Commit Graph

4243 Commits

Author SHA1 Message Date
Cullen Rhodes 8a397b66b2 [AArch64][SVE] Add support for spilling/filling ZPR2/3/4
Summary:
This patch enables the register allocator to spill/fill lists of 2, 3
and 4 SVE vectors registers to/from the stack. This is implemented with
pseudo instructions that get expanded to individual LDR_ZXI/STR_ZXI
instructions in AArch64ExpandPseudoInsts.

Patch by Sander de Smalen.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D75988
2020-05-28 10:02:57 +00:00
Ties Stuij 78bd0c0e5e [AArch64][BFloat] add BFloat instruction support for AArch64
Summary:
Add support for lowering various BFloat related SelDAG nodes:
- load/store (ldrh/strh)
- concat
- dup/duplane
- bitconvert/bitcast
- insert_subvector/insert_subreg

This patch is part of a series implementing the Bfloat16 extension of the
Armv8.6-a architecture, as detailed here:

https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a

The bfloat type, and its properties are specified in the Arm Architecture
Reference Manual:

https://developer.arm.com/docs/ddi0487/latest/arm-architecture-reference-manual-armv8-for-armv8-a-architecture-profile

Reviewers: ab, t.p.northover, john.brawn, fpetrogalli, sdesmalen, LukeGeeson

Reviewed By: fpetrogalli

Subscribers: LukeGeeson, pbarrio, kristof.beyls, hiraditya, danielkiss, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79712
2020-05-27 15:36:54 +01:00
Ties Stuij 42eba9b40b [AArch64][BFloat] basic AArch64 bfloat support
Summary:
This patch adds the bfloat type to the AArch64 backend:
- adds it as part of the FPR16 register class
- adds bfloat calling conventions
- as f16 is now not the only FPR16 type anymore, we need to constrain a number
  of instruction patterns using FPR16Op to help out the TableGen type inferrer

This patch is part of a series implementing the Bfloat16 extension of the
Armv8.6-a architecture, as detailed here:

https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a

The bfloat type, and its properties are specified in the Arm Architecture
Reference Manual:

https://developer.arm.com/docs/ddi0487/latest/arm-architecture-reference-manual-armv8-for-armv8-a-architecture-profile

Reviewers: t.p.northover, c-rhodes, fpetrogalli, sdesmalen, ostannard, LukeGeeson, ab

Reviewed By: fpetrogalli

Subscribers: pbarrio, LukeGeeson, kristof.beyls, hiraditya, danielkiss, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79709
2020-05-27 15:26:40 +01:00
Jessica Paquette ae597a771e [AArch64][GlobalISel] Do not modify predicate when optimizing G_ICMP
This fixes a bug in `tryOptArithImmedIntegerCompare`.

It is unsafe to update the predicate on a MachineOperand when optimizing a
G_ICMP, because it may be used in more than one place.

For example, when we are optimizing G_SELECT, we allow compares which are used
in more than one G_SELECT. If we modify the G_ICMP, then we'll break one of
the G_SELECTs.

Since the compare is being produced to either

1) Select a G_ICMP
2) Fold a G_ICMP into an instruction when profitable

there's no reason to actually modify it. The change is local to the specific
compare.

Instead, pass a `CmpInst::Predicate` to `tryOptArithImmedIntegerCompare` which
can be modified by reference.

Differential Revision: https://reviews.llvm.org/D80585
2020-05-26 17:51:08 -07:00
Matt Arsenault 8bc03d2168 GlobalISel: Merge G_PTR_MASK with llvm.ptrmask intrinsic
Confusingly, these were unrelated and had different semantics. The
G_PTR_MASK instruction predates the llvm.ptrmask intrinsic, but has a
different format. G_PTR_MASK only allows clearing the low bits of a
pointer, and only a constant number of bits. The ptrmask intrinsic
allows an arbitrary mask. Replace G_PTR_MASK to match the intrinsic.

