Porting r10221 to ARM (avoid bailing out to runtime for short substrings).
Review URL: http://codereview.chromium.org/8923002 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10250 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
yangguo@chromium.org
parent
1bdac10670
commit
33a9e76808
@ -5785,37 +5785,23 @@ void SubStringStub::Generate(MacroAssembler* masm) {
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static const int kFromOffset = 1 * kPointerSize;
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static const int kStringOffset = 2 * kPointerSize;
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// Check bounds and smi-ness.
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Register to = r6;
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Register from = r7;
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__ Ldrd(to, from, MemOperand(sp, kToOffset));
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__ Ldrd(r2, r3, MemOperand(sp, kToOffset));
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STATIC_ASSERT(kFromOffset == kToOffset + 4);
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STATIC_ASSERT(kSmiTag == 0);
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STATIC_ASSERT(kSmiTagSize + kSmiShiftSize == 1);
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// I.e., arithmetic shift right by one un-smi-tags.
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__ mov(r2, Operand(to, ASR, 1), SetCC);
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__ mov(r3, Operand(from, ASR, 1), SetCC, cc);
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__ mov(r2, Operand(r2, ASR, 1), SetCC);
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__ mov(r3, Operand(r3, ASR, 1), SetCC, cc);
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// If either to or from had the smi tag bit set, then carry is set now.
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__ b(cs, &runtime); // Either "from" or "to" is not a smi.
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__ b(mi, &runtime); // From is negative.
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// Both to and from are smis.
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// Both r2 and r3 are untagged integers.
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__ sub(r2, r2, Operand(r3), SetCC);
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__ b(mi, &runtime); // Fail if from > to.
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// Special handling of sub-strings of length 1 and 2. One character strings
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// are handled in the runtime system (looked up in the single character
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// cache). Two character strings are looked for in the symbol cache in
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// generated code.
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__ cmp(r2, Operand(2));
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__ b(lt, &runtime);
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// r2: result string length
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// r3: from index (untagged smi)
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// r6 (a.k.a. to): to (smi)
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// r7 (a.k.a. from): from offset (smi)
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// Make sure first argument is a sequential (or flat) string.
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// Make sure first argument is a string.
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__ ldr(r0, MemOperand(sp, kStringOffset));
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STATIC_ASSERT(kSmiTag == 0);
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__ JumpIfSmi(r0, &runtime);
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@ -5830,67 +5816,15 @@ void SubStringStub::Generate(MacroAssembler* masm) {
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__ cmp(r2, Operand(r4, ASR, 1));
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__ b(eq, &return_r0);
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Label create_slice;
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if (FLAG_string_slices) {
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__ cmp(r2, Operand(SlicedString::kMinLength));
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__ b(ge, &create_slice);
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}
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// r0: original string
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// r1: instance type
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// r2: result string length
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// r3: from index (untagged smi)
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// r6 (a.k.a. to): to (smi)
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// r7 (a.k.a. from): from offset (smi)
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Label seq_string;
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__ and_(r4, r1, Operand(kStringRepresentationMask));
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STATIC_ASSERT(kSeqStringTag < kConsStringTag);
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STATIC_ASSERT(kConsStringTag < kExternalStringTag);
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STATIC_ASSERT(kConsStringTag < kSlicedStringTag);
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__ cmp(r4, Operand(kConsStringTag));
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__ b(gt, &runtime); // Slices and external strings go to runtime.
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__ b(lt, &seq_string); // Sequential strings are handled directly.
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// Cons string. Try to recurse (once) on the first substring.
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// (This adds a little more generality than necessary to handle flattened
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// cons strings, but not much).
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__ ldr(r0, FieldMemOperand(r0, ConsString::kFirstOffset));
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__ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
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__ ldrb(r1, FieldMemOperand(r4, Map::kInstanceTypeOffset));
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__ tst(r1, Operand(kStringRepresentationMask));
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STATIC_ASSERT(kSeqStringTag == 0);
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__ b(ne, &runtime); // Cons, slices and external strings go to runtime.
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// Definitly a sequential string.
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__ bind(&seq_string);
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// r0: original string
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// r1: instance type
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// r2: result string length
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// r3: from index (untagged smi)
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// r6 (a.k.a. to): to (smi)
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// r7 (a.k.a. from): from offset (smi)
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__ ldr(r4, FieldMemOperand(r0, String::kLengthOffset));
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__ cmp(r4, Operand(to));
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__ b(lt, &runtime); // Fail if to > length.
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to = no_reg;
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// r0: original string or left hand side of the original cons string.
