Commit Graph

7 Commits

Author SHA1 Message Date
Jay Foad 3d76824b7f [AMDGPU] Better support for VMEM soft clauses in GCNHazardRecognizer
VMEM soft clauses only contain VMEM and FLAT instructions. Teaching
GCNHazardRecognizer::checkSoftClauseHazards that other kinds of
instructions will naturally break the clause means there are far fewer
cases where it has to insert an s_nop instruction to forcibly break the
clause.

Differential Revision: https://reviews.llvm.org/D79353
2020-05-05 15:49:09 +01:00
Sebastian Neubauer 3bc7ffdaab [AMDGPU] Use v3f32 type in image instructions
This should lower the amount of used registers for gfx9.

I updated some of the changed tests with the update script because
changing them by hand is tedious.

Differential Revision: https://reviews.llvm.org/D73884
2020-02-05 10:35:41 +01:00
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
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
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 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
Nicolai Haehnle 2f5a73820c AMDGPU: Dimension-aware image intrinsics
Summary:
These new image intrinsics contain the texture type as part of
their name and have each component of the address/coordinate as
individual parameters.

This is a preparatory step for implementing the A16 feature, where
coordinates are passed as half-floats or -ints, but the Z compare
value and texel offsets are still full dwords, making it difficult
or impossible to distinguish between A16 on or off in the old-style
intrinsics.

Additionally, these intrinsics pass the 'texfailpolicy' and
'cachectrl' as i32 bit fields to reduce operand clutter and allow
for future extensibility.

v2:
- gather4 supports 2darray images
- fix a bug with 1D images on SI

Change-Id: I099f309e0a394082a5901ea196c3967afb867f04

Reviewers: arsenm, rampitec, b-sumner

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

Differential Revision: https://reviews.llvm.org/D44939

llvm-svn: 329166
2018-04-04 10:58:54 +00:00