the compilation time and there is no case for which we see any improvement in
performance. This patch removes this pass and its associated test cases from
the tree.
Differential Revision: https://reviews.llvm.org/D101313
Change-Id: I0599169a7609c19a887f8d847a71e664030cc141
Prefer to keep uniform (non-divergent) multiplies on the scalar ALU when
possible. This significantly improves some game cases by eliminating
v_readfirstlane instructions when the result feeds into a scalar
operation, like the address calculation for a scalar load or store.
Since isDivergent is only an approximation of whether a value is in
SGPRs, it can potentially regress some situations where a uniform value
ends up in a VGPR. These should be rare in real code, although the test
changes do contain a number of examples.
Most of the test changes are just using s_mul instead of v_mul/mad which
is generally better for both register pressure and latency (at least on
GFX10 where sgpr pressure doesn't affect occupancy and vector ALU
instructions have significantly longer latency than scalar ALU). Some
R600 tests now use MULLO_INT instead of MUL_UINT24.
GlobalISel appears to handle more scenarios in the desirable way,
although it can also be thrown off and fails to select the 24-bit
multiplies in some cases.
Alternative solution considered and rejected was to allow selecting
MUL_[UI]24 to S_MUL_I32. I've rejected this because the definition of
those SD operations works is don't-care on the most significant 8 bits,
and this fact is used in some combines via SimplifyDemandedBits.
Based on a patch by Nicolai Hähnle.
Differential Revision: https://reviews.llvm.org/D97063
Enabled "bound_ctrl:1" and disabled "bound_ctrl:-1" syntax.
Corrected printer to output "bound_ctrl:1" instead of "bound_ctrl:0".
See bug 35397 for detailed issue description.
Differential Revision: https://reviews.llvm.org/D97048
Move implementation of kill intrinsics to WQM pass. Add live lane
tracking by updating a stored exec mask when lanes are killed.
Use live lane tracking to enable early termination of shader
at any point in control flow.
Reviewed By: piotr
Differential Revision: https://reviews.llvm.org/D94746
This is a (last big?) part of the patch series to make SimplifyCFG
preserve DomTree. Currently, it still does not actually preserve it,
even thought it is pretty much fully updated to preserve it.
Once the default is flipped, a valid DomTree must be passed into
simplifyCFG, which means that whatever pass calls simplifyCFG,
should also be smart about DomTree's.
As far as i can see from `check-llvm` with default flipped,
this is the last LLVM test batch (other than bugpoint tests)
that needed fixes to not break with default flipped.
The changes here are boringly identical to the ones i did
over 42+ times/commits recently already,
so while AMDGPU is outside of my normal ecosystem,
i'm going to go for post-commit review here,
like in all the other 42+ changes.
Note that while the pass is taught to preserve {,Post}DomTree,
it still doesn't do that by default, because simplifycfg
still doesn't do that by default, and flipping default
in this pass will implicitly flip the default for simplifycfg.
That will happen, but not right now.
Pseudo-registers allow different register encodings
between gpu generations. Make sure we resolve the
pseudo regs to real regs whenever we get their
hardware encoding.
Using the correct encodings revealed a register
bank conflict and an unnecessary write dependency.
Tests have been updated to match.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D90721
Change-Id: I73c154cd24aecc820993b50bebaf4df97a5710ca
Exec mask manipulation inserted by SIWholeQuadMode barriers to
instruction scheduling. Move the entire pass after the machine
instruction scheduler and make changes so pass is correct for
non-SSA operation. These changes should leave the pass still
usable pre-scheduler, although tests have be updated to reflect
post-scheduler results.
Reviewed By: nhaehnle
Differential Revision: https://reviews.llvm.org/D88081
Passes that are run after the post-RA scheduler may insert instructions like
waitcnt which eliminate the need for certain noops. After this patch the
scheduler is still aware of possible latency from hazards but noops will
not be inserted until the dedicated hazard recognizer pass is run.
Depends on D89753.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D89754
This was assumed to be a simple move, and interpreting the immediate
modifier operand as a materialized immediate. Apparently the SDWA pass
never produces these, but GlobalISel does emit these for some vector
shuffles.
Add a new llvm.amdgcn.ballot intrinsic modeled on the ballot function
in GLSL and other shader languages. It returns a bitfield containing the
result of its boolean argument in all active lanes, and zero in all
inactive lanes.
This is intended to replace the existing llvm.amdgcn.icmp and
llvm.amdgcn.fcmp intrinsics after a suitable transition period.
Use the new intrinsic in the atomic optimizer pass.
Differential Revision: https://reviews.llvm.org/D65088
The current implementation of skip insertion (SIInsertSkip) makes it a
mandatory pass required for correctness. Initially, the idea was to
have an optional pass. This patch inserts the s_cbranch_execz upfront
during SILowerControlFlow to skip over the sections of code when no
lanes are active. Later, SIRemoveShortExecBranches removes the skips
for short branches, unless there is a sideeffect and the skip branch is
really necessary.
This new pass will replace the handling of skip insertion in the
existing SIInsertSkip Pass.
Differential revision: https://reviews.llvm.org/D68092
The current implementation of skip insertion (SIInsertSkip) makes it a
mandatory pass required for correctness. Initially, the idea was to
have an optional pass. This patch inserts the s_cbranch_execz upfront
during SILowerControlFlow to skip over the sections of code when no
lanes are active. Later, SIRemoveShortExecBranches removes the skips
for short branches, unless there is a sideeffect and the skip branch is
really necessary.
This new pass will replace the handling of skip insertion in the
existing SIInsertSkip Pass.
Differential revision: https://reviews.llvm.org/D68092
Summary:
Add support for gfx10, where all DPP operations are confined to work
within a single row of 16 lanes, and wave32.
Reviewers: arsenm, sheredom, critson, rampitec
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, t-tye, hiraditya, jfb, dstuttard, tpr, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65644
llvm-svn: 369745
Summary:
r363675 changed the exec modification helper function, now called
execMayBeModifiedBeforeUse, so that if no UseMI is specified it checks
all instructions in the basic block, even beyond the last use. That
meant that the DPP combiner no longer worked in any basic block that
ended with a control flow instruction, and in particular it didn't work
on code sequences generated by the atomic optimizer.
Fix it by reinstating the old behaviour but in a new helper function
execMayBeModifiedBeforeAnyUse, and limiting the number of instructions
scanned.
Reviewers: arsenm, vpykhtin
Subscribers: kzhuravl, nemanjai, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, kbarton, MaskRay, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64393
llvm-svn: 365910
This commit fixes the DPP sequence in the atomic optimizer (which was
previously missing the row_shr:3 step), and works around a read_register
exec bug by using a ballot instead.
Differential Revision: https://reviews.llvm.org/D57737
llvm-svn: 353703
The new atomic optimizer I previously added in D51969 did not work
correctly when a pixel shader was using derivatives, and had helper
lanes active.
To fix this we add an llvm.amdgcn.ps.live call that guards a branch
around the entire atomic operation - ensuring that all helper lanes are
inactive within the wavefront when we compute our atomic results.
I've added a test case that can cause derivatives, and exposes the
problem.
Differential Revision: https://reviews.llvm.org/D53930
llvm-svn: 346128
Baptiste Saleil