示例#1
0
MacroAssemblerCodeRef stringLengthTrampolineGenerator(VM* vm)
{
    JSInterfaceJIT jit;

#if USE(JSVALUE64)
    // Check eax is a string
    JSInterfaceJIT::Jump failureCases1 = jit.emitJumpIfNotJSCell(JSInterfaceJIT::regT0);
    JSInterfaceJIT::Jump failureCases2 = jit.branchPtr(
            JSInterfaceJIT::NotEqual, JSInterfaceJIT::Address(
                JSInterfaceJIT::regT0, JSCell::structureOffset()),
            JSInterfaceJIT::TrustedImmPtr(vm->stringStructure.get()));

    // Checks out okay! - get the length from the Ustring.
    jit.load32(
        JSInterfaceJIT::Address(JSInterfaceJIT::regT0, JSString::offsetOfLength()),
        JSInterfaceJIT::regT0);

    JSInterfaceJIT::Jump failureCases3 = jit.branch32(
            JSInterfaceJIT::LessThan, JSInterfaceJIT::regT0, JSInterfaceJIT::TrustedImm32(0));

    // regT0 contains a 64 bit value (is positive, is zero extended) so we don't need sign extend here.
    jit.emitFastArithIntToImmNoCheck(JSInterfaceJIT::regT0, JSInterfaceJIT::regT0);

#else // USE(JSVALUE64)
    // regT0 holds payload, regT1 holds tag

    JSInterfaceJIT::Jump failureCases1 = jit.branch32(
            JSInterfaceJIT::NotEqual, JSInterfaceJIT::regT1,
            JSInterfaceJIT::TrustedImm32(JSValue::CellTag));
    JSInterfaceJIT::Jump failureCases2 = jit.branchPtr(
            JSInterfaceJIT::NotEqual,
            JSInterfaceJIT::Address(JSInterfaceJIT::regT0, JSCell::structureOffset()),
            JSInterfaceJIT::TrustedImmPtr(vm->stringStructure.get()));

    // Checks out okay! - get the length from the Ustring.
    jit.load32(
        JSInterfaceJIT::Address(JSInterfaceJIT::regT0, JSString::offsetOfLength()),
        JSInterfaceJIT::regT2);

    JSInterfaceJIT::Jump failureCases3 = jit.branch32(
            JSInterfaceJIT::Above, JSInterfaceJIT::regT2, JSInterfaceJIT::TrustedImm32(INT_MAX));
    jit.move(JSInterfaceJIT::regT2, JSInterfaceJIT::regT0);
    jit.move(JSInterfaceJIT::TrustedImm32(JSValue::Int32Tag), JSInterfaceJIT::regT1);
#endif // USE(JSVALUE64)

    jit.ret();

    JSInterfaceJIT::Call failureCases1Call = jit.makeTailRecursiveCall(failureCases1);
    JSInterfaceJIT::Call failureCases2Call = jit.makeTailRecursiveCall(failureCases2);
    JSInterfaceJIT::Call failureCases3Call = jit.makeTailRecursiveCall(failureCases3);

    LinkBuffer patchBuffer(*vm, &jit, GLOBAL_THUNK_ID);

    patchBuffer.link(failureCases1Call, FunctionPtr(cti_op_get_by_id_string_fail));
    patchBuffer.link(failureCases2Call, FunctionPtr(cti_op_get_by_id_string_fail));
    patchBuffer.link(failureCases3Call, FunctionPtr(cti_op_get_by_id_string_fail));

    return FINALIZE_CODE(patchBuffer, ("string length trampoline"));
}
示例#2
0
MacroAssemblerCodeRef arityFixup(VM* vm)
{
    JSInterfaceJIT jit;

    // We enter with fixup count in regT0
#if USE(JSVALUE64)
#  if CPU(X86_64)
    jit.pop(JSInterfaceJIT::regT4);
#  endif
    jit.addPtr(JSInterfaceJIT::TrustedImm32(-8), JSInterfaceJIT::callFrameRegister, JSInterfaceJIT::regT3);
    jit.load32(JSInterfaceJIT::Address(JSInterfaceJIT::callFrameRegister, JSStack::ArgumentCount * 8), JSInterfaceJIT::regT2);
    jit.add32(JSInterfaceJIT::TrustedImm32(JSStack::CallFrameHeaderSize), JSInterfaceJIT::regT2);

    // Move current frame regT0 number of slots
    JSInterfaceJIT::Label copyLoop(jit.label());
    jit.load64(JSInterfaceJIT::regT3, JSInterfaceJIT::regT1);
    jit.store64(JSInterfaceJIT::regT1, MacroAssembler::BaseIndex(JSInterfaceJIT::regT3, JSInterfaceJIT::regT0, JSInterfaceJIT::TimesEight));
    jit.subPtr(JSInterfaceJIT::TrustedImm32(8), JSInterfaceJIT::regT3);
    jit.branchSub32(MacroAssembler::NonZero, JSInterfaceJIT::TrustedImm32(1), JSInterfaceJIT::regT2).linkTo(copyLoop, &jit);