Only selects the cases that look like the old instruction. More work
is needed to select the general case. Also new legalization code is
still needed to deal with the case where the incoming mask size does
not match the pointer size, which has a specified behavior in the
langref.
2020-05-26 11:48:13 -04:00
Sam Parker 8aaabadece [CostModel] Unify getCastInstrCost
Add the remaining cast instruction opcodes to the base implementation
of getUserCost and directly return the result. This allows
getInstructionThroughput to return getUserCost for the casts. This
has required changes to PPC and SystemZ because they implement
getUserCost and/or getCastInstrCost with adjustments for vector
operations. Adjusts have also been made in the remaining backends
that implement the method so that they still produce a cost of zero
or one for cost kinds other than throughput.

Differential Revision: https://reviews.llvm.org/D79848
2020-05-26 11:29:57 +01:00
Craig Topper 80cc43b420 [AArch64] Set i32 ISD::MULHU/S to Expand instead of Legal.
Looks like there are no isel patterns for these. A DAG combine
turns it into i64 multiply and a shift which hides this.

Extracted from D80485
2020-05-26 00:41:09 -07:00
Sanjay Patel 7eed772a27 [PatternMatch] abbreviate vector inst matchers; NFC
Readability is not reduced with these opcodes/match lines,
so reduce odds of awkward wrapping from 80-col limit.
2020-05-24 09:19:47 -04:00
Amara Emerson 99660217e9 [AArch64][GlobalISel] When generating SUBS for compares, don't write to wzr/xzr.
Although writing to wzr/xzr is correct since we don't care about the result
of the sub, only the flags, doing so causes tail merge blocks to fail.

Writing to an unused virtual register instead allows the optimization to fire,
improving performance significantly on 256.bzip2.

Differential Revision: https://reviews.llvm.org/D80460
2020-05-23 22:59:49 -07:00
Fangrui Song 0840d725c4 [MC] Change MCCFIInstruction::createDefCfaOffset to cfiDefCfaOffset which does not negate Offset
The negative Offset has caused a bunch of problems and confused quite a
few call sites. Delete the unneeded negation and fix all call sites.
2020-05-22 17:07:11 -07:00
Fangrui Song 7e49dc6184 [MC] Change MCCFIInstruction::createDefCfa to cfiDefCfa which does not negate Offset
The negative Offset has caused a bunch of problems and confused quite a
few call sites. Delete the unneeded negation and fix all call sites.
2020-05-22 15:47:26 -07:00
Jessica Paquette 49a4f3f7d8 [AArch64][GlobalISel] Add a post-legalizer combiner with a very simple combine.
(This patch is by Jessica, I'm just committing it on her behalf because I need
a post-legalizer combiner for something else).

This supersedes D77250, which did equivalent work in the selector. This can be
done pre-legalization or post-legalization. Post-legalization is more likely to
hit, since G_IMPLICIT_DEFs tend to appear during legalization. There's no reason
to not do it pre-legalization though-- if it can be caught earlier, great.

(I also think that it might be worth reimplementing D78769 using a
target-specific post-legalization combine too after thinking about it for a
while.)

Differential Revision: https://reviews.llvm.org/D78852
2020-05-21 18:47:32 -07:00
Alexey Lapshin bf242c067e [AARCH64][NEON] Allow to sink operands of aarch64_neon_pmull64.
Summary:
This patch fixes a problem when pmull2 instruction is not
generated for vmull_high_p64 intrinsic.

ISel has a pattern for int_aarch64_neon_pmull64 intrinsic to generate
PMULL2 instruction. That pattern assumes that extraction operations
are located in the same basic block. We need to sink them
if they are not. Handle operands of int_aarch64_neon_pmull64
into AArch64TargetLowering::shouldSinkOperands.

Reviewed by: efriedma

Differential Revision: https://reviews.llvm.org/D80320
2020-05-22 01:35:24 +03:00
Eli Friedman f09d220c71 [AArch64][SVE] Fill out missing unpredicated load/store patterns.
The set of patterns for unpredicated load/store was incomplete: it only
included non-extending stores.  Fill out the remaining patterns for
extending stores, and add the corresponding support to frame offset
lowering.

Differential Revision: https://reviews.llvm.org/D80349
2020-05-21 13:29:30 -07:00
Eli Friedman b4f9b34701 [AArch64] Fix unwind info generated by outliner.
The offsets were wrong. The result is now the same as what the compiler
would generate for a function that spills lr normally.

