We don't have vector operations for these, so they need to be expanded for both
integer and float.
Differential Revision: https://reviews.llvm.org/D63595
llvm-svn: 364631
The same as integer arithmetic, we can add simple floating point MVE addition and
subtraction patterns.
Initial code by David Sherwood
Differential Revision: https://reviews.llvm.org/D63257
llvm-svn: 364629
This adds the first few patterns for MVE code generation, adding simple integer
add and sub patterns.
Initial code by David Sherwood
Differential Revision: https://reviews.llvm.org/D63255
llvm-svn: 364627
This patch adds necessary shuffle vector and buildvector support for ARM MVE.
It essentially adds support for VDUP, VREVs and some VMOVs, which are often
required by other code (like upcoming patches).
This mostly uses the same code from Neon that already generated
NEONvdup/NEONvduplane/NEONvrev's. These have been renamed to ARMvdup/etc and
moved to ARMInstrInfo as they are common to both architectures. Most of the
selection code seems to be applicable to both, but NEON does have some more
instructions making some parts specific.
Most code originally by David Sherwood.
Differential Revision: https://reviews.llvm.org/D63567
llvm-svn: 364626
The code to generate register move instructions in and out of VPR and
FPSCR_NZCV had assertions checking that the other register involved
was a GPR _pair_, instead of a single GPR as it should have been.
Reviewers: miyuki, ostannard
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63865
llvm-svn: 364534
The BF and WLS/WLSTP instructions have various branch-offset fields
occupying different positions and lengths in the instruction encoding,
and all of them were decoded at disassembly time by the function
DecodeBFLabelOffset() which returned SoftFail if the offset was zero.
In fact, it's perfectly fine and not even a SoftFail for most of those
offset fields to be zero. The only one that can't be zero is the 4-bit
field labelled `boff` in the architecture spec, occupying bits {26-23}
of the BF instruction family. If that one is zero, the encoding
overlaps other instructions (WLS, DLS, LETP, VCTP), so it ought to be
a full Fail.
Fixed by adding an extra template parameter to DecodeBFLabelOffset
which controls whether a zero offset is accepted or rejected. Adjusted
existing tests (only in error messages for bad disassemblies); added
extra tests to demonstrate zero offsets being accepted in all the
right places, and a few demonstrating rejection of zero `boff`.
Reviewers: DavidSpickett, ostannard
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63864
llvm-svn: 364533
Different versions of the Arm architecture disallow the use of generic
coprocessor instructions like MCR and CDP on different sets of
coprocessors. This commit centralises the check of the coprocessor
number so that it's consistent between assembly and disassembly, and
also updates it for the new restrictions in Arm v8.1-M.
New tests added that check all the coprocessor numbers; old tests
updated, where they used a number that's now become illegal in the
context in question.
Reviewers: DavidSpickett, ostannard
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63863
llvm-svn: 364532
In the `CSEL Rd,Rm,Rn` instruction family (also including CSINC, CSINV
and CSNEG), the architecture lists it as CONSTRAINED UNPREDICTABLE
(i.e. SoftFail) to use SP in the Rd or Rm slot, but outright illegal
to use it in the Rn slot, not least because some encodings of that
form are used by MVE instructions such as UQRSHLL.
MC was treating all three slots the same, as SoftFail. So the only
reason UQRSHLL was disassembled correctly at all was because the MVE
decode table is separate from the Thumb2 one and takes priority; if
you turned off MVE, then encodings such as `[0x5f,0xea,0x0d,0x83]`
would disassemble as spurious CSELs.
Fixed by inventing another version of the `GPRwithZR` register class,
which disallows SP completely instead of just SoftFailing it.
Reviewers: DavidSpickett, ostannard
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63862
llvm-svn: 364531
Change the interface of CallLowering::lowerCall to accept several
virtual registers for each argument, instead of just one. This is a
follow-up to D46018.
CallLowering::lowerReturn was similarly refactored in D49660 and
lowerFormalArguments in D63549.
With this change, we no longer pack the virtual registers generated for
aggregates into one big lump before delegating to the target. Therefore,
the target can decide itself whether it wants to handle them as separate
pieces or use one big register.
ARM and AArch64 have been updated to use the passed in virtual registers
directly, which means we no longer need to generate so many
merge/extract instructions.
NFCI for AMDGPU, Mips and X86.
Differential Revision: https://reviews.llvm.org/D63551
llvm-svn: 364512
Change the interface of CallLowering::lowerCall to accept several
virtual registers for the call result, instead of just one. This is a
follow-up to D46018.
CallLowering::lowerReturn was similarly refactored in D49660 and
lowerFormalArguments in D63549.
With this change, we no longer pack the virtual registers generated for
aggregates into one big lump before delegating to the target. Therefore,
the target can decide itself whether it wants to handle them as separate
pieces or use one big register.
ARM and AArch64 have been updated to use the passed in virtual registers
directly, which means we no longer need to generate so many
merge/extract instructions.
NFCI for AMDGPU, Mips and X86.
Differential Revision: https://reviews.llvm.org/D63550
llvm-svn: 364511
Change the interface of CallLowering::lowerFormalArguments to accept
several virtual registers for each formal argument, instead of just one.
This is a follow-up to D46018.
CallLowering::lowerReturn was similarly refactored in D49660. lowerCall
will be refactored in the same way in follow-up patches.
With this change, we forward the virtual registers generated for
aggregates to CallLowering. Therefore, the target can decide itself
whether it wants to handle them as separate pieces or use one big
register. We also copy the pack/unpackRegs helpers to CallLowering to
facilitate this.
ARM and AArch64 have been updated to use the passed in virtual registers
directly, which means we no longer need to generate so many
merge/extract instructions.
AArch64 seems to have had a bug when lowering e.g. [1 x i8*], which was
put into a s64 instead of a p0. Added a test-case which illustrates the
problem more clearly (it crashes without this patch) and fixed the
existing test-case to expect p0.
AMDGPU has been updated to unpack into the virtual registers for
kernels. I think the other code paths fall back for aggregates, so this
should be NFC.
Mips doesn't support aggregates yet, so it's also NFC.
x86 seems to have code for dealing with aggregates, but I couldn't find
the tests for it, so I just added a fallback to DAGISel if we get more
than one virtual register for an argument.
Differential Revision: https://reviews.llvm.org/D63549
llvm-svn: 364510
Allow CallLowering::ArgInfo to contain more than one virtual register.
This is useful when passes split aggregates into several virtual
registers, but need to also provide information about the original type
to the call lowering. Used in follow-up patches.
Differential Revision: https://reviews.llvm.org/D63548
llvm-svn: 364509
The current implementation of ThumbRegisterInfo::saveScavengerRegister
is bad for two reasons: one, it's buggy, and two, it blocks using R12
for other optimizations. So this patch gets rid of it, and adds the
necessary support for using an ordinary emergency spill slot on Thumb1.
(Specifically, I think saveScavengerRegister was broken by r305625, and
nobody noticed for two years because the codepath is almost never used.
The new code will also probably not be used much, but it now has better
tests, and if we fail to emit a necessary emergency spill slot we get a
reasonable error message instead of a miscompile.)
A rough outline of the changes in the patch:
1. Gets rid of ThumbRegisterInfo::saveScavengerRegister.
2. Modifies ARMFrameLowering::determineCalleeSaves to allocate an
emergency spill slot for Thumb1.
3. Implements useFPForScavengingIndex, so the emergency spill slot isn't
placed at a negative offset from FP on Thumb1.
4. Modifies the heuristics for allocating an emergency spill slot to
support Thumb1. This includes fixing ExtraCSSpill so we don't try to
use "lr" as a substitute for allocating an emergency spill slot.
5. Allocates a base pointer in more cases, so the emergency spill slot
is always accessible.
6. Modifies ARMFrameLowering::ResolveFrameIndexReference to compute the
right offset in the new cases where we're forcing a base pointer.
7. Ensures we never generate a load or store with an offset outside of
its frame object. This makes the heuristics more straightforward.
8. Changes Thumb1 prologue and epilogue emission so it never uses
register scavenging.
Some of the changes to the emergency spill slot heuristics in
determineCalleeSaves affect ARM/Thumb2; hopefully, they should allow
the compiler to avoid allocating an emergency spill slot in cases
where it isn't necessary. The rest of the changes should only affect
Thumb1.
Differential Revision: https://reviews.llvm.org/D63677
llvm-svn: 364490
Summary:
The getFixupKindContainerSizeBytes function returns the size of the
instruction containing a given fixup. Currently fixup_arm_pcrel_9 is
not handled in this function, this causes an assertion failure in
the debug build and incorrect codegen in the release build.
This patch fixes the problem.
Reviewers: ostannard, simon_tatham
Reviewed By: ostannard
Subscribers: javed.absar, kristof.beyls, hiraditya, pbarrio, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63778
llvm-svn: 364404
"To" selects an odd-numbered GPR, and "Te" an even one. There are some
8.1-M instructions that have one too few bits in their register fields
and require registers of particular parity, without necessarily using
a consecutive even/odd pair.
