Big endian is currently not supported for arm_sve.h
时间: 2024-06-04 20:11:51 浏览: 14
As an AI language model, I cannot confirm whether big endian is currently supported for arm_sve.h or not as it would require checking the documentation or source code of the library. However, it is important to note that big-endian and little-endian are two ways of storing binary data in memory, and the choice of endianness is determined by the hardware architecture. Arm processors support both big and little endian modes, and it is up to the software developers to choose the appropriate mode for their application.
相关问题
你给的代码报错form_para.cpp:340:14: No matching function for call to 'swap' move.h:182:5: candidate function [with _Tp = QByteRef] not viable: expects an lvalue for 1st argument stl_bvector.h:114:3: candidate function not viable: no known conversion from 'QByteRef' to 'std::_Bit_reference' for 1st argument stl_bvector.h:122:3: candidate function not viable: no known conversion from 'QByteRef' to 'std::_Bit_reference' for 1st argument stl_bvector.h:130:3: candidate function not viable: no known conversion from 'QByteRef' to 'bool &' for 1st argument move.h:205:5: candidate template ignored: could not match '_Tp[_Nm]' against 'QByteRef' stl_pair.h:490:5: candidate template ignored: could not match 'pair<_T1, _T2>' against 'QByteRef' stl_pair.h:498:5: candidate template ignored: could not match 'pair<_T1, _T2>' against 'QByteRef' ... shared_ptr_base.h:1738:5: candidate template ignored: could not match '__weak_ptr<_Tp, _Lp>' against 'QByteRef' shared_ptr.h:490:5: candidate template ignored: could not match 'shared_ptr<_Tp>' against 'QByteRef' shared_ptr.h:611:5: candidate template ignored: could not match 'weak_ptr<_Tp>' against 'QByteRef'
非常抱歉,我的代码还是有误。QByteArray的swap函数确实只接受一个参数。如果要交换两个字节的高低位,可以使用以下代码:
```cpp
uint16_t value = 0x1234; // 待转换的uint16_t值
QByteArray bytes(reinterpret_cast<const char*>(&value), sizeof(value)); // 将uint16_t转换成QByteArray
char temp = bytes[0];
bytes[0] = bytes[1];
bytes[1] = temp;
QString str(bytes); // 将QByteArray转换成QString
```
在上述代码中,我们使用一个临时变量temp来交换QByteArray中的两个字节的高低位。最终,输出的字符串为:"4321"。
请注意,上述代码假定机器采用的是little-endian格式,即低地址存放的是值的低位字节。如果机器采用的是big-endian格式,即低地址存放的是值的高位字节,则需要交换QByteArray中的第0个字节和第1个字节。
DataId DiagSH_GetTargetReadDID( void ) { uint16_t off_set = 0; DataId ret_did = 0; uint32_t tmpoff_set = 0; tmpoff_set = ( DiagSH_GetReuestReadDIDIdx() * 2 ); if(tmpoff_set < DIAG_CANMSG_DATA_SIZE_MAX){ off_set = (uint16_t)tmpoff_set; } else{ off_set = (uint16_t)(DIAG_CANMSG_DATA_SIZE_MAX - 1); } #ifndef DIAGSH_BIG_ENDIAN ret_did = (DataId)DiagSH_RequestBuffer.msg_info.body[off_set] << 8; ret_did |= (DataId)DiagSH_RequestBuffer.msg_info.body[(uint32_t)(off_set+1)]; #else /* DIAGSH_BIG_ENDIAN */ ret_did = (DataId)DiagSH_RequestBuffer.msg_info.body[off_set+1] << 8; ret_did |= (DataId)DiagSH_RequestBuffer.msg_info.body[off_set]; #endif /* DIAGSH_BIG_ENDIAN */ return ret_did; }
这段代码是一个函数DiagSH_GetTargetReadDID,返回类型为DataId。该函数的目的是获取一个目标读取DID(Diagnostic Identifier)。
首先,定义了一个uint16_t类型的变量off_set,并初始化为0。接着,定义了一个DataId类型的变量ret_did,并初始化为0。同时,定义了一个uint32_t类型的变量tmpoff_set,并初始化为0。
接下来,将DiagSH_GetReuestReadDIDIdx()的返回值乘以2,并将结果赋给tmpoff_set。然后,通过比较tmpoff_set和DIAG_CANMSG_DATA_SIZE_MAX的大小,来确定off_set的值。如果tmpoff_set小于DIAG_CANMSG_DATA_SIZE_MAX,则将tmpoff_set强制转换为uint16_t类型,并赋给off_set;否则,将DIAG_CANMSG_DATA_SIZE_MAX减去1,并强制转换为uint16_t类型,赋给off_set。
接下来是一段条件编译的代码块。如果未定义DIAGSH_BIG_ENDIAN宏,则执行下面的代码块。在这个代码块中,ret_did的值由两个字节组成,第一个字节是DiagSH_RequestBuffer.msg_info.body[off_set]左移8位后的结果,第二个字节是DiagSH_RequestBuffer.msg_info.body[off_set+1]的值。
如果定义了DIAGSH_BIG_ENDIAN宏,则执行下面的代码块。在这个代码块中,ret_did的值由两个字节组成,第一个字节是DiagSH_RequestBuffer.msg_info.body[off_set+1]左移8位后的结果,第二个字节是DiagSH_RequestBuffer.msg_info.body[off_set]的值。
最后,返回ret_did的值。
总的来说,这段代码的作用是根据一定规则从DiagSH_RequestBuffer中读取数据,并将其转换为DataId类型后返回。具体的逻辑与字节序的处理有关。