https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104529
--- Comment #2 from Tamar Christina <tnfchris at gcc dot gnu.org> --- I don't quite see how this is a CSE problem, There's only one of each constant and none of them are needed before the call. unlike in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86892 You don't need the values of your array until you allocate memory for said array. x86 has the following sequence in GIMPLE _32 = operator new (6); MEM <unsigned int> [(char * {ref-all})_32] = 255; MEM <unsigned short> [(char * {ref-all})_32 + 4B] = 0; operator delete (_32, 6); which is optimal, you create the object, store the values, and remove it. AArch64 however has this MEM <unsigned int> [(unsigned char *)&D.24688] = 255; MEM <unsigned short> [(unsigned char *)&D.24688 + 4B] = 0; _34 = operator new (6); MEM <unsigned char[6]> [(char * {ref-all})_34] = MEM <unsigned char[6]> [(char * {ref-all})&D.24688]; D.24688 ={v} {CLOBBER(eol)}; operator delete (_34, 6); which is where the issue comes from. So this has nothing to do with CSE as far as I can tell. The GIMPLE is just suboptimal.
