ICL 9.1 codegeneration bug (rw_char.h)

[Farid Zaripov]

   When I compiled 21.string.io.cpp using Intel C++ 9.1 I've found that 
a number of rw_asserts is different than with using MSVC++ 7.1.

   I investigated this and detected the problem in UserInt::to_char() 
method.

Incubator\stdcxx\trunk\tests\include\rw_char.h

     UserChar UserInt::to_char () const {
         const UserChar tmp = { 0, i_ };
         return tmp;
     }

   Assembler code, generated by ICL 9.1:

     UserChar to_char () const {
00439A44  push        ebp
00439A45  mov         ebp,esp
00439A47  push        esi
00439A48  mov         dword ptr [ebp-4],ecx
         const UserChar tmp = { 0, i_ };
00439A4B  fldz
00439A4D  mov         eax,dword ptr [ebp+8]
00439A50  fstp        qword ptr [eax]
         return tmp;
00439A52  mov         eax,dword ptr [ebp+8]
00439A55  leave
00439A56  ret         4

   As I see tmp.c is not initialized by value this->i_ and as a result 
it contains a random value.

   I tried to remove the const clause situated before UserChar, but 
nothing was changed.

     UserChar UserInt::to_char () const {
         UserChar tmp = { 0, i_ };
         return tmp;
     }

   Then I tried the following variant and it was compiled without the bug:

     UserChar to_char () const {
         UserChar tmp;
         tmp.f = 0;
         tmp.c = static_cast<unsigned char>(i_);
         return tmp;
     }

   I attached the test case to illustrate the problem.


Farid.
#include <cassert>

struct UserChar
{
    long double f;
    unsigned char c;
};

struct UserInt
{
    int   i_;

    UserChar to_char () const
    {
        const UserChar tmp = { 0, i_ };
        return tmp;
    }

    UserChar to_char2 () const
    {
        UserChar tmp = { 0, i_ };
        return tmp;
    }

    UserChar to_char3 () const
    {
        UserChar tmp = { 0 };
        tmp.c = i_;
        return tmp;
    }
};

int main(int argc, char* argv[])
{
    const char TEST_CHAR = 'a';

    UserInt ui = { TEST_CHAR };

    UserChar uc = ui.to_char ();
    assert (TEST_CHAR == uc.c);

    UserChar uc2 = ui.to_char2 ();
    assert (TEST_CHAR == uc2.c);

    UserChar uc3 = ui.to_char3 ();
    assert (TEST_CHAR == uc3.c);

    return 0; 
}