nThis avoids the nasty problems caused by using
memory instructions that read the exec mask while
spilling / restoring registers used for control flow
masking, but only for VI when these were added.
This always uses the scalar stores when enabled currently,
but it may be better to still try to spill to a VGPR
and use this on the fallback memory path.
The cache also needs to be flushed before wave termination
if a scalar store is used.
llvm-svn: 286766
Summary:
This pass was assuming that when a PHI instruction defined a register
used by another PHI instruction that the defining insstruction would
be legalized before the using instruction.
This assumption was causing the pass to not legalize some PHI nodes
within divergent flow-control.
This fixes a bug that was uncovered by r285762.
Reviewers: nhaehnle, arsenm
Subscribers: kzhuravl, wdng, nhaehnle, yaxunl, tony-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D26303
llvm-svn: 286676
If the branch was on a read-undef of vcc, passes that used
analyzeBranch to invert the branch condition wouldn't preserve
the undef flag resulting in a verifier error.
Fixes verifier failures in a future commit.
Also fix verifier error when inserting copy for vccz
corruption bug.
llvm-svn: 286133
Summary:
The post-RA scheduler occasionally uses additional implicit operands when
the vector implicit operand as a whole is killed, but some subregisters
are still live because they are directly referenced later. Unfortunately,
this seems incredibly subtle to reproduce.
Fixes piglit spec/glsl-110/execution/variable-indexing/vs-temp-array-mat2-index-wr.shader_test
and others.
Reviewers: arsenm, tstellarAMD
Subscribers: kzhuravl, wdng, yaxunl, tony-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D25656
llvm-svn: 285835
Summary:
Flat instruction can return out of order, so we need always need to wait
for all the outstanding flat operations.
Reviewers: tony-tye, arsenm
Subscribers: kzhuravl, wdng, nhaehnle, llvm-commits, yaxunl
Differential Revision: https://reviews.llvm.org/D25998
llvm-svn: 285479
Also add glc bit to the scalar loads since they exist on VI
and change the caching behavior.
This currently has an assembler bug where the glc bit is incorrectly
accepted on SI/CI which do not have it.
llvm-svn: 285463
Add unit tests for checking a few tricky instruction sizes. Also remove the old
tests for the instruction sizes, which were clunky and brittle.
Since this is the first set of target-specific unit tests, we need to add some
CMake plumbing. In the future, adding unit tests for a given target will be as
simple as creating a directory with the same name as the target under
unittests/Target. The tests are only run if the target is enabled in
LLVM_TARGETS_TO_BUILD.
Differential Revision: https://reviews.llvm.org/D24548
llvm-svn: 283990
This changes MachineRegisterInfo to be initializes after parsing all
instructions. This is in preparation for upcoming commits that allow the
register class specification on the operand or deduce them from the
MCInstrDesc.
This commit removes the unused feature of having nonsequential register
numbers. This was confusing anyway as the vreg numbers would be
different after parsing when you had "holes" in your numbering.
This patch also introduces the concept of an incomplete virtual
register. An incomplete virtual register may be used during .mir parsing
to construct MachineOperands without knowing the exact register class
(or register bank) yet.
NFC except for some error messages.
Differential Revision: https://reviews.llvm.org/D22397
llvm-svn: 283848
Fixes to allow spilling all registers at the end of the block
work with exec modifications. Don't emit s_and_saveexec_b64 for
if lowering, and instead emit copies. Mark control flow mask
instructions as terminators to get correct spill code placement
with fast regalloc, and then have a separate optimization pass
form the saveexec.
This should work if SGPRs are spilled to VGPRs, but
will likely fail in the case that an SGPR spills to memory
and no workitem takes a divergent branch.
llvm-svn: 282667
Summary:
The current implementation of isConstantPhysReg() checks for defs of
physical registers to determine if they are constant. Some
architectures (e.g. AArch64 XZR/WZR) have registers that are constant
and may be used as destinations to indicate the generated value is
discarded, preventing isConstantPhysReg() from returning true. This
change adds a TargetRegisterInfo hook that overrides the no defs check
for cases such as this.
Reviewers: MatzeB, qcolombet, t.p.northover, jmolloy
Subscribers: junbuml, aemerson, mcrosier, rengolin
Differential Revision: https://reviews.llvm.org/D24570
llvm-svn: 282543
We currently return 4 for stackmaps and patchpoints, which is very optimistic
and can in rare cases cause the branch relaxation pass to fail to relax certain
branches.
This patch causes getInstSizeInBytes to return a pessimistic estimate of the
size as the number of bytes requested in the stackmap/patchpoint. In the future,
we could provide a more accurate estimate by sharing some of the logic in
AArch64::LowerSTACKMAP/PATCHPOINT.
Fixes part of https://llvm.org/bugs/show_bug.cgi?id=28750
Differential Revision: https://reviews.llvm.org/D24073
llvm-svn: 281301
Some generic instructions have multiple types. While in theory these always be
discovered by inspecting the single definition of each generic vreg, in
practice those definitions won't always be local and traipsing through a big
function to find them will not be fun.
So this changes MIRPrinter to print out the type of uses as well as defs, if
they're known to be different or not known to be the same.
On the parsing side, we're a little more flexible: provided each register is
given a type in at least one place it's mentioned (and all types are
consistent) we accept the MIR. This doesn't introduce ambiguity but makes
writing tests manually a bit less painful.
llvm-svn: 281204
We want each register to have a canonical type, which means the best place to
store this is in MachineRegisterInfo rather than on every MachineInstr that
happens to use or define that register.
