Occupancy is expressed as waves per SIMD. This means that we need to
take into account the number of SIMDs per "CU" or, to be more precise,
the number of SIMDs over which a workgroup may be distributed.
getOccupancyWithLocalMemSize was wrong because it didn't take SIMDs
into account at all.
At the same time, we need to take into account that WGP mode offers
access to a larger total amount of LDS, since this can affect how
non-power-of-two LDS allocations are rounded. To make this work
consistently, we distinguish between (available) local memory size and
addressable local memory size (which is always limited by 64kB on
gfx10+, even with WGP mode).
This change results in a massive amount of test churn. A lot of it is
caused by the fact that the default work group size is 1024, which means
that (due to rounding effects) the default occupancy on older hardware
is 8 instead of 10, which affects scheduling via register pressure
estimates. I've adjusted most tests by just running the UTC tools, but
in some cases I manually changed the work group size to 32 or 64 to make
sure that work group size chunkiness has no effect.
Differential Revision: https://reviews.llvm.org/D139468
We will use this for more accurate occupancy computations. Note that
IsaInfo takes WGP mode vs. CU mode into account on gfx10+.
Differential Revision: https://reviews.llvm.org/D139467
Tablegen definitions for subtarget features and cpp predicate functions to
access the features.
New Sub-TargetProcessors and common latencies.
Simple changes to MIR codegen tests which pass on gfx11 because they have the
same output as previous subtargets or operate on pseudo instructions which
are reused from previous subtargets.
Contributors:
Jay Foad <jay.foad@amd.com>
Petar Avramovic <Petar.Avramovic@amd.com>
Patch 4/N for upstreaming of AMDGPU gfx11 architecture
Depends on D124538
Reviewed By: Petar.Avramovic, foad
Differential Revision: https://reviews.llvm.org/D125261
Use default member initializers in AMDGPUSubtarget and subclasses. This
is to guard against adding a new feature boolean in AMDGPUSubtarget.h
but forgetting to initialize it to false in AMDGPUSubtarget.cpp.
This was mostly autogenerated by:
clang-tidy -checks=-*,cppcoreguidelines-prefer-member-initializer,modernize-use-default-member-init -header-filter=Subtarget -fix lib/Target/AMDGPU/*Subtarget.cpp
Differential Revision: https://reviews.llvm.org/D123613
This was inheriting the mesa behavior, and as far as I know nobody is
using opencl kernels with amdpal. The isMesaKernel check was
irrelevant because this property needs to be held for all functions.
Add an overload to pass the flat workgroup range in separately. This
will allow the attributor to use the assumed value for
amdgpu-flat-workgroup-sizes when inferring amdgpu-waves-per-eu.
Added support to check if architecture supports s_mulhi which is used as part of
the decision whether or not to use valu 24 bit mul (if the mulhi gets
transformed to a valu op anyway, then may as well use it).
This is an extension of the work in D97063
Differential Revision: https://reviews.llvm.org/D103321
Change-Id: I80b1323de640a52623d69ac005a97d06a5d42a14
Currently, the compiler crashes in instruction selection of global
load/stores in gfx600 due to the lack of FLAT instructions. This patch
fix the crash by selecting MUBUF instructions for global load/stores
in gfx600.
Authored-by: Praveen Velliengiri <Praveen.Velliengiri@amd.com>
Reviewed by: t-tye
Differential revision: https://reviews.llvm.org/D92483
- Add an internal option `-amdgpu-use-aa-in-codegen` to enable or
disable this feature. By Default, it's enabled.
Differential Revision: https://reviews.llvm.org/D89320
The support is disabled by default. So far there is instruction
selection, spilling, and frame elimination. It also changes SP
from unswizzled to swizzled as used by flat scratch instructions,
so it cannot be mixed with MUBUF stack access.
At the very least missing:
- GlobalISel;
- Some optimizations in frame elimination in between vector
and scalar ALU;
- It shall finally allow to always materialize frame index
as an SGPR, but that is not implemented and frame elimination
cannot handle it yet;
- Unaligned and/or multidword flat scratch shall work, but it
is legalized now for MUBUF;
- Operand folding cannot optimize FI like with MUBUF yet;
- It will need scaling the value of the SP/FP in the DWARF
expression to recover the unswizzled scratch address;
Differential Revision: https://reviews.llvm.org/D89170
GFX10 enables third addressing mode for flat scratch instructions,
an ST mode. In that mode both register operands are omitted and
only swizzled offset is used in addition to flat_scratch base.
