Commit Graph

586 Commits

Author SHA1 Message Date
Sanjay Patel 284472be6d [SelectionDAG] remove constant folding limitations based on FP exceptions
We don't have FP exception limits in the IR constant folder for the binops (apart from strict ops),
so it does not make sense to have them here in the DAG either. Nothing else in the backend tries
to preserve exceptions (again outside of strict ops), so I don't see how this could have ever
worked for real code that cares about FP exceptions.

There are still cases (examples: unary opcodes in SDAG, FMA in IR) where we are trying (at least
partially) to preserve exceptions without even asking if the target supports FP exceptions. Those
should be corrected in subsequent patches.

Real support for FP exceptions requires several changes to handle the constrained/strict FP ops.

Differential Revision: https://reviews.llvm.org/D61331

llvm-svn: 359791
2019-05-02 14:47:59 +00:00
Stanislav Mekhanoshin 64399da8b8 [AMDGPU] gfx1010 lost VOP2 forms of some add/sub
Add legalization of V_ADD_I32, V_SUB_I32, V_SUBREV_I32.

Differential Revision:

llvm-svn: 359757
2019-05-02 04:26:35 +00:00
Stanislav Mekhanoshin 692560dc98 [AMDGPU] gfx1010 MIMG implementation
Differential Revision: https://reviews.llvm.org/D61339

llvm-svn: 359698
2019-05-01 16:32:58 +00:00
Stanislav Mekhanoshin a224f68a10 [AMDGPU] gfx1010 DS implementation
Differential Revision: https://reviews.llvm.org/D61332

llvm-svn: 359696
2019-05-01 16:11:11 +00:00
Sjoerd Meijer 180f1ae57c [TargetLowering] Change getOptimalMemOpType to take a function attribute list
The MachineFunction wasn't used in getOptimalMemOpType, but more importantly,
this allows reuse of findOptimalMemOpLowering that is calling getOptimalMemOpType.

This is the groundwork for the changes in D59766 and D59787, that allows
implementation of TTI::getMemcpyCost.

Differential Revision: https://reviews.llvm.org/D59785

llvm-svn: 359537
2019-04-30 08:38:12 +00:00
Matt Arsenault 055e4dce45 AMDGPU: Remove dx10-clamp from subtarget features
Since this can be set with s_setreg*, it should not be a subtarget
property. Set a default based on the calling convention, and Introduce
a new amdgpu-dx10-clamp attribute to override this if desired.

Also introduce a new amdgpu-ieee attribute to match.

The values need to match to allow inlining. I think it is OK for the
caller's dx10-clamp attribute to override the callee, but there
doesn't appear to be the infrastructure to do this currently without
definining the attribute in the generic Attributes.td.

Eventually the calling convention lowering will need to insert a mode
switch somewhere for these.

llvm-svn: 357302
2019-03-29 19:14:54 +00:00
Tim Renouf 6f0191a55a [AMDGPU] Use three- and five-dword result type in image ops
Some image ops return three or five dwords.  Previously, we modeled that
with a 4 or 8 dword register class.  The register allocator could
cleverly spot that some subregs were dead and allocate something else
there, but that caused the de-optimization that waitcnt insertion would
think that the result was used immediately.

This commit allows such an image op to have a result with a three or
five dword result, avoiding the above de-optimization.

Differential Revision: https://reviews.llvm.org/D58905

Change-Id: I3651211bbd7ed22721ee7b9fefd7bcc60a809d8b
llvm-svn: 356757
2019-03-22 15:21:11 +00:00
Tim Renouf 677387d8dc [AMDGPU] Implemented dwordx3 variants of buffer/tbuffer load/store intrinsics
Now we have vec3 MVTs, this commit implements dwordx3 variants of the
buffer intrinsics.

On gfx6, a dwordx3 buffer load intrinsic is implemented as a dwordx4
instruction, and a dwordx3 buffer store intrinsic is not supported.
We need to support the dwordx3 load intrinsic because it is generated by
subtarget-unaware code in InstCombine.

Differential Revision: https://reviews.llvm.org/D58904

Change-Id: I016729d8557b98a52f529638ae97c340a5922a4e
llvm-svn: 356755
2019-03-22 14:58:02 +00:00
Tim Renouf 033f99a2e5 [AMDGPU] Added v5i32 and v5f32 register classes
They are not used by anything yet, but a subsequent commit will start
using them for image ops that return 5 dwords.

