Try to fix bug 49974.
This patch fixes two issues:
1. BL does not use predicate (BL_pred is the predicate version of BL),
so we shouldn't add predicate operands in DecodeBranchImmInstruction.
2. Inside DecodeT2AddSubSPImm, we shouldn't add predicate operands into
the MCInst because ARMDisassembler::AddThumbPredicate will do that for us.
However, we should handle CC-out operand for t2SUBspImm and t2AddspImm.
Differential Revision: https://reviews.llvm.org/D100585
Summary:
This fixes Bugzilla #46616 in which it was reported
that "tbb [pc, r0]" was marked as SoftFail
(aka unpredictable) incorrectly.
Expected behaviour is:
* ARMv8 is required to use sp as rn or rm
(tbb/tbh only have a Thumb encoding so using Arm mode
is not an option)
* If rm is the pc then the instruction is always
unpredictable
Some of this was implemented already and this fixes the
rest. Added tests cover the new and pre-existing handling.
Reviewers: ostannard
Reviewed By: ostannard
Subscribers: kristof.beyls, hiraditya, danielkiss, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D84227
Vector bitwise selects are matched by pseudo VBSP instruction
and expanded to VBSL/VBIT/VBIF after register allocation
depend on operands registers to minimize extra copies.
This patch upstreams support for the Armv8.6-a Matrix Multiplication
Extension. A summary of the features can be found here:
https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a
This patch includes:
- Assembly support for AArch32 and Assembly Parsing
D77872 has already added the MC representations of the instructions so that
they can be used in code gen; this patch fills in the details needed to
make assembly parsing work, and adds tests for asm and disasm
This is part of a patch series, starting with BFloat16 support and
the other components in the armv8.6a extension (in previous patches
linked in phabricator)
Based on work by:
- Luke Geeson
- Oliver Stannard
- Luke Cheeseman
Reviewers: t.p.northover, simon_tatham
Reviewed By: simon_tatham
Subscribers: simon_tatham, ostannard, kristof.beyls, hiraditya,
danielkiss, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77874
From Arm v8 Architecture Reference Manual F5.1.84 LDREXD
The ldrexd instruction in Arm state has the following conditions:
t = UInt(Rt); t2 = t + 1; n = UInt(Rn);
if Rt<0> == '1' || t2 == 15 || n == 15 then UNPREDICTABLE;
In when Rt is odd or if Rt is 14 (making t2 15).
In the implementation when the pair is the UNPREDICTABLE R14_R15 we
would ideally return SOFT_FAIL. We can't because there is no R14_R15
value for us to return so we fail early returning FAIL.
The early return for registers outside the bounds of the table means
the check for Rt == 14 (0xE) redundant which causes a static analyzer
to flag the condition as never being true.
To fix the warning I've removed the check and replaced with a comment
explaining the difference with the specification.
Fixes pr41660
Differential Revision: https://reviews.llvm.org/D77463
Summary:
This patch introduces command-line support for the Armv8.6-a architecture and assembly support for BFloat16. Details can be found
https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a
in addition to the GCC patch for the 8..6-a CLI:
https://gcc.gnu.org/legacy-ml/gcc-patches/2019-11/msg02647.html
In detail this patch
- march options for armv8.6-a
- BFloat16 assembly
This is part of a patch series, starting with command-line and Bfloat16
assembly support. The subsequent patches will upstream intrinsics
support for BFloat16, followed by Matrix Multiplication and the
remaining Virtualization features of the armv8.6-a architecture.
Based on work by:
- labrinea
- MarkMurrayARM
- Luke Cheeseman
- Javed Asbar
- Mikhail Maltsev
- Luke Geeson
Reviewers: SjoerdMeijer, craig.topper, rjmccall, jfb, LukeGeeson
Reviewed By: SjoerdMeijer
Subscribers: stuij, kristof.beyls, hiraditya, dexonsmith, danielkiss, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D76062
Summary:
This patch adds assembly-level support for a new Arm M-profile
architecture extension, Custom Datapath Extension (CDE).
