Revision: 9127
Author: [email protected]
Date: Mon Sep 5 02:05:52 2011
Log: MIPS: port Generated code for substring slices in x64 and arm.
Ported r9111 (2b946464)
BUG=
TEST=
Review URL: http://codereview.chromium.org/7835025
http://code.google.com/p/v8/source/detail?r=9127
Modified:
/branches/bleeding_edge/src/mips/code-stubs-mips.cc
/branches/bleeding_edge/src/mips/macro-assembler-mips.cc
/branches/bleeding_edge/src/mips/macro-assembler-mips.h
=======================================
--- /branches/bleeding_edge/src/mips/code-stubs-mips.cc Mon Sep 5 02:04:32
2011
+++ /branches/bleeding_edge/src/mips/code-stubs-mips.cc Mon Sep 5 02:05:52
2011
@@ -5642,11 +5642,6 @@
Register to = t2;
Register from = t3;
- if (FLAG_string_slices) {
- __ nop(); // Jumping as first instruction would crash the code
generation.
- __ jmp(&sub_string_runtime);
- }
-
// Check bounds and smi-ness.
__ lw(to, MemOperand(sp, kToOffset));
__ lw(from, MemOperand(sp, kFromOffset));
@@ -5670,7 +5665,8 @@
// Special handling of sub-strings of length 1 and 2. One character
strings
// are handled in the runtime system (looked up in the single character
- // cache). Two character strings are looked for in the symbol cache.
+ // cache). Two character strings are looked for in the symbol cache in
+ // generated code.
__ Branch(&sub_string_runtime, lt, a2, Operand(2));
// Both to and from are smis.
@@ -5682,19 +5678,32 @@
// t5: to index (untagged smi)
// Make sure first argument is a sequential (or flat) string.
- __ lw(t1, MemOperand(sp, kStringOffset));
- __ Branch(&sub_string_runtime, eq, t1, Operand(kSmiTagMask));
-
- __ lw(a1, FieldMemOperand(t1, HeapObject::kMapOffset));
+ __ lw(v0, MemOperand(sp, kStringOffset));
+ __ Branch(&sub_string_runtime, eq, v0, Operand(kSmiTagMask));
+
+ __ lw(a1, FieldMemOperand(v0, HeapObject::kMapOffset));
__ lbu(a1, FieldMemOperand(a1, Map::kInstanceTypeOffset));
- __ And(t4, a1, Operand(kIsNotStringMask));
+ __ And(t4, v0, Operand(kIsNotStringMask));
__ Branch(&sub_string_runtime, ne, t4, Operand(zero_reg));
+ // Short-cut for the case of trivial substring.
+ Label return_v0;
+ // v0: original string
+ // a2: result string length
+ __ lw(t0, FieldMemOperand(v0, String::kLengthOffset));
+ __ sra(t0, t0, 1);
+ __ Branch(&return_v0, eq, a2, Operand(t0));
+
+ Label create_slice;
+ if (FLAG_string_slices) {
+ __ Branch(&create_slice, ge, a2, Operand(SlicedString::kMinLength));
+ }
+
+ // v0: original string
// a1: instance type
// a2: result string length
// a3: from index (untagged smi)
- // t1: string
// t2: (a.k.a. to): to (smi)
// t3: (a.k.a. from): from offset (smi)
// t5: to index (untagged smi)
@@ -5703,8 +5712,9 @@
__ And(t0, a1, Operand(kStringRepresentationMask));
STATIC_ASSERT(kSeqStringTag < kConsStringTag);
STATIC_ASSERT(kConsStringTag < kExternalStringTag);
-
- // External strings go to runtime.
+ STATIC_ASSERT(kConsStringTag < kSlicedStringTag);
+
+ // Slices and external strings go to runtime.
__ Branch(&sub_string_runtime, gt, t0, Operand(kConsStringTag));
// Sequential strings are handled directly.