Differential Revision: https://reviews.llvm.org/D58903

Change-Id: I63e1904081e39a6d66e4eb96d51df25ad399d271
llvm-svn: 356735
2019-03-22 10:11:21 +00:00
Tim Renouf 361b5b2193 [AMDGPU] Support for v3i32/v3f32
Added support for dwordx3 for most load/store types, but not DS, and not
intrinsics yet.

SI (gfx6) does not have dwordx3 instructions, so they are not enabled
there.

Some of this patch is from Matt Arsenault, also of AMD.

Differential Revision: https://reviews.llvm.org/D58902

Change-Id: I913ef54f1433a7149da8d72f4af54dbb13436bd9
llvm-svn: 356659
2019-03-21 12:01:21 +00:00
David Stuttard fc2a747345 [AMDGPU] Allow MIMG with no uses in adjustWritemask in isel
Summary:
If an MIMG instruction has managed to get through to adjustWritemask in isel but
has no uses (and doesn't enable TFC) then prevent an assertion by not attempting
to adjust the writemask.

The instruction will be removed anyway.

Change-Id: I9a5dba6bafe1f35ac99c1b73df390936e2ac27a7

Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, tpr, t-tye, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58964

llvm-svn: 356540
2019-03-20 09:29:55 +00:00
Ryan Taylor 00e063ab92 [AMDGPU] Add buffer/load 8/16 bit overloaded intrinsics
Summary:
Add buffer store/load 8/16 overloaded intrinsics for buffer, raw_buffer and struct_buffer

Change-Id: I166a29f071b2ff4e4683fb0392564b1f223ac61d

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59265

llvm-svn: 356465
2019-03-19 16:07:00 +00:00
Neil Henning e85f6bd64f [AMDGPU] Ban i8 min3 promotion.
I found this really weird WWM-related case whereby through the WWM
transformations our isel lowering was trying to promote 2 min's into a
min3 for the i8 type, which our hardware doesn't support.

The new min3_i8.ll test case would previously spew the error:

PromoteIntegerResult #0: t69: i8 = SMIN3 t70, Constant:i8<0>, t68

Before the simple fix to our isel lowering to not do it for i8 MVT's.

Differential Revision: https://reviews.llvm.org/D59543

llvm-svn: 356464
2019-03-19 15:50:24 +00:00
Tim Renouf 2e94f6e584 [AMDGPU] Asm/disasm v_cndmask_b32_e64 with abs/neg source modifiers
This commit allows v_cndmask_b32_e64 with abs, neg source
modifiers on src0, src1 to be assembled and disassembled.

This does appear to be allowed, even though they are floating point
modifiers and the operand type is b32.

To do this, I added src0_modifiers and src1_modifiers to the
MachineInstr, which involved fixing up several places in codegen and mir
tests.

Differential Revision: https://reviews.llvm.org/D59191

Change-Id: I69bf4a8c73ebc65744f6110bb8fc4e937d79fbea
llvm-svn: 356398
2019-03-18 19:25:39 +00:00
Neil Henning 523dab0788 [AMDGPU] Add an experimental buffer fat pointer address space.
Add an experimental buffer fat pointer address space that is currently
unhandled in the backend. This commit reserves address space 7 as a
non-integral pointer repsenting the 160-bit fat pointer (128-bit buffer
descriptor + 32-bit offset) that is heavily used in graphics workloads
using the AMDGPU backend.

Differential Revision: https://reviews.llvm.org/D58957

llvm-svn: 356373
2019-03-18 14:44:28 +00:00
Matt Arsenault bc6d07ca46 MIR: Allow targets to serialize MachineFunctionInfo
This has been a very painful missing feature that has made producing
reduced testcases difficult. In particular the various registers
determined for stack access during function lowering were necessary to
avoid undefined register errors in a large percentage of
cases. Implement a subset of the important fields that need to be
preserved for AMDGPU.

Most of the changes are to support targets parsing register fields and
properly reporting errors. The biggest sort-of bug remaining is for
fields that can be initialized from the IR section will be overwritten
by a default initialized machineFunctionInfo section. Another
remaining bug is the machineFunctionInfo section is still printed even
if empty.

llvm-svn: 356215
2019-03-14 22:54:43 +00:00
Matt Arsenault caf1316f71 IR: Add immarg attribute
This indicates an intrinsic parameter is required to be a constant,
and should not be replaced with a non-constant value.

Add the attribute to all AMDGPU and generic intrinsics that comments
indicate it should apply to. I scanned other target intrinsics, but I
don't see any obvious comments indicating which arguments are intended
to be only immediates.

