Commit Graph

9294 Commits

Author SHA1 Message Date
Javed Absar 37b2286564 [ARM] Tidy-up Cortex-A15 DPR-SPR optimizer implementation
Modernise the code with range-loops etc

Reviewed by: @fhahn, @rovka
Differential Revision: https://reviews.llvm.org/D36502

llvm-svn: 310807
2017-08-14 01:38:01 +00:00
Craig Topper 2251ef95a3 [X86][ARM][TargetLowering] Add SrcVT to isExtractSubvectorCheap
Summary:
Without the SrcVT its hard to know what is really being asked for. For example if your target has 128, 256, and 512 bit vectors. Maybe extracting 128 from 256 is cheap, but maybe extracting 128 from 512 is not.

For x86 we do support extracting a quarter of a 512-bit register. But for i1 vectors we don't have isel patterns for extracting arbitrary pieces. So we need this to have a correct implementation of isExtractSubvectorCheap for mask vectors.

Reviewers: RKSimon, zvi, efriedma

Reviewed By: RKSimon

Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D36649

llvm-svn: 310793
2017-08-13 17:29:07 +00:00
Florian Hahn a5ba4ee8bc [Triple] Add isThumb and isARM functions.
Summary:
isThumb returns true for Thumb triples (little and big endian), isARM
returns true for ARM triples (little and big endian).
There are a few more checks using arm/thumb that are not covered by
those functions, e.g. that the architecture is either ARM or Thumb
(little endian) or ARM/Thumb little endian only.

Reviewers: javed.absar, rengolin, kristof.beyls, t.p.northover

Reviewed By: rengolin

Subscribers: llvm-commits, aemerson

Differential Revision: https://reviews.llvm.org/D34682

llvm-svn: 310781
2017-08-12 17:40:18 +00:00
Sjoerd Meijer 7426c97bc6 [ARM] Assembler support for the ARMv8.2a dot product instructions
Commit r310480 added the AArch64 ARMv8.2a dot product instructions;
this adds the AArch32 instructions.

Differential Revision: https://reviews.llvm.org/D36575

llvm-svn: 310701
2017-08-11 09:52:30 +00:00
Eli Friedman e9499dd4c7 [ARM] Clarify legal addressing modes for ARM and Thumb2. NFC
The existing code is very clever, but not clear, which seems
like the wrong tradeoff here.

Differential Revision: https://reviews.llvm.org/D36559

llvm-svn: 310653
2017-08-10 19:31:27 +00:00
Krzysztof Parzyszek bea30c6286 Add "Restored" flag to CalleeSavedInfo
The liveness-tracking code assumes that the registers that were saved
in the function's prolog are live outside of the function. Specifically,
that registers that were saved are also live-on-exit from the function.
This isn't always the case as illustrated by the LR register on ARM.

Differential Revision: https://reviews.llvm.org/D36160

llvm-svn: 310619
2017-08-10 16:17:32 +00:00
Sam Parker 9d95764c3b [ARM][AArch64] ARMv8.3-A enablement
The beta ARMv8.3 ISA specifications have been released for AArch64
and AArch32, these can be found at:
https://developer.arm.com/products/architecture/a-profile/exploration-tools

An introduction to this architecture update can be found at:
https://community.arm.com/processors/b/blog/posts/armv8-a-architecture-2016-additions

This patch is the first in a series which will add ARM v8.3-A support
in LLVM and Clang. It adds the necessary changes that create targets
for both the ARM and AArch64 backends.

Differential Revision: https://reviews.llvm.org/D36514

llvm-svn: 310561
2017-08-10 09:41:00 +00:00
Matthias Braun a88587ce0c ARM: Fix CMP_SWAP expansion
Clean up after my misguided attempt in r304267 to "fix" CMP_SWAP
returning an uninitialized status value.

- I was always using tMOVi8 to zero the status register which cannot
  encode higher register numbers and llvm would silently miscompile)

- Nobody was ever looking at that status value outside the expansion.
  ARMDAGToDAGISel::SelectCMP_SWAP() the only place creating CMP_SWAP
  instructions was not mapping anything to it. (The cmpxchg status value
  from llvm IR is lowered to a manual comparison after the CMP_SWAP)

So this:
- Renames the register from "status" to "temp" it make it obvious that
  it isn't used outside the expansion.
- Remove the zeroing status/temp register.
- Keep the live-in list improvements from r304267

Fixes http://llvm.org/PR34056

llvm-svn: 310534
2017-08-09 22:22:05 +00:00
Florian Hahn d68bc7ae8d [ARM] Emit error when ARM exec mode is not available.
Summary:
A similar error message has been removed from the ARMTargetMachineBase
constructor in r306939. With this patch, we generate an error message
for the example below, compiled with -mcpu=cortex-m0, which does not
have ARM execution mode.