@@ -5713,32 +5723,32 @@
// Cons string. Try to recurse (once) on the first substring.
// (This adds a little more generality than necessary to handle flattened
// cons strings, but not much).
- __ lw(t1, FieldMemOperand(t1, ConsString::kFirstOffset));
- __ lw(t0, FieldMemOperand(t1, HeapObject::kMapOffset));
+ __ lw(v0, FieldMemOperand(v0, ConsString::kFirstOffset));
+ __ lw(t0, FieldMemOperand(v0, HeapObject::kMapOffset));
__ lbu(a1, FieldMemOperand(t0, Map::kInstanceTypeOffset));
STATIC_ASSERT(kSeqStringTag == 0);
- // Cons and External strings go to runtime.
+ // Cons, slices and external strings go to runtime.
__ Branch(&sub_string_runtime, ne, a1,
Operand(kStringRepresentationMask));
// Definitly a sequential string.
__ bind(&seq_string);
+ // v0: original string
// a1: instance type
// a2: result string length
// a3: from index (untagged smi)
- // t1: string
// t2: (a.k.a. to): to (smi)
// t3: (a.k.a. from): from offset (smi)
// t5: to index (untagged smi)
- __ lw(t0, FieldMemOperand(t1, String::kLengthOffset));
+ __ lw(t0, FieldMemOperand(v0, String::kLengthOffset));
__ Branch(&sub_string_runtime, lt, t0, Operand(to)); // Fail if to >
length.
to = no_reg;
+ // v0: original string or left hand side of the original cons string.
// a1: instance type
// a2: result string length
// a3: from index (untagged smi)
- // t1: string
// t3: (a.k.a. from): from offset (smi)
// t5: to index (untagged smi)
@@ -5754,84 +5764,147 @@
// Sub string of length 2 requested.
// Get the two characters forming the sub string.
- __ Addu(t1, t1, Operand(a3));
- __ lbu(a3, FieldMemOperand(t1, SeqAsciiString::kHeaderSize));
- __ lbu(t0, FieldMemOperand(t1, SeqAsciiString::kHeaderSize + 1));
+ __ Addu(v0, v0, Operand(a3));
+ __ lbu(a3, FieldMemOperand(v0, SeqAsciiString::kHeaderSize));
+ __ lbu(t0, FieldMemOperand(v0, SeqAsciiString::kHeaderSize + 1));
// Try to lookup two character string in symbol table.
Label make_two_character_string;
StringHelper::GenerateTwoCharacterSymbolTableProbe(
masm, a3, t0, a1, t1, t2, t3, t4, &make_two_character_string);
Counters* counters = masm->isolate()->counters();
- __ IncrementCounter(counters->sub_string_native(), 1, a3, t0);
- __ Addu(sp, sp, Operand(3 * kPointerSize));
- __ Ret();
-
+ __ jmp(&return_v0);
// a2: result string length.
// a3: two characters combined into halfword in little endian byte order.
__ bind(&make_two_character_string);
__ AllocateAsciiString(v0, a2, t0, t1, t4, &sub_string_runtime);
__ sh(a3, FieldMemOperand(v0, SeqAsciiString::kHeaderSize));
- __ IncrementCounter(counters->sub_string_native(), 1, a3, t0);
- __ Addu(sp, sp, Operand(3 * kPointerSize));
- __ Ret();
+ __ jmp(&return_v0);
__ bind(&result_longer_than_two);
+ // Locate 'from' character of string.
+ __ Addu(t1, v0, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+ __ sra(t4, from, 1);
+ __ Addu(t1, t1, t4);
+
// Allocate the result.
__ AllocateAsciiString(v0, a2, t4, t0, a1, &sub_string_runtime);
- // v0: result string.
- // a2: result string length.
+ // v0: result string
+ // a2: result string length
// a3: from index (untagged smi)
- // t1: string.
+ // t1: first character of substring to copy
// t3: (a.k.a. from): from offset (smi)
// Locate first character of result.