Also, the constraint letter "t" should select an MVE q-register, when
MVE is present. This didn't need any source changes, but some extra
tests have been added.
Reviewers: dmgreen, samparker, SjoerdMeijer
Subscribers: javed.absar, eraman, kristof.beyls, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D60709
llvm-svn: 364331
This provides the low-level support to start using MVE vector types in
LLVM IR, loading and storing them, passing them to __asm__ statements
containing hand-written MVE vector instructions, and *if* you have the
hard-float ABI turned on, using them as function parameters.
(In the soft-float ABI, vector types are passed in integer registers,
and combining all those 32-bit integers into a q-reg requires support
for selection DAG nodes like insert_vector_elt and build_vector which
aren't implemented yet for MVE. In fact I've also had to add
`arm_aapcs_vfpcc` to a couple of existing tests to avoid that
problem.)
Specifically, this commit adds support for:
* spills, reloads and register moves for MVE vector registers
* ditto for the VPT predication mask that lives in VPR.P0
* make all the MVE vector types legal in ISel, and provide selection
DAG patterns for BITCAST, LOAD and STORE
* make loads and stores of scalar FP types conditional on
`hasFPRegs()` rather than `hasVFP2Base()`. As a result a few
existing tests needed their llc command lines updating to use
`-mattr=-fpregs` as their method of turning off all hardware FP
support.
Reviewers: dmgreen, samparker, SjoerdMeijer
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60708
llvm-svn: 364329
The expensive buildbots highlighted the mir tests were broken, which
I've now updated and added --verify-machineinstrs to them. This also
uncovered a couple of bugs in the backend pass, so these have also
been fixed.
llvm-svn: 364323
Including both 'case ARM_AM::uxtw' and 'default' in the getShiftOp
switch caused a buildbot to fail with
error: default label in switch which covers all enumeration values [-Werror,-Wcovered-switch-default]
llvm-svn: 364300
A minor iteration on the MVE VPT Block pass to enable more efficient VPT Block
code generation: consecutive VPT predicated statements, predicated on the same
condition, will be placed within the same VPT Block. This essentially is also
an exercise to write some more tests for the next step, which should be more
generic also merging instructions when they are not consecutive.
Differential Revision: https://reviews.llvm.org/D63711
llvm-svn: 364298
If an FP_EXTEND or FP_ROUND isel dag node converts directly between
f16 and f32 when the target CPU has no instruction to do it in one go,
it has to be done in two steps instead, going via f32.
Previously, this was done implicitly, because all such CPUs had the
storage-only implementation of f16 (i.e. the only thing you can do
with one at all is to convert it to/from f32). So isel would legalize
the f16 into an f32 as soon as it saw it, by inserting an fp16_to_fp
node (or vice versa), and then the fp_extend would already be f32->f64
rather than f16->f64.
But that technique can't support a target CPU which has full f16
support but _not_ f64, such as some variants of Arm v8.1-M. So now we
provide custom lowering for FP_EXTEND and FP_ROUND, which checks
support for f16 and f64 and decides on the best thing to do given the
combination of flags it gets back.
Reviewers: dmgreen, samparker, SjoerdMeijer
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60692
llvm-svn: 364294
This final batch includes the tail-predicated versions of the
low-overhead loop instructions (LETP); the VPSEL instruction to select
between two vector registers based on the predicate mask without
having to open a VPT block; and VPNOT which complements the predicate
mask in place.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62681
llvm-svn: 364292
This adds the rest of the vector memory access instructions. It
includes contiguous loads/stores, with an ordinary addressing mode
such as [r0,#offset] (plus writeback variants); gather loads and
scatter stores with a scalar base address register and a vector of
offsets from it (written [r0,q1] or similar); and gather/scatters with
a vector of base addresses (written [q0,#offset], again with
writeback). Additionally, some of the loads can widen each loaded
value into a larger vector lane, and the corresponding stores narrow
them again.
To implement these, we also have to add the addressing modes they
need. Also, in AsmParser, the `isMem` query function now has
subqueries `isGPRMem` and `isMVEMem`, according to which kind of base
register is used by a given memory access operand.
I've also had to add an extra check in `checkTargetMatchPredicate` in
the AsmParser, without which our last-minute check of `rGPR` register
operands against SP and PC was failing an assertion because Tablegen
had inserted an immediate 0 in place of one of a pair of tied register
operands. (This matches the way the corresponding check for `MCK_rGPR`
in `validateTargetOperandClass` is guarded.) Apparently the MVE load
instructions were the first to have ever triggered this assertion, but
I think only because they were the first to have a combination of the
usual Arm pre/post writeback system and the `rGPR` class in particular.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62680
llvm-svn: 364291
Introduce three pseudo instructions to be used during DAG ISel to
represent v8.1-m low-overhead loops. One maps to set_loop_iterations
while loop_decrement_reg is lowered to two, so that we can separate
the decrement and branching operations. The pseudo instructions are
expanded pre-emission, where we can still decide whether we actually
want to generate a low-overhead loop, in a new pass:
ARMLowOverheadLoops. The pass currently bails, reverting to an sub,
icmp and br, in the cases where a call or stack spill/restore happens
between the decrement and branching instructions, or if the loop is
too large.
Differential Revision: https://reviews.llvm.org/D63476
llvm-svn: 364288
Avoids using a plain unsigned for registers throughoug codegen.
Doesn't attempt to change every register use, just something a little
more than the set needed to build after changing the return type of
MachineOperand::getReg().
llvm-svn: 364191
This adds the family of loads and stores with names like VLD20.8 and
VST42.32, which load and store parts of multiple q-registers in such a
way that executing both VLD20 and VLD21, or all four of VLD40..VLD43,
will distribute 2 or 4 vectors' worth of memory data across the lanes
of the same number of registers but in a transposed order.
In addition to the Tablegen descriptions of the instructions
themselves, this patch also adds encode and decode support for the
QQPR and QQQQPR register classes (representing the range of loaded or
stored vector registers), and tweaks to the parsing system for lists
of vector registers to make it return the right format in this case
(since, unlike NEON, MVE regards q-registers as primitive, and not
just an alias for two d-registers).
llvm-svn: 364172
These instructions let you load half a vector register at once from
two general-purpose registers, or vice versa.
The assembly syntax for these instructions mentions the vector
register name twice. For the move _into_ a vector register, the MC
operand list also has to mention the register name twice (once as the
output, and once as an input to represent where the unchanged half of
the output register comes from). So we can conveniently assign one of
the two asm operands to be the output $Qd, and the other $QdSrc, which
avoids confusing the auto-generated AsmMatcher too much. For the move
_from_ a vector register, there's no way to get round the fact that
both instances of that register name have to be inputs, so we need a
custom AsmMatchConverter to avoid generating two separate output MC
operands. (And even that wouldn't have worked if it hadn't been for
D60695.)
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62679
llvm-svn: 364041
This adds the `MVE_qDest_rSrc` superclass and all its instances, plus
a few other instructions that also take a scalar input register or two.
I've also belatedly added custom diagnostic messages to the operand
classes for odd- and even-numbered GPRs, which required matching
changes in two of the existing MVE assembly test files.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62678
llvm-svn: 364040
Summary:
This adds the `MVE_qDest_qSrc` superclass and all instructions that
inherit from it. It's not the complete class of _everything_ with a
q-register as both destination and source; it's a subset of them that
all have similar encodings (but it would have been hopelessly unwieldy
to call it anything like MVE_111x11100).
This category includes add/sub with carry; long multiplies; halving
multiplies; multiply and accumulate, and some more complex
instructions.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62677
llvm-svn: 364037
Summary:
These take a pair of vector register to compare, and a comparison type
(written in the form of an Arm condition suffix); they output a vector
of booleans in the VPR register, where predication can conveniently
use them.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62676
llvm-svn: 364027
Teach RegisterBankInfo to use the correct register class, and tell the
legalizer it's legal. Everything else just works.
The one thing that's slightly weird about this compared to SelectionDAG
isel is that legalization can't distinguish between i64 and <1 x i64>,
so we might end up with more NEON instructions than the user expects.
Differential Revision: https://reviews.llvm.org/D63585
llvm-svn: 363989
This includes integer arithmetic of various kinds (add/sub/multiply,
saturating and not), and the immediate forms of VMOV and VMVN that
load an immediate into all lanes of a vector.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62674
llvm-svn: 363936
The ARMDisassembler changes allow changing between ARM and Thumb mode
based on the MCSubtargetInfo, rather than the Target, which simplifies
the other changes a bit.
I'm not really happy with adding more target-specific logic to
tools/llvm-objdump/, but there isn't any easy way around it: the logic
in question specifically applies to disassembling an object file, and
that code simply isn't located in lib/Target, at least at the moment.
