#pragma push
#pragma Otime
#pragma O3

//Тут переменные, функции , константы, макросы............

//Точка входа в main с уровнем оптимизации не более O1, если поставить выше, то в некоторых случаях может не заработать. Глюк Keil ???
#pragma push
#pragma Otime
#pragma O1

int main(void)
{
#pragma push
#pragma Otime
#pragma O3

//тут программа.........

#pragma pop
}

#pragma pop

#pragma pop

inline u32  rev16(u32 x)
{
__asm("REV16 x,x");
  return x;
}

*pL++=(__REV16(G)&0xFF0000FF)|(R&0x00FF0000)|(B&0x0000FF00);

...
    RRS     r0,r0,r1
        STR      r0,[r4],#4
        MOV      r0,r11
        BL       __asm___6_main_c_NEXT____REV16
        BFC      r0,#8,#16
        AND      r1,r7,#0xff0000
        ORRS     r0,r0,r1
...

    AREA ||.rev16_text||, CODE
    THUMB
    EXPORT |__asm___6_main_c_NEXT____REV16|
#line 129 "C:\\Keil_v5\\ARM\\CMSIS\\Include\\core_cmInstr.h"
|__asm___6_main_c_NEXT____REV16| PROC
#line 130

rev16 r0, r0
bx lr
    ENDP
...

static void DAC_DMA_IRQ_Config()
{
DMA_DeInit(DMA1_Stream5);

DMA_InitTypeDef *DMA_InitStructure=malloc(sizeof(DMA_InitTypeDef));

DMA_InitStructure->DMA_Channel           =DMA_Channel_7;
DMA_InitStructure->DMA_PeripheralBaseAddr=DAC_DHR12R1;
DMA_InitStructure->DMA_Memory0BaseAddr   =(u32)&AudioBuffer;
DMA_InitStructure->DMA_DIR               =DMA_DIR_MemoryToPeripheral;
DMA_InitStructure->DMA_BufferSize        =L<<1;
DMA_InitStructure->DMA_PeripheralInc     =DMA_PeripheralInc_Disable;
DMA_InitStructure->DMA_MemoryInc         =DMA_MemoryInc_Enable;
DMA_InitStructure->DMA_PeripheralDataSize=DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure->DMA_MemoryDataSize    =DMA_MemoryDataSize_HalfWord;
DMA_InitStructure->DMA_Mode              =DMA_Mode_Circular;
DMA_InitStructure->DMA_Priority          =DMA_Priority_VeryHigh;
DMA_InitStructure->DMA_FIFOMode          =DMA_FIFOMode_Disable;
DMA_InitStructure->DMA_FIFOThreshold     =DMA_FIFOThreshold_HalfFull;
DMA_InitStructure->DMA_MemoryBurst       =DMA_MemoryBurst_Single;
DMA_InitStructure->DMA_PeripheralBurst   =DMA_PeripheralBurst_Single;

DMA_Init(DMA1_Stream5,DMA_InitStructure);

free(DMA_InitStructure);

DMA_ITConfig(DMA1_Stream5,DMA_IT_HT|DMA_IT_TC,ENABLE);

NVIC_InitTypeDef *NVIC_InitStructure=malloc(sizeof(NVIC_InitStructure));

NVIC_InitStructure->NVIC_IRQChannel=DMA1_Stream5_IRQn;
NVIC_InitStructure->NVIC_IRQChannelPreemptionPriority=0;
NVIC_InitStructure->NVIC_IRQChannelSubPriority=0;
NVIC_InitStructure->NVIC_IRQChannelCmd=ENABLE;

NVIC_Init(NVIC_InitStructure);

free(NVIC_InitStructure);

DAC_InitTypeDef *DAC_InitStructure=malloc(sizeof(DAC_InitTypeDef));

DAC_InitStructure->DAC_Trigger       =DAC_Trigger_T6_TRGO;
DAC_InitStructure->DAC_WaveGeneration=DAC_WaveGeneration_None;
DAC_InitStructure->DAC_OutputBuffer  =DAC_OutputBuffer_Enable;
DAC_Init(DAC_Channel_1,DAC_InitStructure);

free(DAC_InitStructure);
}