__ Addu(a1, v0, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
- // Locate 'from' character of string.
- __ Addu(t1, t1, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
- __ Addu(t1, t1, Operand(a3));
-
- // v0: result string.
- // a1: first character of result string.
- // a2: result string length.
- // t1: first character of sub string to copy.
+
+ // v0: result string
+ // a1: first character of result string
+ // a2: result string length
+ // t1: first character of substring to copy
STATIC_ASSERT((SeqAsciiString::kHeaderSize & kObjectAlignmentMask) == 0);
StringHelper::GenerateCopyCharactersLong(
masm, a1, t1, a2, a3, t0, t2, t3, t4, COPY_ASCII |
DEST_ALWAYS_ALIGNED);
- __ IncrementCounter(counters->sub_string_native(), 1, a3, t0);
- __ Addu(sp, sp, Operand(3 * kPointerSize));
- __ Ret();
+ __ jmp(&return_v0);
__ bind(&non_ascii_flat);
- // a2: result string length.
- // t1: string.
+ // a2: result string length
+ // t1: string
// t3: (a.k.a. from): from offset (smi)
// Check for flat two byte string.
+ // Locate 'from' character of string.
+ __ Addu(t1, v0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+ // As "from" is a smi it is 2 times the value which matches the size of
a two
+ // byte character.
+ STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
+ __ Addu(t1, t1, Operand(from));
+
// Allocate the result.
__ AllocateTwoByteString(v0, a2, a1, a3, t0, &sub_string_runtime);
- // v0: result string.
- // a2: result string length.
- // t1: string.
+ // v0: result string
+ // a2: result string length
+ // t1: first character of substring to copy
// Locate first character of result.
__ Addu(a1, v0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
- // Locate 'from' character of string.
- __ Addu(t1, t1, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
- // As "from" is a smi it is 2 times the value which matches the size of
a two
- // byte character.
- __ Addu(t1, t1, Operand(from));
+
from = no_reg;
// v0: result string.
// a1: first character of result.
// a2: result length.
- // t1: first character of string to copy.
+ // t1: first character of substring to copy.
STATIC_ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) ==
0);
StringHelper::GenerateCopyCharactersLong(
masm, a1, t1, a2, a3, t0, t2, t3, t4, DEST_ALWAYS_ALIGNED);
+ __ jmp(&return_v0);
+
+ if (FLAG_string_slices) {
+ __ bind(&create_slice);
+ // v0: original string
+ // a1: instance type
+ // a2: length
+ // a3: from index (untagged smi)
+ // t2 (a.k.a. to): to (smi)
+ // t3 (a.k.a. from): from offset (smi)
+ Label allocate_slice, sliced_string, seq_string;
+ STATIC_ASSERT(kSeqStringTag == 0);
+ __ And(t4, a1, Operand(kStringRepresentationMask));
+ __ Branch(&seq_string, eq, t4, Operand(zero_reg));
+ STATIC_ASSERT(kIsIndirectStringMask == (kSlicedStringTag &
kConsStringTag));
+ STATIC_ASSERT(kIsIndirectStringMask != 0);
+ __ And(t4, a1, Operand(kIsIndirectStringMask));
+ // External string. Jump to runtime.
+ __ Branch(&sub_string_runtime, eq, t4, Operand(zero_reg));
+
+ __ And(t4, a1, Operand(kSlicedNotConsMask));
+ __ Branch(&sliced_string, ne, t4, Operand(zero_reg));
+ // Cons string. Check whether it is flat, then fetch first part.
+ __ lw(t1, FieldMemOperand(v0, ConsString::kSecondOffset));
+ __ LoadRoot(t5, Heap::kEmptyStringRootIndex);
+ __ Branch(&sub_string_runtime, ne, t1, Operand(t5));
+ __ lw(t1, FieldMemOperand(v0, ConsString::kFirstOffset));
+ __ jmp(&allocate_slice);
+
+ __ bind(&sliced_string);
+ // Sliced string. Fetch parent and correct start index by offset.
