[regexp] Port RegExpExecStub to CSA (mostly)

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 1320d90e8b9e303699b2363d76a09993307b9652..56ce2c52133bb74f5190dc857145b5b8dc014da5 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -463,170 +463,10 @@ void MathPowStub::Generate(MacroAssembler* masm) {
 }
 
 void RegExpExecStub::Generate(MacroAssembler* masm) {
-  // Just jump directly to runtime if native RegExp is not selected at compile
-  // time or if regexp entry in generated code is turned off runtime switch or
-  // at compilation.
 #ifdef V8_INTERPRETED_REGEXP
-  __ TailCallRuntime(Runtime::kRegExpExec);
+  // This case is handled prior to the RegExpExecStub call.
+  __ Abort(kUnexpectedRegExpExecCall);
 #else  // V8_INTERPRETED_REGEXP
-
-  // Stack frame on entry.
-  //  esp[0]: return address
-  //  esp[4]: last_match_info (expected JSArray)
-  //  esp[8]: previous index
-  //  esp[12]: subject string
-  //  esp[16]: JSRegExp object
-
-  static const int kLastMatchInfoOffset = 1 * kPointerSize;
-  static const int kPreviousIndexOffset = 2 * kPointerSize;
-  static const int kSubjectOffset = 3 * kPointerSize;
-  static const int kJSRegExpOffset = 4 * kPointerSize;
-
-  Label runtime;
-  Factory* factory = isolate()->factory();
-
-  // Ensure that a RegExp stack is allocated.
-  ExternalReference address_of_regexp_stack_memory_address =
-      ExternalReference::address_of_regexp_stack_memory_address(isolate());
-  ExternalReference address_of_regexp_stack_memory_size =
-      ExternalReference::address_of_regexp_stack_memory_size(isolate());
-  __ mov(ebx, Operand::StaticVariable(address_of_regexp_stack_memory_size));
-  __ test(ebx, ebx);
-  __ j(zero, &runtime);
-
-  // Check that the first argument is a JSRegExp object.
-  __ mov(eax, Operand(esp, kJSRegExpOffset));
-  STATIC_ASSERT(kSmiTag == 0);
-  __ JumpIfSmi(eax, &runtime);
-  __ CmpObjectType(eax, JS_REGEXP_TYPE, ecx);
-  __ j(not_equal, &runtime);
-
-  // Check that the RegExp has been compiled (data contains a fixed array).
-  __ mov(ecx, FieldOperand(eax, JSRegExp::kDataOffset));
-  if (FLAG_debug_code) {
-    __ test(ecx, Immediate(kSmiTagMask));
-    __ Check(not_zero, kUnexpectedTypeForRegExpDataFixedArrayExpected);
-    __ CmpObjectType(ecx, FIXED_ARRAY_TYPE, ebx);
-    __ Check(equal, kUnexpectedTypeForRegExpDataFixedArrayExpected);
-  }
-
-  // ecx: RegExp data (FixedArray)
-  // Check the type of the RegExp. Only continue if type is JSRegExp::IRREGEXP.
-  __ mov(ebx, FieldOperand(ecx, JSRegExp::kDataTagOffset));
-  __ cmp(ebx, Immediate(Smi::FromInt(JSRegExp::IRREGEXP)));
-  __ j(not_equal, &runtime);
-
-  // ecx: RegExp data (FixedArray)
-  // Check that the number of captures fit in the static offsets vector buffer.
-  __ mov(edx, FieldOperand(ecx, JSRegExp::kIrregexpCaptureCountOffset));
-  // Check (number_of_captures + 1) * 2 <= offsets vector size
-  // Or          number_of_captures * 2 <= offsets vector size - 2
-  // Multiplying by 2 comes for free since edx is smi-tagged.
-  STATIC_ASSERT(kSmiTag == 0);
-  STATIC_ASSERT(kSmiTagSize + kSmiShiftSize == 1);
-  STATIC_ASSERT(Isolate::kJSRegexpStaticOffsetsVectorSize >= 2);
-  __ cmp(edx, Isolate::kJSRegexpStaticOffsetsVectorSize - 2);
-  __ j(above, &runtime);
-
-  // Reset offset for possibly sliced string.
-  __ Move(edi, Immediate(0));
-  __ mov(eax, Operand(esp, kSubjectOffset));
-  __ JumpIfSmi(eax, &runtime);
-  __ mov(edx, eax);  // Make a copy of the original subject string.
-
-  // eax: subject string
-  // edx: subject string
-  // ecx: RegExp data (FixedArray)
-  // Handle subject string according to its encoding and representation:
-  // (1) Sequential two byte?  If yes, go to (9).
