_of_capture_registers, number_of_capture_registers, 2);
   __ B(mi, &done);
   // Read two 32 bit values from the static offsets vector buffer into
   // an X register
   __ Ldr(current_offset,
          MemOperand(offsets_vector_index, kWRegSize * 2, PostIndex));
   // Store the smi values in the last match info.
   __ SmiTag(x10, current_offset);
   // Clearing the 32 bottom bits gives us a Smi.
-  STATIC_ASSERT(kSmiShift == 32);
-  __ And(x11, current_offset, ~kWRegMask);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ Bic(x11, current_offset, kSmiShiftMask);
   __ Stp(x10,
          x11,
          MemOperand(last_match_offsets, kXRegSize * 2, PostIndex));
   __ B(&next_capture);
   __ Bind(&done);
 
   // Return last match info.
   __ Peek(x0, kLastMatchInfoOffset);
   __ PopCPURegList(used_callee_saved_registers);
   // Drop the 4 arguments of the stub from the stack.
@@ skipping 618 matching lines @@
 }
 
 
 void StringCharFromCodeGenerator::GenerateFast(MacroAssembler* masm) {
   __ JumpIfNotSmi(code_, &slow_case_);
   __ Cmp(code_, Smi::FromInt(String::kMaxOneByteCharCode));
   __ B(hi, &slow_case_);
 
   __ LoadRoot(result_, Heap::kSingleCharacterStringCacheRootIndex);
   // At this point code register contains smi tagged ASCII char code.
-  STATIC_ASSERT(kSmiShift > kPointerSizeLog2);
-  __ Add(result_, result_, Operand(code_, LSR, kSmiShift - kPointerSizeLog2));
+  __ Add(result_, result_, Operand::UntagSmiAndScale(code_, kPointerSizeLog2));
   __ Ldr(result_, FieldMemOperand(result_, FixedArray::kHeaderSize));
   __ JumpIfRoot(result_, Heap::kUndefinedValueRootIndex, &slow_case_);
   __ Bind(&exit_);
 }
 
 
 void StringCharFromCodeGenerator::GenerateSlow(
     MacroAssembler* masm,
     const RuntimeCallHelper& call_helper) {
   __ Abort(kUnexpectedFallthroughToCharFromCodeSlowCase);
@@ skipping 348 matching lines @@
 
 
 void StringHelper::GenerateHashInit(MacroAssembler* masm,
                                     Register hash,
                                     Register character) {
   ASSERT(!AreAliased(hash, character));
 
   // hash = character + (character << 10);
   __ LoadRoot(hash, Heap::kHashSeedRootIndex);
   // Untag smi seed and add the character.
-  __ Add(hash, character, Operand(hash, LSR, kSmiShift));
+  __ Add(hash, character, Operand::UntagSmi(hash));
 
   // Compute hashes modulo 2^32 using a 32-bit W register.
   Register hash_w = hash.W();
 
   // hash += hash << 10;
   __ Add(hash_w, hash_w, Operand(hash_w, LSL, 10));
   // hash ^= hash >> 6;
   __ Eor(hash_w, hash_w, Operand(hash_w, LSR, 6));
 }
 
@@ skipping 1566 matching lines @@
                               MemOperand(fp, 6 * kPointerSize),
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64