Changeset 43331 in webkit for trunk/JavaScriptCore/jit/JIT.cpp

Timestamp:

May 6, 2009, 5:06:07 PM (16 years ago)

Author:

[email protected]

Message:

2009-05-06 Gavin Barraclough <​[email protected]>

Reviewed by Maciej Stachowiak & Darin Adler.

Improve string concatenation (as coded in JS as a sequence of adds).

Detect patterns corresponding to string concatenation, and change the bytecode
generation to emit a new op_strcat instruction. By handling the full set of
additions within a single function we do not need allocate JSString wrappers
for intermediate results, and we can calculate the size of the output string
prior to allocating storage, in order to prevent reallocation of the buffer.

1.5%-2% progression on Sunspider, largely due to a 30% progression on date-format-xparb.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::dump):

Add new opcodes.

• bytecode/Opcode.h:

Add new opcodes.

• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::emitStrcat): (JSC::BytecodeGenerator::emitToPrimitive):

Add generation of new opcodes.

• bytecompiler/BytecodeGenerator.h:

Add generation of new opcodes.

• interpreter/Interpreter.cpp: (JSC::Interpreter::privateExecute):

Add implmentation of new opcodes.

• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass): (JSC::JIT::privateCompileSlowCases):

Add implmentation of new opcodes.

• jit/JITStubs.cpp: (JSC::JITStubs::cti_op_to_primitive): (JSC::JITStubs::cti_op_strcat):

Add implmentation of new opcodes.

• jit/JITStubs.h:

Add implmentation of new opcodes.

• parser/Nodes.cpp: (JSC::BinaryOpNode::emitStrcat): (JSC::BinaryOpNode::emitBytecode): (JSC::ReadModifyResolveNode::emitBytecode):

Add generation of new opcodes.

• parser/Nodes.h: (JSC::ExpressionNode::): (JSC::AddNode::):

Add methods to allow identification of add nodes.

• parser/ResultType.h: (JSC::ResultType::definitelyIsString): (JSC::ResultType::forAdd):

Fix error in detection of adds that will produce string results.

• runtime/Operations.h: (JSC::concatenateStrings):

Add implmentation of new opcodes.

• runtime/UString.cpp: (JSC::UString::appendNumeric):

Add methods to append numbers to an existing string.

• runtime/UString.h: (JSC::UString::Rep::createEmptyBuffer): (JSC::UString::BaseString::BaseString):

Add support for creating an empty string with a non-zero capacity available in the BaseString.

File:

• trunk/JavaScriptCore/jit/JIT.cpp (modified) (2 diffs)

trunk/JavaScriptCore/jit/JIT.cpp

@@ -464 +464 @@
             NEXT_OPCODE(op_construct_verify);
         }
+        case op_to_primitive: {
+            int dst = currentInstruction[1].u.operand;
+            int src = currentInstruction[2].u.operand;
+
+            emitGetVirtualRegister(src, regT0);
+            
+            Jump isImm = emitJumpIfNotJSCell(regT0);
+            addSlowCase(branchPtr(NotEqual, Address(regT0), ImmPtr(m_globalData->jsStringVPtr)));
+            isImm.link(this);
+
+            if (dst != src)
+                emitPutVirtualRegister(dst);
+
+            NEXT_OPCODE(op_to_primitive);
+        }
+        case op_strcat: {
+            emitPutJITStubArgConstant(currentInstruction[2].u.operand, 1);
+            emitPutJITStubArgConstant(currentInstruction[3].u.operand, 2);
+            emitCTICall(JITStubs::cti_op_strcat);
+            emitPutVirtualRegister(currentInstruction[1].u.operand);
+
+            NEXT_OPCODE(op_strcat);
+        }
         case op_get_by_val: {
             emitGetVirtualRegisters(currentInstruction[2].u.operand, regT0, currentInstruction[3].u.operand, regT1);
@@ -1167 +1190 @@
             NEXT_OPCODE(op_construct_verify);
         }
+        case op_to_primitive: {
+            linkSlowCase(iter);
+
+            emitPutJITStubArg(regT0, 1);
+            emitCTICall(JITStubs::cti_op_to_primitive);
+            emitPutVirtualRegister(currentInstruction[1].u.operand);
+
+            NEXT_OPCODE(op_to_primitive);
+        }
         case op_get_by_val: {
             // The slow case that handles accesses to arrays (below) may jump back up to here.