Summary:
Mesa and other users must set this to enable coalescing:
- STRIDE = 0
- SWIZZLE_ENABLE = 1
This makes one particular compute shader 8x faster.
Reviewers: tstellarAMD, arsenm
Subscribers: arsenm, kzhuravl
Differential Revision: http://reviews.llvm.org/D21136
llvm-svn: 272556
The condition reg of the cndmask_b64 expansion can't be killed by
the first one, and the implicit super register implicit def is needed.
llvm-svn: 272554
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.
llvm-svn: 272512
The current SGPR spilling test does not stress this
because it is using s_buffer_load instructions to
increase SGPR pressure and spill, but their output
operands have the same SReg_32_XM0 constraint. This fixes
an error when the SReg_32 output from most instructions
is spilled.
llvm-svn: 270301
We only really need this to be true for SIFixSGPRCopies.
I'm not sure there's any way this could happen before that point.
Fixes a case where MachineCSE could introduce a cross block
scc use.
llvm-svn: 269391
Summary:
This includes a hazard recognizer implementation to replace some of
the hazard handling we had during frame index elimination.
Reviewers: arsenm
Subscribers: qcolombet, arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D18602
llvm-svn: 268143
Summary:
These instructions can add an immediate offset to the address, like other
ds instructions.
Reviewers: arsenm
Subscribers: arsenm, scchan
Differential Revision: http://reviews.llvm.org/D19233
llvm-svn: 268043
Summary:
The expression is detected as a redundant expression.
Turn out, this is probably a bug.
```
/home/etienneb/llvm/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp:306:26: warning: both side of operator are equivalent [misc-redundant-expression]
if (isSMRD(*FirstLdSt) && isSMRD(*FirstLdSt)) {
```
Reviewers: rnk, tstellarAMD
Subscribers: arsenm, cfe-commits
Differential Revision: http://reviews.llvm.org/D19460
llvm-svn: 267415
Summary:
This intrinsic returns true if the current thread belongs to a live pixel
and false if it belongs to a pixel that we are executing only for derivative
computation. It will be used by Mesa to implement gl_HelperInvocation.
Note that for pixels that are killed during the shader, this implementation
also returns true, but it doesn't matter because those pixels are always
disabled in the EXEC mask.
This unearthed a corner case in the instruction verifier, which complained
about a v_cndmask 0, 1, exec, exec<imp-use> instruction. That's stupid but
correct code, so make the verifier accept it as such.
Reviewers: arsenm, tstellarAMD
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D19191
llvm-svn: 267102
Summary:
The added testcase, which triggered this, was derived from a shader-db case
via bugpoint. A separate question is why scalar branching wasn't used.
Reviewers: arsenm, tstellarAMD
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D19208
llvm-svn: 266825
Perform store clustering just like load clustering. This change add
StoreClusterMutation in machine-scheduler. To control StoreClusterMutation,
added enableClusterStores() in TargetInstrInfo.h. This is enabled only on
AArch64 for now.
This change also add support for unscaled stores which were not handled in
getMemOpBaseRegImmOfs().
llvm-svn: 266437
Summary:
It seems like this was broken in r252327. I thought we had test cases
for this, but it's really hard to tirgger spills of this exact register
size since they aren't used very much.
Reviewers: arsenm, nhaehnle
Subscribers: nhaehnle, arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D19021
llvm-svn: 266152
Summary: This makes it possible to insert nops at the end of blocks.
Reviewers: arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D18549
llvm-svn: 265678
This makes it possible to distinguish between mesa shaders
and other kernels even in the presence of compute shaders.
Patch By: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Differential Revision: http://reviews.llvm.org/D18559
llvm-svn: 265589
Summary:
This helps prevent load clustering from drastically increasing register
pressure by trying to cluster 4 SMRDx8 loads together. The limit of 16
bytes was chosen, because it seems like that was the original intent
of setting the limit to 4 instructions, but more analysis could show
that a different limit is better.