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// r1: instance type
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// r2: result string length
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// r3: from index (untagged smi)
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// r7 (a.k.a. from): from offset (smi)
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// Check for flat ASCII string.
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Label non_ascii_flat;
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__ tst(r1, Operand(kStringEncodingMask));
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STATIC_ASSERT(kTwoByteStringTag == 0);
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__ b(eq, &non_ascii_flat);
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Label result_longer_than_two;
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// Check for special case of two character ascii string, in which case
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// we do a lookup in the symbol table first.
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__ cmp(r2, Operand(2));
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__ b(gt, &result_longer_than_two);
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__ b(lt, &runtime);
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__ JumpIfInstanceTypeIsNotSequentialAscii(r1, r1, &runtime);
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// Sub string of length 2 requested.
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// Get the two characters forming the sub string.
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__ add(r0, r0, Operand(r3));
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__ ldrb(r3, FieldMemOperand(r0, SeqAsciiString::kHeaderSize));
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@ -5900,7 +5834,6 @@ void SubStringStub::Generate(MacroAssembler* masm) {
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Label make_two_character_string;
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StringHelper::GenerateTwoCharacterSymbolTableProbe(
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masm, r3, r4, r1, r5, r6, r7, r9, &make_two_character_string);
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Counters* counters = masm->isolate()->counters();
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__ jmp(&return_r0);
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// r2: result string length.
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@ -5911,18 +5844,114 @@ void SubStringStub::Generate(MacroAssembler* masm) {
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__ jmp(&return_r0);
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__ bind(&result_longer_than_two);
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// Deal with different string types: update the index if necessary
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// and put the underlying string into r5.
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// r0: original string
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// r1: instance type
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// r2: length
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// r3: from index (untagged)
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Label underlying_unpacked, sliced_string, seq_or_external_string;
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// If the string is not indirect, it can only be sequential or external.
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STATIC_ASSERT(kIsIndirectStringMask == (kSlicedStringTag & kConsStringTag));
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STATIC_ASSERT(kIsIndirectStringMask != 0);
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__ tst(r1, Operand(kIsIndirectStringMask));
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__ b(eq, &seq_or_external_string);
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// Locate 'from' character of string.
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__ add(r5, r0, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
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__ add(r5, r5, Operand(from, ASR, 1));
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__ tst(r1, Operand(kSlicedNotConsMask));
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__ b(ne, &sliced_string);
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// Cons string. Check whether it is flat, then fetch first part.
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__ ldr(r5, FieldMemOperand(r0, ConsString::kSecondOffset));
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__ CompareRoot(r5, Heap::kEmptyStringRootIndex);
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__ b(ne, &runtime);
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__ ldr(r5, FieldMemOperand(r0, ConsString::kFirstOffset));
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// Update instance type.
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__ ldr(r1, FieldMemOperand(r5, HeapObject::kMapOffset));
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__ ldrb(r1, FieldMemOperand(r1, Map::kInstanceTypeOffset));
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__ jmp(&underlying_unpacked);
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// Allocate the result.
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__ AllocateAsciiString(r0, r2, r3, r4, r1, &runtime);
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__ bind(&sliced_string);
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// Sliced string. Fetch parent and correct start index by offset.
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__ ldr(r5, FieldMemOperand(r0, SlicedString::kOffsetOffset));
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__ add(r3, r3, Operand(r5, ASR, 1));
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__ ldr(r5, FieldMemOperand(r0, SlicedString::kParentOffset));
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// Update instance type.
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__ ldr(r1, FieldMemOperand(r5, HeapObject::kMapOffset));
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__ ldrb(r1, FieldMemOperand(r1, Map::kInstanceTypeOffset));
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__ jmp(&underlying_unpacked);
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// r0: result string
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// r2: result string length
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// r5: first character of substring to copy
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// r7 (a.k.a. from): from offset (smi)
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__ bind(&seq_or_external_string);
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// Sequential or external string. Just move string to the expected register.
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__ mov(r5, r0);
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__ bind(&underlying_unpacked);
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if (FLAG_string_slices) {
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Label copy_routine;
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// r5: underlying subject string
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// r1: instance type of underlying subject string
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// r2: length
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// r3: adjusted start index (untagged)
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__ cmp(r2, Operand(SlicedString::kMinLength));
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// Short slice. Copy instead of slicing.
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__ b(lt, ©_routine);
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// Allocate new sliced string. At this point we do not reload the instance
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// type including the string encoding because we simply rely on the info
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// provided by the original string. It does not matter if the original
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// string's encoding is wrong because we always have to recheck encoding of
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// the newly created string's parent anyways due to externalized strings.
