This adds the CostKind to getMVEVectorCostFactor, so that it can
automatically account for CodeSize costs, where it returns a cost of 1
not the MVEFactor used for Throughput/Latency. This helps simplify the
caller code and allows us to get the codesize cost more correct in more
cases.
In the tablegen architecture definition, the Name field for the
ARMv87a record read "ARMv86a". All the other records contain their own
names.
Corrected it to "ARMv87a", and added the necessary value in
ARMArchEnum for that to refer to.
Reviewed By: pratlucas
Differential Revision: https://reviews.llvm.org/D96493
This patch upstreams support for the Armv8-a Cortex-A78C
processor for AArch64 and ARM.
In detail:
Adding cortex-a78c as cpu option for aarch64 and arm targets in clang
Adding Cortex-A78C CPU name and ProcessorModel in llvm
Details of the CPU can be found here:
https://www.arm.com/products/silicon-ip-cpu/cortex-a/cortex-a78c
Adds ARMBankConflictHazardRecognizer. This hazard recognizer
looks for a few situations where the same base pointer is used and
then checks whether the offsets lead to a bank conflict. Two
parameters are also added to permit overriding of the target
assumptions:
arm-data-bank-mask=<int> - Mask of bits which are to be checked for
conflicts. If all these bits are equal in the offsets, there is a
conflict.
arm-assume-itcm-bankconflict=<bool> - Assume that there will be bank
conflicts on any loads to a constant pool.
This hazard recognizer is enabled for Cortex-M7, where the Technical
Reference Manual states that there are two DTCM banks banked using bit
2 and one ITCM bank.
Differential Revision: https://reviews.llvm.org/D93054
To make sure that no barrier gets placed on the architectural execution
path, each indirect call calling the function in register rN, it gets
transformed to a direct call to __llvm_slsblr_thunk_mode_rN. mode is
either arm or thumb, depending on the mode of where the indirect call
happens.
The llvm_slsblr_thunk_mode_rN thunk contains:
bx rN
<speculation barrier>
Therefore, the indirect call gets split into 2; one direct call and one
indirect jump.
This transformation results in not inserting a speculation barrier on
the architectural execution path.
The mitigation is off by default and can be enabled by the
harden-sls-blr subtarget feature.
As a linker is allowed to clobber r12 on function calls, the
above code transformation is not correct in case a linker does so.
Similarly, the transformation is not correct when register lr is used.
Avoiding r12/lr being used is done in a follow-on patch to make
reviewing this code easier.
Differential Revision: https://reviews.llvm.org/D92468
Some processors may speculatively execute the instructions immediately
following indirect control flow, such as returns, indirect jumps and
indirect function calls.
To avoid a potential miss-speculatively executed gadget after these
instructions leaking secrets through side channels, this pass places a
speculation barrier immediately after every indirect control flow where
control flow doesn't return to the next instruction, such as returns and
indirect jumps, but not indirect function calls.
Hardening of indirect function calls will be done in a later,
independent patch.
This patch is implementing the same functionality as the AArch64 counter
part implemented in https://reviews.llvm.org/D81400.
For AArch64, returns and indirect jumps only occur on RET and BR
instructions and hence the function attribute to control the hardening
is called "harden-sls-retbr" there. On AArch32, there is a much wider
variety of instructions that can trigger an indirect unconditional
control flow change. I've decided to stick with the name
"harden-sls-retbr" as introduced for the corresponding AArch64
mitigation.
This patch implements this for ARM mode. A future patch will extend this
to also support Thumb mode.
The inserted barriers are never on the correct, architectural execution
path, and therefore performance overhead of this is expected to be low.
To ensure these barriers are never on an architecturally executed path,
when the harden-sls-retbr function attribute is present, indirect
control flow is never conditionalized/predicated.
On targets that implement that Armv8.0-SB Speculation Barrier extension,
a single SB instruction is emitted that acts as a speculation barrier.
On other targets, a DSB SYS followed by a ISB is emitted to act as a
speculation barrier.