    // Fill in regT0 missing arg slots with undefined
    jit.move(JSInterfaceJIT::regT0, JSInterfaceJIT::regT2);
    jit.move(JSInterfaceJIT::TrustedImm64(ValueUndefined), JSInterfaceJIT::regT1);
    JSInterfaceJIT::Label fillUndefinedLoop(jit.label());
    jit.store64(JSInterfaceJIT::regT1, MacroAssembler::BaseIndex(JSInterfaceJIT::regT3, JSInterfaceJIT::regT0, JSInterfaceJIT::TimesEight));
    jit.subPtr(JSInterfaceJIT::TrustedImm32(8), JSInterfaceJIT::regT3);
    jit.branchSub32(MacroAssembler::NonZero, JSInterfaceJIT::TrustedImm32(1), JSInterfaceJIT::regT2).linkTo(fillUndefinedLoop, &jit);

    // Adjust call frame register to account for missing args
    jit.lshift32(JSInterfaceJIT::TrustedImm32(3), JSInterfaceJIT::regT0);
    jit.addPtr(JSInterfaceJIT::regT0, JSInterfaceJIT::callFrameRegister);

#  if CPU(X86_64)
    jit.push(JSInterfaceJIT::regT4);
#  endif
    jit.ret();
#else
#  if CPU(X86)
    jit.pop(JSInterfaceJIT::regT4);
#  endif
    jit.addPtr(JSInterfaceJIT::TrustedImm32(-8), JSInterfaceJIT::callFrameRegister, JSInterfaceJIT::regT3);
    jit.load32(JSInterfaceJIT::Address(JSInterfaceJIT::callFrameRegister, JSStack::ArgumentCount * 8), JSInterfaceJIT::regT2);
    jit.add32(JSInterfaceJIT::TrustedImm32(JSStack::CallFrameHeaderSize), JSInterfaceJIT::regT2);

    // Move current frame regT0 number of slots
    JSInterfaceJIT::Label copyLoop(jit.label());
    jit.load32(JSInterfaceJIT::regT3, JSInterfaceJIT::regT1);
    jit.store32(JSInterfaceJIT::regT1, MacroAssembler::BaseIndex(JSInterfaceJIT::regT3, JSInterfaceJIT::regT0, JSInterfaceJIT::TimesEight));
    jit.load32(MacroAssembler::Address(JSInterfaceJIT::regT3, 4), JSInterfaceJIT::regT1);
    jit.store32(JSInterfaceJIT::regT1, MacroAssembler::BaseIndex(JSInterfaceJIT::regT3, JSInterfaceJIT::regT0, JSInterfaceJIT::TimesEight, 4));
    jit.subPtr(JSInterfaceJIT::TrustedImm32(8), JSInterfaceJIT::regT3);
    jit.branchSub32(MacroAssembler::NonZero, JSInterfaceJIT::TrustedImm32(1), JSInterfaceJIT::regT2).linkTo(copyLoop, &jit);

    // Fill in regT0 missing arg slots with undefined
    jit.move(JSInterfaceJIT::regT0, JSInterfaceJIT::regT2);
    JSInterfaceJIT::Label fillUndefinedLoop(jit.label());
    jit.move(JSInterfaceJIT::TrustedImm32(0), JSInterfaceJIT::regT1);
    jit.store32(JSInterfaceJIT::regT1, MacroAssembler::BaseIndex(JSInterfaceJIT::regT3, JSInterfaceJIT::regT0, JSInterfaceJIT::TimesEight));
    jit.move(JSInterfaceJIT::TrustedImm32(JSValue::UndefinedTag), JSInterfaceJIT::regT1);
    jit.store32(JSInterfaceJIT::regT1, MacroAssembler::BaseIndex(JSInterfaceJIT::regT3, JSInterfaceJIT::regT0, JSInterfaceJIT::TimesEight, 4));

    jit.subPtr(JSInterfaceJIT::TrustedImm32(8), JSInterfaceJIT::regT3);
    jit.branchSub32(MacroAssembler::NonZero, JSInterfaceJIT::TrustedImm32(1), JSInterfaceJIT::regT2).linkTo(fillUndefinedLoop, &jit);

    // Adjust call frame register to account for missing args
    jit.lshift32(JSInterfaceJIT::TrustedImm32(3), JSInterfaceJIT::regT0);
    jit.addPtr(JSInterfaceJIT::regT0, JSInterfaceJIT::callFrameRegister);

#  if CPU(X86)
    jit.push(JSInterfaceJIT::regT4);
#  endif
    jit.ret();
#endif

    LinkBuffer patchBuffer(*vm, &jit, GLOBAL_THUNK_ID);
    return FINALIZE_CODE(patchBuffer, ("fixup arity"));
}