1

以下のコードの目的がわかりません。オクテオンのSDKを読み取るとき、レジスタの割り当てに列挙型はどのように使用されますか？そして、どうすればcvmx_fau_reg_64_tを使用できますか？

/*************************  FAU allocation ********************************/
/* The fetch and add registers are allocated here.  They are arranged
    in order of descending size so that all alignment constraints are
    automatically met.
    The enums are linked so that the following enum continues allocating
    where the previous one left off, so the numbering within each
    enum always starts with zero.  The macros take care of the address
    increment size, so the values entered always increase by 1.
    FAU registers are accessed with byte addresses. */

#define CVMX_FAU_REG_64_ADDR(x) ((x <<3) + CVMX_FAU_REG_64_START)
typedef enum
{
    CVMX_FAU_REG_64_START          = 0, 
    CVMX_FAU_REG_64_END            = CVMX_FAU_REG_64_ADDR(0),
} cvmx_fau_reg_64_t;

#define CVMX_FAU_REG_32_ADDR(x) ((x <<2) + CVMX_FAU_REG_32_START)
typedef enum
{
    CVMX_FAU_REG_32_START          = CVMX_FAU_REG_64_END,
    CVMX_FAU_REG_32_END            = CVMX_FAU_REG_32_ADDR(0),
} cvmx_fau_reg_32_t;

#define CVMX_FAU_REG_16_ADDR(x) ((x <<1) + CVMX_FAU_REG_16_START)
typedef enum
{
    CVMX_FAU_REG_16_START          = CVMX_FAU_REG_32_END,
    CVMX_FAU_REG_16_END            = CVMX_FAU_REG_16_ADDR(0),
} cvmx_fau_reg_16_t;

#define CVMX_FAU_REG_8_ADDR(x) ((x) + CVMX_FAU_REG_8_START)
typedef enum {
    CVMX_FAU_REG_8_START           = CVMX_FAU_REG_16_END,
    CVMX_FAU_REG_8_END             = CVMX_FAU_REG_8_ADDR(0),
} cvmx_fau_reg_8_t;

/* The name CVMX_FAU_REG_AVAIL_BASE is provided to indicate the first available
   FAU address that is not allocated in cvmx-config.h. This is 64 bit aligned. */
#define CVMX_FAU_REG_AVAIL_BASE ((CVMX_FAU_REG_8_END + 0x7) & (~0x7ULL))
#define CVMX_FAU_REG_END (2048)
4

2 に答える 2

0

Cでは、列挙型は符号付き整数データ型に似ています。これはあなたがどのように使うべきかですcvmx_fau_reg_64_t：

cvmx_fau_reg_64_t myRegister;

myRegister=CVMX_FAU_REG_64_START;

//Do something with the *myRegister* variable

myRegister=CVMX_FAU_REG_64_END;
于 2012-08-06T05:50:22.270 に答える