llvm-project/llvm
Neil Henning 6641657453 [AMDGPU] Add an AMDGPU specific atomic optimizer.
This commit adds a new IR level pass to the AMDGPU backend to perform
atomic optimizations. It works by:

- Running through a function and finding atomicrmw add/sub or uses of
  the atomic buffer intrinsics for add/sub.
- If all arguments except the value to be added/subtracted are uniform,
  record the value to be optimized.
- Run through the atomic operations we can optimize and, depending on
  whether the value is uniform/divergent use wavefront wide operations
  (DPP in the divergent case) to calculate the total amount to be
  atomically added/subtracted.
- Then let only a single lane of each wavefront perform the atomic
  operation, reducing the total number of atomic operations in flight.
- Lastly we recombine the result from the single lane to each lane of
  the wavefront, and calculate our individual lanes offset into the
  final result.

Differential Revision: https://reviews.llvm.org/D51969

llvm-svn: 343973
2018-10-08 15:49:19 +00:00
..
benchmarks Pull google/benchmark library to the LLVM tree 2018-08-28 09:42:41 +00:00
bindings [bindings/go] Add Go bindings to the Token type 2018-09-28 17:39:59 +00:00
cmake [cmake] Also create lowercase extension WinSDK symlinks 2018-10-05 00:08:27 +00:00
docs [doc] Update the programmer's manual about SmallSet's iterator 2018-10-04 12:33:33 +00:00
examples [ORC] Fix BuildingAJIT tutorial examples that were broken by r343059. 2018-09-26 04:00:58 +00:00
include [IRBuilder] Fixup CreateIntrinsic to allow specifying Types to Mangle. 2018-10-08 10:32:33 +00:00
lib [AMDGPU] Add an AMDGPU specific atomic optimizer. 2018-10-08 15:49:19 +00:00
projects
resources
runtimes
test [AMDGPU] Add an AMDGPU specific atomic optimizer. 2018-10-08 15:49:19 +00:00
tools [PDB] Add the ability to lookup global symbols by name. 2018-10-08 04:19:16 +00:00
unittests [IRBuilder] Fixup CreateIntrinsic to allow specifying Types to Mangle. 2018-10-08 10:32:33 +00:00
utils [utils] Ensure that update_mca_test_checks.py writes prefixes in alphabetical order 2018-10-04 14:42:19 +00:00
.arcconfig
.clang-format
.clang-tidy
.gitattributes
.gitignore
CMakeLists.txt [WebAssembly] Add WebAssembly to LLVM_ALL_TARGETS 2018-10-03 23:56:52 +00:00
CODE_OWNERS.TXT
CREDITS.TXT
LICENSE.TXT
LLVMBuild.txt
README.txt Test commit. 2018-09-22 01:01:03 +00:00
RELEASE_TESTERS.TXT
configure
llvm.spec.in

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