https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86541
Bug ID: 86541
Summary: Use SSE to emulate __attribute__((vector_size(8)))
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: rth at gcc dot gnu.org
Target Milestone: ---
In order to be more compatible across platforms, it would be
helpful if vector_size(8) was better supported for i386/x86_64.
The vast majority of the operations can be supported easily
with existing vector_size(16) instructions, and using either
(V)MOVQ to zero-extend the input or VPBROADCASTD/MOVDDUP to
replicate the input across the xmm register.
For integer operations it probably doesn't matter, but fp
operations would have different exception characteristics
with a zero-extension. Replicating the inputs across the
lanes would avoid extra fp exceptions.
