Load(args->at(0));
Load(args->at(1));
- frame_->CallRuntime(Runtime::kStringAdd, 2);
+ StringAddStub stub(NO_STRING_ADD_FLAGS);
+ frame_->CallStub(&stub, 2);
frame_->EmitPush(r0);
}
// r1 : first argument
// r0 : second argument
// sp[0] : second argument
- // sp[1] : first argument
+ // sp[4] : first argument
Label not_strings, not_string1, string1;
__ tst(r1, Operand(kSmiTagMask));
__ b(ge, &string1);
// First and second argument are strings.
- __ TailCallRuntime(ExternalReference(Runtime::kStringAdd), 2, 1);
+ StringAddStub stub(NO_STRING_CHECK_IN_STUB);
+ __ TailCallStub(&stub);
// Only first argument is a string.
__ bind(&string1);
__ b(ge, ¬_strings);
// Only second argument is a string.
- __ b(¬_strings);
__ InvokeBuiltin(Builtins::STRING_ADD_RIGHT, JUMP_JS);
__ bind(¬_strings);
__ b(eq, &done);
__ bind(&loop);
+ __ ldrb(scratch, MemOperand(src, 1, PostIndex));
+ // Perform sub between load and dependent store to get the load time to
+ // complete.
__ sub(count, count, Operand(1), SetCC);
- __ ldrb(scratch, MemOperand(src, count), pl);
- // Move branch between load and dependent store to not waste the cycle for
- // each iteration of the loop. It does cost an extra instruction on the
+ __ strb(scratch, MemOperand(dest, 1, PostIndex));
// last iteration.
- __ b(mi, &done);
- __ strb(scratch, MemOperand(dest, count));
- __ b(&loop);
+ __ b(gt, &loop);
+
__ bind(&done);
}
Label runtime;
// Stack frame on entry.
- // sp[0]: return address
- // sp[4]: right string
- // sp[8]: left string
-
- __ ldr(r0, MemOperand(sp, 2 * kPointerSize)); // left
- __ ldr(r1, MemOperand(sp, 1 * kPointerSize)); // right
+ // sp[0]: right string
+ // sp[4]: left string
+ __ ldr(r0, MemOperand(sp, 1 * kPointerSize)); // left
+ __ ldr(r1, MemOperand(sp, 0 * kPointerSize)); // right
Label not_same;
__ cmp(r0, r1);
}
+void StringAddStub::Generate(MacroAssembler* masm) {
+ Label string_add_runtime;
+ // Stack on entry:
+ // sp[0]: second argument.
+ // sp[4]: first argument.
+
+ // Load the two arguments.
+ __ ldr(r0, MemOperand(sp, 1 * kPointerSize)); // First argument.
+ __ ldr(r1, MemOperand(sp, 0 * kPointerSize)); // Second argument.
+
+ // Make sure that both arguments are strings if not known in advance.
+ if (string_check_) {
+ ASSERT_EQ(0, kSmiTag);
+ __ JumpIfEitherSmi(r0, r1, &string_add_runtime);
+ // Load instance types.
+ __ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
+ __ ldr(r5, FieldMemOperand(r1, HeapObject::kMapOffset));
+ __ ldrb(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
+ __ ldrb(r5, FieldMemOperand(r5, Map::kInstanceTypeOffset));
+ ASSERT_EQ(0, kStringTag);
+ // If either is not a string, go to runtime.
+ __ tst(r4, Operand(kIsNotStringMask));
+ __ tst(r5, Operand(kIsNotStringMask), eq);
+ __ b(ne, &string_add_runtime);
+ }
+
+ // Both arguments are strings.
+ // r0: first string
+ // r1: second string
+ // r4: first string instance type (if string_check_)
+ // r5: second string instance type (if string_check_)
+ {
+ Label strings_not_empty;
+ // Check if either of the strings are empty. In that case return the other.