    __attribute__((target("arm"))) int foo(int a, int b)
    {
        return a + b % a;
    }

    __attribute__((target("thumb"))) int bar(int a, int b)
    {
        return a + b % a;
    }

By adding this error message to ARMBaseTargetMachine::getSubtargetImpl,
we can deal with functions that set -thumb-mode in target-features.
At the moment it seems like Clang does not have access to target-feature
specific information, so adding the error message to the frontend will
be harder.

Reviewers: echristo, richard.barton.arm, t.p.northover, rengolin, efriedma

Reviewed By: echristo, efriedma

Subscribers: efriedma, aemerson, javed.absar, kristof.beyls

Differential Revision: https://reviews.llvm.org/D35627

llvm-svn: 310486
2017-08-09 15:39:10 +00:00
Florian Hahn fc4b3951e9 [ARM] Remove FeatureNoARM implies ModeThumb.
Summary:
By removing FeatureNoARM implies ModeThumb, we can detect cases where a
function's target-features contain -thumb-mode (enables ARM codegen for the
function), but the architecture does not support ARM mode. Previously, the
implication caused the FeatureNoARM bit to be cleared for functions with
-thumb-mode, making the assertion in ARMSubtarget::ARMSubtarget [1]
pointless for such functions.

This assertion is the only guard against generating ARM code for
architectures without ARM codegen support. Is there a place where we
could easily generate error messages for the user? At the moment, we
would generate ARM code for Thumb-only architectures. X86 has the same
behavior as ARM, as in it only has an assertion and no error message,
but I think for ARM an error message would be helpful. What do you
think?

For the example below, `llc -mtriple=armv7m-eabi test.ll -o -` will
generate ARM assembler (or fail with an assertion error with this patch).
Note that if we run the resulting assembler through llvm-mc, we get
an appropriate error message, but not when codegen is handled
through clang.

```
define void @bar() #0 {
entry:
  ret void
}

attributes #0 = { "target-features"="-thumb-mode" }
```

[1] c1f7b54cef/lib/Target/ARM/ARMSubtarget.cpp (L147)

Reviewers: t.p.northover, rengolin, peter.smith, aadg, silviu.baranga, richard.barton.arm, echristo

Reviewed By: rengolin, echristo

Subscribers: efriedma, aemerson, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D35569

llvm-svn: 310476
2017-08-09 13:53:28 +00:00
Quentin Colombet 8dd90fb54b Revert "[GlobalISel] Remove the GISelAccessor API."
This reverts commit r310115.

It causes a linker failure for the one of the unittests of AArch64 on one
of the linux bot:
http://lab.llvm.org:8011/builders/clang-ppc64le-linux-multistage/builds/3429

: && /home/fedora/gcc/install/gcc-7.1.0/bin/g++   -fPIC
-fvisibility-inlines-hidden -Werror=date-time -std=c++11 -Wall -W
-Wno-unused-parameter -Wwrite-strings -Wcast-qual
-Wno-missing-field-initializers -pedantic -Wno-long-long
-Wno-maybe-uninitialized -Wdelete-non-virtual-dtor -Wno-comment
-ffunction-sections -fdata-sections -O2
-L/home/fedora/gcc/install/gcc-7.1.0/lib64 -Wl,-allow-shlib-undefined
-Wl,-O3 -Wl,--gc-sections
unittests/Target/AArch64/CMakeFiles/AArch64Tests.dir/InstSizes.cpp.o  -o
unittests/Target/AArch64/AArch64Tests
lib/libLLVMAArch64CodeGen.so.6.0.0svn lib/libLLVMAArch64Desc.so.6.0.0svn
lib/libLLVMAArch64Info.so.6.0.0svn lib/libLLVMCodeGen.so.6.0.0svn
lib/libLLVMCore.so.6.0.0svn lib/libLLVMMC.so.6.0.0svn
lib/libLLVMMIRParser.so.6.0.0svn lib/libLLVMSelectionDAG.so.6.0.0svn
lib/libLLVMTarget.so.6.0.0svn lib/libLLVMSupport.so.6.0.0svn -lpthread
lib/libgtest_main.so.6.0.0svn lib/libgtest.so.6.0.0svn -lpthread
-Wl,-rpath,/home/buildbots/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/lib
&& :
unittests/Target/AArch64/CMakeFiles/AArch64Tests.dir/InstSizes.cpp.o:(.toc+0x0):
undefined reference to `vtable for llvm::LegalizerInfo'
unittests/Target/AArch64/CMakeFiles/AArch64Tests.dir/InstSizes.cpp.o:(.toc+0x8):
undefined reference to `vtable for llvm::RegisterBankInfo'

