Previously, `CCState::AllocateStack` always allocated stack space by increasing
offsets. For targets with stack growing up (away from zero) it is more
convenient to allocate arguments by decreasing offsets, so that the first
argument is at the top of the stack. This is important when calling a function
with variable number of arguments: the callee does not know the size of the
stack, but must be able to access "fixed" arguments. For that to work, the
"fixed" arguments should have fixed offsets relative to the stack top, i.e. the
variadic arguments area should be at the stack bottom (at lowest addresses).
The in-tree target with stack growing up is AMDGPU, but it allocates
arguments by increasing addresses. It does not support variadic arguments.
A drive-by change is to promote stack size/offset to 64-bit integer.
This is what MachineFrameInfo expects.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D149575
The term "next stack offset" is misleading because the next argument is
not necessarily allocated at this offset due to alignment constrains.
It also does not make much sense when allocating arguments at negative
offsets (introduced in a follow-up patch), because the returned offset
would be past the end of the next argument.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D149566
Define intersectWith and unionWith as two complementary ways of
combining KnownBits. The names are chosen for consistency with
ConstantRange.
Deprecate commonBits as a synonym for intersectWith.
Differential Revision: https://reviews.llvm.org/D150443
Make sure that the upper bits of the offset is placed in bits 20-21 of the
instruction word.
This fixes the encoding of backwards (negative offset) BPr branches.
(Previously, the upper two bits of the offset would overwrite parts of the rs1
field, causing it to branch on the wrong register, with the wrong offset)
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D144012
This reduces dependencies on `llvm-tblgen` so much.
`CodeGenTypes` depends on `Support` at the moment.
Be careful to append deps on this, since Targets' tablegens
depend on this.
Depends on D149024
Differential Revision: https://reviews.llvm.org/D148769
Make sure that the upper bits of the offset is placed in bits 20-21 of the
instruction word.
This fixes the encoding of backwards (negative offset) BPr branches.
(Previously, the upper two bits of the offset would overwrite parts of the rs1
field, causing it to branch on the wrong register, with the wrong offset)
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D144012
On 64-bit target, when doing i64 BR_CC where one of the comparison operands is a
constant zero, try to fold the compare and BPcc into a BPr instruction.
For all integers, EQ and NE comparison are available, additionally for signed
integers, GT, GE, LT, and LE is also available.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D142461
Similar to the existing SelectionDAG::SplitVector helper, this helper creates the EXTRACT_ELEMENT nodes for the LO/HI halves of the scalar source.
Differential Revision: https://reviews.llvm.org/D147264
On 64-bit target, when doing i64 BR_CC where one of the comparison operands is a
constant zero, try to fold the compare and BPcc into a BPr instruction.
For all integers, EQ and NE comparison are available, additionally for signed
integers, GT, GE, LT, and LE is also available.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D142461
Integrate the BranchRelaxation pass to help with relaxing out-of-range
conditional branches.
This is mostly of concern for SPARCv9, which uses conditional branches with
much smaller range than its v8 counterparts.
(Some large autogenerated code, such as the ones generated by TableGen, already
hits this limitation when building in Release)
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D142458
The motivation behind this change is as follows.
Targets with stack growing up (there are no such in-tree targets) pass
arguments at negative offsets relative to the stack pointer. This makes
it hard to use the generic value assigner because CCValAssign stores the
offset as an unsigned integer, which is then zero-extended when
converted to int64_t, e.g. when passing to `CreateFixedObject`. This
results in conversion of, for example, -4 into 4294967292, which is not
desired.
While it is possible to insert a cast to `int` before passing the result
of `getLocMemOffset` into `CreateFixedObject` in backend code, this is
error-prone, and some uses of `getLocMemOffset` are located in
places common to all backends (e.g. `CallLowering::handleAssignments`).
That said, I wanted to change the type of the memory offset from
`unsigned` to `int64_t` (this would be consistent with other places
where stack offsets are used). However, the `Loc` field which stores the
offset is shared between three different kinds of the location:
register, memory, and "pending". Storing a register number as `int64_t`
does not seem right (there are `Register` and `MCRegister` for this), so
I did the most straightforward change - replaced the `Loc` field with
std::variant.
The main change that changes the type of the memory offset from
`unsigned` to `int64_t` will be in a follow-up patch to simplify the
review.
