Commit Graph

31 Commits

Author SHA1 Message Date
Yaxun Liu 494770403a CodeGen: Fix pointer info in SplitVecOp_EXTRACT_VECTOR_ELT/SplitVecRes_INSERT_VECTOR_ELT
Two issues found when doing codegen for splitting vector with non-zero alloca addr space:

DAGTypeLegalizer::SplitVecRes_INSERT_VECTOR_ELT/SplitVecOp_EXTRACT_VECTOR_ELT uses dummy pointer info for creating
SDStore. Since one pointer operand contains multiply and add, InferPointerInfo is unable to
infer the correct pointer info, which ends up with a dummy pointer info for the target to lower
store and results in isel failure. The fix is to introduce MachinePointerInfo::getUnknownStack to
represent MachinePointerInfo which is known in alloca address space but without other information.

TargetLowering::getVectorElementPointer uses value type of pointer in addr space 0 for
multiplication of index and then add it to the pointer. However the pointer may be in an addr
space which has different size than addr space 0. The fix is to use the pointer value type for
index multiplication.

Differential Revision: https://reviews.llvm.org/D39758

llvm-svn: 319622
2017-12-02 22:13:22 +00:00
Matt Arsenault 1cc47f8413 AMDGPU: Figure out private memory regs after lowering
Introduce pseudo-registers for registers needed for stack
access, which are replaced during finalizeLowering.
Note these pseudo-registers are currently only used for the
used register location, and not for determining their
input argument register.

This is better because it avoids the need to try to predict
whether a call will be emitted from the IR, and also
detects stack objects introduced by legalization.

Test changes are from the HasStackObjects check being more
accurate since stack objects introduced during legalization
are now known.

llvm-svn: 308325
2017-07-18 16:44:56 +00:00
Matt Arsenault 7c525903ef AMDGPU: Remove SITypeRewriter
This was an old workaround for using v16i8 in some old intrinsics
for resource descriptors.

llvm-svn: 306603
2017-06-28 21:38:50 +00:00
Matt Arsenault b600e138cc AMDGPU: Remove llvm.SI.vs.load.input
llvm-svn: 299391
2017-04-03 21:45:13 +00:00
Marek Olsak 5c7a61d221 AMDGPU: Buffer descriptor changes for GFX9
Reviewers: arsenm

Subscribers: qcolombet, kzhuravl, wdng, nhaehnle, yaxunl, tony-tye, dstuttard, tpr

Differential Revision: https://reviews.llvm.org/D31158

llvm-svn: 298397
2017-03-21 17:00:39 +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 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
Stanislav Mekhanoshin 582a5237f9 [AMDGPU] Revert failed scheduling
This patch reverts region's scheduling to the original untouched state
in case if we have have decreased occupancy.

In addition it switches to use TargetRegisterInfo occupancy callback
for pressure limits instead of gradually increasing limits which were
just passed by. We are going to stay with the best schedule so we do
not need to tolerate worsened scheduling anymore.

Differential Revision: https://reviews.llvm.org/D29971

llvm-svn: 295206
2017-02-15 17:19:50 +00:00
Sanjoy Das 3336f681e3 [Verifier] Add verification for TBAA metadata
Summary:
This change adds some verification in the IR verifier around struct path
TBAA metadata.

Other than some basic sanity checks (e.g. we get constant integers where
we expect constant integers), this checks:

 - That by the time an struct access tuple `(base-type, offset)` is
   "reduced" to a scalar base type, the offset is `0`.  For instance, in
   C++ you can't start from, say `("struct-a", 16)`, and end up with
   `("int", 4)` -- by the time the base type is `"int"`, the offset
   better be zero.  In particular, a variant of this invariant is needed
   for `llvm::getMostGenericTBAA` to be correct.

 - That there are no cycles in a struct path.

 - That struct type nodes have their offsets listed in an ascending
   order.

 - That when generating the struct access path, you eventually reach the
   access type listed in the tbaa tag node.

Reviewers: dexonsmith, chandlerc, reames, mehdi_amini, manmanren

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D26438

llvm-svn: 289402
2016-12-11 20:07:15 +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 dad553a5cf Revert "AMDGPU: Fix MMO when splitting spill"
This reverts commit 79d4f8b8b1ce430c3d5dac4fc72a9eebaed24fe1.

llvm-svn: 287935
2016-11-25 16:03:27 +00:00
Matt Arsenault 2669a76f01 AMDGPU: Fix MMO when splitting spill
The size and offset were wrong. The size of the object was
being used for the size of the access, when here it is really
being split into 4-byte accesses. The underlying object size
is set in the MachinePointerInfo, which also didn't have the
offset set.

llvm-svn: 287806
2016-11-23 20:52:53 +00:00
Nirav Dave a81682aad4 Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
This reverts commit r284151 which appears to be triggering a LTO
failures on Hexagon

llvm-svn: 284157
2016-10-13 20:23:25 +00:00
Nirav Dave 4b36957243 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Retrying after upstream changes.