The particularity of this bot is that it is built with
BUILD_SHARED_LIBS=ON

However, I was not able to reproduce the problem so far.
Reverting to unblock the bot.

llvm-svn: 310425
2017-08-08 22:22:30 +00:00
Tim Northover f370f2e3c6 Revert "[ARM] Fix assembly and disassembly for VMRS/VMSR"
This reverts r310243. Only MVFR2 is actually restricted to v8 and it'll be a
little while before we can get a proper fix together. Better that we allow
incorrect code than reject correct in the meantime.

llvm-svn: 310384
2017-08-08 17:16:46 +00:00
Andre Vieira 7dffb9bfa6 [ARM] Fix assembly and disassembly for VMRS/VMSR
This patch addresses two issues with assembly and disassembly for VMRS/VMSR:

1.currently VMRS/VMSR instructions accessing fpsid, mvfr{0-2} and fpexc, are
  accepted for non ARMv8-A targets.

2. all VMRS/VMSR instructions accept writing/reading to PC and SP, when only
   ARMv7-A and ARMv8-A should be allowed to write/read to SP and none to PC.

This patch addresses those issues and adds tests for these cases.

Differential Revision: https://reviews.llvm.org/D36306

llvm-svn: 310243
2017-08-07 08:41:05 +00:00
Florian Hahn d51a35e339 [ARM] The ARM backend is MachineVerifier clean now.
Summary: Thanks everyone involved in fixing the outstanding issues.

Reviewers: rovka, MatzeB, efriedma

Reviewed By: MatzeB

Subscribers: aemerson, javed.absar, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D36153

llvm-svn: 310180
2017-08-05 15:14:06 +00:00
Quentin Colombet c046208c52 [GlobalISel] Remove the GISelAccessor API.
Its sole purpose was to avoid spreading around ifdefs related to
building global-isel. Since r309990, GlobalISel is not optional anymore,
thus, we can get rid of this mechanism all together.

NFC.

llvm-svn: 310115
2017-08-04 20:15:46 +00:00
Javed Absar 9cda599151 [ARM] Use searchable-table for banked registers
This is a continuation of https://reviews.llvm.org/D36219

This patch uses reverse mapping (encoding->name) in
ARMInstPrinter::printBankedRegOperand to get rid of
hard-coded values (as pointed out by @olista01).

Reviewed by: @fhahn, @rovka, @olista01
Differential Revision: https://reviews.llvm.org/D36260

llvm-svn: 310072
2017-08-04 17:10:11 +00:00
Quentin Colombet 250e050a50 [GlobalISel] Make GlobalISel a non-optional library.
With this change, the GlobalISel library gets always built. In
particular, this is not possible to opt GlobalISel out of the build
using the LLVM_BUILD_GLOBAL_ISEL variable any more.

llvm-svn: 309990
2017-08-03 21:52:25 +00:00
Nico Weber bfde70b097 Revert r309923, it caused PR34045.
llvm-svn: 309950
2017-08-03 15:41:26 +00:00
Diana Picus 930e6ec8f3 [ARM] GlobalISel: Select simple G_GLOBAL_VALUE instructions
Add support in the instruction selector for G_GLOBAL_VALUE for ELF and
MachO for the static relocation model. We don't handle Windows yet
because that's Thumb-only, and we don't handle Thumb in general at the
moment.

Support for PIC, ROPI, RWPI and TLS will be added in subsequent commits.