+ __ ldr(r2, FieldMemOperand(r0, String::kLengthOffset));
+ __ ldr(r3, FieldMemOperand(r1, String::kLengthOffset));
+ __ cmp(r2, Operand(0)); // Test if first string is empty.
+ __ mov(r0, Operand(r1), LeaveCC, eq); // If first is empty, return second.
+ __ cmp(r3, Operand(0), ne); // Else test if second string is empty.
+ __ b(ne, &strings_not_empty); // If either string was empty, return r0.
+
+ __ IncrementCounter(&Counters::string_add_native, 1, r2, r3);
+ __ add(sp, sp, Operand(2 * kPointerSize));
+ __ Ret();
+
+ __ bind(&strings_not_empty);
+ }
+
+ // Both strings are non-empty.
+ // r0: first string
+ // r1: second string
+ // r2: length of first string
+ // r3: length of second string
+ // r4: first string instance type (if string_check_)
+ // r5: second string instance type (if string_check_)
+ // Look at the length of the result of adding the two strings.
+ Label string_add_flat_result;
+ // Adding two lengths can't overflow.
+ ASSERT(String::kMaxLength * 2 > String::kMaxLength);
+ __ add(r6, r2, Operand(r3));
+ // Use the runtime system when adding two one character strings, as it
+ // contains optimizations for this specific case using the symbol table.
+ __ cmp(r6, Operand(2));
+ __ b(eq, &string_add_runtime);
+ // Check if resulting string will be flat.
+ __ cmp(r6, Operand(String::kMinNonFlatLength));
+ __ b(lt, &string_add_flat_result);
+ // Handle exceptionally long strings in the runtime system.
+ ASSERT((String::kMaxLength & 0x80000000) == 0);
+ ASSERT(IsPowerOf2(String::kMaxLength + 1));
+ // kMaxLength + 1 is representable as shifted literal, kMaxLength is not.
+ __ cmp(r6, Operand(String::kMaxLength + 1));
+ __ b(hs, &string_add_runtime);
+
+ // If result is not supposed to be flat, allocate a cons string object.
+ // If both strings are ascii the result is an ascii cons string.
+ if (!string_check_) {
+ __ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
+ __ ldr(r5, FieldMemOperand(r1, HeapObject::kMapOffset));
+ __ ldrb(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
+ __ ldrb(r5, FieldMemOperand(r5, Map::kInstanceTypeOffset));
+ }
+ Label non_ascii, allocated;
+ ASSERT_EQ(0, kTwoByteStringTag);
+ __ tst(r4, Operand(kStringEncodingMask));
+ __ tst(r5, Operand(kStringEncodingMask), ne);
+ __ b(eq, &non_ascii);
+
+ // Allocate an ASCII cons string.
+ __ AllocateAsciiConsString(r7, r6, r4, r5, &string_add_runtime);
+ __ bind(&allocated);
+ // Fill the fields of the cons string.
+ __ str(r0, FieldMemOperand(r7, ConsString::kFirstOffset));
+ __ str(r1, FieldMemOperand(r7, ConsString::kSecondOffset));
+ __ mov(r0, Operand(r7));
+ __ IncrementCounter(&Counters::string_add_native, 1, r2, r3);
+ __ add(sp, sp, Operand(2 * kPointerSize));
+ __ Ret();
+
+ __ bind(&non_ascii);
+ // Allocate a two byte cons string.
+ __ AllocateTwoByteConsString(r7, r6, r4, r5, &string_add_runtime);
+ __ jmp(&allocated);
+
+ // Handle creating a flat result. First check that both strings are
+ // sequential and that they have the same encoding.
+ // r0: first string
+ // r1: second string
+ // r2: length of first string
+ // r3: length of second string
+ // r4: first string instance type (if string_check_)
+ // r5: second string instance type (if string_check_)
+ // r6: sum of lengths.
+ __ bind(&string_add_flat_result);
+ if (!string_check_) {
+ __ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
+ __ ldr(r5, FieldMemOperand(r1, HeapObject::kMapOffset));
+ __ ldrb(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
+ __ ldrb(r5, FieldMemOperand(r5, Map::kInstanceTypeOffset));
+ }
+ // Check that both strings are sequential.
