我有以下代码在 Debug模式下可以正常运行，但在 Release模式下会产生错误的输出。
该代码很简单，它只是创建一个4x4的单位矩阵并将其写入标准输出。
#include <iostream>
struct mat4{
float a00; float a01; float a02; float a03;
float a10; float a11; float a12; float a13;
float a20; float a21; float a22; float a23;
float a30; float a31; float a32; float a33;
};
mat4 make_identity(){
mat4 v;
v.a00 = 1; v.a01 = 0; v.a02 = 0; v.a03 = 0;
v.a10 = 0; v.a11 = 1; v.a12 = 0; v.a13 = 0;
v.a20 = 0; v.a21 = 0; v.a22 = 1; v.a23 = 0;
v.a30 = 0; v.a31 = 0; v.a32 = 0; v.a33 = 1;
return v;
}
int main(){
mat4 Rm = make_identity();
std::cout << Rm.a00 << " " << Rm.a01 << " " << Rm.a02 << " " << Rm.a03 << std::endl;
std::cout << Rm.a10 << " " << Rm.a11 << " " << Rm.a12 << " " << Rm.a13 << std::endl;
std::cout << Rm.a20 << " " << Rm.a21 << " " << Rm.a22 << " " << Rm.a23 << std::endl;
std::cout << Rm.a30 << " " << Rm.a31 << " " << Rm.a32 << " " << Rm.a33 << std::endl;
system("PAUSE");
return 0;
}
Release模式下的输出在每次运行时以及在不同的计算机上都是相同的，也就是说，它不是随机的。
1 1.4013e-045 0 0
0 0 1.1547e+014 0
0 7.63318e-038 3.46682e-039 0
0 0 0 0
我编译时启用了完全优化(/ Ox)。
请注意，如果我禁用了内联函数扩展(/ Ob0)，则代码将正常工作。
我真的希望它不是编译器错误。
您有什么建议可以帮助我理解问题吗？
我的平台是:
Windows 7的
视觉工作室2010 10.0.30319.1
在 Release模式下生成的汇编代码为
int main(){
000000013F2F1000 sub rsp,68h
mat4 Rm = make_identity();
000000013F2F1004 movaps xmm1,xmmword ptr [__xi_z+90h (13F2F2260h)]
000000013F2F100B movaps xmm0,xmmword ptr [__xi_z+80h (13F2F2250h)]
std::cout << Rm.a00 << " " << Rm.a01 << " " << Rm.a02 << " " << Rm.a03 << std::endl;
000000013F2F1012 mov rcx,qword ptr [__imp_std::cout (13F2F20B8h)]
000000013F2F1019 movss dword ptr [rsp+30h],xmm1
000000013F2F101F movss dword ptr [rsp+20h],xmm0
000000013F2F1025 movaps xmm1,xmmword ptr [__xi_z+0B0h (13F2F2280h)]
000000013F2F102C movaps xmm0,xmmword ptr [__xi_z+0A0h (13F2F2270h)]
000000013F2F1033 movss dword ptr [rsp+50h],xmm1
000000013F2F1039 movss xmm1,dword ptr [rsp+20h]
000000013F2F103F movss dword ptr [rsp+40h],xmm0
000000013F2F1045 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F104B lea rdx,[__xi_z+48h (13F2F2218h)]
000000013F2F1052 mov rcx,rax
000000013F2F1055 call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F105A mov rcx,rax
000000013F2F105D movss xmm1,dword ptr [rsp+24h]
000000013F2F1063 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F1069 lea rdx,[__xi_z+44h (13F2F2214h)]
000000013F2F1070 mov rcx,rax
000000013F2F1073 call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F1078 mov rcx,rax
000000013F2F107B movss xmm1,dword ptr [rsp+28h]
000000013F2F1081 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F1087 lea rdx,[__xi_z+40h (13F2F2210h)]
000000013F2F108E mov rcx,rax
000000013F2F1091 call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F1096 mov rcx,rax
000000013F2F1099 movss xmm1,dword ptr [rsp+2Ch]
000000013F2F109F call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F10A5 mov rdx,qword ptr [__imp_std::endl (13F2F2088h)]
000000013F2F10AC mov rcx,rax
000000013F2F10AF call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F2098h)]
std::cout << Rm.a10 << " " << Rm.a11 << " " << Rm.a12 << " " << Rm.a13 << std::endl;
000000013F2F10B5 mov rcx,qword ptr [__imp_std::cout (13F2F20B8h)]
000000013F2F10BC movss xmm1,dword ptr [rsp+30h]
000000013F2F10C2 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F10C8 lea rdx,[__xi_z+54h (13F2F2224h)]
000000013F2F10CF mov rcx,rax
000000013F2F10D2 call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F10D7 mov rcx,rax
000000013F2F10DA movss xmm1,dword ptr [rsp+34h]
000000013F2F10E0 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F10E6 lea rdx,[__xi_z+50h (13F2F2220h)]
000000013F2F10ED mov rcx,rax
