[stubs] Port SubStringStub to TurboFan

src/ppc/code-stubs-ppc.cc

Index: src/ppc/code-stubs-ppc.cc
diff --git a/src/ppc/code-stubs-ppc.cc b/src/ppc/code-stubs-ppc.cc
index 82318685dfd156b54fdcb497d4174cddfc9663c6..1a1c28d25c4522ed22389f5abc25aaceeb93047c 100644
--- a/src/ppc/code-stubs-ppc.cc
+++ b/src/ppc/code-stubs-ppc.cc
@@ -2207,230 +2207,6 @@ void StringHelper::GenerateCopyCharacters(MacroAssembler* masm, Register dest,
   __ bind(&done);
 }
 
-
-void SubStringStub::Generate(MacroAssembler* masm) {
-  Label runtime;
-
-  // Stack frame on entry.
-  //  lr: return address
-  //  sp[0]: to
-  //  sp[4]: from
-  //  sp[8]: string
-
-  // This stub is called from the native-call %_SubString(...), so
-  // nothing can be assumed about the arguments. It is tested that:
-  //  "string" is a sequential string,
-  //  both "from" and "to" are smis, and
-  //  0 <= from <= to <= string.length.
-  // If any of these assumptions fail, we call the runtime system.
-
-  const int kToOffset = 0 * kPointerSize;
-  const int kFromOffset = 1 * kPointerSize;
-  const int kStringOffset = 2 * kPointerSize;
-
-  __ LoadP(r5, MemOperand(sp, kToOffset));
-  __ LoadP(r6, MemOperand(sp, kFromOffset));
-
-  // If either to or from had the smi tag bit set, then fail to generic runtime
-  __ JumpIfNotSmi(r5, &runtime);
-  __ JumpIfNotSmi(r6, &runtime);
-  __ SmiUntag(r5);
-  __ SmiUntag(r6, SetRC);
-  // Both r5 and r6 are untagged integers.
-
-  // We want to bailout to runtime here if From is negative.
-  __ blt(&runtime, cr0);  // From < 0.
-
-  __ cmpl(r6, r5);
-  __ bgt(&runtime);  // Fail if from > to.
-  __ sub(r5, r5, r6);
-
-  // Make sure first argument is a string.
-  __ LoadP(r3, MemOperand(sp, kStringOffset));
-  __ JumpIfSmi(r3, &runtime);
-  Condition is_string = masm->IsObjectStringType(r3, r4);
-  __ b(NegateCondition(is_string), &runtime, cr0);
-
-  Label single_char;
-  __ cmpi(r5, Operand(1));
-  __ b(eq, &single_char);
-
-  // Short-cut for the case of trivial substring.
-  Label return_r3;
-  // r3: original string
-  // r5: result string length
-  __ LoadP(r7, FieldMemOperand(r3, String::kLengthOffset));
-  __ SmiUntag(r0, r7);
-  __ cmpl(r5, r0);
-  // Return original string.
-  __ beq(&return_r3);
-  // Longer than original string's length or negative: unsafe arguments.
-  __ bgt(&runtime);
-  // Shorter than original string's length: an actual substring.
-
-  // Deal with different string types: update the index if necessary
-  // and put the underlying string into r8.
-  // r3: original string
-  // r4: instance type
-  // r5: length
-  // r6: from index (untagged)
-  Label underlying_unpacked, sliced_string, seq_or_external_string;
-  // If the string is not indirect, it can only be sequential or external.
-  STATIC_ASSERT(kIsIndirectStringMask == (kSlicedStringTag & kConsStringTag));
-  STATIC_ASSERT(kIsIndirectStringMask != 0);
-  __ andi(r0, r4, Operand(kIsIndirectStringMask));
-  __ beq(&seq_or_external_string, cr0);
-
-  __ andi(r0, r4, Operand(kSlicedNotConsMask));
-  __ bne(&sliced_string, cr0);
-  // Cons string.  Check whether it is flat, then fetch first part.
-  __ LoadP(r8, FieldMemOperand(r3, ConsString::kSecondOffset));
-  __ CompareRoot(r8, Heap::kempty_stringRootIndex);
-  __ bne(&runtime);
-  __ LoadP(r8, FieldMemOperand(r3, ConsString::kFirstOffset));
-  // Update instance type.
-  __ LoadP(r4, FieldMemOperand(r8, HeapObject::kMapOffset));
-  __ lbz(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
-  __ b(&underlying_unpacked);
-
-  __ bind(&sliced_string);
-  // Sliced string.  Fetch parent and correct start index by offset.
-  __ LoadP(r8, FieldMemOperand(r3, SlicedString::kParentOffset));
-  __ LoadP(r7, FieldMemOperand(r3, SlicedString::kOffsetOffset));
-  __ SmiUntag(r4, r7);
-  __ add(r6, r6, r4);  // Add offset to index.
-  // Update instance type.
-  __ LoadP(r4, FieldMemOperand(r8, HeapObject::kMapOffset));
-  __ lbz(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
-  __ b(&underlying_unpacked);
-
-  __ bind(&seq_or_external_string);
-  // Sequential or external string.  Just move string to the expected register.
-  __ mr(r8, r3);
-
-  __ bind(&underlying_unpacked);
-
-  if (FLAG_string_slices) {
-    Label copy_routine;
-    // r8: underlying subject string
-    // r4: instance type of underlying subject string
-    // r5: length
-    // r6: adjusted start index (untagged)
-    __ cmpi(r5, Operand(SlicedString::kMinLength));
-    // Short slice.  Copy instead of slicing.
-    __ blt(&copy_routine);