This fixes yields small decreases in register usage with shader-db, but
also helps avoid a large increase in register usage when lane mask
tracking is enabled in the machine scheduler, because lane mask tracking
enables more opportunities for load clustering.
shader-db stats:
2379 shaders in 477 tests
Totals:
SGPRS: 49744 -> 48600 (-2.30 %)
VGPRS: 34120 -> 34076 (-0.13 %)
Code Size: 1282888 -> 1283184 (0.02 %) bytes
LDS: 28 -> 28 (0.00 %) blocks
Scratch: 495616 -> 492544 (-0.62 %) bytes per wave
Max Waves: 6843 -> 6853 (0.15 %)
Wait states: 0 -> 0 (0.00 %)
Reviewers: nhaehnle, arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D18451
llvm-svn: 264589
Summary:
Whole quad mode is already enabled for pixel shaders that compute
derivatives, but it must be suspended for instructions that cause a
shader to have side effects (i.e. stores and atomics).
This pass addresses the issue by storing the real (initial) live mask
in a register, masking EXEC before instructions that require exact
execution and (re-)enabling WQM where required.
This pass is run before register coalescing so that we can use
machine SSA for analysis.
The changes in this patch expose a problem with the second machine
scheduling pass: target independent instructions like COPY implicitly
use EXEC when they operate on VGPRs, but this fact is not encoded in
the MIR. This can lead to miscompilation because instructions are
moved past changes to EXEC.
This patch fixes the problem by adding use-implicit operands to
target independent instructions. Some general codegen passes are
relaxed to work with such implicit use operands.
Reviewers: arsenm, tstellarAMD, mareko
Subscribers: MatzeB, arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D18162
llvm-svn: 263982
The constant is now at source operand 1 (previously at 2).
This is also how it is in legacy AMD sp3 assembler.
Update tests.
Differential Revision: http://reviews.llvm.org/D17984
llvm-svn: 263212
Summary:
This is necessary for when we run out of VGPRs and can no
longer use v_{read,write}_lane for spilling SGPRs.
Reviewers: arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D17592
llvm-svn: 262732
Summary:
This patch impleemnts DS_PERMUTE/DS_BPERMUTE instruction definitions and intrinsics,
which are new since VI.
Reviewers: tstellarAMD, arsenm
Subscribers: llvm-commits, arsenm
Differential Revision: http://reviews.llvm.org/D17614
llvm-svn: 262356
Summary:
Instead of trying to replace SMRD instructions with a VGPR base pointer
with an equivalent MUBUF instruction, we now copy the base pointer to
SGPRs using v_readfirstlane.
This is safe to do, because any load selected as an SMRD instruction
has been proven to have a uniform base pointer, so each thread in the
wave will have the same pointer value in VGPRs.
This will fix some errors on VI from trying to replace SMRD instructions
with addr64-enabled MUBUF instructions that don't exist.
Reviewers: arsenm, cfang, nhaehnle
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D17305
llvm-svn: 261385
Summary: This change renames output operand for VOP instructions from dst to vdst. This is needed to enable decoding named operands for disassembler.
Reviewers: vpykhtin, tstellarAMD, arsenm
Subscribers: arsenm, llvm-commits, nhaustov
Projects: #llvm-amdgpu-spb
Differential Revision: http://reviews.llvm.org/D16920
llvm-svn: 260986
Introduce a subtarget feature for this, and leave the default with
the current behavior which assumes up to 16-byte loads/stores can
be used. The field also seems to have the ability to be set to 2 bytes,
but I'm not sure what that would be used for.
llvm-svn: 260651
Summary:
It's possible to have resource descriptors and samplers stored in
VGPRs, either by a VMEM instruction or in the case of samplers,
floating-point calculations. When this happens, we need to use
v_readfirstlane to copy these values back to sgprs.
Reviewers: mareko, arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D17102
llvm-svn: 260599
Summary:
When we split SMRD instructions into two MUBUFs we were adding the users
of the newly created MUBUFs to the VALU worklist. However, the only
users these instructions had was the REG_SEQUENCE that was inserted
by splitSMRD when the original SMRD instruction was split.
