Commit Graph

67 Commits

Author SHA1 Message Date
Tom Stellard fa8f204c5b AMDGPU/SI: When splitting SMRD instructions, add its users to VALU worklist
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
2016-02-11 21:14:34 +00:00
Matt Arsenault fcb345f172 AMDGPU: Fix constant bus use check with subregisters
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
2016-02-11 06:15:39 +00:00
Tom Stellard 1242ce9695 AMDGPU: Remove some purely R600 functions from AMDGPUInstrInfo
Reviewers: arsenm

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D16862

llvm-svn: 259900
2016-02-05 18:44:57 +00:00
Tom Stellard 2ff726272a AMDGPU: Move subtarget specific code out of AMDGPUInstrInfo.cpp
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
2016-01-28 16:04:37 +00:00
Nicolai Haehnle 02c3291566 AMDGPU/SI: Add SI Machine Scheduler
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
2016-01-13 16:10:10 +00:00
Nicolai Haehnle 82fc962c20 AMDGPU/SI: Fold operands with sub-registers
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
2016-01-07 17:10:29 +00:00
Nicolai Haehnle 6bcf8b2890 AMDGPU/SI: use S_MOV_B64 for larger copies in copyPhysReg
Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D15629

llvm-svn: 256073
2015-12-19 01:36:26 +00:00
Nicolai Haehnle dd58705af6 AMDGPU: fix overlapping copies in copyPhysReg
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
2015-12-19 01:16:06 +00:00
Changpeng Fang c9963936e7 AMDGPU/SI: Test commit
Summary: This is just my first commit. Test!

    Reviewers: none

    Subscribers: none

    Differential Revision: none

llvm-svn: 256022
2015-12-18 20:04:28 +00:00
Changpeng Fang ef735b74c1 Revert "AMDGPU/SI: Test commit"
This reverts commit a493cb636e0152ad28210934a47c6c44b1437193.

llvm-svn: 256021
2015-12-18 20:04:26 +00:00
Changpeng Fang 7fdf674c2e AMDGPU/SI: Test commit
Summary: This is just my first commit. Test!

Reviewers: none

Subscribers: none

Differential Revision: none

llvm-svn: 256020
2015-12-18 19:57:41 +00:00
Nicolai Haehnle 87323da6eb AMDGPU: Fix off-by-one in SIRegisterInfo::eliminateFrameIndex
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
2015-12-17 16:46:42 +00:00
Tom Stellard c93fc11f36 AMDGPU/SI: Emit constant arrays in the .text section
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
2015-12-10 02:13:01 +00:00
Matt Arsenault 856d1928a8 AMDGPU: Optimize VOP2 operand legalization
Don't use commuteInstruction, and don't commute if
doing so will not improve legality. Skip the more
complex checks for literal operands and constant bus restrictions,
which are not a concern for VOP2 instructions because src1
does not accept SGPRs or constants and few implicitly
read vcc.

This gets called quite a few times and the
attempts at commuting are a significant fraction
of the time spent in SIFixSGPRCopies, so it's
somewhat worthwhile to optimize. With this patch and others
leading up to it, this reduces the compile time of SIFixSGPRCopies
on some of the LuxMark 2 kernels from ~8ms to ~5ms on my system.

llvm-svn: 254452
2015-12-01 19:57:17 +00:00
Matt Arsenault 26f8f3db39 AMDGPU: Rework how private buffer passed for HSA
If we know we have stack objects, we reserve the registers
that the private buffer resource and wave offset are passed
and use them directly.

If not, reserve the last 5 SGPRs just in case we need to spill.
After register allocation, try to pick the next available registers
instead of the last SGPRs, and then insert copies from the inputs
to the reserved registers in the progloue.

This also only selectively enables all of the input registers
which are really required instead of always enabling them.

llvm-svn: 254331
2015-11-30 21:16:03 +00:00
Matt Arsenault ac234b604d AMDGPU: Rename enums to be consistent with HSA code object terminology
llvm-svn: 254330
2015-11-30 21:15:57 +00:00
Matt Arsenault 0e3d38937e AMDGPU: Remove SIPrepareScratchRegs
It does not work because of emergency stack slots.
This pass was supposed to eliminate dummy registers for the
spill instructions, but the register scavenger can introduce
more during PrologEpilogInserter, so some would end up
left behind if they were needed.

The potential for spilling the scratch resource descriptor
and offset register makes doing something like this
overly complicated. Reserve registers to use for the resource
descriptor and use them directly in eliminateFrameIndex.

Also removes creating another scratch resource descriptor
when directly selecting scratch MUBUF instructions.

