Commit Graph

26 Commits

Author SHA1 Message Date
Matthias Braun 5b7c90b4e2 RegAllocFast: Leave unassigned virtreg entries in map
Set `LiveReg::PhysReg` to zero when freeing a register instead of
removing it from the entry from `LiveRegMap`. This way no iterators get
invalidated and we can avoid passing around and updating iterators all
over the place.

This does not change any allocator decisions. It is not completely NFC
because the arbitrary iteration order through `LiveRegMap` in
`spillAll()` changes so we may get a different order in those spill
sequences (the amount of spills does not change).

This is in preparation of https://reviews.llvm.org/D52010.

llvm-svn: 346298
2018-11-07 06:57:03 +00:00
Scott Linder c6c627253d [AMDGPU] Remove FeatureVGPRSpilling
This feature is only relevant to shaders, and is no longer used. When disabled,
lowering of reserved registers for shaders causes a compiler crash.

Remove the feature and add a test for compilation of shaders at OptNone.

Differential Revision: https://reviews.llvm.org/D53829

llvm-svn: 345763
2018-10-31 18:54:06 +00:00
Tim Renouf 18a1e9d03a [AMDGPU] Don't force WQM for DS op
Summary:
Previously, all DS ops forced WQM in a pixel shader. That was a hack to
allow for graphics frontends using ds_swizzle to implement explicit
derivatives, on SI/CI at least where DPP is not available. But it forced
WQM for _any_ DS op.

With this commit, DS ops no longer force WQM. Both graphics frontends
(Mesa and LLPC) need to change to issue an explicit llvm.amdgcn.wqm
intrinsic call when calculating explicit derivatives.

The required Mesa change is: "amd/common: use llvm.amdgcn.wqm for
explicit derivatives".

Subscribers: qcolombet, arsenm, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D46051

Change-Id: I9b745b626fa91bbd66456e6cf41ee07eeea42f81
llvm-svn: 331633
2018-05-07 13:21:26 +00:00
Yaxun Liu 0124b5484c [AMDGPU] Change constant addr space to 4
Differential Revision: https://reviews.llvm.org/D43170

llvm-svn: 325030
2018-02-13 18:00:25 +00:00
Tim Renouf 660ba2b8af [AMDGPU] exp should not be in WQM mode
A mrt exp with vm=1 must be in exact (non-WQM) mode, as it also exports
the exec mask as the valid mask to determine which pixels to render.

This commit marks any exp as needing to be in exact mode.

Actually, if there are multiple mrt exps, only one needs to have vm=1,
and only that one needs to be in exact mode. But that is an optimization
for another day.

Differential Revision: https://reviews.llvm.org/D36305

llvm-svn: 312915
2017-09-11 13:55:39 +00:00
Matthias Braun 7a482e2302 RegisterScavenging: Followup to r305625
This does some improvements/cleanup to the recently introduced
scavengeRegisterBackwards() functionality:

- Rewrite findSurvivorBackwards algorithm to use the existing
  LiveRegUnit::accumulateBackward() code. This also avoids the Available
  and Candidates bitset and just need 1 LiveRegUnit instance
  (= 1 bitset).
- Pick registers in allocation order instead of register number order.

llvm-svn: 305817
2017-06-20 18:43:14 +00:00
Mark Searles 70359ac60d [AMDGPU] Turn on the new waitcnt insertion pass. Adjust tests.
-enable-si-insert-waitcnts=1 becomes the default
-enable-si-insert-waitcnts=0 to use old pass

Differential Revision: https://reviews.llvm.org/D33730

llvm-svn: 304551
2017-06-02 14:19:25 +00:00
Stanislav Mekhanoshin bd5394be3d [AMDGPU] Merge M0 initializations
Merges equivalent initializations of M0 and hoists them into a common
dominator block. Technically the same code can be used with any
register, physical or virtual.

Differential Revision: https://reviews.llvm.org/D32279

llvm-svn: 301228
2017-04-24 19:37:54 +00:00
Matt Arsenault 3dbeefa978 AMDGPU: Mark all unspecified CC functions in tests as amdgpu_kernel
Currently the default C calling convention functions are treated
the same as compute kernels. Make this explicit so the default
calling convention can be changed to a non-kernel.

Converted with perl -pi -e 's/define void/define amdgpu_kernel void/'
on the relevant test directories (and undoing in one place that actually
wanted a non-kernel).

llvm-svn: 298444
2017-03-21 21:39:51 +00:00
Matt Arsenault 707780b420 AMDGPU: Always allocate emergency stack slot at offset 0
This allows us to ensure that 0 is never a valid pointer
to a user object, and ensures that the offset is always legal
without needing a register to access it. This comes at the cost
of usable offsets and wasted stack space.

llvm-svn: 295877
2017-02-22 21:05:25 +00:00
Matt Arsenault 1f17c66890 AMDGPU: Add cvt.pkrtz intrinsic
Convert llvm.SI.packf16 test uses

llvm-svn: 295797
2017-02-22 00:27:34 +00:00
Matt Arsenault 3ea06336fc AMDGPU: Remove some uses of llvm.SI.export in tests
Merge some of the old, smaller tests into more complete versions.

llvm-svn: 295792
2017-02-22 00:02:21 +00:00
Matt Arsenault d2c8a337aa AMDGPU: Remove SI_fs_constant and SI_fs_interp intrinsics
Update test uses with expansion in terms of new intrinsics.

llvm-svn: 295269
2017-02-16 02:01:13 +00:00
Marek Olsak 693e9be918 AMDGPU/SI: Don't reserve FLAT_SCR on non-HSA targets & without stack objects
Summary: This frees 2 scalar registers.

