Select G_SEXT and G_ZEXT with destination types smaller than 32 bits in
the exact same way as 32 bits. This overwrites the higher bits, but that
should be ok since all legal users of types smaller than 32 bits ignore
those bits anyway.
llvm-svn: 359768
Make it possible to TableGen code for FCONSTS and FCONSTD.
We need to make two changes to the TableGen descriptions of vfp_f32imm
and vfp_f64imm respectively:
* add GISelPredicateCode to check that the immediate fits in 8 bits;
* extract the SDNodeXForms into separate definitions and create a
GISDNodeXFormEquiv and a custom renderer function for each of them.
There's a lot of boilerplate to get the actual value of the immediate,
but it basically just boils down to calling ARM_AM::getFP32Imm or
ARM_AM::getFP64Imm.
llvm-svn: 358063
G_SELECT uses a 1-bit scalar for the condition, and is currently
implemented with a plain CMPri against 0. This means that values such as
0x1110 are interpreted as true, when instead the higher bits should be
treated as undefined and therefore ignored. Replace the CMPri with a
TSTri against 0x1, which performs an implicit AND, yielding the expected
result.
llvm-svn: 357153
1) GCC complains that KnownValid is set but not used.
2) In ARMInstructionSelector::selectGlobal() the code is mixing "enumeral
and non-enumeral type in conditional expression". Solve this by casting
to unsigned which is the final type anyway.
Differential Revision: https://reviews.llvm.org/D58834
llvm-svn: 355304
This gets rid of some duplication in the TableGen definition, but it
forces us to keep both a pointer and a reference to the subtarget in the
ARMInstructionSelector. That is pretty ugly but it might be a reasonable
trade-off, since the TableGen descriptions should outlive the code in
the selector (or in the worst case we can update to use just the
reference when we get rid of DAGISel).
Differential Revision: https://reviews.llvm.org/D58031
llvm-svn: 355083
Add the same level of support as for ARM mode (i.e. still no TLS
support).
In most cases, it is sufficient to replace the opcodes with the
t2-equivalent, but there are some idiosyncrasies that I decided to
preserve because I don't understand the full implications:
* For ARM we use LDRi12 to load from constant pools, but for Thumb we
use t2LDRpci (I'm not sure if the ideal would be to use t2LDRi12 for
Thumb as well, or to use LDRcp for ARM).
* For Thumb we don't have an equivalent for MOV|LDRLIT_ga_pcrel_ldr, so
we have to generate MOV|LDRLIT_ga_pcrel plus a load from GOT.
The tests are in separate files because they're hard enough to read even
without doubling the number of checks.
llvm-svn: 355077
Add the opcode for ADDrr / t2ADDrr to the Opcode cache, as we did for
all other opcodes where the handling is otherwise the same between arm
mode and thumb2.
llvm-svn: 354115
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
Refactor the ARMInstructionSelector to cache some opcodes in the
constructor instead of checking all the time if we're in ARM or Thumb
mode.
llvm-svn: 349143
Mark G_SEXT, G_ZEXT and G_ANYEXT to 32 bits as legal and add support for
them in the instruction selector. This uses handwritten code again
because the patterns that are generated with TableGen are tuned for what
the DAG combiner would produce and not for simple sext/zext nodes.
Luckily, we only need to update the opcodes to use the Thumb2 variants,
everything else can be reused from ARM.
llvm-svn: 349026
Unfortunately we can't use TableGen for this because it doesn't yet
support predicates on the source pattern root. Therefore, add a bit of
handwritten code to the instruction selector to handle the most basic
cases.
Also mark them as legal and extract their legalizer test cases to a new
test file.
llvm-svn: 348920
Also bringing ARMRegisterBankInfo::getRegBankFromRegClass
implementation up to speed with the *.td-definition.
Reviewed By: qcolombet
Differential Revision: https://reviews.llvm.org/D43982
llvm-svn: 333056
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
Select G_PHI to PHI and manually constrain the result register. This is
very similar to how COPY is handled, so extract and reuse some of that
code.
llvm-svn: 321797
We used to handle G_CONSTANT with pointer type by forcing the type of
the result register to s32 and then letting TableGen handle it.
