Commit Graph

11 Commits

Author SHA1 Message Date
Matt Arsenault 3c7581bbeb AMDGPU: Use correct register names in inline assembly
Fixes using physical registers in inline asm from clang.

llvm-svn: 305004
2017-06-08 19:03:20 +00:00
Matt Arsenault a3566f2149 AMDGPU: Use MachineRegisterInfo to find max used register
Avoid looping through program to determine register counts.
This avoids needing to look at regmask operands.

Also fixes some counting errors with flat_scr when there
are no stack objects.

llvm-svn: 300482
2017-04-17 19:48:30 +00:00
Matt Arsenault 3dbeefa978 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).

llvm-svn: 298444
2017-03-21 21:39:51 +00:00
Matt Arsenault 7aad8fd8f4 Enable FeatureFlatForGlobal on Volcanic Islands
This switches to the workaround that HSA defaults to
for the mesa path.

This should be applied to the 4.0 branch.

Patch by Vedran Miletić <vedran@miletic.net>

llvm-svn: 292982
2017-01-24 22:02:15 +00:00
Marek Olsak 0f55fbae6c 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

llvm-svn: 289262
2016-12-09 19:49:54 +00:00
Marek Olsak 693e9be918 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

llvm-svn: 289261
2016-12-09 19:49:48 +00:00
Wei Ding 5e832e866e AMDGPU : Add XNACK feature to GPUs that support it.
Differential Revision: http://reviews.llvm.org/D24276

llvm-svn: 280742
2016-09-06 19:55:17 +00:00
Matt Arsenault 07f65718bb AMDGPU: Add missing tests for xnack option for HSA
llvm-svn: 276765
2016-07-26 16:45:50 +00:00
Nicolai Haehnle 3c05d6d3b5 AMDGPU/SI: xnack_mask is always reserved on VI
Summary:
Somehow, I first interpreted the docs as saying space for xnack_mask is only
reserved when XNACK is enabled via SH_MEM_CONFIG. I felt uneasy about this and
went back to actually test what is happening, and it turns out that xnack_mask
is always reserved at least on Tonga and Carrizo, in the sense that flat_scr
is always fixed below the SGPRs that are used to implement xnack_mask, whether
or not they are actually used.

I confirmed this by writing a shader using inline assembly to tease out the
aliasing between flat_scratch and regular SGPRs. For example, on Tonga, where
we fix the number of SGPRs to 80, s[74:75] aliases flat_scratch (so
xnack_mask is s[76:77] and vcc is s[78:79]).

This patch changes both the calculation of the total number of SGPRs and the
various register reservations to account for this.

It ought to be possible to use the gap left by xnack_mask when the feature
isn't used, but this patch doesn't try to do that. (Note that the same applies
to vcc.)

Note that previously, even before my earlier change in r256794, the SGPRs that
alias to xnack_mask could end up being used as well when flat_scr was unused
and the total number of SGPRs happened to fall on the right alignment
(e.g. highest regular SGPR being used s29 and VCC used would lead to number
of SGPRs being 32, where s28 and s29 alias with xnack_mask). So if there
were some conflict due to such aliasing, we should have noticed that already.

Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D15898

llvm-svn: 257073
2016-01-07 17:10:20 +00:00
Nicolai Haehnle 5b50497617 AMDGPU: add +xnack feature
Summary:
Enabling this feature will account for the two SGPRs used by the hardware
to store the XNACK_MASK physically.

The hardware only requires this reservation when the XNACK feature is
explicitly enabled. At some point, HSA will probably want to do that, but
it does increase SGPR register pressure, so leave it disabled by default
for now (but do add a small test).

Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D15869

llvm-svn: 256794
2016-01-04 23:35:53 +00:00
Tom Stellard caaa3aa07c AMDGPU/SI: Reserve appropriate number of sgprs for flat scratch init.
Reviewers: tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D15583

Patch by: Changpeng Fang

llvm-svn: 255908
2015-12-17 17:05:09 +00:00