-    // Allocate new sliced string.  At this point we do not reload the instance
-    // type including the string encoding because we simply rely on the info
-    // provided by the original string.  It does not matter if the original
-    // string's encoding is wrong because we always have to recheck encoding of
-    // the newly created string's parent anyways due to externalized strings.
-    Label two_byte_slice, set_slice_header;
-    STATIC_ASSERT((kStringEncodingMask & kOneByteStringTag) != 0);
-    STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
-    __ andi(r0, r4, Operand(kStringEncodingMask));
-    __ beq(&two_byte_slice, cr0);
-    __ AllocateOneByteSlicedString(r3, r5, r9, r10, &runtime);
-    __ b(&set_slice_header);
-    __ bind(&two_byte_slice);
-    __ AllocateTwoByteSlicedString(r3, r5, r9, r10, &runtime);
-    __ bind(&set_slice_header);
-    __ SmiTag(r6);
-    __ StoreP(r8, FieldMemOperand(r3, SlicedString::kParentOffset), r0);
-    __ StoreP(r6, FieldMemOperand(r3, SlicedString::kOffsetOffset), r0);
-    __ b(&return_r3);
-
-    __ bind(&copy_routine);
-  }
-
-  // r8: underlying subject string
-  // r4: instance type of underlying subject string
-  // r5: length
-  // r6: adjusted start index (untagged)
-  Label two_byte_sequential, sequential_string, allocate_result;
-  STATIC_ASSERT(kExternalStringTag != 0);
-  STATIC_ASSERT(kSeqStringTag == 0);
-  __ andi(r0, r4, Operand(kExternalStringTag));
-  __ beq(&sequential_string, cr0);
-
-  // Handle external string.
-  // Rule out short external strings.
-  STATIC_ASSERT(kShortExternalStringTag != 0);
-  __ andi(r0, r4, Operand(kShortExternalStringTag));
-  __ bne(&runtime, cr0);
-  __ LoadP(r8, FieldMemOperand(r8, ExternalString::kResourceDataOffset));
-  // r8 already points to the first character of underlying string.
-  __ b(&allocate_result);
-
-  __ bind(&sequential_string);
-  // Locate first character of underlying subject string.
-  STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqOneByteString::kHeaderSize);
-  __ addi(r8, r8, Operand(SeqOneByteString::kHeaderSize - kHeapObjectTag));
-
-  __ bind(&allocate_result);
-  // Sequential acii string.  Allocate the result.
-  STATIC_ASSERT((kOneByteStringTag & kStringEncodingMask) != 0);
-  __ andi(r0, r4, Operand(kStringEncodingMask));
-  __ beq(&two_byte_sequential, cr0);
-
-  // Allocate and copy the resulting one-byte string.
-  __ AllocateOneByteString(r3, r5, r7, r9, r10, &runtime);
-
-  // Locate first character of substring to copy.
-  __ add(r8, r8, r6);
-  // Locate first character of result.
-  __ addi(r4, r3, Operand(SeqOneByteString::kHeaderSize - kHeapObjectTag));
-
-  // r3: result string
-  // r4: first character of result string
-  // r5: result string length
-  // r8: first character of substring to copy
-  STATIC_ASSERT((SeqOneByteString::kHeaderSize & kObjectAlignmentMask) == 0);
-  StringHelper::GenerateCopyCharacters(masm, r4, r8, r5, r6,
-                                       String::ONE_BYTE_ENCODING);
-  __ b(&return_r3);
-
-  // Allocate and copy the resulting two-byte string.
-  __ bind(&two_byte_sequential);
-  __ AllocateTwoByteString(r3, r5, r7, r9, r10, &runtime);
-
-  // Locate first character of substring to copy.
-  __ ShiftLeftImm(r4, r6, Operand(1));
-  __ add(r8, r8, r4);
-  // Locate first character of result.
-  __ addi(r4, r3, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
-
-  // r3: result string.
-  // r4: first character of result.
-  // r5: result length.
-  // r8: first character of substring to copy.
-  STATIC_ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) == 0);
-  StringHelper::GenerateCopyCharacters(masm, r4, r8, r5, r6,
-                                       String::TWO_BYTE_ENCODING);
-
-  __ bind(&return_r3);
-  Counters* counters = isolate()->counters();
-  __ IncrementCounter(counters->sub_string_native(), 1, r6, r7);
-  __ Drop(3);
-  __ Ret();
-
-  // Just jump to runtime to create the sub string.
-  __ bind(&runtime);
-  __ TailCallRuntime(Runtime::kSubString);
-
-  __ bind(&single_char);
-  // r3: original string
-  // r4: instance type
-  // r5: length
-  // r6: from index (untagged)
-  __ SmiTag(r6, r6);
-  StringCharAtGenerator generator(r3, r6, r5, r3, &runtime, &runtime, &runtime,
-                                  RECEIVER_IS_STRING);
-  generator.GenerateFast(masm);
-  __ Drop(3);
-  __ Ret();
-  generator.SkipSlow(masm, &runtime);
-}
-
 void ToStringStub::Generate(MacroAssembler* masm) {
   // The ToString stub takes one argument in r3.
   Label is_number;