This is my first bug I report. I hope I do everything well:
If I want to use SSE-instruction I use the build-in datatype. As long as you
only use this one everything goes well.
If this type is am member of a class then there occures a misalignment when
allocating this with new:
Here is a sample code:
#include <iostream>
#include <cstdlib>
typedef float V4SF __attribute__ ((mode(V4SF)));
#define ALIGN16 __attribute__((aligned(16)))
#define __class16 class __attribute__((__aligned__(16)))
//ALIGN16 struct SVector //neither ALIGN16
__class16 SVector //nor this variant works
{
public:
V4SF v;
};
using namespace std;
int main(int argc, char *argv[])
{
V4SF* pv = new V4SF;
cout << "Alignment (that should be): " << __alignof__(V4SF) << endl;
cout << "Adress dividable through 16? " << unsigned(&(*pv))%16 << endl;//This
works
SVector* ps = new SVector;
cout << "Alignment (that should be): " << __alignof__(SVector) << endl;
cout << "Adress dividable through 16? " << unsigned(&(*ps))%16 << endl;//This
doesn't work
//as you can see a movaps or similar instruction will crash the System
return EXIT_SUCCESS;
}
--
Summary: misaligned SSE-datatype
Product: gcc
Version: 3.4.3
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: Pferdebert at west dot de
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19432