These speculation barriers are implemented as pseudo instructions to
avoid later passes to analyze them and potentially remove them.
The mitigation is off by default and can be enabled by the
harden-sls-retbr subtarget feature.
Differential Revision: https://reviews.llvm.org/D92395
This introduces support for the v8.7-A architecture through a new
subtarget feature called "v8.7a". It adds two new "WFET" and "WFIT"
instructions, the nXS limited-TLB-maintenance qualifier for DSB and TLBI
instructions, a new CPU id register, ID_AA64ISAR2_EL1, and the new
HCRX_EL2 system register.
Based on patches written by Simon Tatham and Victor Campos.
Reviewed By: ostannard
Differential Revision: https://reviews.llvm.org/D91772
Add support for the Neoverse V1 CPU to the ARM and AArch64 backends.
This is based on patches from Mark Murray and Victor Campos.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D90765
This patch implements initial backend support for a -mtune CPU controlled by a "tune-cpu" function attribute. If the attribute is not present X86 will use the resolved CPU from target-cpu attribute or command line.
This patch adds MC layer support a tune CPU. Each CPU now has two sets of features stored in their GenSubtargetInfo.inc tables . These features lists are passed separately to the Processor and ProcessorModel classes in tablegen. The tune list defaults to an empty list to avoid changes to non-X86. This annoyingly increases the size of static tables on all target as we now store 24 more bytes per CPU. I haven't quantified the overall impact, but I can if we're concerned.
One new test is added to X86 to show a few tuning features with mismatched tune-cpu and target-cpu/target-feature attributes to demonstrate independent control. Another new test is added to demonstrate that the scheduler model follows the tune CPU.
I have not added a -mtune to llc/opt or MC layer command line yet. With no attributes we'll just use the -mcpu for both. MC layer tools will always follow the normal CPU for tuning.
Differential Revision: https://reviews.llvm.org/D85165
This patch upstreams support for the Arm-v8 Cortex-A78 and Cortex-X1
processors for AArch64 and ARM.
In detail:
- Adding cortex-a78 and cortex-x1 as cpu options for aarch64 and arm targets in clang
- Adding Cortex-A78 and Cortex-X1 CPU names and ProcessorModels in llvm
details of the CPU can be found here:
https://www.arm.com/products/cortex-xhttps://www.arm.com/products/silicon-ip-cpu/cortex-a/cortex-a78
The following people contributed to this patch:
- Luke Geeson
- Mikhail Maltsev
Reviewers: t.p.northover, dmgreen
Reviewed By: dmgreen
Subscribers: dmgreen, kristof.beyls, hiraditya, danielkiss, cfe-commits,
llvm-commits, miyuki
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D83206
This patch upstreams support for the Arm-v8 Cortex-A77
processor for AArch64 and ARM.
In detail:
- Adding cortex-a77 as a cpu option for aarch64 and arm targets in clang
- Cortex-A77 CPU name and ProcessorModel in llvm
details of the CPU can be found here:
https://www.arm.com/products/silicon-ip-cpu/cortex-a/cortex-a77
and a similar submission to GCC can be found here:
e0664b7a63
The following people contributed to this patch:
- Luke Geeson
- Mikhail Maltsev
Reviewers: t.p.northover, dmgreen, ostannard, SjoerdMeijer
Reviewed By: dmgreen
Subscribers: dmgreen, kristof.beyls, hiraditya, danielkiss, cfe-commits,
llvm-commits, miyuki
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D82887
This patch adds basic support for BFloat in the Arm backend.
For now the code generation relies on fullfp16 being present.
Briefly:
* adds the bfloat scalar and vector types in the necessary register classes,
* adjusts the calling convention to cope with bfloat argument passing and return,
* adds codegen patterns for moves, loads and stores.
It's tested mostly by the intrinsic patches that depend on it (load/store, convert/copy).