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Label two_byte_slice, set_slice_header;
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STATIC_ASSERT((kStringEncodingMask & kAsciiStringTag) != 0);
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STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
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__ tst(r1, Operand(kStringEncodingMask));
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__ b(eq, &two_byte_slice);
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__ AllocateAsciiSlicedString(r0, r2, r6, r7, &runtime);
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__ jmp(&set_slice_header);
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__ bind(&two_byte_slice);
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__ AllocateTwoByteSlicedString(r0, r2, r6, r7, &runtime);
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__ bind(&set_slice_header);
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__ mov(r3, Operand(r3, LSL, 1));
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__ str(r3, FieldMemOperand(r0, SlicedString::kOffsetOffset));
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__ str(r5, FieldMemOperand(r0, SlicedString::kParentOffset));
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__ jmp(&return_r0);
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__ bind(©_routine);
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}
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// r5: underlying subject string
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// r1: instance type of underlying subject string
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// r2: length
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// r3: adjusted start index (untagged)
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Label two_byte_sequential, sequential_string, allocate_result;
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STATIC_ASSERT(kExternalStringTag != 0);
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STATIC_ASSERT(kSeqStringTag == 0);
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__ tst(r1, Operand(kExternalStringTag));
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__ b(eq, &sequential_string);
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// Handle external string.
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// Rule out short external strings.
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STATIC_CHECK(kShortExternalStringTag != 0);
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__ tst(r1, Operand(kShortExternalStringTag));
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__ b(ne, &runtime);
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__ ldr(r5, FieldMemOperand(r5, ExternalString::kResourceDataOffset));
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// r5 already points to the first character of underlying string.
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__ jmp(&allocate_result);
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__ bind(&sequential_string);
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// Locate first character of underlying subject string.
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STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqAsciiString::kHeaderSize);
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__ add(r5, r5, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
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__ bind(&allocate_result);
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// Sequential acii string. Allocate the result.
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STATIC_ASSERT((kAsciiStringTag & kStringEncodingMask) != 0);
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__ tst(r1, Operand(kStringEncodingMask));
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__ b(eq, &two_byte_sequential);
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// Allocate and copy the resulting ascii string.
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__ AllocateAsciiString(r0, r2, r4, r6, r7, &runtime);
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// Locate first character of substring to copy.
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__ add(r5, r5, r3);
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// Locate first character of result.
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__ add(r1, r0, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
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@ -5935,30 +5964,16 @@ void SubStringStub::Generate(MacroAssembler* masm) {
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COPY_ASCII | DEST_ALWAYS_ALIGNED);
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__ jmp(&return_r0);
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__ bind(&non_ascii_flat);
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// r0: original string
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// r2: result string length
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// r7 (a.k.a. from): from offset (smi)
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// Check for flat two byte string.
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// Allocate and copy the resulting two-byte string.
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__ bind(&two_byte_sequential);
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__ AllocateTwoByteString(r0, r2, r4, r6, r7, &runtime);
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// Locate 'from' character of string.
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__ add(r5, r0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
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// As "from" is a smi it is 2 times the value which matches the size of a two
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// byte character.
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// Locate first character of substring to copy.
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STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
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__ add(r5, r5, Operand(from));
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// Allocate the result.
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__ AllocateTwoByteString(r0, r2, r1, r3, r4, &runtime);
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// r0: result string
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// r2: result string length
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// r5: first character of substring to copy
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__ add(r5, r5, Operand(r3, LSL, 1));
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// Locate first character of result.
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__ add(r1, r0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
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from = no_reg;
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// r0: result string.
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// r1: first character of result.
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// r2: result length.
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@ -5966,69 +5981,9 @@ void SubStringStub::Generate(MacroAssembler* masm) {
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STATIC_ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) == 0);
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StringHelper::GenerateCopyCharactersLong(
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masm, r1, r5, r2, r3, r4, r6, r7, r9, DEST_ALWAYS_ALIGNED);
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__ jmp(&return_r0);
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if (FLAG_string_slices) {
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__ bind(&create_slice);
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// r0: original string
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// r1: instance type
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// r2: length
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// r3: from index (untagged smi)
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// r6 (a.k.a. to): to (smi)
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// r7 (a.k.a. from): from offset (smi)
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Label allocate_slice, sliced_string, seq_or_external_string;
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// If the string is not indirect, it can only be sequential or external.