Differential Revision: https://reviews.llvm.org/D35883

llvm-svn: 309927
2017-08-03 09:14:59 +00:00
Roger Ferrer Ibanez 854980341b [ARM] Use ADDCARRY / SUBCARRY
This patch:

- makes nodes ISD::ADDCARRY and ISD::SUBCARRY legal for i32
- lowering is done by first converting the boolean value into the carry flag
  using (_, C) <- (ARMISD::ADDC R, -1) and converted back to an integer value
  using (R, _) <- (ARMISD::ADDE 0, 0, C). An ARMISD::ADDE between the two
  operations does the actual addition.
- for subtraction, given that ISD::SUBCARRY second result is actually a
  borrow, we need to invert the value of the second operand and result before
  and after using ARMISD::SUBE. We need to invert the carry result of
  ARMISD::SUBE to preserve the semantics.
- given that the generic combiner may lower ISD::ADDCARRY and
  ISD::SUBCARRY into ISD::UADDO and ISD::USUBO we need to update their lowering
  as well otherwise i64 operations now would require branches. This implies
  updating the corresponding test for unsigned.
- add new combiner to remove the redundant conversions from/to carry flags
  to/from boolean values (ARMISD::ADDC (ARMISD::ADDE 0, 0, C), -1) -> C

Differential Revision: https://reviews.llvm.org/D35192

llvm-svn: 309923
2017-08-03 07:45:10 +00:00
Rafael Espindola 79e238afee Delete Default and JITDefault code models
IMHO it is an antipattern to have a enum value that is Default.

At any given piece of code it is not clear if we have to handle
Default or if has already been mapped to a concrete value. In this
case in particular, only the target can do the mapping and it is nice
to make sure it is always done.

This deletes the two default enum values of CodeModel and uses an
explicit Optional<CodeModel> when it is possible that it is
unspecified.

llvm-svn: 309911
2017-08-03 02:16:21 +00:00
Javed Absar 054d1aef43 [ARM] Tidy up banked registers encoding
Moves encoding (SYSm) information of banked registers to ARMSystemRegister.td,
where it rightly belongs and forms a single point of reference in the code.

Reviewed by: @fhahn, @rovka, @olista01
Differential Revision: https://reviews.llvm.org/D36219

llvm-svn: 309910
2017-08-03 01:24:12 +00:00
Strahinja Petrovic 25e9e1b866 [ARM] Add the option to directly access TLS pointer
This patch enables choice for accessing thread local
storage pointer (like '-mtp' in gcc).

Differential Revision: https://reviews.llvm.org/D34408

llvm-svn: 309381
2017-07-28 12:54:57 +00:00
Matthias Braun c618a466f1 ARMFrameLowering: Only set ExtraCSSpill for actually unused registers.
The code assumed that unclobbered/unspilled callee saved registers are
unused in the function. This is not true for callee saved registers that are
also used to pass parameters such as swiftself.

rdar://33401922

llvm-svn: 309350
2017-07-28 01:36:32 +00:00
Florian Hahn e3583bdf91 [ARM] Add use-misched feature, to enable the MachineScheduler.
Summary:
This change makes it easier to experiment with the MachineScheduler in
the ARM backend and also makes it very explicit which CPUs use the
MachineScheduler (currently only swift and cyclone).



Reviewers: MatzeB, t.p.northover, javed.absar

Reviewed By: MatzeB

Subscribers: aemerson, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D35935

llvm-svn: 309316
2017-07-27 19:56:44 +00:00
Florian Hahn 67ddd1d08f [TargetParser] Use enum classes for various ARM kind enums.
Summary:
Using c++11 enum classes ensures that only valid enum values are used
for ArchKind, ProfileKind, VersionKind and ISAKind. This removes the
need for checks that the provided values map to a proper enum value,
allows us to get rid of AK_LAST and prevents comparing values from
different enums. It also removes a bunch of static_cast
from unsigned to enum values and vice versa, at the cost of introducing
static casts to access AArch64ARCHNames and ARMARCHNames by ArchKind.

FPUKind and ArchExtKind are the only remaining old-style enum in
TargetParser.h. I think it's beneficial to keep ArchExtKind as old-style
enum, but FPUKind can be converted too, but this patch is quite big, so
could do this in a follow-up patch. I could also split this patch up a
bit, if people would prefer that.

Reviewers: rengolin, javed.absar, chandlerc, rovka

Reviewed By: rovka

Subscribers: aemerson, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D35882

llvm-svn: 309287
2017-07-27 16:27:56 +00:00
Florian Hahn db479524dd [ARM] Mark labels in skipAlignedDPRCS2Spills as fallthrough (NFC).
The comment at the top of the switch statement indicates that the
fall-through behavior is intentional. By using LLVM_FALLTHROUGH,
-Wimplicit-fallthrough are silenced, which is enabled by default in GCC
7.

llvm-svn: 309272
2017-07-27 14:37:17 +00:00
Daniel Sanders 8e82af2be6 Re-commit: r309094 [globalisel][tablegen] Fuse the generated tables together.
Summary:
Now that we have control flow in place, fuse the per-rule tables into a
single table. This is a compile-time saving at this point. However, this will
also enable the optimization of a table so that similar instructions can be
tested together, reducing the time spent on the matching the code.

