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Unified Diff: src/ppc/code-stubs-ppc.cc

Issue 2365413002: Revert of [stubs] Port SubStringStub to TurboFan (Closed)
Patch Set: Created 4 years, 3 months ago
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Index: src/ppc/code-stubs-ppc.cc
diff --git a/src/ppc/code-stubs-ppc.cc b/src/ppc/code-stubs-ppc.cc
index 1a1c28d25c4522ed22389f5abc25aaceeb93047c..82318685dfd156b54fdcb497d4174cddfc9663c6 100644
--- a/src/ppc/code-stubs-ppc.cc
+++ b/src/ppc/code-stubs-ppc.cc
@@ -2207,6 +2207,230 @@
__ 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;
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