https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104169
Bug ID: 104169 Summary: GDB unable to set $xmm2-7 register but able to set $xmm0-1 on non-AVX machines Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: debug Assignee: unassigned at gcc dot gnu.org Reporter: contact at lsferreira dot net Target Milestone: --- When running on my "Intel(R) Xeon(R) CPU E7-4860", I can't set xmm2 to xmm7 registers on GDB. On a more recent CPU "Intel(R) Core(TM) m3-7Y30" this seems to set just fine. I also tested this on a libvirt clean environment with an Intel Core 2 Duo and Intel Ivy Bridge family CPU (emulated settings), and the one without AVX did fail to set. To reproduce the issue, you can run any process on a non-AVX machine: $ gdb /usr/bin/bash > r -c 'kill -SIGILL $$' > p $xmm7.uint128 > set $xmm7.uint128 = 35322350018591 > p $xmm7.uint128 If you try with $xmm0 or $xmm1 it works just fine.