A brief description of the extension is available at
https://developer.arm.com/architectures/instruction-sets/custom-instructions
The latest specification for CDE is currently a beta release and is
available at
https://static.docs.arm.com/ddi0607/aa/DDI0607A_a_armv8m_arm_supplement_cde.pdf
CDE allows chip vendors to add custom CPU instructions. The CDE
instructions re-use the same encoding space as existing coprocessor
instructions (such as MRC, MCR, CDP etc.). Each coprocessor in range
cp0-cp7 can be configured as either general purpose (GCP) or custom
datapath (CDEv1). This configuration is defined by the CPU vendor and
is provided to LLVM using 8 subtarget features: cdecp0 ... cdecp7.
The semantics of CDE instructions are implementation-defined, but the
instructions are guaranteed to be pure (that is, they are stateless,
they do not access memory or any registers except their explicit
inputs/outputs).
CDE requires the CPU to support at least Armv8.0-M mainline
architecture. CDE includes 3 sets of instructions:
* Instructions that operate on general purpose registers and NZCV
flags
* Instructions that operate on the S or D register file (require
either FP or MVE extension)
* Instructions that operate on the Q register file, require MVE
The user-facing names that can be specified on the command line are
the same as the 8 subtarget feature names. For example:
$ clang -target arm-none-none-eabi -march=armv8m.main+cdecp0+cdecp3
tells the compiler that the coprocessors 0 and 3 are configured as
CDEv1 and the remaining coprocessors are configured as GCP (which is
the default).
Reviewers: simon_tatham, ostannard, dmgreen, eli.friedman
Reviewed By: simon_tatham
Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D74044
This adds some missing MVE opcodes to evaluateBranch, which results in
llvm-objdump being able to print the PC relative branch target as an
annotation.
Differential Revision: https://reviews.llvm.org/D73553
Summary:
This patch fixes pr23772 [ARM] r226200 can emit illegal thumb2 instruction: "sub sp, r12, #80".
The violation was that SUB and ADD (reg, immediate) instructions can only write to SP if the source register is also SP. So the above instructions was unpredictable.
To enforce that the instruction t2(ADD|SUB)ri does not write to SP we now enforce the destination register to be rGPR (That exclude PC and SP).
Different than the ARM specification, that defines one instruction that can read from SP, and one that can't, here we inserted one that can't write to SP, and other that can only write to SP as to reuse most of the hard-coded size optimizations.
When performing this change, it uncovered that emitting Thumb2 Reg plus Immediate could not emit all variants of ADD SP, SP #imm instructions before so it was refactored to be able to. (see test/CodeGen/Thumb2/mve-stacksplot.mir where we use a subw sp, sp, Imm12 variant )
It also uncovered a disassembly issue of adr.w instructions, that were only written as SUBW instructions (see llvm/test/MC/Disassembler/ARM/thumb2.txt).
Reviewers: eli.friedman, dmgreen, carwil, olista01, efriedma, andreadb
Reviewed By: efriedma
Subscribers: gbedwell, john.brawn, efriedma, ostannard, kristof.beyls, hiraditya, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70680
Summary:
This patch fixes pr23772 [ARM] r226200 can emit illegal thumb2 instruction: "sub sp, r12, #80".
The violation was that SUB and ADD (reg, immediate) instructions can only write to SP if the source register is also SP. So the above instructions was unpredictable.
To enforce that the instruction t2(ADD|SUB)ri does not write to SP we now enforce the destination register to be rGPR (That exclude PC and SP).
Different than the ARM specification, that defines one instruction that can read from SP, and one that can't, here we inserted one that can't write to SP, and other that can only write to SP as to reuse most of the hard-coded size optimizations.
When performing this change, it uncovered that emitting Thumb2 Reg plus Immediate could not emit all variants of ADD SP, SP #imm instructions before so it was refactored to be able to. (see test/CodeGen/Thumb2/mve-stacksplot.mir where we use a subw sp, sp, Imm12 variant )
It also uncovered a disassembly issue of adr.w instructions, that were only written as SUBW instructions (see llvm/test/MC/Disassembler/ARM/thumb2.txt).
Reviewers: eli.friedman, dmgreen, carwil, olista01, efriedma
Reviewed By: efriedma
Subscribers: john.brawn, efriedma, ostannard, kristof.beyls, hiraditya, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70680
The family of 'dual-accumulating' vector multiply-add instructions
(VMLADAV, VMLALDAV and VRMLALDAVH) can all operate on both signed and
unsigned integer types, and they all have an 'exchange' variant (with
an X in the name) that modifies which pairs of vector lanes in the two
inputs are multiplied together. But there's a clause in the spec that
says that the X variants //don't// operate on unsigned integer types,
only signed. You can have X, or unsigned, or neither, but not both.