-  // (2) Sequential one byte?  If yes, go to (5).
-  // (3) Sequential or cons?  If not, go to (6).
-  // (4) Cons string.  If the string is flat, replace subject with first string
-  //     and go to (1). Otherwise bail out to runtime.
-  // (5) One byte sequential.  Load regexp code for one byte.
-  // (E) Carry on.
-  /// [...]
-
-  // Deferred code at the end of the stub:
-  // (6) Long external string?  If not, go to (10).
-  // (7) External string.  Make it, offset-wise, look like a sequential string.
-  // (8) Is the external string one byte?  If yes, go to (5).
-  // (9) Two byte sequential.  Load regexp code for two byte. Go to (E).
-  // (10) Short external string or not a string?  If yes, bail out to runtime.
-  // (11) Sliced or thin string.  Replace subject with parent. Go to (1).
-
-  Label seq_one_byte_string /* 5 */, seq_two_byte_string /* 9 */,
-      external_string /* 7 */, check_underlying /* 1 */,
-      not_seq_nor_cons /* 6 */, check_code /* E */, not_long_external /* 10 */;
-
-  __ bind(&check_underlying);
-  // (1) Sequential two byte?  If yes, go to (9).
-  __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
-  __ movzx_b(ebx, FieldOperand(ebx, Map::kInstanceTypeOffset));
-
-  __ and_(ebx, kIsNotStringMask |
-               kStringRepresentationMask |
-               kStringEncodingMask |
-               kShortExternalStringMask);
-  STATIC_ASSERT((kStringTag | kSeqStringTag | kTwoByteStringTag) == 0);
-  __ j(zero, &seq_two_byte_string);  // Go to (9).
-
-  // (2) Sequential one byte?  If yes, go to (5).
-  // Any other sequential string must be one byte.
-  __ and_(ebx, Immediate(kIsNotStringMask |
-                         kStringRepresentationMask |
-                         kShortExternalStringMask));
-  __ j(zero, &seq_one_byte_string, Label::kNear);  // Go to (5).
-
-  // (3) Sequential or cons?  If not, go to (6).
-  // We check whether the subject string is a cons, since sequential strings
-  // have already been covered.
-  STATIC_ASSERT(kConsStringTag < kExternalStringTag);
-  STATIC_ASSERT(kSlicedStringTag > kExternalStringTag);
-  STATIC_ASSERT(kThinStringTag > kExternalStringTag);
-  STATIC_ASSERT(kIsNotStringMask > kExternalStringTag);
-  STATIC_ASSERT(kShortExternalStringTag > kExternalStringTag);
-  __ cmp(ebx, Immediate(kExternalStringTag));
-  __ j(greater_equal, &not_seq_nor_cons);  // Go to (6).
-
-  // (4) Cons string.  Check that it's flat.
-  // Replace subject with first string and reload instance type.
-  __ cmp(FieldOperand(eax, ConsString::kSecondOffset), factory->empty_string());
-  __ j(not_equal, &runtime);
-  __ mov(eax, FieldOperand(eax, ConsString::kFirstOffset));
-  __ jmp(&check_underlying);
-
-  // eax: sequential subject string (or look-alike, external string)
-  // edx: original subject string
-  // ecx: RegExp data (FixedArray)
-  // (5) One byte sequential.  Load regexp code for one byte.
-  __ bind(&seq_one_byte_string);
-  // Load previous index and check range before edx is overwritten.  We have
-  // to use edx instead of eax here because it might have been only made to
-  // look like a sequential string when it actually is an external string.
-  __ mov(ebx, Operand(esp, kPreviousIndexOffset));
-  __ JumpIfNotSmi(ebx, &runtime);
-  __ cmp(ebx, FieldOperand(edx, String::kLengthOffset));
-  __ j(above_equal, &runtime);
-  __ mov(edx, FieldOperand(ecx, JSRegExp::kDataOneByteCodeOffset));
-  __ Move(ecx, Immediate(1));  // Type is one byte.
-
-  // (E) Carry on.  String handling is done.
-  __ bind(&check_code);
-  // edx: irregexp code
-  // Check that the irregexp code has been generated for the actual string
-  // encoding. If it has, the field contains a code object otherwise it contains
-  // a smi (code flushing support).
-  __ JumpIfSmi(edx, &runtime);
-
-  // eax: subject string
-  // ebx: previous index (smi)
-  // edx: code
-  // ecx: encoding of subject string (1 if one_byte, 0 if two_byte);
-  // All checks done. Now push arguments for native regexp code.