This breaks one questionable testcase for the autoupgrade. I'm unclear
on whether the autoupgrade is supposed to really handle declarations
which were never valid. The verifier fails because the attributes now
refer to a parameter past the end of the argument list.

llvm-svn: 355981
2019-03-12 21:02:54 +00:00
Matt Arsenault 26e76ef0e2 DAG: Don't try to cluster loads with tied inputs
This avoids breaking possible value dependencies when sorting loads by
offset.

AMDGPU has some load instructions that write into the high or low bits
of the destination register, and have a tied input for the other input
bits. These can easily have the same base pointer, but be a swizzle so
the high address load needs to come first. This was inserting glue
forcing the opposite ordering, producing a cycle the InstrEmitter
would assert on. It may be potentially expensive to look for the
dependency between the other loads, so just skip any where this could
happen.

Fixes bug 40936 by reverting r351379, which added a hacky attempt to
fix this by adding chains in this case, which I think was just working
around broken glue before the InstrEmitter. The core of the patch is
re-implementing the fix for that problem.

llvm-svn: 355728
2019-03-08 20:46:15 +00:00
Dmitry Preobrazhensky ef92035827 [AMDGPU][MC][GFX8+] Added syntactic sugar for 'vgpr index' operand of instructions s_set_gpr_idx_on and s_set_gpr_idx_mode
See bug 39331: https://bugs.llvm.org/show_bug.cgi?id=39331

Reviewers: artem.tamazov, arsenm

Differential Revision: https://reviews.llvm.org/D58288

llvm-svn: 354969
2019-02-27 13:12:12 +00:00
Stanislav Mekhanoshin da1628eb67 [AMDGPU] Fixed hang during DAG combine
SITargetLowering::reassociateScalarOps() does not touch constants
so that DAGCombiner::ReassociateOps() does not revert the combine.
However a global address is not a ConstantSDNode.

Switched to the method used by DAGCombiner::ReassociateOps() itself
to detect constants.

Differential Revision: https://reviews.llvm.org/D58695

llvm-svn: 354926
2019-02-26 20:56:25 +00:00
Matt Arsenault aa6fb4c45e AMDGPU: Remove debugger related subtarget features
As far as I know these aren't needed anymore.

llvm-svn: 354634
2019-02-21 23:27:46 +00:00
Stanislav Mekhanoshin 42e229e130 [AMDGPU] fix commuted case of sub combine
Differential Revision: https://reviews.llvm.org/D58481

llvm-svn: 354543
2019-02-21 02:58:00 +00:00
Stanislav Mekhanoshin 871821f786 [AMDGPU] Ressociate 'add (add x, y), z' to use SALU
Reassociate adds to collect scalar operands in a single
instruction when possible. That will result in a scalar
add followed by vector instead of two vector adds, thus
better utilizing SALU.

Differential Revision: https://reviews.llvm.org/D58220

llvm-svn: 354066
2019-02-14 22:11:25 +00:00
Stanislav Mekhanoshin 0e858b028d [AMDGPU] Split dot-insts feature
Differential Revision: https://reviews.llvm.org/D57971

llvm-svn: 353587
2019-02-09 00:34:21 +00:00
Craig Topper 784929d045 Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

llvm-svn: 353563
2019-02-08 20:48:56 +00:00
Matt Arsenault a8b4339c2f AMDGPU/GlobalISel: Legalize addrspacecast
Use a placeholder constant for now on targets
that need the load from the queue ptr.

llvm-svn: 353497
2019-02-08 02:40:47 +00:00
Scott Linder e2c5847414 [AMDGPU] Consider XOR in waterfall loop as a terminator
Ensure the XOR in the waterfall loop for indirect addressing is considered a terminator.

Differential Revision: https://reviews.llvm.org/D57703

llvm-svn: 353207
2019-02-05 19:50:32 +00:00
Scott Linder d19d197221 [AMDGPU] Support emitting GOT relocations for function calls
Differential Revision: https://reviews.llvm.org/D57416

llvm-svn: 353083
2019-02-04 20:00:07 +00:00
Tim Corringham fa3e4e5b53 [AMDGPU] Fix for vector element insertion
Summary:
Incorrect code was generated when lowering insertelement operations
for vectors with 8 or 16 bit elements.  The value being inserted was
not adjusted for the position of the element within the 32 bit word
and so only the low element within each 32 bit word could receive
the intended value.