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STATIC_ASSERT(kIsIndirectStringMask == (kSlicedStringTag & kConsStringTag));
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STATIC_ASSERT(kIsIndirectStringMask != 0);
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__ tst(r1, Operand(kIsIndirectStringMask));
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__ b(eq, &seq_or_external_string);
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__ tst(r1, Operand(kSlicedNotConsMask));
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__ b(ne, &sliced_string);
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// Cons string. Check whether it is flat, then fetch first part.
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__ ldr(r5, FieldMemOperand(r0, ConsString::kSecondOffset));
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__ LoadRoot(r9, Heap::kEmptyStringRootIndex);
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__ cmp(r5, r9);
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__ b(ne, &runtime);
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__ ldr(r5, FieldMemOperand(r0, ConsString::kFirstOffset));
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__ jmp(&allocate_slice);
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__ bind(&sliced_string);
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// Sliced string. Fetch parent and correct start index by offset.
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__ ldr(r5, FieldMemOperand(r0, SlicedString::kOffsetOffset));
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__ add(r7, r7, r5);
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__ ldr(r5, FieldMemOperand(r0, SlicedString::kParentOffset));
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__ jmp(&allocate_slice);
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__ bind(&seq_or_external_string);
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// Sequential or external string. Just move string to the correct register.
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__ mov(r5, r0);
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__ bind(&allocate_slice);
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// r1: instance type of original string
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// r2: length
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// r5: underlying subject string
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// r7 (a.k.a. from): from offset (smi)
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// Allocate new sliced string. At this point we do not reload the instance
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// type including the string encoding because we simply rely on the info
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// provided by the original string. It does not matter if the original
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// string's encoding is wrong because we always have to recheck encoding of
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// the newly created string's parent anyways due to externalized strings.
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Label two_byte_slice, set_slice_header;
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STATIC_ASSERT((kStringEncodingMask & kAsciiStringTag) != 0);
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STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
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__ tst(r1, Operand(kStringEncodingMask));
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__ b(eq, &two_byte_slice);
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__ AllocateAsciiSlicedString(r0, r2, r3, r4, &runtime);
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__ jmp(&set_slice_header);
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__ bind(&two_byte_slice);
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__ AllocateTwoByteSlicedString(r0, r2, r3, r4, &runtime);
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__ bind(&set_slice_header);
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__ str(r7, FieldMemOperand(r0, SlicedString::kOffsetOffset));
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__ str(r5, FieldMemOperand(r0, SlicedString::kParentOffset));
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}
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__ bind(&return_r0);
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Counters* counters = masm->isolate()->counters();
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__ IncrementCounter(counters->sub_string_native(), 1, r3, r4);
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__ add(sp, sp, Operand(3 * kPointerSize));
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__ Ret();
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@ -6120,20 +6120,20 @@ void SubStringStub::Generate(MacroAssembler* masm) {
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FieldOperand(eax, edx, times_1, SeqAsciiString::kHeaderSize + 1));
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// Try to lookup two character string in symbol table.
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Label make_two_character_string;
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Label combine_two_char, save_two_char;
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StringHelper::GenerateTwoCharacterSymbolTableProbe(
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masm, ebx, ecx, eax, edx, edi,
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&make_two_character_string, &make_two_character_string);
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masm, ebx, ecx, eax, edx, edi, &combine_two_char, &save_two_char);
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__ IncrementCounter(counters->sub_string_native(), 1);
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__ ret(3 * kPointerSize);
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__ bind(&make_two_character_string);
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// Setup registers for allocating the two character string.
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__ mov(eax, Operand(esp, 3 * kPointerSize));
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__ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
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__ movzx_b(ebx, FieldOperand(ebx, Map::kInstanceTypeOffset));
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__ Set(ecx, Immediate(Smi::FromInt(2)));
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__ mov(edx, Operand(esp, 2 * kPointerSize)); // Load index.
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__ bind(&combine_two_char);
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__ shl(ecx, kBitsPerByte);
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__ or_(ebx, ecx);
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__ bind(&save_two_char);
|
||||
__ AllocateAsciiString(eax, 2, ecx, edx, &runtime);
|
||||
__ mov_w(FieldOperand(eax, SeqAsciiString::kHeaderSize), ebx);
|
||||
__ IncrementCounter(counters->sub_string_native(), 1);
|
||||
__ ret(3 * kPointerSize);
|
||||
|
||||
__ bind(&result_longer_than_two);
|
||||
// eax: string
|
||||
|
||||
Loading…
Reference in New Issue
Block a user