Change tests for string type in RegExpExecStub on all platforms.

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
===================================================================
--- src/ia32/codegen-ia32.cc	(revision 4853)
+++ src/ia32/codegen-ia32.cc	(working copy)
@@ -11305,58 +11305,58 @@
 
   // ecx: RegExp data (FixedArray)
   // Check the representation and encoding of the subject string.
-  Label seq_string, seq_two_byte_string, check_code;
-  const int kStringRepresentationEncodingMask =
-      kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask;
+  Label seq_ascii_string, seq_two_byte_string, check_code;
   __ mov(eax, Operand(esp, kSubjectOffset));
   __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
   __ movzx_b(ebx, FieldOperand(ebx, Map::kInstanceTypeOffset));
-  __ and_(ebx, kStringRepresentationEncodingMask);
-  // First check for sequential string.
-  ASSERT_EQ(0, kStringTag);
-  ASSERT_EQ(0, kSeqStringTag);
+  // First check for flat two byte string.
+  __ and_(ebx,
+          kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask);
+  ASSERT_EQ(0, kStringTag | kSeqStringTag | kTwoByteStringTag);
+  __ j(zero, &seq_two_byte_string);
+  // Any other flat string must be a flat ascii string.
   __ test(Operand(ebx),
           Immediate(kIsNotStringMask | kStringRepresentationMask));
-  __ j(zero, &seq_string);
+  __ j(zero, &seq_ascii_string);
 
   // Check for flat cons string.
   // A flat cons string is a cons string where the second part is the empty
   // string. In that case the subject string is just the first part of the cons
   // string. Also in this case the first part of the cons string is known to be
   // a sequential string or an external string.
-  __ and_(ebx, kStringRepresentationMask);
-  __ cmp(ebx, kConsStringTag);
-  __ j(not_equal, &runtime);
+  ASSERT(kExternalStringTag !=0);
+  ASSERT_EQ(0, kConsStringTag & kExternalStringTag);
+  __ test(Operand(ebx),
+          Immediate(kIsNotStringMask | kExternalStringTag));
+  __ j(not_zero, &runtime);
+  // String is a cons string.
   __ mov(edx, FieldOperand(eax, ConsString::kSecondOffset));
   __ cmp(Operand(edx), Factory::empty_string());
   __ j(not_equal, &runtime);
   __ mov(eax, FieldOperand(eax, ConsString::kFirstOffset));
   __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
-  __ movzx_b(ebx, FieldOperand(ebx, Map::kInstanceTypeOffset));
-  ASSERT_EQ(0, kSeqStringTag);
-  __ test(ebx, Immediate(kStringRepresentationMask));
+  // String is a cons string with empty second part.
+  // eax: first part of cons string.
+  // ebx: map of first part of cons string.
+  // Is first part a flat two byte string?
+  __ test_b(FieldOperand(ebx, Map::kInstanceTypeOffset),
+            kStringRepresentationMask | kStringEncodingMask);
+  ASSERT_EQ(0, kSeqStringTag | kTwoByteStringTag);
+  __ j(zero, &seq_two_byte_string);
+  // Any other flat string must be ascii.
+  __ test_b(FieldOperand(ebx, Map::kInstanceTypeOffset),
+            kStringRepresentationMask);
   __ j(not_zero, &runtime);
-  __ and_(ebx, kStringRepresentationEncodingMask);
 
-  __ bind(&seq_string);
-  // eax: subject string (sequential either ascii to two byte)
-  // ebx: suject string type & kStringRepresentationEncodingMask
+  __ bind(&seq_ascii_string);
+  // eax: subject string (flat ascii)
   // ecx: RegExp data (FixedArray)
-  // Check that the irregexp code has been generated for an ascii string. If
-  // it has, the field contains a code object otherwise it contains the hole.
-  const int kSeqTwoByteString = kStringTag | kSeqStringTag | kTwoByteStringTag;
-  __ cmp(ebx, kSeqTwoByteString);
-  __ j(equal, &seq_two_byte_string);
-  if (FLAG_debug_code) {
-    __ cmp(ebx, kStringTag | kSeqStringTag | kAsciiStringTag);
-    __ Check(equal, "Expected sequential ascii string");
-  }
   __ mov(edx, FieldOperand(ecx, JSRegExp::kDataAsciiCodeOffset));
   __ Set(edi, Immediate(1));  // Type is ascii.
   __ jmp(&check_code);
 
   __ bind(&seq_two_byte_string);
-  // eax: subject string
+  // eax: subject string (flat two byte)
   // ecx: RegExp data (FixedArray)
   __ mov(edx, FieldOperand(ecx, JSRegExp::kDataUC16CodeOffset));
   __ Set(edi, Immediate(0));  // Type is two byte.
@@ -12897,7 +12897,7 @@
   __ j(zero, &string_add_runtime);
 
   __ bind(&make_flat_ascii_string);
-  // Both strings are ascii strings. As they are short they are both flat.
+  // Both strings are ascii strings.  As they are short they are both flat.
   // ebx: length of resulting flat string as a smi
   __ SmiUntag(ebx);
   __ AllocateAsciiString(eax, ebx, ecx, edx, edi, &string_add_runtime);