Fixed by simply replicating the value to each element of a
congruent vector before the mask and or operation used to
update the intended element.

A number of affected LIT tests have been updated appropriately.

before the mask & or into the intended

Reviewers: arsenm, nhaehnle

Reviewed By: arsenm

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57588

llvm-svn: 352885
2019-02-01 16:51:09 +00:00
Matt Arsenault cdd191d9db AMDGPU: Add DS append/consume intrinsics
Since these pass the pointer in m0 unlike other DS instructions, these
need to worry about whether the address is uniform or not. This
assumes the address is dynamically uniform, and just uses
readfirstlane to get a copy into an SGPR.

I don't know if these have the same 16-bit add for the addressing mode
offset problem on SI or not, but I've just assumed they do.

Also includes some misc. changes to avoid test differences between the
LDS and GDS versions.

llvm-svn: 352422
2019-01-28 20:14:49 +00:00
Tim Corringham 824ca3f3dd [AMDGPU] Add intrinsics for 16 bit interpolation
Summary:
Added the intrinsics llvm.amdgcn.interp.p1.f16() and
llvm.amdgcn.interp.p2.f16() and related LIT test.

The p1 intrinsic generates code appropriate for both 16 and 32
bank LDS.

Reviewers: #amdgpu, dstuttard, arsenm, tpr

Reviewed By: #amdgpu, arsenm

Subscribers: jvesely, mgorny, arsenm, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D46754

llvm-svn: 352357
2019-01-28 13:48:59 +00:00
Matt Arsenault a5840c3c39 Codegen support for atomicrmw fadd/fsub
llvm-svn: 351851
2019-01-22 18:36:06 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Matt Arsenault 85af701e85 AMDGPU: Remove llvm.SI.load.const
It's taken 3 years, but now all of the old AMDGPU and SI intrinsics
are finally gone

llvm-svn: 351586
2019-01-18 20:27:02 +00:00
Changpeng Fang fe9269f804 AMDGPU: Adjust the chain for loads writing to the HI part of a register.
Summary:
  For these loads that write to the HI part of a register, we should chain them to the op that writes to the LO part
of the register to maintain the appropriate order.

Reviewers:
  rampitec, arsenm

Differential Revision:
  https://reviews.llvm.org/D56454

llvm-svn: 351379
2019-01-16 21:32:53 +00:00
Marek Olsak c5cec5e1fa AMDGPU: Add llvm.amdgcn.ds.ordered.add & swap
Reviewers: arsenm, nhaehnle

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D52944

llvm-svn: 351351
2019-01-16 15:43:53 +00:00
Marek Olsak 33eb4d947d AMDGPU: Add a fast path for icmp.i1(src, false, NE)
Summary:
This allows moving the condition from the intrinsic to the standard ICmp
opcode, so that LLVM can do simplifications on it. The icmp.i1 intrinsic
is an identity for retrieving the SGPR mask.

And we can also get the mask from and i1, or i1, xor i1.

Reviewers: arsenm, nhaehnle

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D52060

llvm-svn: 351150
2019-01-15 02:13:18 +00:00
David Stuttard f77079f892 [AMDGPU] Add support for TFE/LWE in image intrinsics. 2nd try
TFE and LWE support requires extra result registers that are written in the
event of a failure in order to detect that failure case.
The specific use-case that initiated these changes is sparse texture support.

This means that if image intrinsics are used with either option turned on, the
programmer must ensure that the return type can contain all of the expected
results. This can result in redundant registers since the vector size must be a
power-of-2.

This change takes roughly 6 parts:
1. Modify the instruction defs in tablegen to add new instruction variants that
can accomodate the extra return values.
2. Updates to lowerImage in SIISelLowering.cpp to accomodate setting TFE or LWE
(where the bulk of the work for these instruction types is now done)
3. Extra verification code to catch cases where intrinsics have been used but
insufficient return registers are used.
4. Modification to the adjustWritemask optimisation to account for TFE/LWE being
enabled (requires extra registers to be maintained for error return value).
5. An extra pass to zero initialize the error value return - this is because if
the error does not occur, the register is not written and thus must be zeroed
before use. Also added a new (on by default) option to ensure ALL return values
are zero-initialized that is required for sparse texture support.
6. Disable the inst_combine optimization in the presence of tfe/lwe (later TODO
for this to re-enable and handle correctly).

There's an additional fix now to avoid a dmask=0

For an image intrinsic with tfe where all result channels except tfe
were unused, I was getting an image instruction with dmask=0 and only a
single vgpr result for tfe. That is incorrect because the hardware
assumes there is at least one vgpr result, plus the one for tfe.

