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
Summary:
Replace the matcher if-statements for each rule with a state-machine. This
significantly reduces compile time, memory allocations, and cumulative memory
allocation when compiling AArch64InstructionSelector.cpp.o after r303259 is
recommitted.
The following patches will expand on this further to fully fix the regressions.
Reviewers: rovka, ab, t.p.northover, qcolombet, aditya_nandakumar
Reviewed By: ab
Subscribers: vitalybuka, aemerson, javed.absar, igorb, llvm-commits, kristof.beyls
Differential Revision: https://reviews.llvm.org/D33758
llvm-svn: 307079
* Mark as legal for (s32, i1, s32, s32)
* Map everything into GPRs
* Select to two instructions: a CMP of the condition against 0, to set
the flags, and a MOVCCr to select between the two inputs based on the
flags that we've just set
llvm-svn: 306382
Add support throughout the pipeline:
- mark as legal for s32 and pointers
- map to GPRs
- lower to a sequence of instructions, which moves 0 or 1 into the
result register based on the flags set by a CMPrr
We have copied from FastISel a helper function which maps CmpInst
predicates into ARMCC codes. Ideally, we should be able to move it
somewhere that both FastISel and GlobalISel can use.
llvm-svn: 305672
According to the commit message from r296921, G_MERGE_VALUES and
G_INSERT are to be preferred over G_SEQUENCE. Therefore, stop generating
G_SEQUENCE in the ARM backend and remove the code dealing with it.
This boils down to the code breaking up double values for the soft float
calling convention. Use G_MERGE_VALUES + G_UNMERGE_VALUES instead of
G_SEQUENCE + G_EXTRACT for it. This maps very nicely to VMOVDRR +
VMOVRRD and simplifies the code in the instruction selector.
There's one occurence of G_SEQUENCE left in arm-irtranslator.ll, but
that is part of the target-independent code for translating constant
structs. Therefore, it is beyond the scope of this commit.
llvm-svn: 304902
It only failed on llvm-clang-x86_64-expensive-checks-win, probably
because the TableGen stuff hasn't been regenerated.
Requires a clean build.
llvm-svn: 303252
G_ANYEXT can be introduced by the legalizer when widening scalars. Add
support for it in the register bank info (same mapping as everything
else) and in the instruction selector.
When selecting it, we treat it as a COPY, just like G_TRUNC. On this
occasion we get rid of some assertions in selectCopy so we can reuse it.
This shouldn't be a problem at the moment since we're not supporting any
complicated cases (e.g. FPR, different register banks). We might want to
separate the paths when we do.
llvm-svn: 302778
Emit and use the TableGen instruction selector for ARM. At the moment,
this allows us to remove the hand-written code for selecting G_SDIV and
G_UDIV.
Future commits will focus on increasing the code coverage for it and
removing more dead code from the current instruction selector.
llvm-svn: 301905
Declare the ARMInstructionSelector in an anonymous namespace, to make it
more in line with the other targets which were migrated to this in
r299637 in order to avoid TableGen'erated headers being included in
non-GlobalISel builds.
llvm-svn: 301632
Add support for both targets with hardware division and without. For
hardware division we have to add support throughout the pipeline
(legalizer, reg bank select, instruction select). For targets without
hardware division, we only need to mark it as a libcall.
llvm-svn: 301164
When selecting a G_CONSTANT to a MOVi, we need the value to be an Imm
operand. We used to just leave the G_CONSTANT operand unchanged, which
works in some cases (such as the GEP offsets that we create when
referring to stack slots). However, in many other places the G_CONSTANTs
are created with CImm operands. This patch makes sure to handle those as
well, and to error out gracefully if in the end we don't end up with an
Imm operand.
Thanks to Oliver Stannard for reporting this issue.
llvm-svn: 301162
Select them as copies. We only select if both the source and the
destination are on the same register bank, so this shouldn't cause any
trouble.
llvm-svn: 300971
Support G_MUL, very similar to G_ADD and G_SUB. The only difference is
in the instruction selector, where we have to select either MUL or MULv5
depending on the target.
llvm-svn: 300665
A bit more painful than G_INSERT because it was more widely used, but this
should simplify the handling of extract operations in most locations.
llvm-svn: 297100
There used to be a check in the IRTranslator that prevented us from having to
deal with atomic loads/stores. That check has been removed in r294993 and the
AArch64 backend was updated accordingly. This commit does the same thing for the
ARM backend.