The choice of which registers are reserved is temporary.
For now it attempts to pick the next available registers
after the user and system SGPRs.

llvm-svn: 254329
2015-11-30 21:15:53 +00:00
Marek Olsak 7ed6b2f414 AMDGPU/SI: select S_ABS_I32 when possible (v2)
v2: added more tests, moved the SALU->VALU conversion to a separate function

It looks like it's not possible to get subregisters in the S_ABS lowering
code, and I don't feel like guessing without testing what the correct code
would look like.

llvm-svn: 254095
2015-11-25 21:22:45 +00:00
Matt Arsenault 0c90e9501e AMDGPU: Create emergency stack slots during frame lowering
Test has a bogus verifier error which will be fixed by later commits.

llvm-svn: 252327
2015-11-06 18:17:45 +00:00
Matt Arsenault 08f14de244 AMDGPU: Remove unused scratch resource operands
The SGPR spill pseudos don't actually use them.

llvm-svn: 252324
2015-11-06 18:07:53 +00:00
Matt Arsenault 4dc7a5a5c6 AMDGPU: Fix hardcoded alignment of spill.
Instead of forcing 4 alignment when spilled, set register class
alignments.

llvm-svn: 252322
2015-11-06 17:54:47 +00:00
Matt Arsenault 5b22dfa65d AMDGPU: Also track whether SGPRs were spilled
llvm-svn: 252145
2015-11-05 05:27:10 +00:00
Matt Arsenault a40450cba2 AMDGPU: Fix assert when legalizing atomic operands
The operand layout is slightly different for the atomic
opcodes from the usual MUBUF loads and stores.

This should only fix it on SI/CI. VI is still broken
because it still emits the addr64 replacement.

llvm-svn: 252140
2015-11-05 02:46:56 +00:00
Matt Arsenault 6c0674112a AMDGPU: Make findUsedSGPR more readable
Add more comments etc.

llvm-svn: 251996
2015-11-03 22:30:15 +00:00
Matt Arsenault 6005fcbe12 AMDGPU: Simplify VOP3 operand legalization.
This was checking for a variety of situations that should
never happen. This saves a tiny bit of compile time.

We should not be selecting instructions with invalid operands in the
first place. Most of the time for registers copys are inserted
to the correct operand register class.

For VOP3, since all operand types are supported and literal
constants never are, we just need to verify the constant bus
requirements (all immediates should be legal inline ones).

The only possibly tricky case to maybe worry about is if when
legalizing operands in moveToVALU with s_add_i32 and similar
instructions. If the original s_add_i32 had a literal constant
and we need to replace it with v_add_i32_e64 we would have an
unsupported literal operand.  However, I don't think we should worry
about that because SIFoldOperands should handle folding literal
constant operands into the SALU instructions based on the uses.
At SIFoldOperands time, the legality and profitability of
operand types is a bit different.

llvm-svn: 250951
2015-10-21 21:51:02 +00:00
Matt Arsenault e223cebd10 AMDGPU: Fix not checking implicit operands in verifyInstruction
When verifying constant bus restrictions, this wasn't catching
uses in implicit operands.

llvm-svn: 250948
2015-10-21 21:15:01 +00:00
Matt Arsenault 3add6439d0 AMDGPU: Add MachineInstr overloads for instruction format tests
llvm-svn: 250797
2015-10-20 04:35:43 +00:00
Matt Arsenault 284192730a AMDGPU: Use explicit register size indirect pseudos
This stops using an unknown reg class operand.

Currently build_vector selection has a broken looking check
where it tries to use a VGPR reg class and an SGPR one if it
sees an SGPR use.

With the source operand has an explicit VGPR class,
illegal copies will be inserted that SIFixSGPRCopies will take care
of normally later, which will allow removing the weird check
of build_vector users. Without this, when removed v_movrels_b32 would
still be emitted even though all of the values were only stored in
SGPRs.

llvm-svn: 249494
2015-10-07 00:42:51 +00:00
Matt Arsenault d092a068ba AMDGPU/SI: Add verifier check for exec reads
Make sure we aren't accidentally not setting
these in the instruction definitions.

llvm-svn: 249170
2015-10-02 18:58:37 +00:00
Marek Olsak d1a69a2839 AMDGPU/SI: Don't set DATA_FORMAT if ADD_TID_ENABLE is set
to prevent setting a huge stride, because DATA_FORMAT has a different
meaning if ADD_TID_ENABLE is set.

This is a candidate for stable llvm 3.7.

Tested-and-Reviewed-by: Christian König <christian.koenig@amd.com>
llvm-svn: 248858
2015-09-29 23:37:32 +00:00
Matt Arsenault ba6aae785a AMDGPU: Factor switch into separate function
llvm-svn: 248742
2015-09-28 20:54:57 +00:00
Matt Arsenault 73aa8f687a AMDGPU: Fix splitting x16 SMRD loads
When used recursively, this would set the kill flag
on the intermediate step from first splitting
x16 to x8.

llvm-svn: 248741
2015-09-28 20:54:52 +00:00
Matt Arsenault e5d042cd56 AMDGPU: Fix moving SMRD loads with literal offsets on CI
llvm-svn: 248740
2015-09-28 20:54:46 +00:00
Matt Arsenault dd49c5fc1b AMDGPU: Fix splitting SMRD with large offset
The splitting of > 4 dword SMRD instructions
if using an offset in an SGPR instead of an immediate
was not setting the destination register,
resulting an an instruction missing an operand
which would assert later.