Fixed by forcing dmask to 1, which gives the desired two vgpr result
with tfe in the second one.

The TFE or LWE result is returned from the intrinsics using an aggregate
type. Look in the test code provided to see how this works, but in essence IR
code to invoke the intrinsic looks as follows:

%v = call {<4 x float>,i32} @llvm.amdgcn.image.load.1d.v4f32i32.i32(i32 15,
                                      i32 %s, <8 x i32> %rsrc, i32 1, i32 0)
%v.vec = extractvalue {<4 x float>, i32} %v, 0
%v.err = extractvalue {<4 x float>, i32} %v, 1

This re-submit of the change also includes a slight modification in
SIISelLowering.cpp to work-around a compiler bug for the powerpc_le
platform that caused a buildbot failure on a previous submission.

Differential revision: https://reviews.llvm.org/D48826

Change-Id: If222bc03642e76cf98059a6bef5d5bffeda38dda


Work around for ppcle compiler bug

Change-Id: Ie284cf24b2271215be1b9dc95b485fd15000e32b
llvm-svn: 351054
2019-01-14 11:55:24 +00:00
Stanislav Mekhanoshin d3757d3f3a [AMDGPU] Separate feature dot-insts
Differential Revision: https://reviews.llvm.org/D56524

llvm-svn: 350793
2019-01-10 03:25:20 +00:00
Stanislav Mekhanoshin ed0d6c60af Remove check for single use in ShrinkDemandedConstant
This removes check for single use from general ShrinkDemandedConstant
to the BE because of the AArch64 regression after D56289/rL350475.

After several hours of experiments I did not come up with a testcase
failing on any other targets if check is not performed.

Moreover, direct call to ShrinkDemandedConstant is not really needed
and superceed by SimplifyDemandedBits.

Differential Revision: https://reviews.llvm.org/D56406

llvm-svn: 350684
2019-01-09 02:24:22 +00:00
Piotr Sobczak 378131bae0 [AMDGPU] Handle OR as operand of raw load/store
Summary:
Use isBaseWithConstantOffset() which handles OR as an operand
to llvm.amdgcn.raw.buffer.load and llvm.amdgcn.raw.buffer.store.

Change-Id: Ifefb9dc5ded8710d333df07ab1900b230e33539a

Reviewers: nhaehnle, mareko, arsenm

Reviewed By: arsenm

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

Differential Revision: https://reviews.llvm.org/D55999

llvm-svn: 350208
2019-01-02 09:47:41 +00:00
Simon Pilgrim 44dfd81d01 Fix unused variable warning. NFCI.
llvm-svn: 348649
2018-12-07 21:44:25 +00:00
Matt Arsenault ce2e053134 AMDGPU: Allow f32 types for llvm.amdgcn.s.buffer.load
llvm-svn: 348625
2018-12-07 18:41:39 +00:00
Matt Arsenault ca8eb0b672 AMDGPU: Remove llvm.SI.tbuffer.store
llvm-svn: 348619
2018-12-07 18:03:47 +00:00
Matt Arsenault aa9bcd56b1 AMDGPU: Remove llvm.AMDGPU.kill
This is the last of the old AMDGPU intrinsics.

llvm-svn: 348615
2018-12-07 17:46:16 +00:00
Nicolai Haehnle a7b00058e0 AMDGPU: Divergence-driven selection of scalar buffer load intrinsics
Summary:
Moving SMRD to VMEM in SIFixSGPRCopies is rather bad for performance if
the load is really uniform. So select the scalar load intrinsics directly
to either VMEM or SMRD buffer loads based on divergence analysis.

If an offset happens to end up in a VGPR -- either because a floating
point calculation was involved, or due to other remaining deficiencies
in SIFixSGPRCopies -- we use v_readfirstlane.

There is some unrelated churn in tests since we now select MUBUF offsets
in a unified way with non-scalar buffer loads.

Change-Id: I170e6816323beb1348677b358c9d380865cd1a19

Reviewers: arsenm, alex-t, rampitec, tpr

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D53283

llvm-svn: 348050
2018-11-30 22:55:38 +00:00
Nicolai Haehnle a9cc92c247 AMDGPU: Fix various issues around the VirtReg2Value mapping
Summary:
The VirtReg2Value mapping is crucial for getting consistently
reliable divergence information into the SelectionDAG. This
patch fixes a bunch of issues that lead to incorrect divergence
info and introduces tight assertions to ensure we don't regress:

1. VirtReg2Value is generated lazily; there were some cases where
   a lookup was performed before all relevant virtual registers were
   created, leading to an out-of-sync mapping. Those cases were:

  - Complex code to lower formal arguments that generated CopyFromReg
    nodes from live-in registers (fixed by never querying the mapping
    for live-in registers).