Unfortunately, setting the type only works for generic virtual
registers, that haven't yet been constrained to a register class (e.g.
those used only by a COPY later on). If the result register has already
been constrained as a use of a previously selected instruction, then
setting the type will assert.
It would be nice to be able to teach TableGen to select pointer
constants the same as integer constants, but since it's such an edge
case (at the moment the only pointer constant that we're generally
interested in is 0, and that is mostly used for comparisons and selects,
which are also not supported by TableGen) it's probably not worth the
effort right now. Instead, handle pointer constants with some trivial
handwritten code.
llvm-svn: 321793
Pointer constants are pretty rare, since we usually represent them as
integer constants and then cast to pointer. One notable exception is the
null pointer constant, which is represented directly as a G_CONSTANT 0
with pointer type. Mark it as legal and make sure it is selected like
any other integer constant.
llvm-svn: 321354
We get an assertion in RegBankSelect for code along the lines of
my_32_bit_int = my_64_bit_int, which tends to translate into a 64-bit
load, followed by a G_TRUNC, followed by a 32-bit store. This appears in
a couple of places in the test-suite.
At the moment, the legalizer doesn't distinguish between integer and
floating point scalars, so a 64-bit load will be marked as legal for
targets with VFP, and so will the rest of the sequence, leading to a
slightly bizarre G_TRUNC reaching RegBankSelect.
Since the current support for 64-bit integers is rather immature, this
patch works around the issue by explicitly handling this case in
RegBankSelect and InstructionSelect. In the future, we may want to
revisit this decision and make sure 64-bit integer loads are narrowed
before reaching RegBankSelect.
llvm-svn: 321165
This patch splits atomics out of the generic G_LOAD/G_STORE and into their own
G_ATOMIC_LOAD/G_ATOMIC_STORE. This is a pragmatic decision rather than a
necessary one. Atomic load/store has little in implementation in common with
non-atomic load/store. They tend to be handled very differently throughout the
backend. It also has the nice side-effect of slightly improving the common-case
performance at ISel since there's no longer a need for an atomicity check in the
matcher table.
All targets have been updated to remove the atomic load/store check from the
G_LOAD/G_STORE path. AArch64 has also been updated to mark
G_ATOMIC_LOAD/G_ATOMIC_STORE legal.
There is one issue with this patch though which also affects the extending loads
and truncating stores. The rules only match when an appropriate G_ANYEXT is
present in the MIR. For example,
(G_ATOMIC_STORE (G_TRUNC:s16 (G_ANYEXT:s32 (G_ATOMIC_LOAD:s16 X))))
will match but:
(G_ATOMIC_STORE (G_ATOMIC_LOAD:s16 X))
will not. This shouldn't be a problem at the moment, but as we get better at
eliminating extends/truncates we'll likely start failing to match in some
cases. The current plan is to fix this in a patch that changes the
representation of extending-load/truncating-store to allow the MMO to describe
a different type to the operation.
llvm-svn: 319691
When lowering a G_BRCOND, we generate a TSTri of the condition against
1, which sets the flags, and then a Bcc which branches based on the
value of the flags.
Unfortunately, we were using the wrong condition code to check whether
we need to branch (EQ instead of NE), which caused all our branches to
do the opposite of what they were intended to do. This patch fixes the
issue by using the correct condition code.
llvm-svn: 319313
Summary:
This patch adds a LLVM_ENABLE_GISEL_COV which, like LLVM_ENABLE_DAGISEL_COV,
causes TableGen to instrument the generated table to collect rule coverage
information. However, LLVM_ENABLE_GISEL_COV goes a bit further than
LLVM_ENABLE_DAGISEL_COV. The information is written to files
(${CMAKE_BINARY_DIR}/gisel-coverage-* by default). These files can then be
concatenated into ${LLVM_GISEL_COV_PREFIX}-all after which TableGen will
read this information and use it to emit warnings about untested rules.
This technique could also be used by SelectionDAG and can be further
extended to detect hot rules and give them priority over colder rules.
