Changeset 37789 in webkit for trunk/JavaScriptCore/VM/CTI.cpp

Timestamp:

Oct 22, 2008, 2:06:30 PM (17 years ago)

Author:

[email protected]

Message:

2008-10-22 Cameron Zwarich <​[email protected]>

Reviewed by Geoff Garen.

Bug 21803: Fuse op_jfalse with op_eq_null and op_neq_null
<​https://bugs.webkit.org/show_bug.cgi?id=21803>

Fuse op_jfalse with op_eq_null and op_neq_null to make the new opcodes
op_jeq_null and op_jneq_null.

This is a 2.6% speedup on the V8 Raytrace benchmark, and strangely also
a 4.7% speedup on the V8 Arguments benchmark, even though it uses
neither of the two new opcodes.

• VM/CTI.cpp: (JSC::CTI::privateCompileMainPass):
• VM/CodeBlock.cpp: (JSC::CodeBlock::dump):
• VM/CodeGenerator.cpp: (JSC::CodeGenerator::emitJumpIfTrue): (JSC::CodeGenerator::emitJumpIfFalse):
• VM/Machine.cpp: (JSC::Machine::privateExecute):
• VM/Opcode.h:

File:

• trunk/JavaScriptCore/VM/CTI.cpp (modified) (1 diff)

trunk/JavaScriptCore/VM/CTI.cpp

@@ -1575 +1575 @@
             break;
         };
+        case op_jeq_null: {
+            unsigned src = instruction[i + 1].u.operand;
+            unsigned target = instruction[i + 2].u.operand;
+
+            emitGetArg(src, X86::eax);
+            m_jit.testl_i32r(JSImmediate::TagMask, X86::eax);
+            X86Assembler::JmpSrc isImmediate = m_jit.emitUnlinkedJnz();
+
+            m_jit.movl_mr(OBJECT_OFFSET(JSCell, m_structureID), X86::eax, X86::ecx);
+            m_jit.testl_i32m(MasqueradesAsUndefined, OBJECT_OFFSET(StructureID, m_typeInfo.m_flags), X86::ecx);
+            m_jit.setnz_r(X86::eax);
+
+            X86Assembler::JmpSrc wasNotImmediate = m_jit.emitUnlinkedJmp();
+
+            m_jit.link(isImmediate, m_jit.label());
+
+            m_jit.movl_i32r(~JSImmediate::ExtendedTagBitUndefined, X86::ecx);
+            m_jit.andl_rr(X86::eax, X86::ecx);
+            m_jit.cmpl_i32r(JSImmediate::FullTagTypeNull, X86::ecx);
+            m_jit.sete_r(X86::eax);
+
+            m_jit.link(wasNotImmediate, m_jit.label());
+
+            m_jit.movzbl_rr(X86::eax, X86::eax);
+            m_jit.cmpl_i32r(0, X86::eax);
+            m_jmpTable.append(JmpTable(m_jit.emitUnlinkedJnz(), i + 2 + target));            
+
+            i += 3;
+            break;
+        };
+        case op_jneq_null: {
+            unsigned src = instruction[i + 1].u.operand;
+            unsigned target = instruction[i + 2].u.operand;
+
+            emitGetArg(src, X86::eax);
+            m_jit.testl_i32r(JSImmediate::TagMask, X86::eax);
+            X86Assembler::JmpSrc isImmediate = m_jit.emitUnlinkedJnz();
+
+            m_jit.movl_mr(OBJECT_OFFSET(JSCell, m_structureID), X86::eax, X86::ecx);
+            m_jit.testl_i32m(MasqueradesAsUndefined, OBJECT_OFFSET(StructureID, m_typeInfo.m_flags), X86::ecx);
+            m_jit.setz_r(X86::eax);
+
+            X86Assembler::JmpSrc wasNotImmediate = m_jit.emitUnlinkedJmp();
+
+            m_jit.link(isImmediate, m_jit.label());
+
+            m_jit.movl_i32r(~JSImmediate::ExtendedTagBitUndefined, X86::ecx);
+            m_jit.andl_rr(X86::eax, X86::ecx);
+            m_jit.cmpl_i32r(JSImmediate::FullTagTypeNull, X86::ecx);
+            m_jit.setne_r(X86::eax);
+
+            m_jit.link(wasNotImmediate, m_jit.label());
+
+            m_jit.movzbl_rr(X86::eax, X86::eax);
+            m_jit.cmpl_i32r(0, X86::eax);
+            m_jmpTable.append(JmpTable(m_jit.emitUnlinkedJnz(), i + 2 + target));            
+
+            i += 3;
+            break;
+        }
         case op_post_inc: {
             int srcDst = instruction[i + 2].u.operand;