   Simplify Consecutive Merge Store Candidate Search

   Now that address aliasing is much less conservative, push through
   simplified store merging search which only checks for parallel stores
   through the chain subgraph. This is cleaner as the separation of
   non-interfering loads/stores from the store-merging logic.

   Whem merging stores, search up the chain through a single load, and
   finds all possible stores by looking down from through a load and a
   TokenFactor to all stores visited. This improves the quality of the
   output SelectionDAG and generally the output CodeGen (with some
   exceptions).

   Additional Minor Changes:

       1. Finishes removing unused AliasLoad code
       2. Unifies the the chain aggregation in the merged stores across
       code paths
       3. Re-add the Store node to the worklist after calling
       SimplifyDemandedBits.
       4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is
       arbitrary, but seemed sufficient to not cause regressions in
       tests.

   This finishes the change Matt Arsenault started in r246307 and
   jyknight's original patch.

   Many tests required some changes as memory operations are now
   reorderable. Some tests relying on the order were changed to use
   volatile memory operations

   Noteworthy tests:

    CodeGen/AArch64/argument-blocks.ll -
      It's not entirely clear what the test_varargs_stackalign test is
      supposed to be asserting, but the new code looks right.

    CodeGen/AArch64/arm64-memset-inline.lli -
    CodeGen/AArch64/arm64-stur.ll -
    CodeGen/ARM/memset-inline.ll -

      The backend now generates *worse* code due to store merging
      succeeding, as we do do a 16-byte constant-zero store efficiently.

    CodeGen/AArch64/merge-store.ll -
      Improved, but there still seems to be an extraneous vector insert
      from an element to itself?

    CodeGen/PowerPC/ppc64-align-long-double.ll -
      Worse code emitted in this case, due to the improved store->load
      forwarding.

    CodeGen/X86/dag-merge-fast-accesses.ll -
    CodeGen/X86/MergeConsecutiveStores.ll -
    CodeGen/X86/stores-merging.ll -
    CodeGen/Mips/load-store-left-right.ll -
      Restored correct merging of non-aligned stores

    CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll -
      Improved. Correctly merges buffer_store_dword calls

    CodeGen/AMDGPU/si-triv-disjoint-mem-access.ll -
      Improved. Sidesteps loading a stored value and
      merges two stores

    CodeGen/X86/pr18023.ll -
      This test has been removed, as it was asserting incorrect
      behavior. Non-volatile stores *CAN* be moved past volatile loads,
      and now are.

    CodeGen/X86/vector-idiv.ll -
    CodeGen/X86/vector-lzcnt-128.ll -
      It's basically impossible to tell what these tests are actually
      testing. But, looks like the code got better due to the memory
      operations being recognized as non-aliasing.

    CodeGen/X86/win32-eh.ll -
      Both loads of the securitycookie are now merged.

    CodeGen/AMDGPU/vgpr-spill-emergency-stack-slot-compute.ll -
      This test appears to work but no longer exhibits the spill behavior.

Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle

Subscribers: wdng, nhaehnle, nemanjai, arsenm, weimingz, niravd, RKSimon, aemerson, qcolombet, dsanders, resistor, tstellarAMD, t.p.northover, spatel

Differential Revision: https://reviews.llvm.org/D14834

llvm-svn: 284151
2016-10-13 19:20:16 +00:00
Nirav Dave e524f50882 Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
This reverts commit r282600 due to test failues with MCJIT

llvm-svn: 282604
2016-09-28 16:37:50 +00:00
Nirav Dave e17e055b75 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Simplify Consecutive Merge Store Candidate Search

  Now that address aliasing is much less conservative, push through
  simplified store merging search which only checks for parallel stores
  through the chain subgraph. This is cleaner as the separation of
  non-interfering loads/stores from the store-merging logic.

  Whem merging stores, search up the chain through a single load, and
  finds all possible stores by looking down from through a load and a
  TokenFactor to all stores visited. This improves the quality of the
  output SelectionDAG and generally the output CodeGen (with some
  exceptions).

  Additional Minor Changes:

    1. Finishes removing unused AliasLoad code
    2. Unifies the the chain aggregation in the merged stores across
       code paths
    3. Re-add the Store node to the worklist after calling
       SimplifyDemandedBits.
    4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is
       arbitrary, but seemed sufficient to not cause regressions in
       tests.