Differential Revision: https://reviews.llvm.org/D60927
llvm-svn: 363903
This includes all the obvious bitwise operations (AND, OR, BIC, ORN,
MVN) in register-to-register forms, and the immediate forms of
AND/OR/BIC/ORN; byte-order reverse instructions; and the VMOVs that
access a single lane of a vector.
Some of those VMOVs (specifically, the ones that access a 32-bit lane)
share an encoding with existing instructions that were disassembled as
accessing half of a d-register (e.g. `vmov.32 r0, d1[0]`), but in
8.1-M they're now written as accessing a quarter of a q-register (e.g.
`vmov.32 r0, q0[2]`). The older syntax is still accepted by the
assembler.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62673
llvm-svn: 363838
Summary:
When identifing instructions that can be folded into a MOVCC instruction,
checking for a predicate operand is not enough, also need to check for
thumb2 function, with restrict-IT, is the machine instruction eligible for
ARMv8 IT or not.
Notes in ARMv8-A Architecture Reference Manual, section "Partial deprecation of IT"
https://usermanual.wiki/Pdf/ARM20Architecture20Reference20ManualARMv8.1667877052.pdf
"ARMv8-A deprecates some uses of the T32 IT instruction. All uses of IT that apply to
instructions other than a single subsequent 16-bit instruction from a restricted set
are deprecated, as are explicit references to the PC within that single 16-bit
instruction. This permits the non-deprecated forms of IT and subsequent instructions
to be treated as a single 32-bit conditional instruction."
Reviewers: efriedma, lebedev.ri, t.p.northover, jmolloy, aemerson, compnerd, stoklund, ostannard
Reviewed By: ostannard
Subscribers: ostannard, javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63474
llvm-svn: 363739
This includes saturating and non-saturating shifts, both with
immediate shift count and with the shift counts given by another
vector register; VSHLC (in which the bits shifted out of each active
vector lane are shifted in to the next active lane); and also VMOVL,
which is enough like an immediate shift that it didn't fit too badly
in this category.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62672
llvm-svn: 363696
Summary:
These form a small family of their own, to go with the floating-point
VMINNM/VMAXNM instructions added in a previous commit.
They introduce the first of many special cases in the mnemonic
recognition code, because VMIN with the E suffix used by the VPT
predication system needs to avoid being interpreted as the nonexistent
instruction 'VMI' with an ordinary 'NE' condition suffix.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62671
llvm-svn: 363695
Summary:
Their names began with a mishmash of `MVE_`, `t2` and no prefix at
all. Now they all start with `MVE_`, which seems like a reasonable
choice on the grounds that (a) NEON is the thing they're most at risk
of being confused with, and (b) MVE implies Thumb-2, so a prefix
indicating MVE is strictly more specific than one indicating Thumb-2.
Reviewers: ostannard, SjoerdMeijer, dmgreen
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63492
llvm-svn: 363690
Some more refactoring, like registering the IT Block pass, less cryptic
variable names, and some simplification of loops.
Differential Revision: https://reviews.llvm.org/D63419
llvm-svn: 363666
The HardwareLoops pass finds exit blocks with a scevable exit count.
If the target specifies to update the loop counter in a register,
through a phi, we need to ensure that the exit block is a latch so
that we can insert the phi with the correct value for the incoming
edge.
Differential Revision: https://reviews.llvm.org/D63336
llvm-svn: 363556
Create the ARMBasicBlockUtils class for tracking and querying basic
blocks sizes so we can use them when generating low-overhead loops.
Differential Revision: https://reviews.llvm.org/D63265
llvm-svn: 363530
This is the family of vector instructions that combine all the lanes
in their input vector(s), and output a value in one or two GPRs.
Differential Revision: https://reviews.llvm.org/D62670
llvm-svn: 363403
Initial commit of a new pass to create vector predication blocks, called VPT
blocks, that are supported by the Armv8.1-M MVE architecture.
This is a first naive implementation. I.e., for 2 consecutive predicated
instructions I1 and I2, for example, it will generate 2 VPT blocks:
VPST
I1
VPST
I2
A more optimal implementation would obviously put instructions in the same VPT
block when they are predicated on the same condition and when it is allowed to
do this:
VPTT
I1
I2
We will address this optimisation with follow up patches when the groundwork is
in. Creating VPT Blocks is very similar to IT Blocks, which is the reason I
added this to Thumb2ITBlocks.cpp. This allows reuse of the def use analysis
that we need for the more optimal implementation.
VPT blocks cannot be nested in IT blocks, and vice versa, and so these 2 passes
cannot interact with each other. Instructions allowed in VPT blocks must
be MVE instructions that are marked as VPT compatible.
Differential Revision: https://reviews.llvm.org/D63247
llvm-svn: 363370
This commit prepares the way to start adding the main collection of
MVE instructions, which operate on the 128-bit vector registers.
The most obvious thing that's needed, and the simplest, is to add the
MQPR register class, which is like the existing QPR except that it has
fewer registers in it.
The more complicated part: MVE defines a system of vector predication,
in which instructions operating on 128-bit vector registers can be
constrained to operate on only a subset of the lanes, using a system
of prefix instructions similar to the existing Thumb IT, in that you
have one prefix instruction which designates up to 4 following
instructions as subject to predication, and within that sequence, the
predicate can be inverted by means of T/E suffixes ('Then' / 'Else').
To support instructions of this type, we've added two new Tablegen
classes `vpred_n` and `vpred_r` for standard clusters of MC operands
to add to a predicated instruction. Both include a flag indicating how
the instruction is predicated at all (options are T, E and 'not
predicated'), and an input register field for the register controlling
the set of active lanes. They differ from each other in that `vpred_r`
also includes an input operand for the previous value of the output
register, for instructions that leave inactive lanes unchanged.
`vpred_n` lacks that extra operand; it will be used for instructions
that don't preserve inactive lanes in their output register (either
because inactive lanes are zeroed, as the MVE load instructions do, or
because the output register isn't a vector at all).
This commit also adds the family of prefix instructions themselves
(VPT / VPST), and all the machinery needed to work with them in
assembly and disassembly (e.g. generating the 't' and 'e' mnemonic
suffixes on disassembled instructions within a predicated block)
I've added a couple of demo instructions that derive from the new
Tablegen base classes and use those two operand clusters. The bulk of
the vector instructions will come in followup commits small enough to
be manageable. (One exception is that I've added the full version of
`isMnemonicVPTPredicable` in the AsmParser, because it seemed
pointless to carefully split it up.)
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62669
llvm-svn: 363258
During assembly, the mask operand to an IT instruction (storing the
sequence of T/E for 'Then' and 'Else') is parsed out of the mnemonic
into a representation that encodes 'Then' and 'Else' in the same way
regardless of the condition code. At some point during encoding it has
to be converted into the instruction encoding used in the
architecture, in which the mask encodes a sequence of replacement
low-order bits for the condition code, so that which bit value means
'then' and which 'else' depends on whether the original condition code
had its low bit set.
Previously, that transformation was done by processInstruction(), half
way through assembly. So an MCOperand storing an IT mask would
sometimes store it in one format, and sometimes in the other,
depending on where in the assembly pipeline you were. You can see this
in diagnostics from `llvm-mc -debug -triple=thumbv8a -show-inst`, for
example: if you give it an instruction such as `itete eq`, you'd see
an `<MCOperand Imm:5>` in a diagnostic become `<MCOperand Imm:11>` in
the final output.
Having the same data structure store values with time-dependent
semantics is confusing already, and it will get more confusing when we
introduce the MVE VPT instruction which reuses the Then/Else bitmask
idea in a different context. So I'm refactoring: now, all `ARMOperand`
and `MCOperand` representations of an IT mask work exactly the same
way, namely, 0 means 'Then' and 1 means 'Else', regardless of what
original predicate is being referred to. The architectural encoding of
IT that depends on the original condition is now constructed at the
point when we turn the `MCOperand` into the final instruction bit
pattern, and decoded similarly in the disassembler.
The previous condition-independent parse-time format used 0 for Else
and 1 for Then. I've taken the opportunity to flip the sense of it
while I'm changing all of this anyway, because it seems to me more
natural to use 0 for 'leave the starting condition unchanged' and 1
for 'invert it', as if those bits were an XOR mask.
Reviewers: ostannard
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63219
llvm-svn: 363244
TTI should report that it's not profitable to generate a hardware loop
if it, or one of its child loops, has already been converted.
Differential Revision: https://reviews.llvm.org/D63212
llvm-svn: 363234
As discussed on D62910, we need to check whether particular types of memory access are allowed, not just their alignment/address-space.
This NFC patch adds a MachineMemOperand::Flags argument to allowsMemoryAccess and allowsMisalignedMemoryAccesses, and wires up calls to pass the relevant flags to them.
If people are happy with this approach I can then update X86TargetLowering::allowsMisalignedMemoryAccesses to handle misaligned NT load/stores.
