Hi all,
This patch removes UNSPEC_SQXTUN and uses organic RTL codes to represent the
operation.
SQXTUN is an odd one. It's described in the architecture as "Signed saturating
extract Unsigned Narrow".
It's not a straightforward ss_truncate nor a us_truncate.
It is a sort of truncating signed clamp operation with limits derived from the
unsigned extrema of the narrow mode:
(truncate:N
(smin:M
(smax:M (reg:M) (const_int 0))
(const_int <unsigned-max-for-mode-N>)))
This patch implements these semantics. I've checked that the vqmovun tests in
advsimd-intrinsics.exp
now get constant-folded and still pass validation, so I'm pretty confident in
the semantics.
Bootstrapped and tested on aarch64-none-linux-gnu and aarch64_be-none-elf.
Pushing to trunk.
Thanks,
Kyrill
gcc/ChangeLog:
* config/aarch64/aarch64-simd.md (aarch64_sqmovun<mode><vczle><vczbe>):
Rename to...
(*aarch64_sqmovun<mode>_insn<vczle><vczbe>): ... This. Reimplement
with RTL codes.
(aarch64_sqmovun<mode> [SD_HSDI]): Reimplement with RTL codes.
(aarch64_sqxtun2<mode>_le): Likewise.
(aarch64_sqxtun2<mode>_be): Likewise.
(aarch64_sqxtun2<mode>): Adjust for the above.
(aarch64_sqmovun<mode>): New define_expand.
* config/aarch64/iterators.md (UNSPEC_SQXTUN): Delete.
(half_mask): New mode attribute.
* config/aarch64/predicates.md (aarch64_simd_umax_half_mode):
New predicate.
sqxtun.patch
Description: sqxtun.patch