The following people contributed to this patch:
* Alexandros Lamprineas
* Ties Stuij
Differential Revision: https://reviews.llvm.org/D81373
Replace with forward declaration and move dependency down to source files that actually need it.
Both TargetLowering.h and TargetMachine.h are 2 of the most expensive headers (top 10) in the ClangBuildAnalyzer report when building llc.
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
- Intrinsics Support for AArch32 Neon Intrinsics for Matrix
Multiplication
Note: these extensions are optional in the 8.6a architecture and so have
to be enabled by default
No additional IR types or C Types are needed for this extension.
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, miyuki
Reviewed By: miyuki
Subscribers: miyuki, ostannard, kristof.beyls, hiraditya, danielkiss,
cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77872
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 extra scalar handling to isFMAFasterThanFMulAndFAdd, allowing
the target independent code to handle more folds in more situations (for
example if the fast math flags are present, but the global
AllowFPOpFusion option isnt). It also splits apart the HasSlowFPVMLx
into HasSlowFPVFMx, to allow VFMA and VMLA to be controlled separately
if needed.
Differential Revision: https://reviews.llvm.org/D72139
Provides support for using r6-r11 as globally scoped
register variables. This requires a -ffixed-rN flag
in order to reserve rN against general allocation.
If for a given GRV declaration the corresponding flag
is not found, or the the register in question is the
target's FP, we fail with a diagnostic.
Differential Revision: https://reviews.llvm.org/D68862
During register coalescing, we update the live-intervals on-the-fly.
To do that we are in this strange mode where the live-intervals can
be slightly out-of-sync (more precisely they are forward looking)
compared to what the IR actually represents.
This happens because the register coalescer only updates the IR when
it is done with updating the live-intervals and it has to do it this
way because updating the IR on-the-fly would actually clobber some
information on how the live-ranges that are being updated look like.
This is problematic for updates that rely on the IR to accurately
represents the state of the live-ranges. Right now, we have only
one of those: stripValuesNotDefiningMask.
To reconcile this need of out-of-sync IR, this patch introduces a
new argument to LiveInterval::refineSubRanges that allows the code
doing the live range updates to reason about how the code should
look like after the coalescer will have rewritten the registers.
Essentially this captures how a subregister index with be offseted
to match its position in a new register class.
E.g., let say we want to merge:
V1.sub1:<2 x s32> = COPY V2.sub3:<4 x s32>
We do that by choosing a class where sub1:<2 x s32> and sub3:<4 x s32>
overlap, i.e., by choosing a class where we can find "offset + 1 == 3".
Put differently we align V2's sub3 with V1's sub1:
V2: sub0 sub1 sub2 sub3
V1: <offset> sub0 sub1
This offset will look like a composed subregidx in the the class:
V1.(composed sub2 with sub1):<4 x s32> = COPY V2.sub3:<4 x s32>
=> V1.(composed sub2 with sub1):<4 x s32> = COPY V2.sub3:<4 x s32>
Now if we didn't rewrite the uses and def of V1, all the checks for V1
need to account for this offset to match what the live intervals intend
to capture.
Prior to this patch, we would fail to recognize the uses and def of V1
and would end up with machine verifier errors: No live segment at def.
This could lead to miscompile as we would drop some live-ranges and
thus, miss some interferences.
For this problem to trigger, we need to reach stripValuesNotDefiningMask
while having a mismatch between the IR and the live-ranges (i.e.,
we have to apply a subreg offset to the IR.)
This requires the following three conditions:
1. An update of overlapping subreg lanes: e.g., dsub0 == <ssub0, ssub1>
2. An update with Tuple registers with a possibility to coalesce the
subreg index: e.g., v1.dsub_1 == v2.dsub_3
3. Subreg liveness enabled.
looking at the IR to decide what is alive and what is not, i.e., calling
stripValuesNotDefiningMask.
coalescer maintains for the live-ranges information.
None of the targets that currently use subreg liveness (i.e., the targets
that fulfill #3, Hexagon, AMDGPU, PowerPC, and SystemZ IIRC) expose #1 and
and #2, so this patch also artificial enables subreg liveness for ARM,
so that a nice test case can be attached.
