https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64410
--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> --- Created attachment 34402 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34402&action=edit patch to pattern-detect the load/store This pattern matches real/imagpart uses and single-use complex stores and transforms them to component-wise accesses in forwprop. Together we vectorize the loop now and produce: .L28: movupd (%rbx,%rax), %xmm1 movupd (%r15,%rax), %xmm0 addpd %xmm1, %xmm0 movups %xmm0, 0(%r13,%rax) addq $16, %rax cmpq %rax, %rdx jne .L28 note that we need a runtime alias check to disambiguate things (because std::vector memory cannot be disambiguated statically) and similarly we cannot prove sufficent alignment to use aligned loads/stores.