Differential Revision: https://reviews.llvm.org/D80238
2020-05-20 16:39:00 -07:00
Eli Friedman f26bdb539e Make Value::getPointerAlignment() return an Align, not a MaybeAlign.
If we don't know anything about the alignment of a pointer, Align(1) is
still correct: all pointers are at least 1-byte aligned.

Included in this patch is a bugfix for an issue discovered during this
cleanup: pointers with "dereferenceable" attributes/metadata were
assumed to be aligned according to the type of the pointer.  This
wasn't intentional, as far as I can tell, so Loads.cpp was fixed to
stop making this assumption. Frontends may need to be updated.  I
updated clang's handling of C++ references, and added a release note for
this.

Differential Revision: https://reviews.llvm.org/D80072
2020-05-20 16:37:20 -07:00
Francis Visoiu Mistrih 161122ea1c [AArch64] Provide Darwin variants of most calling conventions
With the new SVE stack layout, we now need to provide a Darwin variant
for all the calling conventions based on the main AAPCS CSR save order.

This also changes APCS_SwiftError to have a Darwin and a non-Darwin
version, assuming it could be used on other platforms these days, and
restricts the AArch64_CXX_TLS calling convention to Darwin.

Differential Revision: https://reviews.llvm.org/D73805
2020-05-20 16:03:48 -07:00
Eli Friedman 5d2c3a0b8c [AArch64] Disable MachineOutliner on Windows.
The handling of unwind info is broken, so disable it for now.
2020-05-19 13:49:03 -07:00
Amara Emerson 665da59685 [AArch64][GlobalISel] Add legalizer & selector support for G_FREEZE.
These should legalize like undefs and select into copies.

The ll test is copied from the x86 test, minus the half fp case because
we don't currently support that.
2020-05-18 16:25:33 -07:00
Francesco Petrogalli b572d9b1a7 [llvm][sve] Intrinsics for SVE sudot and usdot instructions.
Summary:
This patch adds IR intrinsics for the mnemonics USDOT and SUDOT of the
8.6 extension of Armv8-a.

Reviewers: sdesmalen, efriedma, david-arm

Subscribers: tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79876
2020-05-18 22:02:19 +00:00
Francesco Petrogalli 01f9d8ce5c [llvm][SVE] IR intrinscs for matrix multiplication instructions.
Summary:
Instructions:

* SMMLA
* UMMLA
* USMMLA
* FMMLA

Reviewers: sdesmalen, efriedma, kmclaughlin

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79638
2020-05-18 22:02:19 +00:00
Eli Friedman 4f04db4b54 AllocaInst should store Align instead of MaybeAlign.
Along the lines of D77454 and D79968.  Unlike loads and stores, the
default alignment is getPrefTypeAlign, to match the existing handling in
various places, including SelectionDAG and InstCombine.

Differential Revision: https://reviews.llvm.org/D80044
2020-05-16 14:53:16 -07:00
Eli Friedman a1ce88b4e3 [AArch64][SVE] Implement AArch64ISD::SETCC_PRED
This unifies SETCC operations along the lines of other operations.

Differential Revision: https://reviews.llvm.org/D79975
2020-05-15 11:53:21 -07:00
Cameron McInally b085e51d81 [AArch64][SVE] Add some integer DestructiveBinaryComm* patterns
Add DestructiveBinaryComm* patterns for ADD, SUB, and SUBR.

Differential Revision: https://reviews.llvm.org/D76711
2020-05-14 16:35:49 -05:00
Wei Zhao 382d3a85e2 [AARch64] Add Marvell ThunderX3T110 support
This is the first checkin to support Marvell ThunderX3T110.

Initial definition of the micro-ops of the instructions in ThunderX3T110
is included.

Differential Revision: https://reviews.llvm.org/D78129
2020-05-13 16:58:51 -07:00
Florian Hahn 824a859332 [AArch64] Don't promote constants with float ConstantExpr.
Currently the AsmPrinter cannot emit some floating point constant
expressions in global initializers. Avoid generating them.

Reviewers: dmgreen, t.p.northover, arsenm, efriedma, Gerolf

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D79865
2020-05-13 23:31:47 +01:00
Eli Friedman a52f10b5a3 [AArch64][SVE] Add patterns for VSELECT of immediate merged with a variable.
This covers forms involving "CPY (immediate, merging)".

