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/*
* Copyright (c) 2014-2015 Advanced Micro Devices, Inc.
* All rights reserved.
*
* For use for simulation and test purposes only
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Author: John Kalamatianos, Sooraj Puthoor
*/
#include "gpu-compute/global_memory_pipeline.hh"
#include "debug/GPUMem.hh"
#include "debug/GPUReg.hh"
#include "gpu-compute/compute_unit.hh"
#include "gpu-compute/gpu_dyn_inst.hh"
#include "gpu-compute/shader.hh"
#include "gpu-compute/vector_register_file.hh"
#include "gpu-compute/wavefront.hh"
GlobalMemPipeline::GlobalMemPipeline(const ComputeUnitParams* p) :
computeUnit(nullptr), gmQueueSize(p->global_mem_queue_size),
inflightStores(0), inflightLoads(0)
{
}
void
GlobalMemPipeline::init(ComputeUnit *cu)
{
computeUnit = cu;
globalMemSize = computeUnit->shader->globalMemSize;
_name = computeUnit->name() + ".GlobalMemPipeline";
}
void
GlobalMemPipeline::exec()
{
// apply any returned global memory operations
GPUDynInstPtr m = !gmReturnedLoads.empty() ? gmReturnedLoads.front() :
!gmReturnedStores.empty() ? gmReturnedStores.front() : nullptr;
bool accessVrf = true;
// check the VRF to see if the operands of a load (or load component
// of an atomic) are accessible
if ((m) && (m->m_op==Enums::MO_LD || MO_A(m->m_op))) {
Wavefront *w = computeUnit->wfList[m->simdId][m->wfSlotId];
accessVrf =
w->computeUnit->vrf[m->simdId]->
vrfOperandAccessReady(m->seqNum(), w, m,
VrfAccessType::WRITE);
}
if ((!gmReturnedStores.empty() || !gmReturnedLoads.empty()) &&
m->latency.rdy() && computeUnit->glbMemToVrfBus.rdy() &&
accessVrf && m->statusBitVector == VectorMask(0) &&
(computeUnit->shader->coissue_return ||
computeUnit->wfWait.at(m->pipeId).rdy())) {
if (m->v_type == VT_32 && m->m_type == Enums::M_U8)
doGmReturn<uint32_t, uint8_t>(m);
else if (m->v_type == VT_32 && m->m_type == Enums::M_U16)
doGmReturn<uint32_t, uint16_t>(m);
else if (m->v_type == VT_32 && m->m_type == Enums::M_U32)
doGmReturn<uint32_t, uint32_t>(m);
else if (m->v_type == VT_32 && m->m_type == Enums::M_S8)
doGmReturn<int32_t, int8_t>(m);
else if (m->v_type == VT_32 && m->m_type == Enums::M_S16)
doGmReturn<int32_t, int16_t>(m);
else if (m->v_type == VT_32 && m->m_type == Enums::M_S32)
doGmReturn<int32_t, int32_t>(m);
else if (m->v_type == VT_32 && m->m_type == Enums::M_F16)
doGmReturn<float, Float16>(m);
else if (m->v_type == VT_32 && m->m_type == Enums::M_F32)
doGmReturn<float, float>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_U8)
doGmReturn<uint64_t, uint8_t>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_U16)
doGmReturn<uint64_t, uint16_t>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_U32)
doGmReturn<uint64_t, uint32_t>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_U64)
doGmReturn<uint64_t, uint64_t>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_S8)
doGmReturn<int64_t, int8_t>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_S16)
doGmReturn<int64_t, int16_t>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_S32)
doGmReturn<int64_t, int32_t>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_S64)