-  Counters* counters = isolate()->counters();
-  __ IncrementCounter(counters->regexp_entry_native(), 1);
-
   // Isolates: note we add an additional parameter here (isolate pointer).
   static const int kRegExpExecuteArguments = 9;
   __ EnterApiExitFrame(kRegExpExecuteArguments);
@@ -639,6 +479,10 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
   __ mov(Operand(esp, 7 * kPointerSize), Immediate(1));
 
   // Argument 7: Start (high end) of backtracking stack memory area.
+  ExternalReference address_of_regexp_stack_memory_address =
+      ExternalReference::address_of_regexp_stack_memory_address(isolate());
+  ExternalReference address_of_regexp_stack_memory_size =
+      ExternalReference::address_of_regexp_stack_memory_size(isolate());
   __ mov(esi, Operand::StaticVariable(address_of_regexp_stack_memory_address));
   __ add(esi, Operand::StaticVariable(address_of_regexp_stack_memory_size));
   __ mov(Operand(esp, 6 * kPointerSize), esi);
@@ -652,228 +496,32 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
          Immediate(ExternalReference::address_of_static_offsets_vector(
              isolate())));
 
-  // Argument 2: Previous index.
-  __ SmiUntag(ebx);
-  __ mov(Operand(esp, 1 * kPointerSize), ebx);
-
-  // Argument 1: Original subject string.
-  // The original subject is in the previous stack frame. Therefore we have to
-  // use ebp, which points exactly to one pointer size below the previous esp.
-  // (Because creating a new stack frame pushes the previous ebp onto the stack
-  // and thereby moves up esp by one kPointerSize.)
-  __ mov(esi, Operand(ebp, kSubjectOffset + kPointerSize));
-  __ mov(Operand(esp, 0 * kPointerSize), esi);
-
-  // esi: original subject string
-  // eax: underlying subject string
-  // ebx: previous index
-  // ecx: encoding of subject string (1 if one_byte 0 if two_byte);
-  // edx: code
   // Argument 4: End of string data
   // Argument 3: Start of string data
-  // Prepare start and end index of the input.
-  // Load the length from the original sliced string if that is the case.
-  __ mov(esi, FieldOperand(esi, String::kLengthOffset));
-  __ add(esi, edi);  // Calculate input end wrt offset.
-  __ SmiUntag(edi);
-  __ add(ebx, edi);  // Calculate input start wrt offset.
-
-  // ebx: start index of the input string
-  // esi: end index of the input string
-  Label setup_two_byte, setup_rest;
-  __ test(ecx, ecx);
-  __ j(zero, &setup_two_byte, Label::kNear);
-  __ SmiUntag(esi);
-  __ lea(ecx, FieldOperand(eax, esi, times_1, SeqOneByteString::kHeaderSize));
-  __ mov(Operand(esp, 3 * kPointerSize), ecx);  // Argument 4.
-  __ lea(ecx, FieldOperand(eax, ebx, times_1, SeqOneByteString::kHeaderSize));
-  __ mov(Operand(esp, 2 * kPointerSize), ecx);  // Argument 3.
-  __ jmp(&setup_rest, Label::kNear);
-
-  __ bind(&setup_two_byte);
-  STATIC_ASSERT(kSmiTag == 0);
-  STATIC_ASSERT(kSmiTagSize == 1);  // esi is smi (powered by 2).
-  __ lea(ecx, FieldOperand(eax, esi, times_1, SeqTwoByteString::kHeaderSize));
-  __ mov(Operand(esp, 3 * kPointerSize), ecx);  // Argument 4.
-  __ lea(ecx, FieldOperand(eax, ebx, times_2, SeqTwoByteString::kHeaderSize));
-  __ mov(Operand(esp, 2 * kPointerSize), ecx);  // Argument 3.
+  __ mov(Operand(esp, 3 * kPointerSize),
+         RegExpExecDescriptor::StringEndRegister());
+  __ mov(Operand(esp, 2 * kPointerSize),
+         RegExpExecDescriptor::StringStartRegister());
 
-  __ bind(&setup_rest);
+  // Argument 2: Previous index.
+  __ mov(Operand(esp, 1 * kPointerSize),
+         RegExpExecDescriptor::LastIndexRegister());
+
+  // Argument 1: Original subject string.
+  __ mov(Operand(esp, 0 * kPointerSize),
+         RegExpExecDescriptor::StringRegister());
 
   // Locate the code entry and call it.