This is NFC in terms of externally visible behaviour but some internals have
changed slightly. State.MIs is no longer reset between each rule that is
attempted because it's not necessary to do so. As a consequence of this the
restriction on the order that instructions are added to State.MIs has been
relaxed to only affect recorded instructions that require new elements to be
added to the vector. GIM_RecordInsn can now write to any element from 1 to
State.MIs.size() instead of just State.MIs.size().

The compile-time regressions from the last commit were caused by the ARM target
including a non-const variable (zero_reg) in the table and therefore generating
an initializer for it. That variable is now const.

Reviewers: ab, t.p.northover, qcolombet, rovka, aditya_nandakumar

Reviewed By: rovka

Subscribers: kristof.beyls, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D35681

llvm-svn: 309264
2017-07-27 11:03:45 +00:00
Evandro Menezes b3ed4bcb8f [ARM] Minor cosmetic edits (NFC)
Change the order of a case and the description for Exynos Mx processors.

llvm-svn: 309184
2017-07-26 21:28:20 +00:00
Peter Collingbourne 081ffe2ff2 Change CallLoweringInfo::CS to be an ImmutableCallSite instead of a pointer. NFCI.
This was a use-after-free waiting to happen.

llvm-svn: 309159
2017-07-26 19:15:29 +00:00
Rafael Espindola e06e4df8be Simplify. NFC.
llvm-svn: 309141
2017-07-26 17:27:27 +00:00
Diana Picus a5d6518e93 [ARM] GlobalISel: Map G_GLOBAL_VALUE to GPR
A G_GLOBAL_VALUE is basically a pointer, so it should live in the GPR.

llvm-svn: 309101
2017-07-26 11:01:13 +00:00
Diana Picus b1fd784936 [ARM] GlobalISel: Mark G_GLOBAL_VALUE as legal
llvm-svn: 309090
2017-07-26 09:25:15 +00:00
Zvi Rackover 1b73682243 TargetLowering: Change isShuffleMaskLegal's mask argument type to ArrayRef<int>. NFCI.
Changing mask argument type from const SmallVectorImpl<int>& to
ArrayRef<int>.

This came up in D35700 where a mask is received as an ArrayRef<int> and
we want to pass it to TargetLowering::isShuffleMaskLegal().
Also saves a few lines of code.

llvm-svn: 309085
2017-07-26 08:06:58 +00:00
Eric Christopher 97ae58686f Update the comments on default subtargets based on feedback.
llvm-svn: 309041
2017-07-25 22:21:08 +00:00
Sam Parker 19a08e42a8 [ARM] Enable partial and runtime unrolling
Enable runtime and partial loop unrolling of simple loops without
calls on M-class cores. The thresholds are calculated based on
whether the target is Thumb or Thumb-2.

Differential Revision: https://reviews.llvm.org/D34619

llvm-svn: 308956
2017-07-25 08:51:30 +00:00
Erich Keane d8f61f8f7e Remove Bitrig: LLVM Changes
Bitrig code has been merged back to OpenBSD, thus the OS has been abandoned.

Differential Revision: https://reviews.llvm.org/D35707

llvm-svn: 308799
2017-07-21 22:48:47 +00:00
Jonas Paulsson 024e319489 [SystemZ, LoopStrengthReduce]
This patch makes LSR generate better code for SystemZ in the cases of memory
intrinsics, Load->Store pairs or comparison of immediate with memory.

In order to achieve this, the following common code changes were made:

 * New TTI hook: LSRWithInstrQueries(), which defaults to false. Controls if
 LSR should do instruction-based addressing evaluations by calling
 isLegalAddressingMode() with the Instruction pointers.
 * In LoopStrengthReduce: handle address operands of memset, memmove and memcpy
 as address uses, and call isFoldableMemAccessOffset() for any LSRUse::Address,
 not just loads or stores.

SystemZ changes:

 * isLSRCostLess() implemented with Insns first, and without ImmCost.
 * New function supportedAddressingMode() that is a helper for TTI methods
 looking at Instructions passed via pointers.