+ __ lw(t1, FieldMemOperand(v0, SlicedString::kOffsetOffset));
+ __ addu(t3, t3, t1);
+ __ lw(t1, FieldMemOperand(v0, SlicedString::kParentOffset));
+ __ jmp(&allocate_slice);
+
+ __ bind(&seq_string);
+ // Sequential string. Just move string to the right register.
+ __ mov(t1, v0);
+
+ __ bind(&allocate_slice);
+ // a1: instance type of original string
+ // a2: length
+ // t1: underlying subject string
+ // t3 (a.k.a. from): from offset (smi)
+ // 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 & kAsciiStringTag) != 0);
+ STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
+ __ And(t4, a1, Operand(kStringEncodingMask));
+ __ Branch(&two_byte_slice, eq, t4, Operand(zero_reg));
+ __ AllocateAsciiSlicedString(v0, a2, a3, t0, &sub_string_runtime);
+ __ jmp(&set_slice_header);
+ __ bind(&two_byte_slice);
+ __ AllocateTwoByteSlicedString(v0, a2, a3, t0, &sub_string_runtime);
+ __ bind(&set_slice_header);
+ __ sw(t3, FieldMemOperand(v0, SlicedString::kOffsetOffset));
+ __ sw(t1, FieldMemOperand(v0, SlicedString::kParentOffset));
+ }
+
+ __ bind(&return_v0);
__ IncrementCounter(counters->sub_string_native(), 1, a3, t0);
__ Addu(sp, sp, Operand(3 * kPointerSize));
__ Ret();
=======================================
--- /branches/bleeding_edge/src/mips/macro-assembler-mips.cc Mon Sep 5
02:04:32 2011
+++ /branches/bleeding_edge/src/mips/macro-assembler-mips.cc Mon Sep 5
02:05:52 2011
@@ -2813,6 +2813,46 @@
scratch1,
scratch2);
}
+
+
+void MacroAssembler::AllocateTwoByteSlicedString(Register result,
+ Register length,
+ Register scratch1,
+ Register scratch2,
+ Label* gc_required) {
+ AllocateInNewSpace(SlicedString::kSize,
+ result,
+ scratch1,
+ scratch2,
+ gc_required,
+ TAG_OBJECT);
+
+ InitializeNewString(result,
+ length,
+ Heap::kSlicedStringMapRootIndex,
+ scratch1,
+ scratch2);
+}
+
+
+void MacroAssembler::AllocateAsciiSlicedString(Register result,
+ Register length,
+ Register scratch1,
+ Register scratch2,
+ Label* gc_required) {
+ AllocateInNewSpace(SlicedString::kSize,
+ result,
+ scratch1,
+ scratch2,
+ gc_required,
+ TAG_OBJECT);
+
+ InitializeNewString(result,
+ length,
+ Heap::kSlicedAsciiStringMapRootIndex,
+ scratch1,
+ scratch2);
+}
// Allocates a heap number or jumps to the label if the young space is
full and
=======================================
--- /branches/bleeding_edge/src/mips/macro-assembler-mips.h Mon Sep 5
02:04:32 2011
+++ /branches/bleeding_edge/src/mips/macro-assembler-mips.h Mon Sep 5
02:05:52 2011
@@ -362,6 +362,16 @@
Register scratch1,
Register scratch2,
Label* gc_required);
+ void AllocateTwoByteSlicedString(Register result,
+ Register length,
+ Register scratch1,
+ Register scratch2,
+ Label* gc_required);
+ void AllocateAsciiSlicedString(Register result,
+ Register length,
+ Register scratch1,
+ Register scratch2,
+ Label* gc_required);
// Allocates a heap number or jumps to the gc_required label if the young
// space is full and a scavenge is needed. All registers are clobbered
also
--
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