xref: /llvm-project/llvm/include/llvm/ADT/Uniformity.h (revision c76acb9dffec2f318f3fafe111c5255ca4e1b309)
1*475ce4c2SSameer Sahasrabuddhe //===- Uniformity.h --------------------------------------*- C++ -*--------===//
2*475ce4c2SSameer Sahasrabuddhe //
3*475ce4c2SSameer Sahasrabuddhe // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*475ce4c2SSameer Sahasrabuddhe // See https://llvm.org/LICENSE.txt for license information.
5*475ce4c2SSameer Sahasrabuddhe // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*475ce4c2SSameer Sahasrabuddhe //
7*475ce4c2SSameer Sahasrabuddhe //===----------------------------------------------------------------------===//
8*475ce4c2SSameer Sahasrabuddhe 
9*475ce4c2SSameer Sahasrabuddhe #ifndef LLVM_ADT_UNIFORMITY_H
10*475ce4c2SSameer Sahasrabuddhe #define LLVM_ADT_UNIFORMITY_H
11*475ce4c2SSameer Sahasrabuddhe 
12*475ce4c2SSameer Sahasrabuddhe namespace llvm {
13*475ce4c2SSameer Sahasrabuddhe 
14*475ce4c2SSameer Sahasrabuddhe /// Enum describing how instructions behave with respect to uniformity and
15*475ce4c2SSameer Sahasrabuddhe /// divergence, to answer the question: if the same instruction is executed by
16*475ce4c2SSameer Sahasrabuddhe /// two threads in a convergent set of threads, will its result value(s) be
17*475ce4c2SSameer Sahasrabuddhe /// uniform, i.e. the same on both threads?
18*475ce4c2SSameer Sahasrabuddhe enum class InstructionUniformity {
19*475ce4c2SSameer Sahasrabuddhe   /// The result values are uniform if and only if all operands are uniform.
20*475ce4c2SSameer Sahasrabuddhe   Default,
21*475ce4c2SSameer Sahasrabuddhe 
22*475ce4c2SSameer Sahasrabuddhe   /// The result values are always uniform.
23*475ce4c2SSameer Sahasrabuddhe   AlwaysUniform,
24*475ce4c2SSameer Sahasrabuddhe 
25*475ce4c2SSameer Sahasrabuddhe   /// The result values can never be assumed to be uniform.
26*475ce4c2SSameer Sahasrabuddhe   NeverUniform
27*475ce4c2SSameer Sahasrabuddhe };
28*475ce4c2SSameer Sahasrabuddhe 
29*475ce4c2SSameer Sahasrabuddhe } // namespace llvm
30*475ce4c2SSameer Sahasrabuddhe #endif // LLVM_ADT_UNIFORMITY_H
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