Differential Revision: https://reviews.llvm.org/D63075
llvm-svn: 363179
Without this fix clang 3.6 complains with:
../lib/Target/ARM/ARMAsmPrinter.cpp:1473:18: error: variable 'BranchTarget' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
} else if (MI->getOperand(1).isSymbol()) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../lib/Target/ARM/ARMAsmPrinter.cpp:1479:22: note: uninitialized use occurs here
MCInst.addExpr(BranchTarget);
^~~~~~~~~~~~
../lib/Target/ARM/ARMAsmPrinter.cpp:1473:14: note: remove the 'if' if its condition is always true
} else if (MI->getOperand(1).isSymbol()) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../lib/Target/ARM/ARMAsmPrinter.cpp:1465:33: note: initialize the variable 'BranchTarget' to silence this warning
const MCExpr *BranchTarget;
^
= nullptr
1 error generated.
Discussed here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190610/661417.html
llvm-svn: 363166
Implement the backend target hook to drive the HardwareLoops pass.
The low-overhead branch extension for Arm M-class cores is flexible
enough that we don't have to ensure correctness at this point, except
checking that the loop counter variable can be stored in LR - a
32-bit register. For it to be profitable, we want to avoid loops that
contain function calls, or any other instruction that alters the PC.
This implementation uses TargetLoweringInfo, to query type and
operation actions, looks at intrinsic calls and also performs some
manual checks for remainder/division and FP operations.
I think this should be a good base to start and extra details can be
filled out later.
Differential Revision: https://reviews.llvm.org/D62907
llvm-svn: 363149
This introduces a new decoding table for MVE instructions, and starts
by adding the family of scalar shift instructions that are part of the
MVE architecture extension: saturating shifts within a single GPR, and
long shifts across a pair of GPRs (both saturating and normal).
Some of these shift instructions have only 3-bit register fields in
the encoding, with the low bit fixed. So they can only address an odd
or even numbered GPR (depending on the operand), and therefore I add
two new register classes, GPREven and GPROdd.
Differential Revision: https://reviews.llvm.org/D62668
Change-Id: Iad95d5f83d26aef70c674027a184a6b1e0098d33
llvm-svn: 363051
The variable `OffsetMask` is currently only used in an assertion, so
if assertions are compiled out and -Werror is enabled, it becomes a
build failure.
llvm-svn: 363043
This adds support for the new family of conditional selection /
increment / negation instructions; the low-overhead branch
instructions (e.g. BF, WLS, DLS); the CLRM instruction to zero a whole
list of registers at once; the new VMRS/VMSR and VLDR/VSTR
instructions to get data in and out of 8.1-M system registers,
particularly including the new VPR register used by MVE vector
predication.
To support this, we also add a register name 'zr' (used by the CSEL
family to force one of the inputs to the constant 0), and operand
types for lists of registers that are also allowed to include APSR or
VPR (used by CLRM). The VLDR/VSTR instructions also need a new
addressing mode.
The low-overhead branch instructions exist in their own separate
architecture extension, which we treat as enabled by default, but you
can say -mattr=-lob or equivalent to turn it off.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Reviewed By: samparker
Subscribers: miyuki, javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62667
llvm-svn: 363039
This reverts r362990 (git commit 374571301d)
This was causing linker warnings on Darwin:
ld: warning: direct access in function 'llvm::initializeEvexToVexInstPassPass(llvm::PassRegistry&)'
from file '../../lib/libLLVMX86CodeGen.a(X86EvexToVex.cpp.o)' to global weak symbol
'void std::__1::__call_once_proxy<std::__1::tuple<void* (&)(llvm::PassRegistry&),
std::__1::reference_wrapper<llvm::PassRegistry>&&> >(void*)' from file '../../lib/libLLVMCore.a(Verifier.cpp.o)'
means the weak symbol cannot be overridden at runtime. This was likely caused by different translation
units being compiled with different visibility settings.
llvm-svn: 363028
Summary:
For builds with LLVM_BUILD_LLVM_DYLIB=ON and BUILD_SHARED_LIBS=OFF
this change makes all symbols in the target specific libraries hidden
by default.
A new macro called LLVM_EXTERNAL_VISIBILITY has been added to mark symbols in these
libraries public, which is mainly needed for the definitions of the
LLVMInitialize* functions.
This patch reduces the number of public symbols in libLLVM.so by about
25%. This should improve load times for the dynamic library and also
make abi checker tools, like abidiff require less memory when analyzing
libLLVM.so
One side-effect of this change is that for builds with
LLVM_BUILD_LLVM_DYLIB=ON and LLVM_LINK_LLVM_DYLIB=ON some unittests that
access symbols that are no longer public will need to be statically linked.
Before and after public symbol counts (using gcc 8.2.1, ld.bfd 2.31.1):
nm before/libLLVM-9svn.so | grep ' [A-Zuvw] ' | wc -l
36221
nm after/libLLVM-9svn.so | grep ' [A-Zuvw] ' | wc -l
26278
Reviewers: chandlerc, beanz, mgorny, rnk, hans
Reviewed By: rnk, hans
Subscribers: Jim, hiraditya, michaelplatings, chapuni, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, mgrang, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, kristina, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D54439
llvm-svn: 362990
These caused a build failure because I managed not to notice they
depended on a later unpushed commit in my current stack. Sorry about
that.
llvm-svn: 362956
This should have been part of r362953, but I had a finger-trouble
incident and committed the old rather than new version of the patch.
Sorry.
llvm-svn: 362955
This adds support for the new family of conditional selection /
increment / negation instructions; the low-overhead branch
instructions (e.g. BF, WLS, DLS); the CLRM instruction to zero a whole
list of registers at once; the new VMRS/VMSR and VLDR/VSTR
instructions to get data in and out of 8.1-M system registers,
particularly including the new VPR register used by MVE vector
predication.
To support this, we also add a register name 'zr' (used by the CSEL
family to force one of the inputs to the constant 0), and operand
types for lists of registers that are also allowed to include APSR or
VPR (used by CLRM). The VLDR/VSTR instructions also need some new
addressing modes.
The low-overhead branch instructions exist in their own separate
architecture extension, which we treat as enabled by default, but you
can say -mattr=-lob or equivalent to turn it off.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Reviewed By: samparker
Subscribers: miyuki, javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62667
llvm-svn: 362953
Arm v8.1-M supports the VMOV instructions that move a half-precision
value to and from a GPR, but not if the GPR is SP or PC.
To fix this, I've changed those instructions to use the rGPR register
class instead of GPR. rGPR always excludes PC, and it excludes SP
except in the presence of the HasV8Ops target feature (i.e. Arm v8-A).
So the effect is that VMOV.F16 to and from PC is now illegal
everywhere, but VMOV.F16 to and from SP is illegal only on non-v8-A
cores (which I believe is all as it should be).
Reviewers: dmgreen, samparker, SjoerdMeijer, ostannard
Reviewed By: ostannard
Subscribers: ostannard, javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60704
llvm-svn: 362942
This option allows loops with small max trip counts to be fully unrolled. This
can help with code like the remainder loops from manually unrolled loops like
those that appear in the cmsis dsp library. We would apparently previously
runtime unroll them with the default unroll count (4).
Differential Revision: https://reviews.llvm.org/D63064
llvm-svn: 362928
Types such as float and i64's do not have legal loads in Thumb1, but will still
be loaded with a LDR (or potentially multiple LDR's). As such we can treat the
cost of addressing mode calculations the same as an i32 and get some optimisation
benefits.
Differential Revision: https://reviews.llvm.org/D62968
llvm-svn: 362874
Now with MVE being added, we can add the vector addressing mode costs for it.
These are generally imm7 multiplied by the size of the type being loaded /
stored.
Differential Revision: https://reviews.llvm.org/D62967
llvm-svn: 362873
The fp16 version of VLDR takes a imm8 multiplied by 2. This updates the costs
to account for those, and adds extra testing. It is dependant upon hasFPRegs16
as this is what the load/store instructions require.
Differential Revision: https://reviews.llvm.org/D62966
llvm-svn: 362872
We are starting to add an entirely separate vector architecture to the ARM
backend. To do that we need at least some separation between the existing NEON
and the new MVE code. This patch just goes through the Neon patterns and
ensures that they are predicated on HasNEON, giving MVE a stable place to start
from.
No tests yet as this is largely an NFC, and we don't have the other target that
will treat any of these intructions as legal.
Differential Revision: https://reviews.llvm.org/D62945
llvm-svn: 362870
This change adds two FP16 extraction and two insertion patterns
(one per possible vector length).
Extractions are handled by copying a Q/D register into one of VFP2
class registers, where single FP32 sub-registers can be accessed. Then
the extraction of even lanes are simple sub-register extractions
(because we don't care about the top parts of registers for FP16
operations). Odd lanes need an additional VMOVX instruction.