Differential Revision: https://reviews.llvm.org/D79803
2020-05-13 15:02:08 -07:00
Craig Topper 8c72b0271b [CodeGen] Use Align in MachineConstantPool. 2020-05-12 10:06:40 -07:00
Benjamin Kramer f242950fdf Fold single-use variables into assert
This avoids unused variable warnings in Release builds.
2020-05-12 15:26:59 +02:00
Sander de Smalen 077d2d6802 [CodeGen][SVE] Add patterns for whole vector predicate select
Added patterns to implement `select i1 %p, <vty> %a, <vty> %b`

Reviewed By: efriedma

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79356
2020-05-12 11:47:39 +01:00
Petre-Ionut Tudor 9682d0d5dc [ARM] Refactor lower to S[LR]I optimization
Summary:
The optimization has been refactored to fix certain bugs and
limitations. The condition for lowering to S[LR]I has been changed
to reflect the manual pseudocode description of SLI and SRI operation.
The optimization can now handle more cases of operand type and order.

Subscribers: kristof.beyls, hiraditya, danielkiss, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79233
2020-05-12 11:00:13 +01:00
Sam Parker 1952c86d61 [AArch64][CostModel] getCastInstrCost
Pass the instruction to the base implementation.

Differential Revision: https://reviews.llvm.org/D79562
2020-05-12 10:02:29 +01:00
Eli Friedman a8874c76e8 [AArch64][SVE] Add patterns for VSELECT of immediates.
This covers forms involving "CPY (immediate, zeroing)".

This doesn't handle the case where the operands are reversed, and the
condition is freely invertible.  Not sure how to handle that.  Maybe a
DAGCombine.

Differential Revision: https://reviews.llvm.org/D79598
2020-05-11 17:04:22 -07:00
Jessica Paquette cd59458f27 [AArch64][GlobalISel] Make LR livein to entry in llvm.returnaddress selection
This fixes a couple verifier failures on this bot:

http://green.lab.llvm.org/green/job/test-suite-verify-machineinstrs-aarch64-globalisel-O0-g/

The failures show up in eeprof-1.c and pr17377.c in the GCC C Torture Suite.

Specifically:

*** Bad machine code: MBB has allocatable live-in, but isn't entry or landing-pad. ***
- function:    foo
- basic block: %bb.3 if.end (0x7fac7106dfc8)
- p. register: $lr

and

*** Bad machine code: Using an undefined physical register ***
- function:    f
- basic block: %bb.1 entry (0x7f8941092588)
- instruction: %18:gpr64 = COPY $lr
- operand 1:   $lr

Unlike SDAG, we were setting LR as a live in to the block containing the
returnaddress.

Also, this ensures that we don't add LR as a livein to the entry block twice.
In MachineBasicBlock.h there's a comment saying

"Note that it is an error to add the same register to the same set more than
once unless the intention is to call sortUniqueLiveIns after all registers are
added."

so it's probably good to avoid adding LR twice.

Surprisingly the verifier doesn't complain about that. Maybe it should.

Differential Revision: https://reviews.llvm.org/D79657
2020-05-11 11:32:12 -07:00
Craig Topper bebdc62c3f [SelectionDAG] Remove ConstantPoolSDNode::getAlignment.
Use getAlign instead.

Differential Revision: https://reviews.llvm.org/D79459
2020-05-08 16:04:11 -07:00
Craig Topper d1119980e5 [SelectionDAG] Use Align/MaybeAlign for ConstantPoolSDNode.
This patch stores the alignment for ConstantPoolSDNode as an
Align and updates the getConstantPool interface to take a MaybeAlign.

Removing getAlignment() will be done as a follow up.

Differential Revision: https://reviews.llvm.org/D79436
2020-05-08 16:04:11 -07:00
Kerry McLaughlin 3bcd3dd473 [CodeGen][SVE] Lowering of shift operations with scalable types
Summary:
Adds AArch64ISD nodes for:
 - SHL_PRED (logical shift left)
 - SHR_PRED (logical shift right)
 - SRA_PRED (arithmetic shift right)

Existing patterns for unpredicated left shift by immediate
have also been moved into the appropriate multiclasses
in SVEInstrFormats.td.