Review: Ulrich Weigand, Quentin Colombet
https://reviews.llvm.org/D35262
https://reviews.llvm.org/D35049

llvm-svn: 308729
2017-07-21 11:59:37 +00:00
Javed Absar e9599e39fe [ARM] Simplify ExpandPseudoInst. NFC.
Remove headers not required and convert to range-loop

Reviewed by: @mcrosier
Differential Revision: https://reviews.llvm.org/D35626

llvm-svn: 308607
2017-07-20 12:35:37 +00:00
Javed Absar 2cb0c95031 [ARM] Unify handling of M-Class system registers
This patch cleans up and fixes issues in the M-Class system register handling:

1. It defines the system registers and the encoding (SYSm values) in one place:
   a new ARMSystemRegister.td using SearchableTable, thereby removing the
   hand-coded values which existed in multiple places.

2. Some system registers e.g. BASEPRI_MAX_NS which do not exist were being allowed!
   Ref: ARMv6/7/8M architecture reference manual.

Reviewed by: @t.p.northover, @olist01, @john.brawn
Differential Revision: https://reviews.llvm.org/D35209

llvm-svn: 308456
2017-07-19 12:57:16 +00:00
Javed Absar 5b8e487b47 [ARM|CodeGen] Improve the code in FastISel
Cleaned up the code in FastISel a bit.
Had to add make_range to MCInstrDesc as that was needed and seems missing.

Reviewed by: @t.p.northover
Differential Revision: https://reviews.llvm.org/D35494

llvm-svn: 308291
2017-07-18 10:19:48 +00:00
Diana Picus da25d5b8b0 [ARM] GlobalISel: Support G_(S|U)REM for s8 and s16
Widen to s32, and then do whatever Lowering/Custom/Libcall action the
subtarget wants.

llvm-svn: 308285
2017-07-18 10:07:01 +00:00
Javed Absar dd2c29ef83 [CodeGen] Add begin-end iterators to MachineInstr
Convert iteration over operands to range-loop.

Reviewed by: @rovka, @echristo
Differential Revision: https://reviews.llvm.org/D35419

llvm-svn: 308173
2017-07-17 13:15:26 +00:00
Hiroshi Inoue a9ee279e70 fix typos in comments; NFC
llvm-svn: 308126
2017-07-16 07:48:48 +00:00
Diana Picus 87a7067983 [ARM] GlobalISel: Support G_BRCOND
Insert a TSTri to set the flags and a Bcc to branch based on their
values. This is a bit inefficient in the (common) cases where the
condition for the branch comes from a compare right before the branch,
since we set the flags both as part of the compare lowering and as part
of the branch lowering. We're going to live with that until we settle on
a principled way to handle this kind of situation, which occurs with
other patterns as well (combines might be the way forward here).

llvm-svn: 308009
2017-07-14 09:46:06 +00:00
Sam Parker 2893448576 [ARM] Allow rematerialization of ARM Thumb literal pool loads
Constants are crucial for code size in the ARM Thumb-1 instruction
set. The 16 bit instruction size often does not offer enough space
for immediate arguments. This means that additional instructions are
frequently used to load constants into registers. Since constants are
hoisted, this can lead to significant register spillage if they are
used multiple times in a single function. This can be avoided by
rematerialization, i.e. recomputing a constant instead of reloading
it from the stack. This patch fixes the rematerialization of literal
pool loads in the ARM Thumb instruction set.

Patch by Philip Ginsbach

Differential Revision: https://reviews.llvm.org/D33936

llvm-svn: 308004
2017-07-14 08:23:56 +00:00
Eric Christopher 4e332c7cf1 Add a set of comments explaining why getSubtargetImpl() is deleted on these targets.
llvm-svn: 307999
2017-07-14 04:33:43 +00:00
Diana Picus c452175642 [ARM] GlobalISel: Support G_BR
This boils down to not crashing in reg bank select due to the lack of
register operands on this instruction, and adding some tests. The
instruction selection is already covered by the TableGen'erated code.

llvm-svn: 307904
2017-07-13 11:09:34 +00:00
Javed Absar d32f9c8190 [ARM] Tidy up and organise better ARM.td. NFC.
This patch tidies up and organises ARM.td
so that it is easier to understandand
and extend in the future.

Reviewed by: @hahn, @rovka
Differential Revision: https://reviews.llvm.org/D35248

llvm-svn: 307897
2017-07-13 10:24:30 +00:00
Diana Picus f69d7b0495 Fixup r307893: Silence warning
Silence unused variable warning in release builds.
*sigh*

llvm-svn: 307896
2017-07-13 09:52:06 +00:00