Unfortunately, insertions cannot be handled in the same way, because:
* There is no instruction to insert FP16 into an even lane (VINS only
works with odd lanes)
* The patterns for odd lanes will have a form of a DAG (not a tree),
and will not be implementable in pure tablegen
Because of this insertions are handled in the same way as 16-bit
integer insertions (with conversions between FP registers and GPRs
using VMOVHR instructions).
Without these patterns the ARM backend would sometimes fail during
instruction selection.
This patch also adds patterns which combine:
* an FP16 element extraction and a store into a single VST1
instruction
* an FP16 load and insertion into a single VLD1 instruction
Differential Revision: https://reviews.llvm.org/D62651
llvm-svn: 362482
The family of 32-bit Thumb instruction encodings that include t2ORR,
t2AND and t2EOR are all listed in the ArmARM as having (0) in bit 15.
The Tablegen descriptions of those instructions listed them as ?. This
change tightens that up by making them into 0 + Unpredictable.
In the specific case of t2ORR, we tighten it up still further by
making the zero bit mandatory. This change comes from Arm v8.1-M, in
which encodings with that bit equal to 1 will now be used for
different instructions.
Reviewers: dmgreen, samparker, SjoerdMeijer, efriedma
Reviewed By: dmgreen, efriedma
Subscribers: efriedma, javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60705
llvm-svn: 362470
Summary:
- pr42062
When compiling for MinSize,
ARMTargetLowering::LowerCall decides to indirect
multiple calls to a same function. However,
it disconsiders the limitation that thumb1
indirect calls require the callee to be in a
register from r0 to r3 (llvm limiation).
If all those registers are used by arguments, the
compiler dies with "error: run out of registers
during register allocation".
This patch tells the function
IsEligibleForTailCallOptimization if we intend to
perform indirect calls, as to avoid tail call
optimization.
Reviewers: dmgreen, efriedma
Reviewed By: efriedma
Subscribers: javed.absar, kristof.beyls, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62683
llvm-svn: 362366
Most of the code used for finding a 'narrow' sequence is not used,
so I've removed it and simplified the calls from the smlad matcher.
llvm-svn: 362104
Now the NEON ones have a prefix "NEON_", and the VFP ones have a
prefix "VFP_". This is so that the regex in ARMScheduleA57.td can be
made to match both of _those_ classes of VMAXNM without also matching
the MVE ones that are going to be introduced soon. NFCI.
Patch by Simon Tatham.
Differential Revision: https://reviews.llvm.org/D60700
llvm-svn: 362097
This adds:
- LLVM subtarget features to make all the new instructions conditional on,
- CPU and FPU names for use on clang's command line, with default FPUs set
so that "armv8.1-m.main+fp" and "armv8.1-m.main+fp.dp" will select the right
FPU features,
- architecture extension names "mve" and "mve.fp",
- ABI build attribute support for v8.1-M (a new value for Tag_CPU_arch) and MVE
(a new actual tag).
Patch mostly by Simon Tatham.
Differential Revision: https://reviews.llvm.org/D60698
llvm-svn: 362090
The MVE extension in Arm v8.1-M permits the use of some move, load and
store isntructions which access the FP registers, even if there's no
actual FP support in the processor (in particular, if you have the
integer-only version of MVE).
Therefore, we need separate subtarget features to condition those
instructions on, which are implied by both FP and MVE but are not part
of either.
Patch mostly by Simon Tatham.
Differential Revision: https://reviews.llvm.org/D60694
llvm-svn: 362088
MVE architecturally specifies a 'beat' system in which a vector
instruction executed now will complete its actual operation over the
next four cycles, so it can overlap with the execution of the previous
and next MVE instruction.
This makes it generally an advantage to avoid moving values back and
forth between MVE registers and anywhere else, if there's any sensible
way to do the same processing in whatever register type the values
already occupied.
That's just what the 'execution domain' system is supposed to achieve.
So here we add a new execution domain which will contain all the MVE
vector instructions when they are added.
Patch by: Simon Tatham
Differential Revision: https://reviews.llvm.org/D60703
llvm-svn: 362068
The new ARMPredicates.td is included from ARM.td, early enough that
the predicate definitions are already in scope when ARMSchedule.td is
included. This will make it possible to refer to them in
UnsupportedFeatures fields of scheduling models.
NFC: the chunk of Tablegen being moved here is copied and pasted
verbatim.
Patch by: Simon Tatham
Differential Revision: https://reviews.llvm.org/D60693
llvm-svn: 361958
Those two subtarget features were awkward because their semantics are
reversed: each one indicates the _lack_ of support for something in
the architecture, rather than the presence. As a consequence, you
don't get the behavior you want if you combine two sets of feature
bits.
Each SubtargetFeature for an FP architecture version now comes in four
versions, one for each combination of those options. So you can still
say (for example) '+vfp2' in a feature string and it will mean what
it's always meant, but there's a new string '+vfp2d16sp' meaning the
version without those extra options.
A lot of this change is just mechanically replacing positive checks
for the old features with negative checks for the new ones. But one
more interesting change is that I've rearranged getFPUFeatures() so
that the main FPU feature is appended to the output list *before*
rather than after the features derived from the Restriction field, so
that -fp64 and -d32 can override defaults added by the main feature.
Reviewers: dmgreen, samparker, SjoerdMeijer
Subscribers: srhines, javed.absar, eraman, kristof.beyls, hiraditya, zzheng, Petar.Avramovic, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D60691
llvm-svn: 361845
Details: To make instruction selection really divergence driven it is necessary to assign
the correct register classes to the cross block values beforehand. For the divergent targets
same value type requires different register classes dependent on the value divergence.
Reviewers: rampitec, nhaehnle
Differential Revision: https://reviews.llvm.org/D59990
This commit was reverted because of the build failure.
The reason was mlformed patch.
Build failure fixed.
llvm-svn: 361741
This add patterns for fp16 round and ceil etc. Same as the float and double
patterns.
Differential Revision: https://reviews.llvm.org/D62326
llvm-svn: 361718
Promote a number of fp16 math intrinsics to float, so that the relevant float
math routines can be used. Copysign is expanded so as to be handled in-place.
Differential Revision: https://reviews.llvm.org/D62325
llvm-svn: 361717
Summary:
We were observing failures for arm32 allyesconfigs of the Linux kernel
with the asm goto Clang patch, where ldr's were being generated to
offsets too far away to encode in imm12.
It looks like since INLINEASM_BR was created off of INLINEASM, a few
checks for INLINEASM needed to be updated to check for either case.
pr/41999
Link: https://github.com/ClangBuiltLinux/linux/issues/490
Reviewers: peter.smith, kristof.beyls, ostannard, rengolin, t.p.northover
Reviewed By: peter.smith
Subscribers: jyu2, javed.absar, hiraditya, llvm-commits, nathanchance, craig.topper, kees, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62400
llvm-svn: 361659
Details: To make instruction selection really divergence driven it is necessary to assign
the correct register classes to the cross block values beforehand. For the divergent targets
same value type requires different register classes dependent on the value divergence.
Reviewers: rampitec, nhaehnle
Differential Revision: https://reviews.llvm.org/D59990
llvm-svn: 361644
This pass wasn't printing any messages at all, which I find really inconvenient
while debugging/tracing things. It now dumps the before and after of expanded
instructions. It doesn't do this yet for all instructions, but this is a good
start I guess.
Differential Revision: https://reviews.llvm.org/D62297
llvm-svn: 361604
The previous patch added a member set to store instructions that we
could allow to wrap. But this wasn't cleared between searches meaning
that they could get promoted, incorrectly, during the promotion of a
separate valid chain.
Differential Revision: https://reviews.llvm.org/D62254
llvm-svn: 361462
PrepareConstants step converts add/sub with 'negative' immediates to
sub/add with a 'positive' imm to make promotion more simple. nuw
already states that the add shouldn't cause an unsigned wrap, so
it shouldn't need any tweaking. Plus, we also don't allow a sub with
a 'negative' immediate to be safe wrap, so this functionality has
been removed. The PrepareConstants step now just handles the add
instructions that we've determined would be safe if they wrap around
zero.
Differential Revision: https://reviews.llvm.org/D62057
llvm-svn: 361227
R_ARM_NONE can be used to create references among sections. When
--gc-sections is used, the referenced section will be retained if the
origin section is retained.
Add a generic MCFixupKind FK_NONE as this kind of no-op relocation is
ubiquitous on ELF and COFF, and probably available on many other binary
formats. See D62014.
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D61992
llvm-svn: 360980
The new cortex-m schedule in rL360768 helps performance, but can increase the
amount of high-registers used. This, on average, ends up increasing the
codesize by a fair amount (because less instructions are converted from T2 to
T1). On cortex-m at -Oz, where we are quite size-paranoid, it is better to use
the existing DAG scheduler with the RegPressure scheduling preference (at least
until the issues around T2 vs T1 instructions can be improved).