Reviewers: sdesmalen, efriedma, ctetreau, huihuiz, rengolin

Reviewed By: efriedma

Subscribers: huihuiz, tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, cfe-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79478
2020-05-07 11:43:49 +01:00
Eli Friedman 2c8546107a [AArch64][SVE] Implement lowering for SIGN_EXTEND etc. of SVE predicates.
Now using patterns, since there's a single-instruction lowering. (We
could convert to VSELECT and pattern-match that, but there doesn't seem
to be much point.)

I think this might be the first instruction to use nested multiclasses
this way? It seems like a good way to reduce duplication between
different integer widths. Let me know if it seems like an improvement.

Also, while I'm here, fix the return type of SETCC so we don't try to
merge a sign-extend with a SETCC.

Differential Revision: https://reviews.llvm.org/D79193
2020-05-06 17:56:32 -07:00
Jessica Paquette b1b86d1c28 [AArch64][GlobalISel] Fold shifts into G_ICMP
Since G_ICMP can be selected to a SUBS, we can fold shifts into such compares.

E.g.

```
cmp	w1, w0, lsl #3
cmp	w1, w0, lsr #3
cmp	w1, w0, asr #3
```

This is done the same way as for adds and subtracts, using
`selectShiftedRegister`.

This gives some minor code size savings on CTMark.

https://reviews.llvm.org/D79365
2020-05-05 18:35:39 -07:00
Sander de Smalen 8cb5663abd [AArch64][SVE] Guard bitcast patterns under IsLE predicate
Reviewed By: efriedma

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79352
2020-05-05 13:18:35 +01:00
Sam Parker 40574fefe9 [NFC][CostModel] Add TargetCostKind to relevant APIs
Make the kind of cost explicit throughout the cost model which,
apart from making the cost clear, will allow the generic parts to
calculate better costs. It will also allow some backends to
approximate and correlate the different costs if they wish. Another
benefit is that it will also help simplify the cost model around
immediate and intrinsic costs, where we currently have multiple APIs.

RFC thread:
http://lists.llvm.org/pipermail/llvm-dev/2020-April/141263.html

Differential Revision: https://reviews.llvm.org/D79002
2020-05-05 10:35:54 +01:00
Raul Tambre 0863e94ebd [AArch64] Add NVIDIA Carmel support
Summary:
NVIDIA's Carmel ARM64 cores are used in Tegra194 chips found in Jetson AGX Xavier, DRIVE AGX Xavier and DRIVE AGX Pegasus.

References:
* https://devblogs.nvidia.com/nvidia-jetson-agx-xavier-32-teraops-ai-robotics/#h.huq9xtg75a5e
* NVIDIA Xavier Series System-on-Chip Technical Reference Manual 1.3 (https://developer.nvidia.com/embedded/downloads#?search=Xavier%20Series%20SoC%20Technical%20Reference%20Manual)

Reviewers: sdesmalen, paquette

Reviewed By: sdesmalen

Subscribers: llvm-commits, ianshmean, kristof.beyls, hiraditya, jfb, danielkiss, cfe-commits, t.p.northover

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D77940
2020-05-04 13:52:30 +01:00
Kerry McLaughlin 19f5da9c1d [SVE][Codegen] Lower legal min & max operations
Summary:
This patch adds AArch64ISD nodes for [S|U]MIN_PRED
and [S|U]MAX_PRED, and lowers both SVE intrinsics and
IR operations for min and max to these nodes.

There are two forms of these instructions for SVE: a predicated
form and an immediate (unpredicated) form. The patterns
which existed for the latter have been updated to match a
predicated node with an immediate and map this
to the immediate instruction.