  - Code that generates CopyToReg for formal arguments that are used
    outside the entry basic block (fixed by never querying the
    mapping for Register nodes, which don't need the divergence info
    anyway).

2. For complex values that are lowered to a sequence of registers,
   all registers must be reflected in the VirtReg2Value mapping.

I am not adding any new tests, since I'm not actually aware of any
bugs that these problems are causing with trunk as-is. However,
I recently added a test case (in r346423) which fails when D53283 is
applied without this change. Also, the new assertions should provide
most of the effective test coverage.

There is one test change in sdwa-peephole.ll. The underlying issue
is that since the divergence info is now correct, the DAGISel will
select V_OR_B32 directly instead of S_OR_B32. This leads to an extra
COPY which affects the behavior of MachineLICM in a way that ends up
with the S_MOV_B32 with the constant in a different basic block than
the V_OR_B32, which is presumably what defeats the peephole.

Reviewers: alex-t, arsenm, rampitec

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D54340

llvm-svn: 348049
2018-11-30 22:55:29 +00:00
David Stuttard c6603861d8 Revert r347871 "Fix: Add support for TFE/LWE in image intrinsic"
Also revert fix r347876

One of the buildbots was reporting a failure in some relevant tests that I can't
repro or explain at present, so reverting until I can isolate.

llvm-svn: 347911
2018-11-29 20:14:17 +00:00
David Stuttard 535c1af0bf Fix: Add support for TFE/LWE in image intrinsic
My change svn-id: 347871 caused a buildbot failure due to an unused
variable def (used in an assert).

Change-Id: Ia882d18bb6fa79b4d7bbfda422b9ea5d23eab336
llvm-svn: 347876
2018-11-29 15:56:36 +00:00
David Stuttard de02e4b1cc Add support for TFE/LWE in image intrinsics
TFE and LWE support requires extra result registers that are written in the
event of a failure in order to detect that failure case.
The specific use-case that initiated these changes is sparse texture support.

This means that if image intrinsics are used with either option turned on, the
programmer must ensure that the return type can contain all of the expected
results. This can result in redundant registers since the vector size must be a
power-of-2.

This change takes roughly 6 parts:
1. Modify the instruction defs in tablegen to add new instruction variants that
can accomodate the extra return values.
2. Updates to lowerImage in SIISelLowering.cpp to accomodate setting TFE or LWE
(where the bulk of the work for these instruction types is now done)
3. Extra verification code to catch cases where intrinsics have been used but
insufficient return registers are used.
4. Modification to the adjustWritemask optimisation to account for TFE/LWE being
enabled (requires extra registers to be maintained for error return value).
5. An extra pass to zero initialize the error value return - this is because if
the error does not occur, the register is not written and thus must be zeroed
before use. Also added a new (on by default) option to ensure ALL return values
are zero-initialized that is required for sparse texture support.
6. Disable the inst_combine optimization in the presence of tfe/lwe (later TODO
for this to re-enable and handle correctly).

There's an additional fix now to avoid a dmask=0

For an image intrinsic with tfe where all result channels except tfe
were unused, I was getting an image instruction with dmask=0 and only a
single vgpr result for tfe. That is incorrect because the hardware
assumes there is at least one vgpr result, plus the one for tfe.

Fixed by forcing dmask to 1, which gives the desired two vgpr result
with tfe in the second one.

The TFE or LWE result is returned from the intrinsics using an aggregate
type. Look in the test code provided to see how this works, but in essence IR
code to invoke the intrinsic looks as follows:

%v = call {<4 x float>,i32} @llvm.amdgcn.image.load.1d.v4f32i32.i32(i32 15,
                                      i32 %s, <8 x i32> %rsrc, i32 1, i32 0)
%v.vec = extractvalue {<4 x float>, i32} %v, 0
%v.err = extractvalue {<4 x float>, i32} %v, 1

Differential revision: https://reviews.llvm.org/D48826

Change-Id: If222bc03642e76cf98059a6bef5d5bffeda38dda
llvm-svn: 347871
2018-11-29 15:21:13 +00:00