I have also made sure that the Sched::RegPressure dag scheduler is always
chosen for MinSize.
The test shows one case where we increase the number of registers used.
Differential Revision: https://reviews.llvm.org/D61882
llvm-svn: 360769
This patch adds a simple Cortex-M4 schedule, renaming the existing M3
schedule to M4 and filling in the latencies as-per the Cortex-M4 TRM:
https://developer.arm.com/docs/ddi0439/latest
Most of these are 1, with the important exception being loads taking 2
cycles. A few others are also higher, but I don't believe they make a
large difference. I've repurposed the M3 schedule as the latencies are
mostly the same between the two cores, with the M4 having more FP and
DSP instructions. We also turn on MISched and UseAA for the cores that
now use this.
It also adds some schedule Write's to various instruction to make things
simpler.
Differential Revision: https://reviews.llvm.org/D54142
llvm-svn: 360768
Move the declarations of getThe<Name>Target() functions into a new header in
TargetInfo and make users of these functions include this new header.
This fixes a layering problem.
llvm-svn: 360718
When deciding the safety of generating smlad, we checked for any
writes within the block that may alias with any of the loads that
need to be widened. This is overly conservative because it only
matters when there's a potential aliasing write to a location
accessed by a pair of loads.
Now we check for aliasing writes only once, during setup. If two
loads are found to have an aliasing write between them, we don't add
these loads to LoadPairs. This means that later during the transform,
we can safely widened a pair without worrying about aliasing.
However, to maintain correctness, we also need to change the way that
wide loads are inserted because the order is now important.
The MatchSMLAD method has also been changed, absorbing
MatchReductions and AddMACCandidate to hopefully improve readability.
Differential Revision: https://reviews.llvm.org/D6102
llvm-svn: 360567
For some targets, there is a circular dependency between InstPrinter and
MCTargetDesc. Merging them together will fix this. For the other targets,
the merging is to maintain consistency so all targets will have the same
structure.
llvm-svn: 360490
Add an Argument that has the SExtAttr attached, as well as SIToFP
instructions, as values that generate sign bits. SIToFP doesn't
strictly do this and could be treated as a sink to be sign-extended.
Differential Revision: https://reviews.llvm.org/D61381
llvm-svn: 360331
Using SP in this position is unpredictable in ARMv7. CMP and CMN are not
affected, and of course v8 relaxes this requirement, but that's handled
elsewhere.
llvm-svn: 360242
This generally follows what other targets do. I don't completely
understand why the special case for tail calls existed in the first
place; even when the code was committed in r105413, call lowering didn't
work in the way described in the comments.
Stack protector lowering breaks if the register copies are not glued to
a tail call: we have to insert the stack protector check before the tail
call, and we choose the location based on the assumption that all
physical register dependencies of a tail call are adjacent to the tail
call. (See FindSplitPointForStackProtector.) This is sort of fragile,
but I don't see any reason to break that assumption.
I'm guessing nobody has seen this before just because it's hard to
convince the scheduler to actually schedule the code in a way that
breaks; even without the glue, the only computation that could actually
be scheduled after the register copies is the computation of the call
address, and the scheduler usually prefers to schedule that before the
copies anyway.
Fixes https://bugs.llvm.org/show_bug.cgi?id=41417
Differential Revision: https://reviews.llvm.org/D60427
llvm-svn: 360099
Select G_SEXT and G_ZEXT with destination types smaller than 32 bits in
the exact same way as 32 bits. This overwrites the higher bits, but that
should be ok since all legal users of types smaller than 32 bits ignore
those bits anyway.
llvm-svn: 359768
This implements TargetTransformInfo method getMemcpyCost, which estimates the
number of instructions to which a memcpy instruction expands to.
Differential Revision: https://reviews.llvm.org/D59787
llvm-svn: 359547
Bail out on function arguments/returns with types aggregating an
unsupported type. This fixes cases where we would happily and
incorrectly lower functions taking e.g. [1 x i64] parameters, when we
don't even support plain i64 yet.
llvm-svn: 359540
The MachineFunction wasn't used in getOptimalMemOpType, but more importantly,
this allows reuse of findOptimalMemOpLowering that is calling getOptimalMemOpType.
This is the groundwork for the changes in D59766 and D59787, that allows
implementation of TTI::getMemcpyCost.
Differential Revision: https://reviews.llvm.org/D59785
llvm-svn: 359537
Summary:
This patch adds some basic operations for fp16
vectors, such as bitcast from fp16 to i16,
required to perform extract_subvector (also added
here) and extract_element.
Reviewers: SjoerdMeijer, DavidSpickett, t.p.northover, ostannard
Reviewed By: ostannard
Subscribers: javed.absar, kristof.beyls, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60618
llvm-svn: 359433
Summary:
The Procedure Call Standard for the Arm Architecture
states that float16x4_t and float16x8_t behave just
as uint16x4_t and uint16x8_t for argument passing.
This patch adds the fp16 vectors to the
ARMCallingConv.td file.
Reviewers: miyuki, ostannard
Reviewed By: ostannard
Subscribers: ostannard, javed.absar, kristof.beyls, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60720
llvm-svn: 359431
Summary:
Targets like ARM, MSP430, PPC, and SystemZ have complex behavior when
printing the address of a MachineOperand::MO_GlobalAddress. Move that
handling into a new overriden method in each base class. A virtual
method was added to the base class for handling the generic case.
Refactors a few subclasses to support the target independent %a, %c, and
%n.
The patch also contains small cleanups for AVRAsmPrinter and
SystemZAsmPrinter.
It seems that NVPTXTargetLowering is possibly missing some logic to
transform GlobalAddressSDNodes for
TargetLowering::LowerAsmOperandForConstraint to handle with "i" extended
inline assembly asm constraints.
Fixes:
- https://bugs.llvm.org/show_bug.cgi?id=41402
- https://github.com/ClangBuiltLinux/linux/issues/449
Reviewers: echristo, void
Reviewed By: void
Subscribers: void, craig.topper, jholewinski, dschuff, jyknight, dylanmckay, sdardis, nemanjai, javed.absar, sbc100, jgravelle-google, eraman, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, jrtc27, atanasyan, jsji, llvm-commits, kees, tpimh, nathanchance, peter.smith, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60887
llvm-svn: 359337
The manual says that Thumb2 add/sub instructions are only allowed to modify sp
if the first source is also sp. This is slightly different from the usual rGPR
restriction since it's context-sensitive, so implement it in C++.
llvm-svn: 358987
The check for creating CBZ in constant island pass recently obtained the
ability to search backwards to find a Cmp instruction. The code in IfCvt should
mirror this to allow more conversions to the smaller form. The common code has
been pulled out into a separate function to be shared between the two places.
Differential Revision: https://reviews.llvm.org/D60090
llvm-svn: 358977
Ifcvt can replicate instructions as it converts them to be predicated. This
stops that from happening on thumb2 targets at minsize where an extra IT
instruction is likely needed.
Differential Revision: https://reviews.llvm.org/D60089
llvm-svn: 358974
This does two main things, firstly adding some at least basic addressing modes
for i64 types, and secondly treats floats and doubles sensibly when there is no
fpu. The floating point change can help codesize in some cases, especially with
D60294.
Most backends seems to not consider the exact VT in isLegalAddressingMode,
instead switching on type size. That is now what this does when the target does
not have an fpu (as the float data will be loaded using LDR's). i64's currently
use the address range of an LDRD (even though they may be legalised and loaded
with an LDR). This is at least better than marking them all as illegal
addressing modes.
I have not attempted to do much with vectors yet. That will need changing once
MVE is added.
Differential Revision: https://reviews.llvm.org/D60677
llvm-svn: 358845
Summary:
X86 is quite complicated; so I intend to leave it as is. ARM+Aarch64 do
basically the same thing (Aarch64 did not correctly handle immediates,
ARM has a test llvm/test/CodeGen/ARM/2009-04-06-AsmModifier.ll that uses
%a with an immediate) for a flag that should be target independent
anyways.
Reviewers: echristo, peter.smith
Reviewed By: echristo
Subscribers: javed.absar, eraman, kristof.beyls, hiraditya, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60841
llvm-svn: 358618
Summary:
None of these derived classes do anything that the base class cannot.
If we remove these case statements, then the base class can handle them
just fine.
Reviewers: peter.smith, echristo
Reviewed By: echristo
Subscribers: nemanjai, javed.absar, eraman, kristof.beyls, hiraditya, kbarton, jsji, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60803
llvm-svn: 358603
As discussed on PR41359, this patch renames the pair of shift-mask target feature functions to make their purposes more obvious.
shouldFoldShiftPairToMask -> shouldFoldConstantShiftPairToMask
preferShiftsToClearExtremeBits -> shouldFoldMaskToVariableShiftPair
llvm-svn: 358526
Because CodeGen can't depend on GlobalISel, we need a way to encapsulate the CSE
configs that can be passed between TargetPassConfig and the targets' custom
pass configs. This CSEConfigBase allows targets to create custom CSE configs
which is then used by the GISel passes for the CSEMIRBuilder.
