e2cfbfcc0c
In the spirit of TRegions [0], this patch provides a simpler and uniform interface for a kernel to set up the device runtime. The OMPIRBuilder is used for reuse in Flang. A custom state machine will be generated in the follow up patch. The "surplus" threads of the "master warp" will not exit early anymore so we need to use non-aligned barriers. The new runtime will not have an extra warp but also require these non-aligned barriers. [0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11 This was in parts extracted from D59319. Reviewed By: ABataev, JonChesterfield Differential Revision: https://reviews.llvm.org/D101976
95 lines
3.1 KiB
C
95 lines
3.1 KiB
C
//===-- target.h ---------- OpenMP device runtime target implementation ---===//
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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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// Target region interfaces are simple interfaces designed to allow middle-end
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// (=LLVM) passes to analyze and transform the code. To achieve good performance
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// it may be required to run the associated passes. However, implementations of
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// this interface shall always provide a correct implementation as close to the
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// user expected code as possible.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_OPENMP_LIBOMPTARGET_DEVICERTLS_COMMON_TARGET_H
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#define LLVM_OPENMP_LIBOMPTARGET_DEVICERTLS_COMMON_TARGET_H
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#include <stdint.h>
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extern "C" {
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/// Forward declaration of the source location identifier "ident".
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typedef struct ident ident_t;
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/// The target region _kernel_ interface for GPUs
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///
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/// This deliberatly simple interface provides the middle-end (=LLVM) with
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/// easier means to reason about the semantic of the code and transform it as
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/// well. The runtime calls are therefore also desiged to carry sufficient
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/// information necessary for optimizations.
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///
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///
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/// Intended usage:
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///
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/// \code
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/// void kernel(...) {
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/// ThreadKind = __kmpc_target_init(Ident, /* IsSPMD */ false,
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/// /* UseGenericStateMachine */ true,
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/// /* RequiresFullRuntime */ ... );
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/// if (ThreadKind == -1) {
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/// // User defined kernel code.
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/// }
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/// __kmpc_target_deinit(...);
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/// }
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/// \endcode
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///
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/// Which can be transformed to:
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///
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/// \code
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/// void kernel(...) {
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/// ThreadKind = __kmpc_target_init(Ident, /* IsSPMD */ false,
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/// /* UseGenericStateMachine */ false,
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/// /* RequiresFullRuntime */ ... );
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/// if (ThreadKind == -1) {
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/// // User defined kernel code.
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/// } else {
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/// assume(ThreadKind == ThreadId);
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/// // Custom, kernel-specific state machine code.
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/// }
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/// __kmpc_target_deinit(...);
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/// }
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/// \endcode
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///
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///
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///{
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/// Initialization
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///
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/// Must be called by all threads.
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///
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/// \param Ident Source location identification, can be NULL.
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///
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int32_t __kmpc_target_init(ident_t *Ident, bool IsSPMD,
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bool UseGenericStateMachine,
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bool RequiresFullRuntime);
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/// De-Initialization
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///
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/// Must be called by the main thread in generic mode, can be called by all
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/// threads. Must be called by all threads in SPMD mode.
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///
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/// In non-SPMD, this function releases the workers trapped in a state machine
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/// and also any memory dynamically allocated by the runtime.
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///
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/// \param Ident Source location identification, can be NULL.
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///
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void __kmpc_target_deinit(ident_t *Ident, bool IsSPMD,
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bool RequiresFullRuntime);
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///}
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}
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#endif
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