1) It was marked as volatile. This is not needed and the only reason
it was done is because it is both load and store and handled
together with atomics. Global load to LDS was marked as volatile
just because buffer load was done that way.
2) Preserve at least LDS (store) pointer which we always have with
the intrinsics.
3) Use PoisonValue instead of nullptr for load memop as a Value.
This is an experimental address space for strided buffers. These buffers
can have structs as elements and
a stride > 1.
These pointers allow the indexed access in units of stride, i.e., they
point at `buffer[index * stride]`.
Thus, we can use the `idxen` modifier for buffer loads.
We assign address space 9 to 192-bit buffer pointers which contain a
128-bit descriptor, a 32-bit offset and a 32-bit index. Essentially,
they are fat buffer pointers with an additional 32-bit index.
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
It seems TypeSize is currently broken in the sense that:
TypeSize::Fixed(4) + TypeSize::Scalable(4) => TypeSize::Fixed(8)
without failing its assert that explicitly tests for this case:
assert(LHS.Scalable == RHS.Scalable && ...);
The reason this fails is that `Scalable` is a static method of class
TypeSize,
and LHS and RHS are both objects of class TypeSize. So this is
evaluating
if the pointer to the function Scalable == the pointer to the function
Scalable,
which is always true because LHS and RHS have the same class.
This patch fixes the issue by renaming `TypeSize::Scalable` ->
`TypeSize::getScalable`, as well as `TypeSize::Fixed` to
`TypeSize::getFixed`,
so that it no longer clashes with the variable in
FixedOrScalableQuantity.
The new methods now also better match the coding standard, which
specifies that:
* Variable names should be nouns (as they represent state)
* Function names should be verb phrases (as they represent actions)
Function parameters marked with inreg are supposed to be allocated to
SGPRs. However, for compute functions, this is ignored and function
parameters are allocated to VGPRs. This fix modifies CC_AMDGPU_Func in
AMDGPUCallingConv.td to use SGPRs if input arg is marked inreg.
---------
Co-authored-by: Jun Wang <jun.wang7@amd.com>
V3 has been deprecated for a while as well, so it can safely be removed
like V2 was removed.
- [Clang] Set minimum code object version to 4
- [lld] Fix tests using code object v3
- Remove code object V3 from the AMDGPU backend, and delete or port v3
tests to v4.
- Update docs to make it clear V3 can no longer be emitted.
Improve selection of the following pattern:
bool cnd = ...
if (amdgcn.ballot(cnd) != 0) {
...
}
which means "execute _then_ if any lane has satisfied the _cnd_
condition".
The @llvm.amdgcn.cs.chain intrinsic is essentially a call. The call
parameters are bundled up into 2 intrinsic arguments, one for those that
should go in the SGPRs (the 3rd intrinsic argument), and one for those
that should go in the VGPRs (the 4th intrinsic argument). Both will
often be some kind of aggregate.
Both instruction selection frameworks have some internal representation
for intrinsics (G_INTRINSIC[_WITH_SIDE_EFFECTS] for GlobalISel,
ISD::INTRINSIC_[VOID|WITH_CHAIN] for DAGISel), but we can't use those
because aggregates are dissolved very early on during ISel and we'd lose
the inreg information. Therefore, this patch shortcircuits both the
IRTranslator and SelectionDAGBuilder to lower this intrinsic as a call
from the very start. It tries to use the existing infrastructure as much
as possible, by calling into the code for lowering tail calls.
This has already gone through a few rounds of review in Phab:
Differential Revision: https://reviews.llvm.org/D153761
moveToVALU previously only handled S_CSELECT_B64 in the trivial case
where it was semantically equivalent to a copy. Implement the general
case using V_CNDMASK_B64_PSEUDO and implement post-RA expansion of
V_CNDMASK_B64_PSEUDO with immediate as well as register operands.
When SI_PC_ADD_REL_OFFSET is expanded to S_GETPC/S_ADD/S_ADDC, the
GlobalAddress operands have to be adjusted by 4 or 12 bytes to account
for the offset from the end of the S_GETPC instruction to the literal
operands. Do this all in SIInstrInfo::expandPostRAPseudo instead of
duplicating the adjustment code in both AMDGPULegalizerInfo and
SITargetLowering. NFCI.