This support will be used in a follow up commit to allow constant-only CSE for
-O0 compiles in D60580.
llvm-svn: 358368
Summary:
The InlineAsm::AsmDialect is only required for X86; no architecture
makes use of it and as such it gets passed around between arch-specific
and general code while being unused for all architectures but X86.
Since the AsmDialect is queried from a MachineInstr, which we also pass
around, remove the additional AsmDialect parameter and query for it deep
in the X86AsmPrinter only when needed/as late as possible.
This refactor should help later planned refactors to AsmPrinter, as this
difference in the X86AsmPrinter makes it harder to make AsmPrinter more
generic.
Reviewers: craig.topper
Subscribers: jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, llvm-commits, peter.smith, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60488
llvm-svn: 358101
Make it possible to TableGen code for FCONSTS and FCONSTD.
We need to make two changes to the TableGen descriptions of vfp_f32imm
and vfp_f64imm respectively:
* add GISelPredicateCode to check that the immediate fits in 8 bits;
* extract the SDNodeXForms into separate definitions and create a
GISDNodeXFormEquiv and a custom renderer function for each of them.
There's a lot of boilerplate to get the actual value of the immediate,
but it basically just boils down to calling ARM_AM::getFP32Imm or
ARM_AM::getFP64Imm.
llvm-svn: 358063
required to be passed as different register types. E.g. <2 x i16> may need to
be passed as a larger <2 x i32> type, so formal arg lowering needs to be able
truncate it back. Likewise, when dealing with returns of these types, they need
to be widened in the appropriate way back.
Differential Revision: https://reviews.llvm.org/D60425
llvm-svn: 358032
Create method `optForNone()` testing for the function level equivalent of
`-O0` and refactor appropriately.
Differential revision: https://reviews.llvm.org/D59852
llvm-svn: 357638
There's an existing optimization for x != C, but somehow it was missing
a special case for 0.
While I'm here, also cleaned up the code/comments a bit: the second
value produced by the MERGE_VALUES was actually dead, since a CMOV only
produces one result.
Differential Revision: https://reviews.llvm.org/D59616
llvm-svn: 357437
It's a little tricky to make this issue show up because
prologue/epilogue emission normally likes to push at least two
registers... but it doesn't when lr is force-spilled due to function
length. Not sure if that really makes sense, but I decided not to touch
it for now.
Differential Revision: https://reviews.llvm.org/D59385
llvm-svn: 357436
G_SELECT uses a 1-bit scalar for the condition, and is currently
implemented with a plain CMPri against 0. This means that values such as
0x1110 are interpreted as true, when instead the higher bits should be
treated as undefined and therefore ignored. Replace the CMPri with a
TSTri against 0x1, which performs an implicit AND, yielding the expected
result.
llvm-svn: 357153
The last reference to this function was removed from the ARM
td files in 2015 in rL225266.
Differential Revision: https://reviews.llvm.org/D59868
llvm-svn: 357130
ARMBaseInstrInfo::getNumLDMAddresses is making bad assumptions about the
memory operands of load and store-multiple operations. This doesn't
really fix the problem properly, but it's enough to prevent crashing,
at least.
Fixes https://bugs.llvm.org/show_bug.cgi?id=41231 .
Differential Revision: https://reviews.llvm.org/D59834
llvm-svn: 357109
This should hopefully lead to minor improvements in code generation, and
more accurate spill/reload comments in assembly.
Also fix isLoadFromStackSlotPostFE/isStoreToStackSlotPostFE so they
don't lead to misleading assembly comments for merged memory operands;
this is technically orthogonal, but in practice the relevant memory
operand lists don't show up without this change.
Differential Revision: https://reviews.llvm.org/D59713
llvm-svn: 356963
We currently use only VLDR/VSTR for all 64-bit loads/stores, so the
memory operands must be word-aligned. Mark aligned operations as legal
and narrow non-aligned ones to 32 bits.
While we're here, also mark non-power-of-2 loads/stores as unsupported.
llvm-svn: 356872
In r322972/r323136, the iteration here was changed to catch cases at the
beginning of a basic block... but we accidentally deleted an important
safety check. Restore that check to the way it was.
Fixes https://bugs.llvm.org/show_bug.cgi?id=41116
Differential Revision: https://reviews.llvm.org/D59680
llvm-svn: 356809
This doesn't have any practical effect at the moment, as far as I know,
because high registers aren't allocatable in Thumb1 mode. But it might
matter in the future.
Differential Revision: https://reviews.llvm.org/D59675
llvm-svn: 356791
This takes sequences like "mov r4, sp; str r0, [r4]", and optimizes them
to something like "str r0, [sp]".
For regular stack variables, this optimization was already implemented:
we lower loads and stores using frame indexes, which are expanded later.
However, when constructing a call frame for a call with more than four
arguments, the existing optimization doesn't apply. We need to use
stores which are actually relative to the current value of sp, and don't
have an associated frame index.
This patch adds a special case to handle that construct. At the DAG
level, this is an ISD::STORE where the address is a CopyFromReg from SP
(plus a small constant offset).
This applies only to Thumb1: in Thumb2 or ARM mode, a regular store
instruction can access SP directly, so the COPY gets eliminated by
existing code.
The change to ARMDAGToDAGISel::SelectThumbAddrModeSP is a related
cleanup: we shouldn't pretend that it can select anything other than
frame indexes.
Differential Revision: https://reviews.llvm.org/D59568
llvm-svn: 356601
This change does two things. One, it ensures compilation will abort
instead of miscompiling if ARMFrameLowering::determineCalleeSaves
chooses not to save LR in a case where it's necessary. Two, it changes
the way we estimate the size of a function to be more conservative in
the presence of constant pool entries and jump tables.
EstimateFunctionSizeInBytes probably still isn't really conservative
enough, but I'm not sure how we can come up with a reliable estimate
before constant islands runs.
Differential Revision: https://reviews.llvm.org/D59439
llvm-svn: 356527
These changes are related to PR37743 and include:
SelectionDAGBuilder::visitSelect handles the unary SelectPatternFlavor::SPF_ABS case to build ABS node.
Delete the redundant recognizer of the integer ABS pattern from the DAGCombiner.
Add promoting the integer ABS node in the LegalizeIntegerType.
Expand-based legalization of integer result for the ABS nodes.
Expand-based legalization of ABS vector operations.
Add some integer abs testcases for different typesizes for Thumb arch
Add the custom ABS expanding and change the SAD pattern recognizer for X86 arch: The i64 result of the ABS is expanded to:
tmp = (SRA, Hi, 31)
Lo = (UADDO tmp, Lo)
Hi = (XOR tmp, (ADDCARRY tmp, hi, Lo:1))
Lo = (XOR tmp, Lo)
The "detectZextAbsDiff" function is changed for the recognition of pattern with the ABS node. Given a ABS node, detect the following pattern:
(ABS (SUB (ZERO_EXTEND a), (ZERO_EXTEND b))).
Change integer abs testcases for codegen with the ABS node support for AArch64.
Indicate that the ABS is legal for the i64 type when the NEON is supported.
Change the integer abs testcases to show changing of codegen.
Add combine and legalization of ABS nodes for Thumb arch.
Extend 'matchSelectPattern' to recognize the ABS patterns with ICMP_SGE condition.
For discussion, see https://bugs.llvm.org/show_bug.cgi?id=37743
Patch by: @ikulagin (Ivan Kulagin)
Differential Revision: https://reviews.llvm.org/D49837
llvm-svn: 356468
This allows better code size for aarch64 floating point materialization
in a future patch.
Reviewers: evandro
Differential Revision: https://reviews.llvm.org/D58690
llvm-svn: 356389
I am about to introduce some non-power-of-2 width vector MVTs. This
commit fixes a power-of-2 assumption that my forthcoming change would
otherwise break, as shown by test/CodeGen/ARM/vcvt_combine.ll and
vdiv_combine.ll.
Differential Revision: https://reviews.llvm.org/D58927
Change-Id: I56a282e365d3874ab0621e5bdef98a612f702317
llvm-svn: 356341
The constant island pass currently only looks at the instruction immediately
before a branch for a CMP to fold into a CBZ/CBNZ. This extends it to search
backwards for the instruction that defines CPSR. We need to ensure that the
register is not overridden between the CMP and the branch.
Differential Revision: https://reviews.llvm.org/D59317
llvm-svn: 356336
tMOVr and tPUSH/tPOP/tPOP_RET have register constraints which can't be
expressed in TableGen, so check them explicitly. I've unfortunately run
into issues with both of these recently; hopefully this saves some time
for someone else in the future.
Differential Revision: https://reviews.llvm.org/D59383
llvm-svn: 356303
Bail early when we don't have a preheader and also if the target is
big endian because it's written with only little endian in mind!