We didn't notice that clause when we implemented the MC support for
these instructions, so LLVM believes that things like VMLADAVX.U8 do
exist, contradicting the spec. Here I fix that by conditioning them
out in Tablegen.
In order to do that, I've reversed the nesting order of the Tablegen
multiclasses for those instructions. Previously, the innermost
multiclass generated the X and not-X variants, and the one outside
that generated the A and not-A variants. Now X is done by the outer
multiclass, which allows me to bypass that one when I only want the
two not-X variants.
Changing the multiclass nesting order also changes the names of the
instruction ids unless I make a special effort not to. I decided that
while I was changing them anyway I'd make them look nicer; so now the
instructions have names like MVE_VMLADAVs32 or MVE_VMLADAVaxs32,
instead of cumbersome _noacc_noexch suffixes.
The corresponding multiply-subtract instructions are unaffected. Those
don't accept unsigned types at all, either in the spec or in LLVM.
Reviewers: ostannard, dmgreen
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67214
llvm-svn: 371405
Specify the Unpredictable bits, and return softfails when appropriate.
Patch by Mark Murray!
Differential revision: https://reviews.llvm.org/D66939
llvm-svn: 371374
Decoding of VMSR doesn't diagnose some unpredictable encodings, as the unpredictable bits are not correctly set.
Diff-reduce this instruction's internals WRT VMRS so I can see the differences better. Mostly this is s/src/Rt/g.
Fill in the "should-be-(0)" bits.
Designate the Unpredictable{} bits for both VMRS and VMSR.
Patch by Mark Murray!
Differential revision: https://reviews.llvm.org/D66938
llvm-svn: 370729
Summary:
According to the Armv8.1-M manual CSEL, CSINC, CSINV and CSNEG are
"constrained unpredictable" when SP is used as the source register Rn.
The assembler should diagnose this case.
Reviewers: momchil.velikov, dmgreen, ostannard, simon_tatham, t.p.northover
Reviewed By: ostannard
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65505
llvm-svn: 367433
Summary:
According to the new Armv8-M specification
https://static.docs.arm.com/ddi0553/bh/DDI0553B_h_armv8m_arm.pdf the
instructions SQRSHRL and UQRSHLL now have an additional immediate
operand <saturate>. The new assembly syntax is:
SQRSHRL<c> RdaLo, RdaHi, #<saturate>, Rm
UQRSHLL<c> RdaLo, RdaHi, #<saturate>, Rm
where <saturate> can be either 64 (the existing behavior) or 48, in
that case the result is saturated to 48 bits.
The new operand is encoded as follows:
#64 Encoded as sat = 0
#48 Encoded as sat = 1
sat is bit 7 of the instruction bit pattern.
This patch adds a new assembler operand class MveSaturateOperand which
implements parsing and encoding. Decoding is implemented in
DecodeMVEOverlappingLongShift.
Reviewers: ostannard, simon_tatham, t.p.northover, samparker, dmgreen, SjoerdMeijer
Reviewed By: simon_tatham
Subscribers: javed.absar, kristof.beyls, hiraditya, pbarrio, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64810
llvm-svn: 366555
The VQDMLAH.U8, VQDMLAH.U16 and VQDMLAH.U32 instructions don't
actually exist: the Armv8.1-M architecture spec only lists signed
forms of that instruction. The unsigned ones were added in error: they
existed in an early draft of the spec, but they were removed before
the public version, and we missed that particular spec change.
Also affects the variant forms VQDMLASH, VQRDMLAH and VQRDMLASH.
Reviewers: miyuki
Subscribers: javed.absar, kristof.beyls, hiraditya, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64502
llvm-svn: 365747
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
This adds some extra RUN lines to existing test files, to check that
things that worked in previous architecture versions haven't
accidentally stopped working in 8.1-M. Also we add some new tests: a
test of scalar floating point instructions that could be easily
confused with the similar-looking vector ones at assembly time, a test
of basic load/store/move access to the FP registers (which has to work
even in integer-only MVE); and one final check of the really obvious
case where turning off MVE should make sure MVE instructions really
are rejected.
Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover
Subscribers: javed.absar, kristof.beyls, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62682
llvm-svn: 364293
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
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
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
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
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
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
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
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
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
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 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
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
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
Igor Kudrin