Usage:
* Enable LLVM_ENABLE_GISEL_COV in CMake
* Build the compiler and run some tests
* cat gisel-coverage-[0-9]* > gisel-coverage-all
* Delete lib/Target/*/*GenGlobalISel.inc*
* Build the compiler
Known issues:
* ${LLVM_GISEL_COV_PREFIX}-all must be generated as a manual
step due to a lack of a portable 'cat' command. It should be the
concatenation of all ${LLVM_GISEL_COV_PREFIX}-[0-9]* files.
* There's no mechanism to discard coverage information when the ruleset
changes
Depends on D39742
Reviewers: ab, qcolombet, t.p.northover, aditya_nandakumar, rovka
Reviewed By: rovka
Subscribers: vsk, arsenm, nhaehnle, mgorny, kristof.beyls, javed.absar, igorb, llvm-commits
Differential Revision: https://reviews.llvm.org/D39747
llvm-svn: 318356
Get rid of the handwritten instruction selector code for handling
G_CONSTANT. This code wasn't checking all the preconditions correctly
anyway, so it's better to leave it to TableGen, which can handle at
least some cases correctly (e.g. MOVi, MOVi16, folding into binary
operations). Also add tests to cover those cases.
llvm-svn: 318146
Summary:
This fixes PR35221.
Use pseudo-instructions to let MachineCSE hoist global address computation.
Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D39871
llvm-svn: 318081
Unfortunately TableGen doesn't handle this yet:
Unable to deduce gMIR opcode to handle Src (which is a leaf).
Just add some temporary hand-written code to generate the proper MOVsr.
llvm-svn: 315071
Use the STI member of ARMInstructionSelector instead of
TII.getSubtarget() and also make use of STI's methods instead of
checking the object format manually.
llvm-svn: 312522
In RWPI code, globals that are not read-only are accessed relative to
the SB register (R9). This is achieved by explicitly generating an ADD
instruction between SB and an offset that we either load from a constant
pool or movw + movt into a register.
llvm-svn: 312521
In the ROPI relocation model, read-only variables are accessed relative
to the PC. We use the (MOV|LDRLIT)_ga_pcrel pseudoinstructions for this.
llvm-svn: 312323
Support the selection of G_GLOBAL_VALUE in the PIC relocation model. For
simplicity we use the same pseudoinstructions for both Darwin and ELF:
(MOV|LDRLIT)_ga_pcrel(_ldr).
This is new for ELF, so it requires a small update to the ARM pseudo
expansion pass to make sure it adds the correct constant pool modifier
and add-current-address in the case of ELF.
Differential Revision: https://reviews.llvm.org/D36507
llvm-svn: 311992
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
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
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
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
Refactor CmpHelper into something simpler. It was overkill to use
templates for this - instead, use a simple CmpConstants structure to
hold the opcodes and other constants that are different when selecting
int / float / double comparisons. Also, extract some of the helpers that
were in CmpHelper into ARMInstructionSelector and make use of some of
them when selecting other things than just compares.
llvm-svn: 307766
We lower to a sequence consisting of:
- MOVi 0 into a register
- VCMPS to do the actual comparison and set the VFP flags
- FMSTAT to move the flags out of the VFP unit
- MOVCCi to either use the "zero register" that we have previously set
with the MOVi, or move 1 into the result register, based on the values
of the flags
As was the case with soft-float, for some predicates (one, ueq) we
actually need two comparisons instead of just one. When that happens, we
generate two VCMPS-FMSTAT-MOVCCi sequences and chain them by means of
using the result of the first MOVCCi as the "zero register" for the
second one. This is a bit overkill, since one comparison followed by
two non-flag-setting conditional moves should be enough. In any case,
the backend manages to CSE one of the comparisons away so it doesn't
matter much.
Note that unlike SelectionDAG and FastISel, we always use VCMPS, and not
VCMPES. This makes the code a lot simpler, and it also seems correct
since the LLVM Lang Ref defines simple true/false returns if the
operands are QNaN's. For SNaN's, even VCMPS throws an Invalid Operand
exception, so they won't be slipping through unnoticed.
Implementation-wise, this introduces a template so we can share the same
code that we use for handling integer comparisons, since the only
differences are in the details (exact opcodes to be used etc). Hopefully
this will be easy to extend to s64 G_FCMP.
llvm-svn: 307365
Diana Picus