We need to make sure to add the users of the original SMRD to the VALU
worklist before it is split.
I have a test case, but it requires one other bug fix, so it will be
added in a later commt.
Reviewers: mareko, arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D17101
llvm-svn: 260588
If the two operands to an instruction were both
subregisters of the same super register, it would incorrectly
think this counted as the same constant bus use.
This fixes the verifier error in fmin_legacy.ll which
was missing -verify-machineinstrs.
llvm-svn: 260495
Summary:
Also delete all the stub functions that are identical to the
implementations in TargetInstrInfo.cpp.
Reviewers: arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D16609
llvm-svn: 259054
Summary:
It is off by default, but can be used
with --misched=si
Patch by: Axel Davy
Reviewers: arsenm, tstellarAMD, nhaehnle
Subscribers: nhaehnle, solenskiner, arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D11885
llvm-svn: 257609
Summary:
Multi-dword constant loads generated unnecessary moves from SGPRs into VGPRs,
increasing the code size and VGPR pressure. These moves are now folded away.
Note that this lack of operand folding was not a problem for VMEM loads,
because COPY nodes from VReg_Nnn to VGPR32 are eliminated by the register
coalescer.
Some tests are updated, note that the fsub.ll test explicitly checks that
the move is elided.
With the IR generated by current Mesa, the changes are obviously relatively
minor:
7063 shaders in 3531 tests
Totals:
SGPRS: 351872 -> 352560 (0.20 %)
VGPRS: 199984 -> 200732 (0.37 %)
Code Size: 9876968 -> 9881112 (0.04 %) bytes
LDS: 91 -> 91 (0.00 %) blocks
Scratch: 1779712 -> 1767424 (-0.69 %) bytes per wave
Wait states: 295164 -> 295337 (0.06 %)
Totals from affected shaders:
SGPRS: 65784 -> 66472 (1.05 %)
VGPRS: 38064 -> 38812 (1.97 %)
Code Size: 1993828 -> 1997972 (0.21 %) bytes
LDS: 42 -> 42 (0.00 %) blocks
Scratch: 795648 -> 783360 (-1.54 %) bytes per wave
Wait states: 54026 -> 54199 (0.32 %)
Reviewers: tstellarAMD, arsenm, mareko
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D15875
llvm-svn: 257074
Summary:
When copying aggregate registers within the same register class, there may
be an overlap between source and destination that forces us to do the copy
backwards.
Do the simplest possible thing that guarantees the correct order of moves
when there are overlaps, and does whatever when there is no overlap. (The
last part forces some trivial adjustments to test cases.)
Together with r255906, this fixes a VM fault in Unreal Elemental Demo.
While at it, change the generation of kill and def flags to something that
looks more reasonable. This method is used very late during compilation, so
it probably doesn't matter in practice, and to be honest, I don't know if
this change is actually correct because the semantics in connection with
aggregate registers vs. sub-registers are not clear to me.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93264
Reviewers: arsenm, tstellarAMD
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D15622
llvm-svn: 256072
Summary:
The method insertNOPs expected the number of wait states to be passed as
parameter, while eliminateFrameIndex passed the immediate argument for the
S_NOP, leading to an off-by-one error. Rename the method to make the
meaning of its parameter clearer. The number of 4 / 5 wait states (which
is what the method has always _tried_ to do according to the comment) is
correct according to the hardware docs.
I stumbled upon this while trying to track down the cause of
https://bugs.freedesktop.org/show_bug.cgi?id=93264. While clearly needed,
this patch unfortunately does not fix that bug...
Reviewers: arsenm, tstellarAMD
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D15542
llvm-svn: 255906
Summary:
This allows us to remove the END_OF_TEXT_LABEL hack we had been using
and simplifies the fixups used to compute the address of constant
arrays.
Reviewers: arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D15257
llvm-svn: 255204