This feature controls whether AA is used into the backend, and was
previously turned on for certain subtargets to help create less
constrained scheduling graphs. This patch turns it on for all
subtargets, so that they can all make use of the extra information to
produce better code.
Differential Revision: https://reviews.llvm.org/D69796
In the ARM backend, for historical reasons we have only some targets
using Machine Scheduling. The rest use the old list scheduler as they
are using itinaries and the list scheduler seems to produce better code
(and not crash running out of register on v6m codes). So whether to use
the MIScheduler or not is checked at runtime from the subtarget
features.
This is fine, except for post-ra scheduling. Whether to use the old
post-ra list scheduler or the post-ra machine schedule is decided as the
pass manager is set up, in arms case from a newly constructed subtarget.
Under some situations, like LTO, this won't include the correct cpu so
can pick the wrong option. This can have a surprising effect on
performance.
To fix that, this patch overrides targetSchedulesPostRAScheduling and
addPreSched2 in the ARM backend, adding _both_ post-ra schedulers and
picking at runtime which to execute. To pick between the two I've had to
add a enablePostRAMachineScheduler() method that normally returns
enableMachineScheduler() && enablePostRAScheduler(), which can be
overridden to enable just one of PostRAMachineScheduler vs
PostRAScheduler.
Thanks to David Penry for the identifying this problem.
Differential Revision: https://reviews.llvm.org/D69775
This lowers a sadd_sat to a qadd by treating it as legal. Also adds qsub at the
same time.
The qadd instruction sets the q flag, but we already have many cases where we
do not model this in llvm.
Differential Revision: https://reviews.llvm.org/D68976
llvm-svn: 375411
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68993
llvm-svn: 375084
r361845 changed the way we handle "D16" vs. "D32" targets; there used to
be a negative "d16" which removed instructions from the instruction set,
and now there's a "d32" feature which adds instructions to the
instruction set. This is good, but there was an oversight in the
implementation: the behavior of VFPv2 was changed. In particular, the
"vfp2" feature was changed to imply "d32". This is wrong: VFPv2 only
supports 16 D registers.
In practice, this means if you specify -mfpu=vfpv2, the compiler will
generate illegal instructions.
This patch gets rid of "vfp2d16" and "vfp2d16sp", and fixes "vfp2" and
"vfp2sp" so they don't imply "d32".
Differential Revision: https://reviews.llvm.org/D67375
llvm-svn: 372186
Summary:
This patch renames functions that takes or returns alignment as log2, this patch will help with the transition to llvm::Align.
The renaming makes it explicit that we deal with log(alignment) instead of a power of two alignment.
A few renames uncovered dubious assignments:
- `MirParser`/`MirPrinter` was expecting powers of two but `MachineFunction` and `MachineBasicBlock` were using deal with log2(align). This patch fixes it and updates the documentation.
- `MachineBlockPlacement` exposes two flags (`align-all-blocks` and `align-all-nofallthru-blocks`) supposedly interpreted as power of two alignments, internally these values are interpreted as log2(align). This patch updates the documentation,
- `MachineFunctionexposes` exposes `align-all-functions` also interpreted as power of two alignment, internally this value is interpreted as log2(align). This patch updates the documentation,
Reviewers: lattner, thegameg, courbet
Subscribers: dschuff, arsenm, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, Jim, s.egerton, llvm-commits, courbet
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65945
llvm-svn: 371045
The MVE architecture has the idea of "beats", where a vector instruction can be
executed over several ticks of the architecture. This adds a similar system
into the Arm backend cost model, multiplying the cost of all vector
instructions by a factor.
This factor essentially becomes the expected difference between scalar code
and vector code, on average. MVE Vector instructions can also overlap so the a
true cost of them is often lower. But equally scalar instructions can in some
situations be dual issued, or have other optimisations such as unrolling or
make use of dsp instructions. The default is chosen as 2. This should not
prevent vectorisation is a most cases (as the vector instructions will still be
doing at least 4 times the work), but it will help prevent over vectorising in
cases where the benefits are less likely.