Reviewed By: MaskRay, nikic
Differential Revision: https://reviews.llvm.org/D136043
In LowerSELECT_CC, SELECT_REG between two f128s should only be emitted if we
have hardware quadfloat enabled.
This should fix issue #59646
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D140515
Follow up to the series:
1. https://reviews.llvm.org/D140161
2. https://reviews.llvm.org/D140349
3. https://reviews.llvm.org/D140331
4. https://reviews.llvm.org/D140323
Completes the work from the previous two for remaining targets.
This creates the following named passes that can be run via
`llc -{start|stop}-{before|after}`:
- arc-isel
- arm-isel
- avr-isel
- bpf-isel
- csky-isel
- hexagon-isel
- lanai-isel
- loongarch-isel
- m68k-isel
- msp430-isel
- mips-isel
- nvptx-isel
- ppc-codegen
- riscv-isel
- sparc-isel
- systemz-isel
- ve-isel
- wasm-isel
- xcore-isel
A nice way to write tests for SelectionDAGISel might be to use a RUN:
line like:
llc -mtriple=<triple> -start-before=<arch>-isel -stop-after=finalize-isel -o -
Fixes: https://github.com/llvm/llvm-project/issues/59538
Reviewed By: asb, zixuan-wu
Differential Revision: https://reviews.llvm.org/D140364
This fixes what I consider to be an API flaw I've tripped over
multiple times. The point this is constructed isn't well defined, so
depending on where this is first called, you can conclude different
information based on the MachineFunction. For example, the AMDGPU
implementation inspected the MachineFrameInfo on construction for the
stack objects and if the frame has calls. This kind of worked in
SelectionDAG which visited all allocas up front, but broke in
GlobalISel which hasn't visited any of the IR when arguments are
lowered.
I've run into similar problems before with the MIR parser and trying
to make use of other MachineFunction fields, so I think it's best to
just categorically disallow dependency on the MachineFunction state in
the constructor and to always construct this at the same time as the
MachineFunction itself.
A missing feature I still could use is a way to access an custom
analysis pass on the IR here.
This is a fairly large changeset, but it can be broken into a few
pieces:
- `llvm/Support/*TargetParser*` are all moved from the LLVM Support
component into a new LLVM Component called "TargetParser". This
potentially enables using tablegen to maintain this information, as
is shown in https://reviews.llvm.org/D137517. This cannot currently
be done, as llvm-tblgen relies on LLVM's Support component.
- This also moves two files from Support which use and depend on
information in the TargetParser:
- `llvm/Support/Host.{h,cpp}` which contains functions for inspecting
the current Host machine for info about it, primarily to support
getting the host triple, but also for `-mcpu=native` support in e.g.
Clang. This is fairly tightly intertwined with the information in
`X86TargetParser.h`, so keeping them in the same component makes
sense.
- `llvm/ADT/Triple.h` and `llvm/Support/Triple.cpp`, which contains
the target triple parser and representation. This is very intertwined
with the Arm target parser, because the arm architecture version
appears in canonical triples on arm platforms.
- I moved the relevant unittests to their own directory.
And so, we end up with a single component that has all the information
about the following, which to me seems like a unified component:
- Triples that LLVM Knows about
- Architecture names and CPUs that LLVM knows about
- CPU detection logic for LLVM
Given this, I have also moved `RISCVISAInfo.h` into this component, as
it seems to me to be part of that same set of functionality.
If you get link errors in your components after this patch, you likely
need to add TargetParser into LLVM_LINK_COMPONENTS in CMake.
Differential Revision: https://reviews.llvm.org/D137838
With D134950, targets get notified when a virtual register is created and/or
cloned. Targets can do the needful with the delegate callback. AMDGPU propagates
the virtual register flags maintained in the target file itself. They are useful
to identify a certain type of machine operands while inserting spill stores and
reloads. Since RegAllocFast spills the physical register itself, there is no way
its virtual register can be mapped back to retrieve the flags. It can be solved
by passing the virtual register as an additional argument. This argument has no
use when the spill interfaces are called during the greedy allocator or even the
PrologEpilogInserter and can pass a null register in such cases.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D138656
Previously we had a shared ID in SelectionDAGISel. AMDGPU has an
initializePass function for its subclass of SelectionDAGISel. No
other target does.
