MDK C++中对内联的极度优化

// 智能IRQ，初始化时备份，销毁时还原
class SmartIRQ
{
public:
    force_inline SmartIRQ(bool enable = false)
    {
        _state = __get_PRIMASK();
        if(enable)
            __enable_irq();
        else
            __disable_irq();
    }

    force_inline ~SmartIRQ()
    {
        __set_PRIMASK(_state);
    }
    
private:
    uint _state;
};

ulong Time::CurrentTicks()
{
    SmartIRQ irq;

    uint value = (SysTick->LOAD - SysTick->VAL);
    if(SysTick->CTRL & SysTick_CTRL_COUNTFLAG)
    {
        Ticks += SysTick->LOAD;
    }

    return Ticks + value;
}

0x08000804 B570      PUSH     {r4-r6,lr}
0x08000806 F3EF8210  MRS      r2,PRIMASK
0x0800080A B672      CPSID    I
0x0800080C 4D0B      LDR      r5,[pc,#44]  ; @0x0800083C
0x0800080E 6969      LDR      r1,[r5,#0x14]
0x08000810 69AB      LDR      r3,[r5,#0x18]
0x08000812 1ACC      SUBS     r4,r1,r3
0x08000814 6929      LDR      r1,[r5,#0x10]
0x08000816 2300      MOVS     r3,#0x00
0x08000818 03C9      LSLS     r1,r1,#15
0x0800081A 2900      CMP      r1,#0x00
0x0800081C DA06      BGE      0x0800082C
0x0800081E 6886      LDR      r6,[r0,#0x08]
0x08000820 68C1      LDR      r1,[r0,#0x0C]
0x08000822 696D      LDR      r5,[r5,#0x14]
0x08000824 1975      ADDS     r5,r6,r5
0x08000826 4159      ADCS     r1,r1,r3
0x08000828 6085      STR      r5,[r0,#0x08]
0x0800082A 60C1      STR      r1,[r0,#0x0C]
0x0800082C 6885      LDR      r5,[r0,#0x08]
0x0800082E 68C1      LDR      r1,[r0,#0x0C]
0x08000830 1928      ADDS     r0,r5,r4
0x08000832 4159      ADCS     r1,r1,r3
0x08000834 F3828810  MSR      PRIMASK,r2
0x08000838 BD70      POP      {r4-r6,pc}