This adds things so far to the obvious places in ARMTargetTransformInfo, and
updates a few related costs like not treating float instructions as cost 2 just
because they are floats.
Differential Revision: https://reviews.llvm.org/D66005
llvm-svn: 368733
Currently we can't keep any state in the selector object that we get from
subtarget. As a result we have to plumb through all our variables through
multiple functions. This change makes it non-const and adds a virtual init()
method to allow further state to be captured for each target.
AArch64 makes use of this in this patch to cache a call to hasFnAttribute()
which is expensive to call, and is used on each selection of G_BRCOND.
Differential Revision: https://reviews.llvm.org/D65984
llvm-svn: 368652
For Thumb2, we prefer low regs (costPerUse = 0) to allow narrow
encoding. However, current allocation order is like:
R0-R3, R12, LR, R4-R11
As a result, a lot of instructs that use R12/LR will be wide instrs.
This patch changes the allocation order to:
R0-R7, R12, LR, R8-R11
for thumb2 and -Osize.
In most cases, there is no extra push/pop instrs as they will be folded
into existing ones. There might be slight performance impact due to more
stack usage, so we only enable it when opt for min size.
https://reviews.llvm.org/D30324
llvm-svn: 365014
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
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
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
In many places in the backend, we like to know whether we're
optimising for code size and this is performed by checking the
current machine function attributes. A subtarget is created on a
per-function basis, so it's possible to know when we're compiling for
code size on construction so record this in the new object.
Differential Revision: https://reviews.llvm.org/D57812
llvm-svn: 353501
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
SB (Speculative Barrier) is only mandatory from 8.5
onwards but is optional from Armv8.0-A. This patch adds a command
line option to enable SB, as it was previously only possible to
enable by selecting -march=armv8.5-a.
This patch also renames FeatureSpecRestrict to FeatureSB.
Reviewed By: olista01, LukeCheeseman
Differential Revision: https://reviews.llvm.org/D55990
llvm-svn: 350299
This is a new barrier which limits speculative execution of the
instructions following it.
Patch by Pablo Barrio!
Differential revision: https://reviews.llvm.org/D52477
llvm-svn: 343213
This patch allows targeting Armv8.5-A, adding the architecture to
tablegen and setting the options to be identical to Armv8.4-A for the
time being. Subsequent patches will add support for the different
features included in the Armv8.5-A Reference Manual.
Patch by Pablo Barrio!
Differential revision: https://reviews.llvm.org/D52470
llvm-svn: 343102
The Technical Reference Manuals for these two CPUs state that branching
to an unaligned 32-bit instruction incurs an extra pipeline reload
penalty. That's bad.
This also enables the optimization at -Os since it costs on average one
byte per loop in return for 1 cycle per iteration, which is pretty good
going.
llvm-svn: 342127
Add +fp16fml feature for new FP16 instructions, which are a
mandatory part of FP16 from v8.4-A and an optional part of FP16
from v8.2-A. It doesn't seem to be possible to model this in
LLVM, but the relationship between the options is handled by
the related clang patch.
In keeping with what I think is the usual practice, the fp16fml
extension is accepted regardless of base architecture version.
Builds on/replaces Sjoerd Meijer's patch to add these instructions at
https://reviews.llvm.org/D49839.
Differential Revision: https://reviews.llvm.org/D50228
llvm-svn: 340013
This feature enables the fusion of such operations on Cortex A57 and Cortex
A72, as recommended in their Software Optimisation Guides, sections 4.14 and
4.11, respectively.
Differential revision: https://reviews.llvm.org/D49563
llvm-svn: 338147
Enable the optimization of operations on DPR and SPR via a feature instead
of checking the target.
Differential revision: https://reviews.llvm.org/D49463
llvm-svn: 337575
David Green