Reviewers: sdesmalen, efriedma, dancgr, rengolin

Reviewed By: efriedma

Subscribers: huihuiz, tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, cfe-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79087
2020-05-04 11:19:19 +01:00
Cullen Rhodes 672b62ea21 [AArch64][SVE] Custom lowering of floating-point reductions
Summary:
This patch implements custom floating-point reduction ISD nodes that
have vector results, which are used to lower the following intrinsics:

    * llvm.aarch64.sve.fadda
    * llvm.aarch64.sve.faddv
    * llvm.aarch64.sve.fmaxv
    * llvm.aarch64.sve.fmaxnmv
    * llvm.aarch64.sve.fminv
    * llvm.aarch64.sve.fminnmv

SVE reduction instructions keep their result within a vector register,
with all other bits set to zero.

Changes in this patch were implemented by Paul Walker and Sander de
Smalen.

Reviewers: sdesmalen, efriedma, rengolin

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D78723
2020-04-30 10:18:40 +00:00
David Sherwood 058cd8c5be [CodeGen] Add support for inserting elements into scalable vectors
Summary:
This patch tries to ensure that we do something sensible when
generating code for the ISD::INSERT_VECTOR_ELT DAG node when operating
on scalable vectors. Previously we always returned 'undef' when
inserting an element into an out-of-bounds lane index, whereas now
we only do this for fixed length vectors. For scalable vectors it
is assumed that the backend will do the right thing in the same way
that we have to deal with variable lane indices.

In this patch I have permitted a few basic combinations for scalable
vector types where it makes sense, but in general avoided most cases
for now as they currently require the use of BUILD_VECTOR nodes.

This patch includes tests for all scalable vector types when inserting
into lane 0, but I've only included one or two vector types for other
cases such as variable lane inserts.

Differential Revision: https://reviews.llvm.org/D78992
2020-04-30 11:14:04 +01:00
Victor Campos d3dc4c32af [AArch64] Remove inexistent system register ERXTS_EL1
Summary:
AArch64's system register ERXTS_EL1 is present in the backend as a
component of the Arm Reliability, Availability and Serviceability (RAS)
extension. However, it has been removed from the specification before
its final release.

This patch removes the register.

Reviewers: SjoerdMeijer, DavidSpickett

Reviewed By: DavidSpickett

Subscribers: DavidSpickett, kristof.beyls, hiraditya, danielkiss, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79007
2020-04-29 16:43:48 +01:00
Jessica Paquette e0dbeb2173 Fix buildbot after 9f31446c
Add missing ifndef to make release builds happy.

Example failure: http://lab.llvm.org:8011/builders/fuchsia-x86_64-linux/builds/4006/steps/ninja-build/logs/stdio
2020-04-28 15:19:17 -07:00
Jessica Paquette 9f31446c99 [AArch64][GlobalISel] Generalize logic for promoting copies
Generalize the 16-bit FPR to 32-bit GPR logic to work for all cases where
destination size is bigger than source size.

Also fixed CheckCopy() always returning true instead of the result of
isValidCopy().

Differential Revision: https://reviews.llvm.org/D77530

Patch by tambre (Raul Tambre)
2020-04-28 14:56:08 -07:00
Jessica Paquette 2af31b3b65 [AArch64][GlobalISel] Select immediate forms of compares by wiggling constants
Similar to code in `getAArch64Cmp` in AArch64ISelLowering.

When we get a compare against a constant, sometimes, that constant isn't valid
for selecting an immediate form.

However, sometimes, you can get a valid constant by adding 1 or subtracting 1,
and updating the condition code.

This implements the following transformations when valid:

- x slt c => x sle c - 1
- x sge c => x sgt c - 1
- x ult c => x ule c - 1
- x uge c => x ugt c - 1

- x sle c => x slt c + 1
- x sgt c => s sge c + 1
- x ule c => x ult c + 1
- x ugt c => s uge c + 1

Valid meaning the constant doesn't wrap around when we fudge it, and the result
gives us a compare which can be selected into an immediate form.

This also moves `getImmedFromMO` higher up in the file so we can use it.

Differential Revision: https://reviews.llvm.org/D78769
2020-04-28 11:35:01 -07:00
Francis Visoiu Mistrih e770153865 [AArch64] Add support for -ffixed-x30
Add support for reserving LR in:

* the driver through `-ffixed-x30`
* cc1 through `-target-feature +reserve-x30`
* the backend through `-mattr=+reserve-x30`
* a subtarget feature `reserve-x30`

the same way we're doing for the other registers.
2020-04-28 08:48:28 -07:00