Commit Graph

6 Commits

Author SHA1 Message Date
Matt Arsenault 4b47213951 AMDGPU: Switch backend default max workgroup size to 1024
Previously this would default to 256, not the maximum supported size
of 1024. Using a maximum lower than the hardware maximum requires
language runtimes to enforce this limit for correctness, which no
language has correctly done. Switch the default to the conservatively
correct maximum, and force frontends to opt-in to the more optimal 256
default maximum.

I don't really understand why the changes in occupancy-levels.ll
increased the computed occupancy, which I expected to decrease. I'm
not sure if these tests should be forcing the old maximum.
2019-11-13 07:11:02 +05:30
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
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 891fccc0c1 AMDGPU: Handle alloca promoting with null operands
If the second pointer in a multi-pointer instruction is
a constant, we can replace the type.

llvm-svn: 269945
2016-05-18 15:57:21 +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
Matt Arsenault a61cb48dd2 AMDGPU: Fix breaking IR on instructions with multiple pointer operands
The promote alloca pass would attempt to promote an alloca with
a select, icmp, or phi user, even though the other operand was
from a non-promotable source, producing a select on two different
pointer types.

Only do this if we know that both operands derive from the same
alloca. In the future we should be able to relax this to an alloca
which will also be promoted.

llvm-svn: 269265
2016-05-12 01:58:58 +00:00