000000013F2F10F0 call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F10F5 mov rcx,rax
000000013F2F10F8 movss xmm1,dword ptr [rsp+38h]
000000013F2F10FE call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F1104 lea rdx,[__xi_z+4Ch (13F2F221Ch)]
000000013F2F110B mov rcx,rax
000000013F2F110E call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F1113 mov rcx,rax
000000013F2F1116 movss xmm1,dword ptr [rsp+3Ch]
000000013F2F111C call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F1122 mov rdx,qword ptr [__imp_std::endl (13F2F2088h)]
000000013F2F1129 mov rcx,rax
000000013F2F112C call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F2098h)]
std::cout << Rm.a20 << " " << Rm.a21 << " " << Rm.a22 << " " << Rm.a23 << std::endl;
000000013F2F1132 mov rcx,qword ptr [__imp_std::cout (13F2F20B8h)]
000000013F2F1139 movss xmm1,dword ptr [rsp+40h]
000000013F2F113F call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F1145 lea rdx,[__xi_z+60h (13F2F2230h)]
000000013F2F114C mov rcx,rax
000000013F2F114F call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F1154 mov rcx,rax
000000013F2F1157 movss xmm1,dword ptr [rsp+44h]
000000013F2F115D call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F1163 lea rdx,[__xi_z+5Ch (13F2F222Ch)]
000000013F2F116A mov rcx,rax
000000013F2F116D call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F1172 mov rcx,rax
000000013F2F1175 movss xmm1,dword ptr [rsp+48h]
000000013F2F117B call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F1181 lea rdx,[__xi_z+58h (13F2F2228h)]
000000013F2F1188 mov rcx,rax
000000013F2F118B call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F1190 mov rcx,rax
000000013F2F1193 movss xmm1,dword ptr [rsp+4Ch]
000000013F2F1199 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F119F mov rdx,qword ptr [__imp_std::endl (13F2F2088h)]
000000013F2F11A6 mov rcx,rax
000000013F2F11A9 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F2098h)]
std::cout << Rm.a30 << " " << Rm.a31 << " " << Rm.a32 << " " << Rm.a33 << std::endl;
000000013F2F11AF movss xmm1,dword ptr [rsp+50h]
000000013F2F11B5 mov rcx,qword ptr [__imp_std::cout (13F2F20B8h)]
000000013F2F11BC call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F11C2 lea rdx,[__xi_z+6Ch (13F2F223Ch)]
000000013F2F11C9 mov rcx,rax
000000013F2F11CC call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F11D1 mov rcx,rax
000000013F2F11D4 movss xmm1,dword ptr [rsp+54h]
000000013F2F11DA call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F11E0 lea rdx,[__xi_z+68h (13F2F2238h)]
000000013F2F11E7 mov rcx,rax
000000013F2F11EA call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F11EF mov rcx,rax
000000013F2F11F2 movss xmm1,dword ptr [rsp+58h]
000000013F2F11F8 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F11FE lea rdx,[__xi_z+64h (13F2F2234h)]
000000013F2F1205 mov rcx,rax
000000013F2F1208 call std::operator<<<std::char_traits<char> > (13F2F12C0h)
000000013F2F120D mov rcx,rax
000000013F2F1210 movss xmm1,dword ptr [rsp+5Ch]
000000013F2F1216 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F20A0h)]
000000013F2F121C mov rdx,qword ptr [__imp_std::endl (13F2F2088h)]
000000013F2F1223 mov rcx,rax
000000013F2F1226 call qword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (13F2F2098h)]
system("PAUSE");
000000013F2F122C lea rcx,[__xi_z+70h (13F2F2240h)]
000000013F2F1233 call qword ptr [__imp_system (13F2F2180h)]
return 0;
000000013F2F1239 xor eax,eax
}
最佳答案
您可以这样写:
mat4 Rm ={1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1};
cppreference.com
关于c++ - 在 Release模式下c++不正确地初始化4x4矩阵，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/25729038/