fbc1dcb946
[libomptarget][devicertl][nfc] Simplify target_atomic abstraction Atomic functions were implemented as a shim around cuda's atomics, with amdgcn implementing those symbols as a shim around gcc style intrinsics. This patch folds target_atomic.h into target_impl.h and folds amdgcn. Further work is likely to be useful here, either changing to openmp's atomic interface or instantiating the templates on the few used types in order to move them into a cuda/c++ implementation file. This change is mostly to group the remaining uses of the cuda api under nvptx' target_impl abstraction. Reviewed By: jdoerfert Differential Revision: https://reviews.llvm.org/D95062
90 lines
3.2 KiB
C++
90 lines
3.2 KiB
C++
//===------- state-queuei.h - OpenMP GPU State Queue ------------- CUDA -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains the implementation of a queue to hand out OpenMP state
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// objects to teams of one or more kernels.
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//
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// Reference:
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// Thomas R.W. Scogland and Wu-chun Feng. 2015.
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// Design and Evaluation of Scalable Concurrent Queues for Many-Core
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// Architectures. International Conference on Performance Engineering.
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//
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//===----------------------------------------------------------------------===//
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#include "state-queue.h"
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template <typename ElementType, uint32_t SIZE>
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INLINE uint32_t omptarget_nvptx_Queue<ElementType, SIZE>::ENQUEUE_TICKET() {
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return __kmpc_atomic_add((unsigned int *)&tail, 1u);
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}
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template <typename ElementType, uint32_t SIZE>
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INLINE uint32_t omptarget_nvptx_Queue<ElementType, SIZE>::DEQUEUE_TICKET() {
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return __kmpc_atomic_add((unsigned int *)&head, 1u);
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}
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template <typename ElementType, uint32_t SIZE>
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INLINE uint32_t
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omptarget_nvptx_Queue<ElementType, SIZE>::ID(uint32_t ticket) {
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return (ticket / SIZE) * 2;
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}
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template <typename ElementType, uint32_t SIZE>
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INLINE bool omptarget_nvptx_Queue<ElementType, SIZE>::IsServing(uint32_t slot,
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uint32_t id) {
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return __kmpc_atomic_add((unsigned int *)&ids[slot], 0u) == id;
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}
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template <typename ElementType, uint32_t SIZE>
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INLINE void
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omptarget_nvptx_Queue<ElementType, SIZE>::PushElement(uint32_t slot,
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ElementType *element) {
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__kmpc_atomic_exchange((unsigned long long *)&elementQueue[slot],
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(unsigned long long)element);
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}
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template <typename ElementType, uint32_t SIZE>
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INLINE ElementType *
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omptarget_nvptx_Queue<ElementType, SIZE>::PopElement(uint32_t slot) {
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return (ElementType *)__kmpc_atomic_add(
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(unsigned long long *)&elementQueue[slot], (unsigned long long)0);
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}
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template <typename ElementType, uint32_t SIZE>
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INLINE void omptarget_nvptx_Queue<ElementType, SIZE>::DoneServing(uint32_t slot,
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uint32_t id) {
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__kmpc_atomic_exchange((unsigned int *)&ids[slot], (id + 1) % MAX_ID);
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}
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template <typename ElementType, uint32_t SIZE>
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INLINE void
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omptarget_nvptx_Queue<ElementType, SIZE>::Enqueue(ElementType *element) {
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uint32_t ticket = ENQUEUE_TICKET();
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uint32_t slot = ticket % SIZE;
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uint32_t id = ID(ticket) + 1;
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while (!IsServing(slot, id))
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;
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PushElement(slot, element);
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DoneServing(slot, id);
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}
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template <typename ElementType, uint32_t SIZE>
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INLINE ElementType *omptarget_nvptx_Queue<ElementType, SIZE>::Dequeue() {
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uint32_t ticket = DEQUEUE_TICKET();
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uint32_t slot = ticket % SIZE;
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uint32_t id = ID(ticket);
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while (!IsServing(slot, id))
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;
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ElementType *element = PopElement(slot);
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// This is to populate the queue because of the lack of GPU constructors.
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if (element == 0)
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element = &elements[slot];
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DoneServing(slot, id);
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return element;
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}
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