Commit Graph

8 Commits

Author SHA1 Message Date
David Green 5805521207 [ARM] Simplify VMOVRRD from extracts of buildvectors
Under the softfp calling convention, we are often left with
VMOVRRD(extract(bitcast(build_vector(a, b, c, d)))) for the return value
of the function. These can be simplified to a,b or c,d directly,
depending on the value of the extract.

Big endian is a little different because the bitcast switches the lanes
around, meaning we end up with b,a or d,c.

Differential Revision: https://reviews.llvm.org/D94989
2021-02-01 16:09:25 +00:00
David Green 6ab792b68d [ARM] Simplify extract of VMOVDRR
Under SoftFP calling conventions, we can be left with
extract(bitcast(BUILD_VECTOR(VMOVDRR(a, b), ..))) patterns that can
simplify to a or b, depending on the extract lane.

Differential Revision: https://reviews.llvm.org/D94990
2021-02-01 10:24:57 +00:00
David Green 2fb0a0fef8 [ARM] Add BE check variants for soft-fp test. NFC 2021-01-27 21:19:46 +00:00
David Green e1c1adf9dc [ARM] Match dual lane vmovs from insert_vector_elt
MVE has a dual lane vector move instruction, capable of moving two
general purpose registers into lanes of a vector register. They look
like one of:
  vmov q0[2], q0[0], r2, r0
  vmov q0[3], q0[1], r3, r1
They only accept these lane indices though (and only insert into an
i32), either moving lanes 1 and 3, or 0 and 2.

This patch adds some tablegen patterns for them, selecting from vector
inserts elements. Because the insert_elements are know to be
canonicalized to ascending order there are several patterns that we need
to select. These lane indices are:

3 2 1 0    -> vmovqrr 31; vmovqrr 20
3 2 1      -> vmovqrr 31; vmov 2
3 1        -> vmovqrr 31
2 1 0      -> vmovqrr 20; vmov 1
2 0        -> vmovqrr 20

With the top one being the most common. All other potential patterns of
lane indices will be matched by a combination of these and the
individual vmov pattern already present. This does mean that we are
selecting several machine instructions at once due to the need to
re-arrange the inserts, but in this case there is nothing else that will
attempt to match an insert_vector_elt node.

This is a recommit of 6cc3d80a84 after
fixing the backward instruction definitions.
2020-12-18 16:13:08 +00:00
David Green 6e913e4451 Revert "[ARM] Match dual lane vmovs from insert_vector_elt"
This one needed more testing.
2020-12-18 13:33:40 +00:00
David Green 6cc3d80a84 [ARM] Match dual lane vmovs from insert_vector_elt
MVE has a dual lane vector move instruction, capable of moving two
general purpose registers into lanes of a vector register. They look
like one of:
  vmov q0[2], q0[0], r2, r0
  vmov q0[3], q0[1], r3, r1
They only accept these lane indices though (and only insert into an
i32), either moving lanes 1 and 3, or 0 and 2.

This patch adds some tablegen patterns for them, selecting from vector
inserts elements. Because the insert_elements are know to be
canonicalized to ascending order there are several patterns that we need
to select. These lane indices are:

3 2 1 0    -> vmovqrr 31; vmovqrr 20
3 2 1      -> vmovqrr 31; vmov 2
3 1        -> vmovqrr 31
2 1 0      -> vmovqrr 20; vmov 1
2 0        -> vmovqrr 20

With the top one being the most common. All other potential patterns of
lane indices will be matched by a combination of these and the
individual vmov pattern already present. This does mean that we are
selecting several machine instructions at once due to the need to
re-arrange the inserts, but in this case there is nothing else that will
attempt to match an insert_vector_elt node.

Differential Revision: https://reviews.llvm.org/D92553
2020-12-15 15:58:52 +00:00
David Green dc56995c57 [ARM] MVE vector for 64bit types
We need to make sure that we are sensibly dealing with vectors of types v2i64
and v2f64, even if most of the time we cannot generate native operations for
them. This mostly adds a lot of testing, plus fixes up a couple of the issues
found. And, or and xor can be legal for v2i64, and shifts combining needs a
slight fixup.

Differential Revision: https://reviews.llvm.org/D64316

llvm-svn: 366106
2019-07-15 18:42:54 +00:00
Simon Tatham bffd099d15 [ARM] MVE: allow soft-float ABI to pass vector types.
Passing a vector type over the soft-float ABI involves it being split
into four GPRs, so the first thing that has to happen at the start of
the function is to recombine those into a vector register. The ABI
types all vectors as v2f64, so we need to support BUILD_VECTOR for
that type, which I do in this patch by allowing it to be expanded in
terms of INSERT_VECTOR_ELT, and writing an ISel pattern for that in
turn. Similarly, I provide a rule for EXTRACT_VECTOR_ELT so that a
returned vector can be marshalled back into GPRs.

While I'm here, I've also added ISD::UNDEF to the list of operations
we turn back on in `setAllExpand`, because I noticed that otherwise it
gets expanded into a BUILD_VECTOR with explicit zero inputs, leading
to pointless machine instructions to zero out a vector register that's
about to have every lane overwritten of in any case.

Reviewers: dmgreen, ostannard

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63937

llvm-svn: 364910
2019-07-02 11:26:11 +00:00