In general, in the ARM backend we introduce fences during the atomic expand
pass, so we don't have to worry about atomics, *except* for the 32-bit ARMv8
target, which handles atomics more like AArch64. Since we don't want to worry
about that yet, just bail out of instruction selection if we find any atomic
loads.
llvm-svn: 295662
Since they're only used for passing around double precision floating point
values into the general purpose registers, we'll lower them to VMOVDRR and
VMOVRRD.
llvm-svn: 295310
Add a register bank for floating point values and select simple instructions
using them (add, copies from GPR).
This assumes that the hardware can cope with a single precision add (VADDS)
instruction, so the legalizer will treat G_FADD as legal and the instruction
selector will refuse to select if the hardware doesn't support it. In the future
we'll want to be more careful about this, and legalize to libcalls if we have to
use soft float.
llvm-svn: 294442
Add support for loading i1, i8 and i16 arguments from the stack, with or without
the ABI extension flags.
When the ABI extension flags are present, we load a 4-byte value, otherwise we
preserve the size of the load and let the instruction selector replace it with a
LDRB/LDRH. This generates the same thing as DAGISel.
Differential Revision: https://reviews.llvm.org/D27803
llvm-svn: 293163
Summary:
Lifetime extension wasn't triggered on the result of BuildMI because the
reference was non-const. However, instead of adding a const, I've
removed the reference entirely as RVO should kick in anyway.
Reviewers: rovka, bkramer
Reviewed By: bkramer
Subscribers: aemerson, rengolin, dberris, llvm-commits, kristof.beyls
Differential Revision: https://reviews.llvm.org/D29124
llvm-svn: 293059
Add support for:
* i1 add
* i1 function arguments, if passed through registers
* i1 returns, with ABI signext/zeroext
Differential Revision: https://reviews.llvm.org/D27706
llvm-svn: 293035
At the moment, this means supporting the signext/zeroext attribute on the return
type of the function. For function arguments, signext/zeroext should be handled
by the caller, so there's nothing for us to do until we start lowering calls.
Note that this does not include support for other extensions (i8 to i16), those
will be added later.
Differential Revision: https://reviews.llvm.org/D27705
llvm-svn: 293034
Replace all uses of AddDefaultCC with add(condCodeOp()).
The transformation has been done automatically with a custom tool based on Clang
AST Matchers + RefactoringTool.
Differential Revision: https://reviews.llvm.org/D28557
llvm-svn: 291893
Replace all uses of AddDefaultPred with MachineInstrBuilder::add(predOps()).
This makes the code building MachineInstrs more readable, because it allows us
to write code like:
MIB.addSomeOperand(blah)
.add(predOps())
.addAnotherOperand(blahblah)
instead of
AddDefaultPred(MIB.addSomeOperand(blah))
.addAnotherOperand(blahblah)
This commit also adds the predOps helper in the ARM backend, as well as the add
method taking a variable number of operands to the MachineInstrBuilder.
The transformation has been done mostly automatically with a custom tool based
on Clang AST Matchers + RefactoringTool.
Differential Revision: https://reviews.llvm.org/D28555
llvm-svn: 291890
Teach the instruction selector that it's ok to copy small values from physical
registers.
First part of https://reviews.llvm.org/D27704
llvm-svn: 290104
Add support for selecting simple G_LOAD and G_FRAME_INDEX instructions (32-bit
scalars only). This will be useful for functions that need to pass arguments on
the stack.
First part of https://reviews.llvm.org/D27195.
llvm-svn: 290096
Add the minimal support necessary to select a function that returns the sum of
two i32 values.
This includes some support for argument/return lowering of i32 values through
registers, as well as the handling of copy and add instructions throughout the
GlobalISel pipeline.
Differential Revision: https://reviews.llvm.org/D26677
llvm-svn: 289940
Daniel Sanders