14 Commits

Author SHA1 Message Date
Matthias Braun cd03942492 RegScavenging: Add scavengeRegisterBackwards()
Re-apply r276044/r279124/r305516. Fixed a problem where we would refuse
to place spills as the very first instruciton of a basic block and thus
artifically increase pressure (test in
test/CodeGen/PowerPC/scavenging.mir:spill_at_begin)

This is a variant of scavengeRegister() that works for
enterBasicBlockEnd()/backward(). The benefit of the backward mode is
that it is not affected by incomplete kill flags.

This patch also changes
PrologEpilogInserter::doScavengeFrameVirtualRegs() to use the register
scavenger in backwards mode.

Differential Revision: http://reviews.llvm.org/D21885

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305625 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-17 02:08:18 +00:00
Matthias Braun bd1a266898 Revert "RegScavenging: Add scavengeRegisterBackwards()"
Revert because of reports of some PPC input starting to spill when it
was predicted that it wouldn't and no spillslot was reserved.

This reverts commit r305516.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305566 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-16 17:48:08 +00:00
Matthias Braun 02688b00ef RegScavenging: Add scavengeRegisterBackwards()
Re-apply r276044/r279124. Trying to reproduce or disprove the ppc64
problems reported in the stage2 build last time, which I cannot
reproduce right now.

This is a variant of scavengeRegister() that works for
enterBasicBlockEnd()/backward(). The benefit of the backward mode is
that it is not affected by incomplete kill flags.

This patch also changes
PrologEpilogInserter::doScavengeFrameVirtualRegs() to use the register
scavenger in backwards mode.

Differential Revision: http://reviews.llvm.org/D21885

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305516 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-15 22:14:55 +00:00
Matt Arsenault d706d030af 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).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298444 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-21 21:39:51 +00:00
Stanislav Mekhanoshin aae13371be [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295206 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-15 17:19:50 +00:00
Valery Pykhtin 9016ce4442 [AMDGPU] Fix typo in GCNSchedStrategy
Differential revision: https://reviews.llvm.org/D28980

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293171 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-26 10:51:47 +00:00
Marek Olsak 29e2dd8cf4 AMDGPU/SI: Don't reserve XNACK when it's disabled
Summary:
This frees 2 additional scalar registers.

These are results from all of my 3 patches combined:

  Polaris:
    Spilled SGPRs: 2231 -> 1517 (-32.00 %)

  Tonga:
    Spilled SGPRs: 3829 -> 2608 (-31.89 %)
    Spilled VGPRs: 100 -> 84 (-16.00 %)

  Tonga even spills SGPRs via VGPRs to scratch. That's a compute shader
  limited to 64 VGPRs.

Reviewers: tstellarAMD

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

Differential Revision: https://reviews.llvm.org/D27151

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289262 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-09 19:49:54 +00:00
Marek Olsak 36d5f19e1d 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289261 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-09 19:49:48 +00:00
Matthias Braun c139fdb8e4 RegisterCoalscer: Only coalesce complete reserved registers.
The coalescer eliminates copies from reserved registers of the form:
   %vregX = COPY %rY
in the case where %rY is a reserved register. However this turns out to
be invalid if only some of the subregisters are reserved (see also
https://reviews.llvm.org/D26648).

Differential Revision: https://reviews.llvm.org/D26687

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288428 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-01 22:39:51 +00:00
Marek Olsak 2a24827c23 AMDGPU/SI: Add back reverted SGPR spilling code, but disable it
suggested as a better solution by Matt

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287942 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-25 17:37:09 +00:00
Marek Olsak 82bcf466c2 Revert "AMDGPU: Implement SGPR spilling with scalar stores"
This reverts commit 4404d0d6e3.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287936 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-25 16:03:34 +00:00
Matt Arsenault 4404d0d6e3 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286766 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-13 18:20:54 +00:00
Matt Arsenault 2d7bc6b1e1 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285435 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-28 19:43:31 +00:00
Konstantin Zhuravlyov 1f99c41083 [AMDGPU] Wave and register controls
- Implemented amdgpu-flat-work-group-size attribute
- Implemented amdgpu-num-active-waves-per-eu attribute
- Implemented amdgpu-num-sgpr attribute
- Implemented amdgpu-num-vgpr attribute
- Dynamic LDS constraints are in a separate patch

Patch by Tom Stellard and Konstantin Zhuravlyov

Differential Revision: https://reviews.llvm.org/D21562



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280747 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-06 20:22:28 +00:00