This adds a combine for extract(x, n); extract(x, n+1) ->
VMOVRRD(extract x, n/2). This allows two vector lanes to be moved at the
same time in a single instruction, and thanks to the other VMOVRRD folds
we have added recently can help reduce the amount of executed
instructions. Floating point types are very similar, but will include a
bitcast to an integer type.
This also adds a shouldRewriteCopySrc, to prevent copy propagation from
DPR to SPR, which can break as not all DPR regs can be extracted from
directly. Otherwise the machine verifier is unhappy.
Differential Revision: https://reviews.llvm.org/D100244
This adds some simple known bits handling for the three CSINC/NEG/INV
instructions. From the operands known bits we can compute the common
bits of the first operand and incremented/negated/inverted second
operand. The first, especially CSINC ZR, ZR, comes up fair amount in the
tests. The others are more rare so a unit test for them is added.
Differential Revision: https://reviews.llvm.org/D97788
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.
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
This patch makes the folding of or(A, B) into not(and(not(A), not(B)))
more agressive for I1 vector. This only affects Thumb2 MVE and improves
codegen, because it removes a lot of msr/mrs instructions on VPR.P0.
This patch also adds a xor(vcmp) -> !vcmp fold for MVE.
Differential Revision: https://reviews.llvm.org/D77202
This patch adds an implementation of PerformVSELECTCombine in the
ARM DAG Combiner that transforms vselect(not(cond), lhs, rhs) into
vselect(cond, rhs, lhs).
Normally, this should be done by the target-independent DAG Combiner,
but it doesn't handle the kind of constants that we generate, so we
have to reimplement it here.
Differential Revision: https://reviews.llvm.org/D77712
MVE has VPT instructions, which perform the duties of both a VCMP and a VPST in
a single instruction, performing the compare and starting the VPT block in one.
This teaches the MVEVPTBlockPass to fold them, searching back through the
basicblock for a valid VCMP and creating the VPT from its operands.
There are some changes to the VPT instructions to accommodate this, altering
the order of the operands to match the VCMP better, and changing P0 register
defs to be VPR defs, as is used in other places.
Differential Revision: https://reviews.llvm.org/D66577
llvm-svn: 371982
The code here seems to date back to r134705, when tablegen lowering was first
being added. I don't believe that we need to include CPSR implicit operands on
the MCInst. This now works more like other backends (like AArch64), where all
implicit registers are skipped.
This allows the AliasInst for CSEL's to match correctly, as can be seen in the
test changes.
Differential revision: https://reviews.llvm.org/D66703
llvm-svn: 370745
Arm 8.1-M adds a number of related CSEL instructions, including CSINC, CSNEG and CSINV. These choose between two values given the content in CPSR and a condition, performing an increment, negation or inverse of the false value.
This adds some selection for them, either from constant values or patterns. It does not include CSEL directly, which is currently not always making code better. It is still useful, but we will have to check more carefully where it should and shouldn't be used.
Code by Ranjeet Singh and Simon Tatham, with some modifications from me.
Differential revision: https://reviews.llvm.org/D66483
llvm-svn: 370739
This adds the patterns required to transform xor P0, -1 to a VPNOT. The
instruction operands have to change a little for this, adding an in and an out
VCCR reg and using a custom DecodeMVEVPNOT for the decode.
Differential Revision: https://reviews.llvm.org/D65133
llvm-svn: 367192
This removes the VCEQ/VCNE/VCGE/VCEQZ/etc nodes, just using two called VCMP and
VCMPZ with an extra operand as the condition code. I believe this will make
some combines simpler, allowing us to just look at these codes and not the
operands. It also helps fill in a missing VCGTUZ MVE selection without adding
extra nodes for it.
Differential Revision: https://reviews.llvm.org/D65072
llvm-svn: 366934
This adds a DeMorgan combine for OR's of compares to turn them into AND's,
helping prevent them from going into and out of gpr registers. It also fills in
the VCLE and VCLT nodes that MVE can select, allowing it to invert more
compares.
Differential Revision: https://reviews.llvm.org/D65059
llvm-svn: 366920
This adds some basic, "worst case" handling for MVE predicate Or/And/Xor. It
does this by going into and out of GPRs, doing the operation on scalars.
Code by David Sherwood.
Differential Revision: https://reviews.llvm.org/D65053
llvm-svn: 366907
David Green