Commit Graph

8 Commits

Author SHA1 Message Date
Changpeng Fang ba92059ca9 AMDGPU/SI: Extend promoting alloca to vector to arrays of up to 16 elements
Summary:
  This patch extends the promotion of alloca to vector to the arrays of up to 16 elements. Also we introduce
an option, -disable-promote-alloca-to-vector, to switch promotion to vector off, if needed.

Reviewers:
  arsenm

Differential Revision:
  https://reviews.llvm.org/D33559

llvm-svn: 325372
2018-02-16 19:14:17 +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
Stanislav Mekhanoshin 19f98c6a09 [AMDGPU] Fix MaxWorkGroupsPerCU for large workgroups
This patch corrects the maximum workgroups per CU if we have big
workgroups (more than 128). This calculation contributes to the
occupancy calculation in respect to LDS size.

Differential Revision: https://reviews.llvm.org/D29974

llvm-svn: 295134
2017-02-15 01:03:59 +00:00
Stanislav Mekhanoshin 2b913b1f49 [AMDGPU] Account workgroup size in LDS occupancy limits
Functions matching LDS use to occupancy return results for a workgroup
of 64 workitems. The numbers has to be adjusted for bigger workgroups.
For example a workgroup of size 256 already occupies 4 waves just by
itself. Given that all numbers of LDS use in the compiler are per
workgroup, occupancy shall be multiplied by 4 in this case. Each 64
workitems still limited by the same number, but 4 subrgoups 64 workitems
each can afford 4 times more LDS to get the same occupancy.

In addition change initializes LDS size in the subtarget to a real value
for SI+ targets. This is required since LDS size is a variable in these
calculations.

Differential Revision: https://reviews.llvm.org/D29423

llvm-svn: 293837
2017-02-01 22:59:50 +00:00
Konstantin Zhuravlyov 1d65026ca6 [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

llvm-svn: 280747
2016-09-06 20:22:28 +00:00
Matt Arsenault 918e81c3d4 AMDGPU: Add more tests for LDS size with occupancy
llvm-svn: 276821
2016-07-26 23:15:59 +00:00
Matt Arsenault 8a028bf4d7 AMDGPU: Fix promote alloca pass creating huge arrays
This was assuming it could use all memory before, which is
a bad decision because it restricts occupancy.

By default, only try to use enough space that could reduce
occupancy to 7, an arbitrarily chosen limit.

Based on the exist LDS usage, try to round up to the limit
in the current tier instead of further hurting occupancy.
This isn't ideal, because it doesn't accurately know how much
space is going to be used for alignment padding.

llvm-svn: 269708
2016-05-16 21:19:59 +00:00
Tom Stellard 79a1fd718c AMDGPU: allow specifying a workgroup size that needs to fit in a compute unit
Summary:
For GL_ARB_compute_shader we need to support workgroup sizes of at least 1024. However, if we want to allow large workgroup sizes, we may need to use less registers, as we have to run more waves per SIMD.

This patch adds an attribute to specify the maximum work group size the compiled program needs to support. It defaults, to 256, as that has no wave restrictions.

Reducing the number of registers available is done similarly to how the registers were reserved for chips with the sgpr init bug.

Reviewers: mareko, arsenm, tstellarAMD, nhaehnle

Subscribers: FireBurn, kerberizer, llvm-commits, arsenm

Differential Revision: http://reviews.llvm.org/D18340

Patch By: Bas Nieuwenhuizen

llvm-svn: 266337
2016-04-14 16:27:07 +00:00