首页
学习
活动
专区
圈层
工具
发布
首页
学习
活动
专区
圈层
工具
MCP广场
社区首页 >问答首页 >看似随机的返回值

看似随机的返回值
EN

Stack Overflow用户
提问于 2012-01-07 00:35:44
回答 1查看 117关注 0票数 1

我试图为一个非常简单的MIPS处理器制作一个简单的汇编程序。不幸的是,C给我带来了很多麻烦,具体来说,strcasecmp没有返回有效/正确的结果。结果有时是正确的。但通常不会,我也无法理解为什么在这个世界上会是这样。除了对修复的任何建议之外,还能有人解释为什么会出现这些错误吗?

注意:我不认为错误是由于传递寄存器表造成的。在转换寄存器函数中声明寄存器表时,也会发生相同的错误。

谢谢!

应该返回与寄存器名称对应的值的函数。注意,RegisterTable 是在 main**.中声明的我这样做是为了迭代和测试** main表中的每个寄存器名

代码语言:javascript
复制
int ConvertRegisterName(char * rname,REG_NAME_PAIR RegisterTable[32])
{
    int i;
    int j=0;
    for (i=1; i<32; i++,i++)
    {
        if (!(strcasecmp(RegisterTable[i].reg_number,rname) & strcasecmp(RegisterTable[i].reg_name,rname)))
        {
            j=i;
            return j;
            break;
        }
    }

    if(!j)
    {
        printf("Error with register name \n");
        return j;
    }
}

main 函数

代码语言:javascript
复制
int main(int argc,char *argv[])
{
    REG_NAME_PAIR RegisterTable[32];
    RegisterTable[1].reg_name    = "at";
    RegisterTable[1].reg_number  = "$1";
    RegisterTable[2].reg_name    = "v0";
    RegisterTable[2].reg_number  = "$2";
    RegisterTable[3].reg_name    = "v1";
    RegisterTable[3].reg_number  = "$3";
    RegisterTable[4].reg_name    = "a0";
    RegisterTable[4].reg_number  = "$4";
    RegisterTable[5].reg_name    = "a1";
    RegisterTable[5].reg_number  = "$5";
    RegisterTable[6].reg_name    = "a2";
    RegisterTable[6].reg_number  = "$6";
    RegisterTable[7].reg_name    = "a3";
    RegisterTable[7].reg_number  = "$7";
    RegisterTable[8].reg_name    = "t0";
    RegisterTable[8].reg_number  = "$8";
    RegisterTable[9].reg_name    = "t1";
    RegisterTable[9].reg_number  = "$9";
    RegisterTable[10].reg_name   = "t2";
    RegisterTable[10].reg_number = "$10";
    RegisterTable[11].reg_name   = "t3";
    RegisterTable[11].reg_number = "$11";
    RegisterTable[12].reg_name   = "t4";
    RegisterTable[12].reg_number = "$12";
    RegisterTable[13].reg_name   = "t5";
    RegisterTable[13].reg_number = "$13";
    RegisterTable[14].reg_name   = "t6";
    RegisterTable[14].reg_number = "$14";
    RegisterTable[15].reg_name   = "t7";
    RegisterTable[15].reg_number = "$15";
    RegisterTable[16].reg_name   = "s0";
    RegisterTable[16].reg_number = "$16";
    RegisterTable[17].reg_name   = "s1";
    RegisterTable[17].reg_number = "$17";
    RegisterTable[18].reg_name   = "s2";
    RegisterTable[18].reg_number = "$18";
    RegisterTable[19].reg_name   = "s3";
    RegisterTable[19].reg_number = "$19";
    RegisterTable[20].reg_name   = "s4";
    RegisterTable[20].reg_number = "$20";
    RegisterTable[21].reg_name   = "s5";
    RegisterTable[21].reg_number = "$21";
    RegisterTable[22].reg_name   = "s6";
    RegisterTable[22].reg_number = "$22";
    RegisterTable[23].reg_name   = "s7";
    RegisterTable[23].reg_number = "$23";
    RegisterTable[24].reg_name   = "t8";
    RegisterTable[24].reg_number = "$24";
    RegisterTable[25].reg_name   = "t9";
    RegisterTable[25].reg_number = "$25";
    RegisterTable[26].reg_name   = "k0";
    RegisterTable[26].reg_number = "$26";
    RegisterTable[27].reg_name   = "k1";
    RegisterTable[27].reg_number = "$27";
    RegisterTable[28].reg_name   = "gp";
    RegisterTable[28].reg_number = "$28";
    RegisterTable[29].reg_name   = "sp";
    RegisterTable[29].reg_number = "$29";
    RegisterTable[30].reg_name   = "fp";
    RegisterTable[30].reg_number = "$30";
    RegisterTable[31].reg_name   = "ra";
    RegisterTable[31].reg_number = "$31";


    int i;
    for (i=1; i<32; i++)
    {
        printf("i is %d\n",i);
        printf("Register Name is %s \n" ,RegisterTable[i].reg_name);
        printf("this is the return value %d",ConvertRegisterName(RegisterTable[i].reg_name,RegisterTable));
        printf("\n");
        printf("Register Number %s\n",RegisterTable[i].reg_number);
        printf("this is the return value %d",ConvertRegisterName(RegisterTable[i].reg_number,RegisterTable));
        printf("\n");
        printf("\n");
    }
}

REG_NAME_PAIR struct

代码语言:javascript
复制
typedef struct
{
    char *reg_name;
    char *reg_number;
} REG_NAME_PAIR;
EN

Stack Overflow用户

发布于 2012-01-07 00:43:58

转换函数可能会被简化并更正为如下所示:

代码语言:javascript
复制
int ConvertRegisterDesc(const char * token, REG_NAME_PAIR RegisterTable[])
{
    for (int i = 1; i != 32; ++i)
    {
        if (strcasecmp(RegisterTable[i].reg_number, token) == 0 ||
            strcasecmp(RegisterTable[i].reg_name,   token) == 0   )
        {
            return i;
        }
    }

   printf("Error with register name \n");
   return 0;
}

现在,ConvertRegisterDesc("foo", RegisterTable)返回名称值为"foo" (大小写变体)的条目的索引,如果找不到这样的条目,则返回0

票数 3
EN
查看全部 1 条回答
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/8766285

复制
相关文章

相似问题

领券
问题归档专栏文章快讯文章归档关键词归档开发者手册归档开发者手册 Section 归档