Reviewers: tstellarAMD

Subscribers: qcolombet, arsenm, kzhuravl, wdng, nhaehnle, yaxunl, tony-tye

Differential Revision: https://reviews.llvm.org/D27150

llvm-svn: 289261
2016-12-09 19:49:48 +00:00
Matt Arsenault c47701c0e9 AMDGPU: Use wider scalar spills for SGPR spilling
Since the spill is for the whole wave, these
don't have the swizzling problems that vector stores do
and a single 4-byte allocation is enough to spill a 64 element
register. This should reduce the number of spill instructions and
put all the spills for a register in the same cacheline.

This should save allocated private size, but for now it doesn't.
The extra slots are allocated for each component, but never used
because the frame layout is essentially finalized before frame
indices are replaced. For always using the scalar store path,
this should probably be moved into processFunctionBeforeFrameFinalized.

llvm-svn: 288445
2016-12-02 00:54:45 +00:00
Matt Arsenault 640c44b893 AMDGPU: Disallow exec as SMEM instruction operand
This is not in the list of valid inputs for the encoding.
When spilling, copies from exec can be folded directly
into the spill instruction which results in broken
stores.

This only fixes the operand constraints, more codegen
work is required to avoid emitting the invalid
spills.

This sort of breaks the dbg.value test. Because the
register class of the s_load_dwordx2 changes, there
is a copy to SReg_64, and the copy is the operand
of dbg_value. The copy is later dead, and removed
from the dbg_value.

llvm-svn: 288191
2016-11-29 19:39:53 +00:00
Marek Olsak 79c05871a2 AMDGPU/SI: Add back reverted SGPR spilling code, but disable it
suggested as a better solution by Matt

llvm-svn: 287942
2016-11-25 17:37:09 +00:00
Marek Olsak e3895bfb47 Revert "AMDGPU: Implement SGPR spilling with scalar stores"
This reverts commit 4404d0d6e354e80dd7f8f0a0e12d8ad809cf007e.

llvm-svn: 287936
2016-11-25 16:03:34 +00:00
Marek Olsak a45dae458d Revert "AMDGPU: Make m0 unallocatable"
This reverts commit 124ad83dae04514f943902446520c859adee0e96.

llvm-svn: 287932
2016-11-25 16:03:15 +00:00
Marek Olsak 18a95bcb3c Revert "AMDGPU: Preserve m0 value when spilling"
This reverts commit a5a179ffd94fd4136df461ec76fb30f04afa87ce.

llvm-svn: 287930
2016-11-25 16:03:02 +00:00
Matt Arsenault 7b54dd039e AMDGPU: Preserve m0 value when spilling
llvm-svn: 287844
2016-11-24 00:26:50 +00:00
Matt Arsenault 9e5c7b1031 AMDGPU: Make m0 unallocatable
m0 may need to be written for spill code, so
we don't want general code uses relying on the
value stored in it.

This introduces a few code quality regressions where copies
from m0 are not coalesced into copies of a copy of m0.

llvm-svn: 287841
2016-11-24 00:26:40 +00:00
Matt Arsenault dc45274d54 AMDGPU: Implement SGPR spilling with scalar stores
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
2016-11-13 18:20:54 +00:00
Matt Arsenault 08906a3c62 AMDGPU: Fix using incorrect private resource with no allocation
It's possible to have a use of the private resource descriptor or
scratch wave offset registers even though there are no allocated
stack objects. This would result in continuing to use the maximum
number reserved registers. This could go over the number of SGPRs
available on VI, or violate the SGPR limit requested by
the function attributes.

llvm-svn: 285435
2016-10-28 19:43:31 +00:00
Matt Arsenault 5d8eb25e78 AMDGPU: Use unsigned compare for eq/ne
For some reason there are both of these available, except
for scalar 64-bit compares which only has u64. I'm not sure
why there are both (I'm guessing it's for the one bit inputs we
don't use), but for consistency always using the
unsigned one.

llvm-svn: 282832
2016-09-30 01:50:20 +00:00
Matt Arsenault 2510a31677 AMDGPU: Fix spilling of m0
readlane/writelane do not support using m0 as the output/input.
Constrain the register class of spill vregs to try to avoid this,
but also handle spilling of the physreg when necessary by inserting
an additional copy to a normal SGPR.

llvm-svn: 280584
2016-09-03 06:57:55 +00:00