This allows working with e.g. v8i8 / v16i8 sources.
It is generally useful, but is primarily beneficial when allowing e.g. v8i8s to be passed to branches directly through registers. As such, this is the first in a series of patches to enable that work. However, it effects https://reviews.llvm.org/D155995, so it has been implemented on top of that.
Differential Revision: https://reviews.llvm.org/D159036
Change-Id: Idfcb57dacd0c32cab040fe4dd4ac2ec762750664
eaf85b9c28 "[AMDGPU] Select VGPR versions of MFMA if possible" prevents
the compiler from reserving AGPRs if a kernel has no inline asm
explicitly using AGPRs, no calls, and runs at least 2 waves with not
more than 256 VGPRs. This, in turn, makes it impossible to allocate AGPR
if necessary. As a result, regalloc fails in case we have an MAI
instruction that has at least one AGPR operand.
This change checks if we have AGPRs and forces operands to VGPR if we do
not have them.
---------
Co-authored-by: Alexander Timofeev <alexander.timofeev@amd.com>
V3 has been deprecated for a while as well, so it can safely be removed
like V2 was removed.
- [Clang] Set minimum code object version to 4
- [lld] Fix tests using code object v3
- Remove code object V3 from the AMDGPU backend, and delete or port v3
tests to v4.
- Update docs to make it clear V3 can no longer be emitted.
The primary ISA-independent justification for using PC-relative
addressing is that it makes code position-independent and therefore
allows sharing of .text pages between processes.
When not sharing .text pages, we can use absolute relocations instead,
which will possibly prevent a bubble introduced by s_getpc_b64.
Co-authored-by: Thomas Symalla <thomas.symalla@amd.com>
This patch adds the DAG isel changes for kernel argument preloading.
These changes are not usable with older firmware but subsequent patches
in the series will make the codegen backwards compatible. This patch
should only be submitted alongside that subsequent patch.
Preloading here begins from the start of the kernel arguments until the
amount of arguments indicated by the CL flag
amdgpu-kernarg-preload-count.
Aggregates and arguments passed by-ref are not supported.
Special care for the alignment of the kernarg segment is needed as well
as consideration of the alignment of addressable SGPR tuples when we
cannot directly use misaligned large tuples that the arguments are
loaded to.
Reviewed By: bcahoon
Differential Revision: https://reviews.llvm.org/D158579
Given a list of constraints for InlineAsm (ex. "imr") I'm looking to
modify the order in which they are chosen. Before doing so, I noticed a
fair
amount of logic is duplicated between SelectionDAGISel and GlobalISel
for this.
That is because SelectionDAGISel is also trying to lower immediates
during selection. If we detangle these concerns into:
1. choose the preferred constraint
2. attempt to lower that constraint
Then we can slide down the list of constraints until we find one that
can be lowered. That allows the implementation to be shared between
instruction selection frameworks.
This makes it so that later I might only need to adjust the priority of
constraints in one place, and have both selectors behave the same.
Pulled out of D159533, which encourages (zext (trunc x)) -> x folds, leading to more ISD::FSHR nodes, which was breaking some existing AMDGPUISD::PERM tests
Differential Revision: https://reviews.llvm.org/D159533
Real True16 instructions are as they are defined in the ISA. Fake True16
instructions are identical to real ones except that they take 32-bit
registers as operands and always use their low halves.
Reviewed By: Joe_Nash
Differential Revision: https://reviews.llvm.org/D156100
This will make it easy for callers to see issues with and fix up calls
to createTargetMachine after a future change to the params of
TargetMachine.
This matches other nearby enums.
For downstream users, this should be a fairly straightforward
replacement,
e.g. s/CodeGenOpt::Aggressive/CodeGenOptLevel::Aggressive
or s/CGFT_/CodeGenFileType::
Make codegen emit correctly rounded sqrt by default.
Emit the fast but only kind of fast expansion in AMDGPUCodeGenPrepare
based on !fpmath, like the fdiv case. Hack around visitation ordering
problems from AMDGPUCodeGenPrepare using forward iteration instead of
a well behaved combiner.
https://reviews.llvm.org/D158129