-  __ add(edx, Immediate(Code::kHeaderSize - kHeapObjectTag));
-  __ call(edx);
+  __ add(RegExpExecDescriptor::CodeRegister(),
+         Immediate(Code::kHeaderSize - kHeapObjectTag));
+  __ call(RegExpExecDescriptor::CodeRegister());
 
   // Drop arguments and come back to JS mode.
   __ LeaveApiExitFrame(true);
 
-  // Check the result.
-  Label success;
-  __ cmp(eax, 1);
-  // We expect exactly one result since we force the called regexp to behave
-  // as non-global.
-  __ j(equal, &success);
-  Label failure;
-  __ cmp(eax, NativeRegExpMacroAssembler::FAILURE);
-  __ j(equal, &failure);
-  __ cmp(eax, NativeRegExpMacroAssembler::EXCEPTION);
-  // If not exception it can only be retry. Handle that in the runtime system.
-  __ j(not_equal, &runtime);
-  // Result must now be exception. If there is no pending exception already a
-  // stack overflow (on the backtrack stack) was detected in RegExp code but
-  // haven't created the exception yet. Handle that in the runtime system.
-  // TODO(592): Rerunning the RegExp to get the stack overflow exception.
-  ExternalReference pending_exception(Isolate::kPendingExceptionAddress,
-                                      isolate());
-  __ mov(edx, Immediate(isolate()->factory()->the_hole_value()));
-  __ mov(eax, Operand::StaticVariable(pending_exception));
-  __ cmp(edx, eax);
-  __ j(equal, &runtime);
-
-  // For exception, throw the exception again.
-  __ TailCallRuntime(Runtime::kRegExpExecReThrow);
-
-  __ bind(&failure);
-  // For failure to match, return null.
-  __ mov(eax, factory->null_value());
-  __ ret(4 * kPointerSize);
-
-  // Load RegExp data.
-  __ bind(&success);
-  __ mov(eax, Operand(esp, kJSRegExpOffset));
-  __ mov(ecx, FieldOperand(eax, JSRegExp::kDataOffset));
-  __ mov(edx, FieldOperand(ecx, JSRegExp::kIrregexpCaptureCountOffset));
-  // Calculate number of capture registers (number_of_captures + 1) * 2.
-  STATIC_ASSERT(kSmiTag == 0);
-  STATIC_ASSERT(kSmiTagSize + kSmiShiftSize == 1);
-  __ add(edx, Immediate(2));  // edx was a smi.
-
-  // edx: Number of capture registers
-  // Check that the last match info is a FixedArray.
-  __ mov(ebx, Operand(esp, kLastMatchInfoOffset));
-  __ JumpIfSmi(ebx, &runtime);
-  // Check that the object has fast elements.
-  __ mov(eax, FieldOperand(ebx, HeapObject::kMapOffset));
-  __ cmp(eax, factory->fixed_array_map());
-  __ j(not_equal, &runtime);
-  // Check that the last match info has space for the capture registers and the
-  // additional information.
-  __ mov(eax, FieldOperand(ebx, FixedArray::kLengthOffset));
-  __ SmiUntag(eax);
-  __ sub(eax, Immediate(RegExpMatchInfo::kLastMatchOverhead));
-  __ cmp(edx, eax);
-  __ j(greater, &runtime);
-
-  // ebx: last_match_info (FixedArray)
-  // edx: number of capture registers
-  // Store the capture count.
-  __ SmiTag(edx);  // Number of capture registers to smi.
-  __ mov(FieldOperand(ebx, RegExpMatchInfo::kNumberOfCapturesOffset), edx);
-  __ SmiUntag(edx);  // Number of capture registers back from smi.
-  // Store last subject and last input.
-  __ mov(eax, Operand(esp, kSubjectOffset));
-  __ mov(ecx, eax);
-  __ mov(FieldOperand(ebx, RegExpMatchInfo::kLastSubjectOffset), eax);
-  __ RecordWriteField(ebx, RegExpMatchInfo::kLastSubjectOffset, eax, edi,
-                      kDontSaveFPRegs);
-  __ mov(eax, ecx);
-  __ mov(FieldOperand(ebx, RegExpMatchInfo::kLastInputOffset), eax);
-  __ RecordWriteField(ebx, RegExpMatchInfo::kLastInputOffset, eax, edi,
-                      kDontSaveFPRegs);
-
-  // Get the static offsets vector filled by the native regexp code.
-  ExternalReference address_of_static_offsets_vector =
-      ExternalReference::address_of_static_offsets_vector(isolate());
-  __ mov(ecx, Immediate(address_of_static_offsets_vector));
-
-  // ebx: last_match_info (FixedArray)
-  // ecx: offsets vector
-  // edx: number of capture registers
-  Label next_capture, done;
-  // Capture register counter starts from number of capture registers and
-  // counts down until wrapping after zero.
