Changeset 58902 in webkit for trunk/JavaScriptCore/interpreter

Timestamp:

May 6, 2010, 12:39:54 PM (15 years ago)

Author:

[email protected]

Message:

2010-05-06 Oliver Hunt <​[email protected]>

Reviewed by Geoffrey Garen.

Improve performance of single character string compares
​https://bugs.webkit.org/show_bug.cgi?id=38659

Add logic to the jit to identify comparisons to single character string literals
and then just perform the comparison inline, rather than ignoring the evidence
and attempting to perform an integer comparison.

Multiple changes required -- add jnlesseq opcode, add helper function to identify
single character string constants, add a helper to load single character strings.
Then add the 32_64 and normal codepaths to the JIT.

• assembler/MacroAssemblerX86Common.h: (JSC::MacroAssemblerX86Common::load16):
• bytecode/CodeBlock.cpp: (JSC::CodeBlock::dump):
• bytecode/Opcode.h:
• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::emitJumpIfTrue):
• interpreter/Interpreter.cpp: (JSC::Interpreter::privateExecute):
• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass): (JSC::JIT::privateCompileSlowCases):
• jit/JIT.h:
• jit/JITArithmetic.cpp: (JSC::JIT::emit_op_jnless): (JSC::JIT::emitSlow_op_jnless): (JSC::JIT::emit_op_jless): (JSC::JIT::emitSlow_op_jless): (JSC::JIT::emit_op_jlesseq): (JSC::JIT::emit_op_jnlesseq): (JSC::JIT::emitSlow_op_jlesseq): (JSC::JIT::emitSlow_op_jnlesseq):
• jit/JITArithmetic32_64.cpp: (JSC::JIT::emit_op_jnless): (JSC::JIT::emitSlow_op_jnless): (JSC::JIT::emit_op_jless): (JSC::JIT::emitSlow_op_jless): (JSC::JIT::emit_op_jlesseq): (JSC::JIT::emit_op_jnlesseq): (JSC::JIT::emitSlow_op_jlesseq): (JSC::JIT::emitSlow_op_jnlesseq): (JSC::JIT::emitBinaryDoubleOp):
• jit/JITInlineMethods.h: (JSC::JIT::emitLoadCharacterString): (JSC::JIT::isOperandConstantImmediateChar):
• jit/JSInterfaceJIT.h: (JSC::ThunkHelpers::stringImplDataOffset): (JSC::ThunkHelpers::jsStringLengthOffset): (JSC::ThunkHelpers::jsStringValueOffset): Moved from ThunkGenerators to make it possible to share.
• jit/ThunkGenerators.cpp:

2010-05-06 Oliver Hunt <​[email protected]>

Reviewed by Geoffrey Garen.

Improve performance of single character string compares
​https://bugs.webkit.org/show_bug.cgi?id=38659

Add many tests of <, >, <=, >=, ==, ===, !=, !== as the existing
tests were woefully inadequate.

• fast/js/comparison-operators-expected.txt: Added.
• fast/js/comparison-operators-greater-expected.txt: Added.
• fast/js/comparison-operators-greater.html: Added.
• fast/js/comparison-operators-less-expected.txt: Added.
• fast/js/comparison-operators-less.html: Added.
• fast/js/comparison-operators.html: Added.
• fast/js/script-tests/comparison-operators-greater.js: Added. (description.makeTest.func.f.toString): (description.makeTest): (doTest):
• fast/js/script-tests/comparison-operators-less.js: Added. (description.makeTest.func.f.toString): (description.makeTest): (doTest):
• fast/js/script-tests/comparison-operators.js: Added. (description.makeTest.func.f.toString): (description.makeTest): (doTest):

File:

• trunk/JavaScriptCore/interpreter/Interpreter.cpp (modified) (1 diff)

trunk/JavaScriptCore/interpreter/Interpreter.cpp

@@ -3210 +3210 @@
 
         vPC += OPCODE_LENGTH(op_jnlesseq);
+        NEXT_INSTRUCTION();
+    }
+    DEFINE_OPCODE(op_jlesseq) {
+        /* jlesseq src1(r) src2(r) target(offset)
+         
+         Checks whether register src1 is less than or equal to
+         register src2, as with the ECMAScript '<=' operator,
+         and then jumps to offset target from the current instruction,
+         if and only if the result of the comparison is true.
+         */
+        JSValue src1 = callFrame->r(vPC[1].u.operand).jsValue();
+        JSValue src2 = callFrame->r(vPC[2].u.operand).jsValue();
+        int target = vPC[3].u.operand;
+        
+        bool result = jsLessEq(callFrame, src1, src2);
+        CHECK_FOR_EXCEPTION();
+        
+        if (result) {
+            vPC += target;
+            NEXT_INSTRUCTION();
+        }
+        
+        vPC += OPCODE_LENGTH(op_jlesseq);
         NEXT_INSTRUCTION();
     }