+ ASSERT_EQ(0, kSeqStringTag);
+ __ tst(r4, Operand(kStringRepresentationMask));
+ __ tst(r5, Operand(kStringRepresentationMask), eq);
+ __ b(ne, &string_add_runtime);
+ // Now check if both strings have the same encoding (ASCII/Two-byte).
+ // r0: first string.
+ // r1: second string.
+ // r2: length of first string.
+ // r3: length of second string.
+ // r6: sum of lengths..
+ Label non_ascii_string_add_flat_result;
+ ASSERT(IsPowerOf2(kStringEncodingMask)); // Just one bit to test.
+ __ eor(r7, r4, Operand(r5));
+ __ tst(r7, Operand(kStringEncodingMask));
+ __ b(ne, &string_add_runtime);
+ // And see if it's ASCII or two-byte.
+ __ tst(r4, Operand(kStringEncodingMask));
+ __ b(eq, &non_ascii_string_add_flat_result);
+
+ // Both strings are sequential ASCII strings. We also know that they are
+ // short (since the sum of the lengths is less than kMinNonFlatLength).
+ __ AllocateAsciiString(r7, r6, r4, r5, r9, &string_add_runtime);
+ // Locate first character of result.
+ __ add(r6, r7, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+ // Locate first character of first argument.
+ __ add(r0, r0, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+ // r0: first character of first string.
+ // r1: second string.
+ // r2: length of first string.
+ // r3: length of second string.
+ // r6: first character of result.
+ // r7: result string.
+ GenerateCopyCharacters(masm, r6, r0, r2, r4, true);
+
+ // Load second argument and locate first character.
+ __ add(r1, r1, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+ // r1: first character of second string.
+ // r3: length of second string.
+ // r6: next character of result.
+ // r7: result string.
+ GenerateCopyCharacters(masm, r6, r1, r3, r4, true);
+ __ mov(r0, Operand(r7));
+ __ IncrementCounter(&Counters::string_add_native, 1, r2, r3);
+ __ add(sp, sp, Operand(2 * kPointerSize));
+ __ Ret();
+
+ __ bind(&non_ascii_string_add_flat_result);
+ // Both strings are sequential two byte strings.
+ // r0: first string.
+ // r1: second string.
+ // r2: length of first string.
+ // r3: length of second string.
+ // r6: sum of length of strings.
+ __ AllocateTwoByteString(r7, r6, r4, r5, r9, &string_add_runtime);
+ // r0: first string.
+ // r1: second string.
+ // r2: length of first string.
+ // r3: length of second string.
+ // r7: result string.
+
+ // Locate first character of result.
+ __ add(r6, r7, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+ // Locate first character of first argument.
+ __ add(r0, r0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+
+ // r0: first character of first string.
+ // r1: second string.
+ // r2: length of first string.
+ // r3: length of second string.
+ // r6: first character of result.
+ // r7: result string.
+ GenerateCopyCharacters(masm, r6, r0, r2, r4, false);
+
+ // Locate first character of second argument.
+ __ add(r1, r1, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+
+ // r1: first character of second string.
+ // r3: length of second string.
+ // r6: next character of result (after copy of first string).
+ // r7: result string.
+ GenerateCopyCharacters(masm, r6, r1, r3, r4, false);
+
+ __ mov(r0, Operand(r7));
+ __ IncrementCounter(&Counters::string_add_native, 1, r2, r3);
+ __ add(sp, sp, Operand(2 * kPointerSize));
+ __ Ret();
+
+ // Just jump to runtime to add the two strings.
+ __ bind(&string_add_runtime);
+ __ TailCallRuntime(ExternalReference(Runtime::kStringAdd), 2, 1);
+}
+
+
#undef __
} } // namespace v8::internal
projects / platform / upstream / v8.git / commitdiff