  This finishes the change Matt Arsenault started in r246307 and
  jyknight's original patch.

  Many tests required some changes as memory operations are now
  reorderable. Some tests relying on the order were changed to use
  volatile memory operations

  Noteworthy tests:

    CodeGen/AArch64/argument-blocks.ll -
      It's not entirely clear what the test_varargs_stackalign test is
      supposed to be asserting, but the new code looks right.

    CodeGen/AArch64/arm64-memset-inline.lli -
    CodeGen/AArch64/arm64-stur.ll -
    CodeGen/ARM/memset-inline.ll -
      The backend now generates *worse* code due to store merging
      succeeding, as we do do a 16-byte constant-zero store efficiently.

    CodeGen/AArch64/merge-store.ll -
      Improved, but there still seems to be an extraneous vector insert
      from an element to itself?

    CodeGen/PowerPC/ppc64-align-long-double.ll -
      Worse code emitted in this case, due to the improved store->load
      forwarding.

    CodeGen/X86/dag-merge-fast-accesses.ll -
    CodeGen/X86/MergeConsecutiveStores.ll -
    CodeGen/X86/stores-merging.ll -
    CodeGen/Mips/load-store-left-right.ll -
      Restored correct merging of non-aligned stores

    CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll -
      Improved. Correctly merges buffer_store_dword calls

    CodeGen/AMDGPU/si-triv-disjoint-mem-access.ll -
      Improved. Sidesteps loading a stored value and merges two stores

    CodeGen/X86/pr18023.ll -
      This test has been removed, as it was asserting incorrect
      behavior. Non-volatile stores *CAN* be moved past volatile loads,
      and now are.

    CodeGen/X86/vector-idiv.ll -
    CodeGen/X86/vector-lzcnt-128.ll -
      It's basically impossible to tell what these tests are actually
      testing. But, looks like the code got better due to the memory
      operations being recognized as non-aliasing.

    CodeGen/X86/win32-eh.ll -
      Both loads of the securitycookie are now merged.

    CodeGen/AMDGPU/vgpr-spill-emergency-stack-slot-compute.ll -
      This test appears to work but no longer exhibits the spill
      behavior.

Reviewers: arsenm, hfinkel, tstellarAMD, nhaehnle, jyknight

Subscribers: wdng, nhaehnle, nemanjai, arsenm, weimingz, niravd, RKSimon, aemerson, qcolombet, resistor, tstellarAMD, t.p.northover, spatel

Differential Revision: https://reviews.llvm.org/D14834

llvm-svn: 282600
2016-09-28 15:50:43 +00:00
Tom Stellard 0d23ebe888 AMDGPU/SI: Implement a custom MachineSchedStrategy
Summary:
GCNSchedStrategy re-uses most of GenericScheduler, it's just uses
a different method to compute the excess and critical register
pressure limits.

It's not enabled by default, to enable it you need to pass -misched=gcn
to llc.

Shader DB stats:

32464 shaders in 17874 tests
Totals:
SGPRS: 1542846 -> 1643125 (6.50 %)
VGPRS: 1005595 -> 904653 (-10.04 %)
Spilled SGPRs: 29929 -> 27745 (-7.30 %)
Spilled VGPRs: 334 -> 352 (5.39 %)
Scratch VGPRs: 1612 -> 1624 (0.74 %) dwords per thread
Code Size: 36688188 -> 37034900 (0.95 %) bytes
LDS: 1913 -> 1913 (0.00 %) blocks
Max Waves: 254101 -> 265125 (4.34 %)
Wait states: 0 -> 0 (0.00 %)

Totals from affected shaders:
SGPRS: 1338220 -> 1438499 (7.49 %)
VGPRS: 886221 -> 785279 (-11.39 %)
Spilled SGPRs: 29869 -> 27685 (-7.31 %)
Spilled VGPRs: 334 -> 352 (5.39 %)
Scratch VGPRs: 1612 -> 1624 (0.74 %) dwords per thread
Code Size: 34315716 -> 34662428 (1.01 %) bytes
LDS: 1551 -> 1551 (0.00 %) blocks
Max Waves: 188127 -> 199151 (5.86 %)
Wait states: 0 -> 0 (0.00 %)

Reviewers: arsenm, mareko, nhaehnle, MatzeB, atrick

Subscribers: arsenm, kzhuravl, llvm-commits

Differential Revision: https://reviews.llvm.org/D23688

llvm-svn: 279995
2016-08-29 19:42:52 +00:00
Matt Arsenault 45f8216cee AMDGPU: Remove superfluous string attributes from tests
Also fix v_mac.ll not testing right thing for fneg

llvm-svn: 275129
2016-07-11 23:35:48 +00:00
Marek Olsak e93f6d6923 AMDGPU/SI: Set INDEX_STRIDE for scratch coalescing
Summary:
Mesa and other users must set this to enable coalescing:
- STRIDE = 0
- SWIZZLE_ENABLE = 1

This makes one particular compute shader 8x faster.

