[Bug middle-end/94941] Expansion of some internal fns can drop the lhs on the floor
cvs-commit at gcc dot gnu.org
Mon May 4 20:22:01 GMT 2020
--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Sandiford <email@example.com>:
Author: Richard Sandiford <firstname.lastname@example.org>
Date: Mon May 4 21:21:16 2020 +0100
internal-fn: Avoid dropping the lhs of some calls [PR94941]
create_output_operand coerces an output operand to the insn's
predicates, using a suggested rtx location if convenient.
But if that rtx location is actually required rather than
optional, the builder of the insn has to emit a move afterwards.
(We could instead add a new interface that does this automatically,
but that's future work.)
This PR shows that we were failing to emit the move for some of the
vector load internal functions. I think there are other routines in
internal-fn.c that potentially have the same problem, but this patch is
supposed to be a conservative subset suitable for backporting to GCC 10.
2020-05-04 Richard Sandiford <email@example.com>
* internal-fn.c (expand_load_lanes_optab_fn): Emit a move if the
chosen lhs is different from the gcall lhs.
* gcc.target/aarch64/sve/acle/general/unoptimized_1.c: New test.
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