[Bug tree-optimization/50417] New: regression: memcpy with known alignment

[wouter.vermaelen at scarlet dot be]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50417

             Bug #: 50417
           Summary: regression: memcpy with known alignment
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: wouter.vermae...@scarlet.be


Consider these functions:

void copy1(char* d, const char* s) {
    memcpy(d, s, 256);
}
void copy2(short* d, const short* s) {
    memcpy(d, s, 256);
}
void copy3(int* d, const int* s) {
    memcpy(d, s, 256);
}
void copy4(long* d, const long* s) {
    memcpy(d, s, 256);
}

g++-4.5.2 is able to generate better code for the later functions. But when I
test with a recent snapshot (SVN revision 178875 on linux x86_64) it generates
the same code for all versions (same as copy1()).