This causes all target specific SelectionDAGISel passes to be known
as "amdgpu-isel".
I'm not sure what would happen if another target tried to implement
an initializePass function too since the ID is already claimed.
This patch gives all targets their own ID and passes it down to
SelectionDAGISel constructor to MachineFunctionPass's constructor.
Unfortunately, I think this causes most targets to lose
print-before/after-all support for their SelectionDAGISel pass.
And they probably no longer support start/stop-before/after. We
can add initializePass functions to fix this as a follow up. NOTE:
This was probably also broken if the AMDGPU target isn't compiled in.
Step 1 to fixing PR59538.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D140161
Add two GNU extension forms of wrpr:
wrpr %reg, %rd -> wrpr %reg, %g0, %rd
wrpr imm, %rd -> wrpr %g0, imm, %rd
Note: since the semantics of wrpr %rs1, %rs2/imm, %rd is %rd <- (%rs1 xor %rs2/imm),
in case (1) it technically doesn't matter whether the %g0 is placed as the first or
second operand, however, I'm placing it as the second operand to match the encoding
of GNU as.
This fixes the wrpr instruction part of bug #40792
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D139535
Materialize zeros by copying from %g0, which is now marked as constant.
This makes it possible for some common operations (like integer negation) to be
performed in fewer instructions.
This continues @arichardson's patch at D132561.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D138887
These targets use `MCInst`, but don't explicitly link
to the library providing it (MC), and just rely on it
being pulled transitively through e.g. MCDisassembler,
but that only pulls includes, and does not link to it.
Case in point, when i add explicit destructor to `MCInst`,
defined in `.cpp`, these targets were failing to link.
On 64-bit target, when doing i64 SELECT_CC where one of the comparison operands
is a constant zero, try to fold the compare and MOVcc into a MOVr instruction.
For all integers, EQ and NE comparison are available, additionally for signed
integers, GT, GE, LT, and LE is also available.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D138922
After https://reviews.llvm.org/D137653 named sub-operands can be used
in the auto-generated instruction decoders. This allows the
auto-generated decoders to work properly, so all the hand-coded
decoders in the sparc target can be removed.
In some instances, a manually-written decoder had not been implemented
for an instruction, and thus that instruction was not decoded
properly. These have been fixed (and tests added).
Differential Revision: https://reviews.llvm.org/D137727
Commit a538d1f13a13 first added support for named sub-operands in
CodeEmitterGen. We now add a few more features to that, enabling
further target cleanups.
1. Adds support for handling an EncoderMethod in a sub-operand in
CodeEmitterGen. Previously, the specified encoder of a sub-operand was
ignored, and only the default used.
2. Adds support for sub-operands in DecoderEmitter, along with support
for tied sub-operands.
The changes to the decoder required a few minor tweaks to a few
targets, where existing brokeness was exposed. In order to keep this
patch small, I left FIXMEs which will be addressed in upcoming
patches. (Except MIPS16, since its object file emission/decoding is
totally broken).
Differential Revision: https://reviews.llvm.org/D137653
Materialize zeros by copying from %g0, which is now marked as constant.
This makes it possible for some common operations (like integer negation) to be
performed in fewer instructions.
This continues @arichardson's patch at D132561.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D138887
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
Don't emit deprecated v8-style FP compares & branches when targeting v9
processors.
For now, always use %fcc0, because currently the allocator requires allocatable
registers to also be spillable, which isn't the case with v9 FCC registers.
The work to enable allocation over the entire FCC register file will be done in
a future patch.
Fixes bug #17834
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D135515
Do not emit deprecated v8-style branches when targeting a v9 processor.
As a side effect, this also fixes the emission of useless ba's when doing
conditional branches on 64-bit integer values.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D130006
This is a follow-on to https://reviews.llvm.org/D134073.
It renames a few fields to have consistent names, as well as renaming
operands to match the field names.
Behavior is unchanged by this cleanup. (The only generated code change
is for the disassembler for LDSTUB/LDSTUBA, but in both old and new
versions, it fails to add enough operands, and thus triggers a runtime
abort. I will address that bug in a future commit.)
Differential Revision: https://reviews.llvm.org/D134201