Differential Revision: https://reviews.llvm.org/D89501
Summary:
This implements a workaround for a hardware bug in gfx8 and gfx9,
where register usage is not estimated correctly for image_store and
image_gather4 instructions when D16 is used.
Change-Id: I4e30744da6796acac53a9b5ad37ac1c2035c8899
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81172
Intrinsic declarations use the default subtarget, but this should be
using the subtarget for the calling function. I haven't been able to
come up with a case where it matters though.
Handle workitem intrinsics. There isn't really away to adequately test
this right now, since none of the known bits users are fine grained
enough to test the edge conditions. This triggers a number of
instances of the new 64-bit to 32-bit shift combine in the existing
tests.
Do not break down local loads and stores so ds_read/write_b96/b128 in
ISelLowering can be selected on subtargets that support them and if align
requirements allow them.
Differential Revision: https://reviews.llvm.org/D84403
Features UnalignedBufferAccess and UnalignedDSAccess are now used to determine
whether hardware supports such access.
UnalignedAccessMode should be used to enable them.
hasUnalignedBufferAccessEnabled() and hasUnalignedDSAccessEnabled() can be
now used to quickly check both.
Differential Revision: https://reviews.llvm.org/D84522
Adjust alignment requirements for ds_read/write_b96/b128.
GFX9 and onwards allow misaligned access for reads and writes but only if
SH_MEM_CONFIG.alignment_mode allows it.
UnalignedDSAccess is set on GCN subtargets from GFX9 onward to let us know if we
can relax alignment requirements.
UnalignedAccessMode acts similary to UnalignedBufferAccess for DS instructions
but only from GFX9 onward and is supposed to match alignment_mode. By default
alignment of 4 is required.
Differential Revision: https://reviews.llvm.org/D82788
This patch implements initial backend support for a -mtune CPU controlled by a "tune-cpu" function attribute. If the attribute is not present X86 will use the resolved CPU from target-cpu attribute or command line.
This patch adds MC layer support a tune CPU. Each CPU now has two sets of features stored in their GenSubtargetInfo.inc tables . These features lists are passed separately to the Processor and ProcessorModel classes in tablegen. The tune list defaults to an empty list to avoid changes to non-X86. This annoyingly increases the size of static tables on all target as we now store 24 more bytes per CPU. I haven't quantified the overall impact, but I can if we're concerned.
One new test is added to X86 to show a few tuning features with mismatched tune-cpu and target-cpu/target-feature attributes to demonstrate independent control. Another new test is added to demonstrate that the scheduler model follows the tune CPU.
I have not added a -mtune to llc/opt or MC layer command line yet. With no attributes we'll just use the -mcpu for both. MC layer tools will always follow the normal CPU for tuning.
Differential Revision: https://reviews.llvm.org/D85165
There were various hacks used to try to avoid making s1 SGPR vs. s1
VCC ambiguous after constraining the register before we had a strategy
to deal with this. This also attempted to handle undef operands, which
are now illegal gMIR.
This was never used, and the only thing it changed was removed in
284472be6da3353d81dfd25b1ac4218e852d1e5f. The floating point mode is
also not a property of the subtarget.
Enable clausing of memory loads on gfx10 by adding a new pass to insert
the s_clause instructions that mark the start of each hard clause.
Differential Revision: https://reviews.llvm.org/D79792
This allows targets to know exactly which operands are contributing to
the dependency, which is required for targets with per-operand
scheduling models.
Differential Revision: https://reviews.llvm.org/D77135
Summary: I think Max in the name was misleading. NFC.
Reviewers: arsenm, rampitec
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76860
Implement the DWARF register mapping described in llvm/docs/AMDGPUUsage.rst.
This enables generating appropriate DWARF register numbers for wave64 and
wave32 modes.
Based on D72931
This adds a new feature called A16 which is enabled for gfx10.
gfx9 keeps the R128A16 feature so it can share all the instruction encodings
with gfx7/8.
Differential Revision: https://reviews.llvm.org/D73956
Use cmp ord instead of cmp_class compared to the DAG version for the
nan check, but mostly try to match the existsing pattern.
I think the sign doesn't matter for fract, so we could do a little
better with the source modifier matching.
I think this is also still broken as in D22898, but I'm leaving it
as-is for now while I don't have an SI system to test on.
Summary:
Up to gfx9, writes to vcc_lo and vcc_hi by instructions like
v_readlane and v_readfirstlane do not update vccz to reflect the new
value of vcc. Fix it by reusing part of the existing vccz bug handling
code, which inserts an "s_mov_b64 vcc, vcc" instruction to restore vccz
just before an instruction that needs the correct value.
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69661