Most changes following from this are pretty simple (you need an MRI anyway if
you're going to be doing any transformations, so just check the type there).
But legalization doesn't really want to check redundant operands (when, for
example, a G_ADD only ever has one type) so I've made use of MCInstrDesc's
operand type field to encode these constraints and limit legalization's work.
As an added bonus, more validation is possible, both in MachineVerifier and
MachineIRBuilder (coming soon).
llvm-svn: 281035
We're intending to move to a world where the type of a register is determined
by its (unique) def. This is incompatible with physregs, which are untyped.
It also means the other passes don't have to worry quite so much about
register-class compatibility and inserting COPYs appropriately.
llvm-svn: 280132
Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.
Differential Revision: http://reviews.llvm.org/D23850
llvm-svn: 279698
tracksSubRegLiveness only depends on the Subtarget and a cl::opt, there
is not need to change it or save/parse it in a .mir file.
Make the field const and move the initialization LiveIntervalAnalysis to the
MachineRegisterInfo constructor. Also cleanup some code and fix some
instances which better use MachineRegisterInfo::subRegLivenessEnabled() instead
of TargetSubtargetInfo::enableSubRegLiveness().
llvm-svn: 279676
Specifying isSSA is an extra line at best and results in invalid MI at
worst. Compute the value instead.
Differential Revision: http://reviews.llvm.org/D22722
llvm-svn: 279600
Selected: the InstructionSelect pass ran and all pre-isel generic
instructions have been eliminated; i.e., all instructions are now
target-specific or non-pre-isel generic instructions (e.g., COPY).
Since only pre-isel generic instructions can have generic virtual register
operands, this also means that all generic virtual registers have been
constrained to virtual registers (assigned to register classes) and that
all sizes attached to them have been eliminated.
This lets us enforce certain invariants across passes.
This property is GlobalISel-specific, but is always available.
llvm-svn: 277482
RegBankSelected: the RegBankSelect pass ran and all generic virtual
registers have been assigned to a register bank.
This lets us enforce certain invariants across passes.
This property is GlobalISel-specific, but is always available.
llvm-svn: 277475
Legalized: The MachineLegalizer ran; all pre-isel generic instructions
have been legalized, i.e., all instructions are now one of:
- generic and always legal (e.g., COPY)
- target-specific
- legal pre-isel generic instructions.
This lets us enforce certain invariants across passes.
This property is GlobalISel-specific, but is always available.
llvm-svn: 277470
The branch relaxation pass is computing the wrong offsets because it assumes
TLSDESC_CALLSEQ eats up 4 bytes, when in fact it is lowered to an instruction
sequence taking up 16 bytes. This can become a problem in huge files with lots
of TLS accesses, as it may slowly move branch targets out of the range computed
by the branch relaxation pass.
Fixes PR24234 https://llvm.org/bugs/show_bug.cgi?id=24234
Differential Revision: https://reviews.llvm.org/D22870
llvm-svn: 277331
Change the syntax to use `%0.sub8` to denote a subregister.
This seems like a more natural fit to denote subregisters; I also plan
to introduce a new ":classname" syntax in upcoming patches to denote the
register class of a vreg.
Note that this commit disallows plain identifiers to start with a '.'
character. This shouldn't affect anything as external names/IR
references are all prefixed with '$'/'%', plain identifiers are only
used for instruction names, register mask names and subreg indexes.
Differential Revision: https://reviews.llvm.org/D22390
llvm-svn: 276815
In an instruction like:
CFI_INSTRUCTION .cfi_def_cfa ...
we can drop the '.cfi_' prefix since that should be obvious by the
context:
CFI_INSTRUCTION def_cfa ...
While being a terser and cleaner syntax this also prepares to dropping
support for identifiers starting with a dot character so we can use it
for expressions.
Differential Revision: http://reviews.llvm.org/D22388
llvm-svn: 276785
When we failed to parse a function in the mir parser, we should abort
the whole compilation instead of continuing in a weird state. Indeed,
this was creating strange machine function passes failures that were
hard to understand, until we notice that the function actually did not
get parsed correctly!
llvm-svn: 276348
This should be all the low-level instruction selection needs to determine how
to implement an operation, with the remaining context taken from the opcode
(e.g. G_ADD vs G_FADD) or other flags not based on type (e.g. fast-math).
llvm-svn: 276158
Also verify that we never try to set the size of a vreg associated
to a register class.
Report an error when we encounter that in MIR. Fix a testcase that
hit that error and had a size for no reason.
llvm-svn: 276012
This does not schedule any passes besides the ones necessary to
construct and print the machine function. This is useful to test .mir
file reading and printing.
Differential Revision: http://reviews.llvm.org/D22432
llvm-svn: 275664
test/CodeGen/MIR/ARM/ARMLoadStoreDBG.mir is an actual test for the ARM
load store optimization pass and not a test of the mir parser/printer.
It belongs to test/CodeGen/ARM; This also updates the test to use the
new -run-pass llc syntax.
llvm-svn: 275662
Currently the MIR framework prints all its outputs (errors and actual
representation) on stderr.
This patch fixes that by printing the regular output in the output
specified with -o.
Differential Revision: http://reviews.llvm.org/D22251
llvm-svn: 275314
Tom Stellard