Test will be included in a following commit
which fixes a related issue.

llvm-svn: 248739
2015-09-28 20:54:42 +00:00
Andrew Kaylor 16c4da03d5 Improved the interface of methods commuting operands, improved X86-FMA3 mem-folding&coalescing.
Patch by Slava Klochkov (vyacheslav.n.klochkov@intel.com)

Differential Revision: http://reviews.llvm.org/D11370

llvm-svn: 248735
2015-09-28 20:33:22 +00:00
Matt Arsenault e229c0c45e AMDGPU: Construct new buffer instruction when moving SMRD
It's easier to understand creating a full instruction
than the current situation where sometimes a new
instruction is created and sometimes it is awkwardly
mutated in place.

llvm-svn: 248627
2015-09-25 22:21:19 +00:00
Matt Arsenault 2d6fdb8495 AMDGPU: Re-justify workaround and fix worked around problem
When buffer resource descriptors were built, the upper two components
of the descriptor were first composed into a 64-bit register because
legalizeOperands assumed all operands had the same register class.
Fix that problem, but keep the workaround. I'm not sure anything
actually is actually emitting such a REG_SEQUENCE now.

If multiple resource descriptors are set up with different base
pointers, this is copied with a single s_mov_b64. We probably
should fix this better by recognizing a pair of s_mov_b32 later,
but for now delete the dead code.

llvm-svn: 248585
2015-09-25 17:08:42 +00:00
Matt Arsenault 3ad55ec946 AMDGPU: Don't create REG_SEQUENCE with SGPR dest and VGPR sources
This avoids needting to re-legalize the new REG_SEQUENCE.

llvm-svn: 248584
2015-09-25 17:08:40 +00:00
Matt Arsenault e068f9a263 AMDGPU: Return after instruction is processed.
llvm-svn: 248476
2015-09-24 07:51:28 +00:00
Matt Arsenault 708586faa2 AMDGPU: Remove another unnecessary check from commuteInstruction
llvm-svn: 248475
2015-09-24 07:51:25 +00:00
Matt Arsenault c8e2ce4046 AMDGPU: Reduce number of copies emitted
Instead of always inserting a copy in case
the super register is itself a subregister,
only extract to the super reg class if this is
actually the case.

This shouldn't really change codegen, but
makes looking at the output of SIFixSGPRCopies
easier to read.

llvm-svn: 248467
2015-09-24 07:16:37 +00:00
Matt Arsenault f11e7489e1 AMDGPU: Remove unnecessary check
If the instruction doesn't have enough operands, it
either shouldn't be marked as isCommutable or is malformed.

llvm-svn: 248242
2015-09-22 04:17:45 +00:00
Matt Arsenault 80f766a032 AMDGPU/SI: Fix more cases of losing exec operands
llvm-svn: 247230
2015-09-10 01:23:28 +00:00
Matt Arsenault ef67d76869 AMDGPU: Extract full 64-bit subregister and use subregs
Instead of extracting both 32-bit components from the 128-bit
register. This produces fewer copies and is easier for
the copy peephole optimizer to understand and see the actual uses
as extracts from a reg_sequence.

This avoids needing to handle subregister composing in the
PeepholeOptimizer's ValueTracker for this case.

llvm-svn: 247162
2015-09-09 17:03:29 +00:00
Matt Arsenault 51d2d0f668 AMDGPU: Fix adding redundant implicit operands
These are already added during the MachineInstr construction,
so this was adding the implicit registers twice.

llvm-svn: 246525
2015-09-01 02:02:21 +00:00
Matt Arsenault 9a32cd3d3b AMDGPU: Set mem operands for spill instructions
llvm-svn: 246357
2015-08-29 06:48:57 +00:00
Matt Arsenault 5c004a7c61 AMDGPU: Fix dropping mem operands when moving to VALU
Without a memory operand, mayLoad or mayStore instructions
are treated as hasUnorderedMemRef, which results in much worse
scheduling.

We really should have a verifier check that any
non-side effecting mayLoad or mayStore has a memory operand.
There are a few instructions (interp and images) which I'm
not sure what / where to add these.

llvm-svn: 246356
2015-08-29 06:48:46 +00:00
Matt Arsenault 8a067121f8 AMDGPU: Delete dead code
There is no context where s_mov_b64 is emitted
and could potentially be moved to the VALU.
It is currently only emitted for materializing
immediates, which can't be dependent on vector sources.

The immediate splitting is already done when selecting
constants. I'm not sure what contexts if any the register
splitting would have been used before.

Also clean up using s_mov_b64 in place of v_mov_b64_pseudo,
although this isn't required and just skips the extra step
of eliminating the copy from the SReg_64.

llvm-svn: 246080
2015-08-26 20:48:08 +00:00
Matt Arsenault 5e7f95e567 AMDGPU: Don't reprocess instructions when splitting i64 bcnt
llvm-svn: 246079
2015-08-26 20:48:04 +00:00
Matt Arsenault 445833cc91 AMDGPU: Fix not moving users of s_bfe_i64 to VALU
This wouldn't propagate to users of the original BFE
and would hit a verifier error.

llvm-svn: 246078
2015-08-26 20:47:58 +00:00