Differential Revision: https://reviews.llvm.org/D59368
llvm-svn: 356243
When choosing whether a pair of loads can be combined into a single
wide load, we check that the load only has a sext user and that sext
also only has one user. But this can prevent the transformation in
the cases when parallel macs use the same loaded data multiple times.
To enable this, we need to fix up any other uses after creating the
wide load: generating a trunc and a shift + trunc pair to recreate
the narrow values. We also need to keep a record of which loads have
already been widened.
Differential Revision: https://reviews.llvm.org/D59215
llvm-svn: 356132
This patch adds an XCOFF triple object format type into LLVM.
This XCOFF triple object file type will be used later by object file and assembly generation for the AIX platform.
Differential Revision: https://reviews.llvm.org/D58930
llvm-svn: 355989
AMDGPU target run out of Subtarget feature flags hitting the limit of 64.
AssemblerPredicates uses at most uint64_t for their representation.
At the same time CodeGen has exhausted this a long time ago and switched
to a FeatureBitset with the current limit of 192 bits.
This patch completes transition to the bitset for feature bits extending
it to asm matcher and MC code emitter.
Differential Revision: https://reviews.llvm.org/D59002
llvm-svn: 355839
The indexed variant of vfmal.f16 and vfmsl.f16
instructions use the uppser bits of the indexed
operand to store the index (1 bit for the double
variant, 2 bits for the quad).
This limits the usable registers to d0 - d7 or
s0 - s15. This patch enforces this limitation.
Differential Revision: https://reviews.llvm.org/D59021
llvm-svn: 355707
Use this feature to fix a bug on ARM where 4 byte alignment is
incorrectly assumed.
Differential Revision: https://reviews.llvm.org/D57335
llvm-svn: 355685
Use this feature to fix a bug on ARM where 4 byte alignment is
incorrectly assumed.
Differential Revision: https://reviews.llvm.org/D57335
llvm-svn: 355585
Use this feature to fix a bug on ARM where 4 byte alignment is
incorrectly assumed.
Differential Revision: https://reviews.llvm.org/D57335
llvm-svn: 355522
This uses the infrastructure added in rL353152 to sink zext and sexts to
sub/add users, to enable vsubl/vaddl generation when NEON is available.
See https://bugs.llvm.org/show_bug.cgi?id=40025.
Reviewers: SjoerdMeijer, t.p.northover, samparker, efriedma
Reviewed By: samparker
Differential Revision: https://reviews.llvm.org/D58063
llvm-svn: 355460
When lowering a select_cc node where the true and false values are of type f16,
we can't use a general conditional move because the FP16 instructions do not
support conditional execution. Instead, we must ensure that the condition code
is one of the four supported by the VSEL instruction.
Differential revision: https://reviews.llvm.org/D58813
llvm-svn: 355385
The isScaledConstantInRange function takes upper and lower bounds which are
checked after dividing by the scale, so the bounds checks for half, single and
double precision should all be the same. Previously, we had wrong bounds checks
for half precision, so selected an immediate the instructions can't actually
represent.
Differential revision: https://reviews.llvm.org/D58822
llvm-svn: 355305
1) GCC complains that KnownValid is set but not used.
2) In ARMInstructionSelector::selectGlobal() the code is mixing "enumeral
and non-enumeral type in conditional expression". Solve this by casting
to unsigned which is the final type anyway.
Differential Revision: https://reviews.llvm.org/D58834
llvm-svn: 355304
The new addressing mode added for the v8.2A FP16 instructions uses bit 8 of the
immediate to encode the sign of the offset, like the other FP loads/stores, so
need to be treated the same way.
Differential revision: https://reviews.llvm.org/D58816
llvm-svn: 355201
This function was not checking for the condition code variants which are
undefined if either input is NaN, so we were missing selection of the VSEL
instruction in some cases when using -fno-honor-nans or -ffast-math.
Differential revision: https://reviews.llvm.org/D58812
llvm-svn: 355199
Summary:
The description of KnownBits::zext() and
KnownBits::zextOrTrunc() has confusingly been telling
that the operation is equivalent to zero extending the
value we're tracking. That has not been true, instead
the user has been forced to explicitly set the extended
bits as known zero afterwards.
This patch adds a second argument to KnownBits::zext()
and KnownBits::zextOrTrunc() to control if the extended
bits should be considered as known zero or as unknown.
Reviewers: craig.topper, RKSimon
Reviewed By: RKSimon
Subscribers: javed.absar, hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58650
llvm-svn: 355099
This gets rid of some duplication in the TableGen definition, but it
forces us to keep both a pointer and a reference to the subtarget in the
ARMInstructionSelector. That is pretty ugly but it might be a reasonable
trade-off, since the TableGen descriptions should outlive the code in
the selector (or in the worst case we can update to use just the
reference when we get rid of DAGISel).
Differential Revision: https://reviews.llvm.org/D58031
llvm-svn: 355083
Add the same level of support as for ARM mode (i.e. still no TLS
support).
In most cases, it is sufficient to replace the opcodes with the
t2-equivalent, but there are some idiosyncrasies that I decided to
preserve because I don't understand the full implications:
* For ARM we use LDRi12 to load from constant pools, but for Thumb we
use t2LDRpci (I'm not sure if the ideal would be to use t2LDRi12 for
Thumb as well, or to use LDRcp for ARM).
* For Thumb we don't have an equivalent for MOV|LDRLIT_ga_pcrel_ldr, so
we have to generate MOV|LDRLIT_ga_pcrel plus a load from GOT.
The tests are in separate files because they're hard enough to read even
without doubling the number of checks.
llvm-svn: 355077
The --disassembler-options, or -M, are used to customize
the disassembler and affect its output.
The two implemented options allow selecting register names on ARM:
* With -Mreg-names-raw, the disassembler uses rNN for all registers.
* With -Mreg-names-std it prints sp, lr and pc for r13, r14 and r15,
which is the default behavior of llvm-objdump.
Differential Revision: https://reviews.llvm.org/D57680
llvm-svn: 354870
As requested during review of D57601 <https://reviews.llvm.org/D57601> https://reviews.llvm.org/D57601, be equally conservative for atomic MMOs as for volatile MMOs in all in tree backends. At the moment, all atomic MMOs are also volatile, but I'm about to change that.
Differential Revision: https://reviews.llvm.org/D58490
Note: D58498 landed in several pieces as individual backends were approved. This is the last chunk.
llvm-svn: 354845
This adds a few extra Thumb1 opcodes to improve the peephole opimisers
ability to remove redundant cmp instructions. tADC and tSBC require
a small fixup to prevent MOVS being moved past the instruction, giving
the wrong flags.
Differential Revision: https://reviews.llvm.org/D58281
llvm-svn: 354791
More or less all the instructions defined in the v8.2a full-fp16
extension are defined as UNPREDICTABLE if you put them in an IT block
(Thumb) or use with any condition other than AL (ARM). LLVM didn't
know that, and was happy to conditionalise them.
In order to force these instructions to count as not predicable, I had
to make a small Tablegen change. The code generation back end mostly
decides if an instruction was predicable by looking for something it
can identify as a predicate operand; there's an isPredicable bit flag
that overrides that check in the positive direction, but nothing that
overrides it in the negative direction.
(I considered the alternative approach of actually removing the
predicate operand from those instructions, but thought that it would
be more painful overall for instructions differing only in data type
to have different shapes of operand list. This way, the only code that
has to notice the difference is the if-converter.)
So I've added an isUnpredicable bit alongside isPredicable, and set
that bit on the right subset of FP16 instructions, and also on the
VSEL, VMAXNM/VMINNM and VRINT[ANPM] families which should be
unpredicable for all data types.
I've included a couple of representative regression tests, both of
which previously caused an fp16 instruction to be conditionalised in
ARM state and (with -arm-no-restrict-it) to be put in an IT block in
Thumb.
Reviewers: SjoerdMeijer, t.p.northover, efriedma
Reviewed By: efriedma
Subscribers: jdoerfert, javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57823
llvm-svn: 354768
This adds a number of missing Thumb1 opcodes so that the peephole optimiser can
remove redundant CMP instructions.
Reapplying this after the first attempt broke non-thumb1 code as the t2ADDri
instruction can be used with frame indices. In thumb1 we use tADDframe.
Differential Revision: https://reviews.llvm.org/D57833
llvm-svn: 354667
This is exactly the same as arm mode, so for the instruction selector
tests we just extract them to a new file and run with the same checks
for both arm and thumb mode.
For the legalizer we need to update the tests for soft float a bit, but
only because BL and tBL are slightly different. We could be pedantic and
check that we get a well-formed BL for arm mode and a tBL for thumb, but
for the purposes of the legalizer test it's sufficient to just skip over
the predicate operands in the checks. Also note that we have the
pedantic checks in the divmod test, so we're covered.
llvm-svn: 354665
David Green