Reviewers: tstellarAMD, arsenm

Subscribers: arsenm, kzhuravl

Differential Revision: http://reviews.llvm.org/D21136

llvm-svn: 272556
2016-06-13 16:05:57 +00:00
Matt Arsenault 7f9eabd2c2 AMDGPU: Define priorities for register classes
Allocating larger register classes first should give better allocation
results (and more importantly for myself, make the lit tests more stable
with respect to scheduler changes).

Patch by Matthias Braun

llvm-svn: 270312
2016-05-21 03:55:07 +00:00
Matt Arsenault e8ed8e59e5 AMDGPU: Change private_element_size to 4
llvm-svn: 269145
2016-05-11 00:28:54 +00:00
Tom Stellard cb6ba62d6f AMDGPU/SI: Enable the post-ra scheduler
Summary:
This includes a hazard recognizer implementation to replace some of
the hazard handling we had during frame index elimination.

Reviewers: arsenm

Subscribers: qcolombet, arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D18602

llvm-svn: 268143
2016-04-30 00:23:06 +00:00
Nikolay Haustov 4f672a34ed AMDGPU/SI: Assembler: Unify parsing/printing of operands.
Summary:
The goal is for each operand type to have its own parse function and
at the same time share common code for tracking state as different
instruction types share operand types (e.g. glc/glc_flat, etc).

Introduce parseAMDGPUOperand which can parse any optional operand.
DPP and Clamp/OMod have custom handling for now. Sam also suggested
to have class hierarchy for operand types instead of table. This
can be done in separate change.

Remove parseVOP3OptionalOps, parseDS*OptionalOps, parseFlatOptionalOps,
parseMubufOptionalOps, parseDPPOptionalOps.
Reduce number of definitions of AsmOperand's and MatchClasses' by using common base class.
Rename AsmMatcher/InstPrinter methods accordingly.
Print immediate type when printing parsed immediate operand.
Use 'off' if offset/index register is unused instead of skipping it to make it more readable (also agreed with SP3).
Update tests.

Reviewers: tstellarAMD, SamWot, artem.tamazov

Subscribers: qcolombet, arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D19584

llvm-svn: 268015
2016-04-29 09:02:30 +00:00
Tom Stellard f110f8f9f7 AMDGPU/SI: Use the correct scratch wave offset register for shaders.
Summary:
The code previously always used s1 as it was using the user + system SGPR
information for compute kernels. This is incorrect for Mesa shaders though,

The register should be the next SGPR after all user and system SGPR's.
We use that Mesa adds arguments for all input and system SGPR's and
take the next available SGPR for the scratch wave offset register.

Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

Reviewers: mareko, arsenm, nhaehnle, tstellarAMD

Subscribers: qcolombet, arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D18941

Patch By: Bas Nieuwenhuizen

llvm-svn: 266336
2016-04-14 16:27:03 +00:00
Nicolai Haehnle df3a20cd80 AMDGPU: Add a shader calling convention
This makes it possible to distinguish between mesa shaders
and other kernels even in the presence of compute shaders.

Patch By: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

Differential Revision: http://reviews.llvm.org/D18559

llvm-svn: 265589
2016-04-06 19:40:20 +00:00
Matt Arsenault f2ddbf00ed AMDGPU: Prepare for reducing private element size.
Tests for the new scalarize all private access options will be
included with a future commit.

The only functional change is to make the split/scalarize behavior
for private access of > 4 element vectors to be consistent
with the flat/global handling. This makes the spilling worse
in the two changed tests.

llvm-svn: 260804
2016-02-13 04:18:53 +00:00
Tom Stellard bc4497b13c AMDGPU/SI: Detect uniform branches and emit s_cbranch instructions
Reviewers: arsenm

Subscribers: mareko, MatzeB, qcolombet, arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D16603

llvm-svn: 260765
2016-02-12 23:45:29 +00:00
Matt Arsenault 24ee0785dd AMDGPU: Set element_size in private resource descriptor
Introduce a subtarget feature for this, and leave the default with
the current behavior which assumes up to 16-byte loads/stores can
be used. The field also seems to have the ability to be set to 2 bytes,
but I'm not sure what that would be used for.

llvm-svn: 260651
2016-02-12 02:40:47 +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 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
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