-  __ bind(&next_capture);
-  __ sub(edx, Immediate(1));
-  __ j(negative, &done, Label::kNear);
-  // Read the value from the static offsets vector buffer.
-  __ mov(edi, Operand(ecx, edx, times_int_size, 0));
-  __ SmiTag(edi);
-  // Store the smi value in the last match info.
-  __ mov(FieldOperand(ebx, edx, times_pointer_size,
-                      RegExpMatchInfo::kFirstCaptureOffset),
-         edi);
-  __ jmp(&next_capture);
-  __ bind(&done);
-
-  // Return last match info.
-  __ mov(eax, ebx);
-  __ ret(4 * kPointerSize);
-
-  // Do the runtime call to execute the regexp.
-  __ bind(&runtime);
-  __ TailCallRuntime(Runtime::kRegExpExec);
-
-  // Deferred code for string handling.
-  // (6) Long external string?  If not, go to (10).
-  __ bind(&not_seq_nor_cons);
-  // Compare flags are still set from (3).
-  __ j(greater, &not_long_external, Label::kNear);  // Go to (10).
-
-  // (7) External string.  Short external strings have been ruled out.
-  __ bind(&external_string);
-  // Reload instance type.
-  __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
-  __ movzx_b(ebx, FieldOperand(ebx, Map::kInstanceTypeOffset));
-  if (FLAG_debug_code) {
-    // Assert that we do not have a cons or slice (indirect strings) here.
-    // Sequential strings have already been ruled out.
-    __ test_b(ebx, Immediate(kIsIndirectStringMask));
-    __ Assert(zero, kExternalStringExpectedButNotFound);
-  }
-  __ mov(eax, FieldOperand(eax, ExternalString::kResourceDataOffset));
-  // Move the pointer so that offset-wise, it looks like a sequential string.
-  STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqOneByteString::kHeaderSize);
-  __ sub(eax, Immediate(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
-  STATIC_ASSERT(kTwoByteStringTag == 0);
-  // (8) Is the external string one byte?  If yes, go to (5).
-  __ test_b(ebx, Immediate(kStringEncodingMask));
-  __ j(not_zero, &seq_one_byte_string);  // Go to (5).
-
-  // eax: sequential subject string (or look-alike, external string)
-  // edx: original subject string
-  // ecx: RegExp data (FixedArray)
-  // (9) Two byte sequential.  Load regexp code for two byte. Go to (E).
-  __ bind(&seq_two_byte_string);
-  // Load previous index and check range before edx is overwritten.  We have
-  // to use edx instead of eax here because it might have been only made to
-  // look like a sequential string when it actually is an external string.
-  __ mov(ebx, Operand(esp, kPreviousIndexOffset));
-  __ JumpIfNotSmi(ebx, &runtime);
-  __ cmp(ebx, FieldOperand(edx, String::kLengthOffset));
-  __ j(above_equal, &runtime);
-  __ mov(edx, FieldOperand(ecx, JSRegExp::kDataUC16CodeOffset));
-  __ Move(ecx, Immediate(0));  // Type is two byte.
-  __ jmp(&check_code);  // Go to (E).
-
-  // (10) Not a string or a short external string?  If yes, bail out to runtime.
-  __ bind(&not_long_external);
-  // Catch non-string subject or short external string.
-  STATIC_ASSERT(kNotStringTag != 0 && kShortExternalStringTag !=0);
-  __ test(ebx, Immediate(kIsNotStringMask | kShortExternalStringTag));
-  __ j(not_zero, &runtime);
-
-  // (11) Sliced or thin string.  Replace subject with parent.  Go to (1).
-  Label thin_string;
-  __ cmp(ebx, Immediate(kThinStringTag));
-  __ j(equal, &thin_string, Label::kNear);
-  // Load offset into edi and replace subject string with parent.
-  __ mov(edi, FieldOperand(eax, SlicedString::kOffsetOffset));
-  __ mov(eax, FieldOperand(eax, SlicedString::kParentOffset));
-  __ jmp(&check_underlying);  // Go to (1).
-
-  __ bind(&thin_string);
-  __ mov(eax, FieldOperand(eax, ThinString::kActualOffset));
-  __ jmp(&check_underlying);  // Go to (1).
+  // TODO(jgruber): Don't tag return value once this is supported by stubs.
+  __ SmiTag(eax);
+  __ ret(0 * kPointerSize);
 #endif  // V8_INTERPRETED_REGEXP
 }