doGmReturn<int64_t, int64_t>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_F16)
doGmReturn<double, Float16>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_F32)
doGmReturn<double, float>(m);
else if (m->v_type == VT_64 && m->m_type == Enums::M_F64)
doGmReturn<double, double>(m);
}
// If pipeline has executed a global memory instruction
// execute global memory packets and issue global
// memory packets to DTLB
if (!gmIssuedRequests.empty()) {
GPUDynInstPtr mp = gmIssuedRequests.front();
if (mp->m_op == Enums::MO_LD ||
(mp->m_op >= Enums::MO_AAND && mp->m_op <= Enums::MO_AMIN) ||
(mp->m_op >= Enums::MO_ANRAND && mp->m_op <= Enums::MO_ANRMIN)) {
if (inflightLoads >= gmQueueSize) {
return;
} else {
++inflightLoads;
}
} else {
if (inflightStores >= gmQueueSize) {
return;
} else if (mp->m_op == Enums::MO_ST) {
++inflightStores;
}
}
mp->initiateAcc(mp);
gmIssuedRequests.pop();
DPRINTF(GPUMem, "CU%d: WF[%d][%d] Popping 0 mem_op = %s\n",
computeUnit->cu_id, mp->simdId, mp->wfSlotId,
Enums::MemOpTypeStrings[mp->m_op]);
}
}
template<typename c0, typename c1>
void
GlobalMemPipeline::doGmReturn(GPUDynInstPtr m)
{
Wavefront *w = computeUnit->wfList[m->simdId][m->wfSlotId];
// Return data to registers
if (m->m_op == Enums::MO_LD || MO_A(m->m_op) || MO_ANR(m->m_op)) {
gmReturnedLoads.pop();
assert(inflightLoads > 0);
--inflightLoads;
if (m->m_op == Enums::MO_LD || MO_A(m->m_op)) {
std::vector<uint32_t> regVec;
// iterate over number of destination register operands since
// this is a load or atomic operation
for (int k = 0; k < m->n_reg; ++k) {
assert((sizeof(c1) * m->n_reg) <= MAX_WIDTH_FOR_MEM_INST);
int dst = m->dst_reg + k;
if (m->n_reg > MAX_REGS_FOR_NON_VEC_MEM_INST)
dst = m->dst_reg_vec[k];
// virtual->physical VGPR mapping
int physVgpr = w->remap(dst, sizeof(c0), 1);
// save the physical VGPR index
regVec.push_back(physVgpr);
c1 *p1 = &((c1*)m->d_data)[k * VSZ];
for (int i = 0; i < VSZ; ++i) {
if (m->exec_mask[i]) {
DPRINTF(GPUReg, "CU%d, WF[%d][%d], lane %d: "
"$%s%d <- %d global ld done (src = wavefront "
"ld inst)\n", w->computeUnit->cu_id, w->simdId,
w->wfSlotId, i, sizeof(c0) == 4 ? "s" : "d",
dst, *p1);
// write the value into the physical VGPR. This is a
// purely functional operation. No timing is modeled.
w->computeUnit->vrf[w->simdId]->write<c0>(physVgpr,
*p1, i);
}
++p1;
}
}
// Schedule the write operation of the load data on the VRF.
// This simply models the timing aspect of the VRF write operation.
// It does not modify the physical VGPR.
loadVrfBankConflictCycles +=
w->computeUnit->vrf[w->simdId]->exec(m->seqNum(),
w, regVec, sizeof(c0),
m->time);
}
} else {
gmReturnedStores.pop();
assert(inflightStores > 0);
--inflightStores;
}
// Decrement outstanding register count
computeUnit->shader->ScheduleAdd(&w->outstanding_reqs, m->time, -1);
if (m->m_op == Enums::MO_ST || MO_A(m->m_op) || MO_ANR(m->m_op) ||
MO_H(m->m_op)) {
computeUnit->shader->ScheduleAdd(&w->outstanding_reqs_wr_gm, m->time,
-1);
}
if (m->m_op == Enums::MO_LD || MO_A(m->m_op) || MO_ANR(m->m_op)) {
computeUnit->shader->ScheduleAdd(&w->outstanding_reqs_rd_gm, m->time,
-1);
}
// Mark write bus busy for appropriate amount of time
computeUnit->glbMemToVrfBus.set(m->time);
if (!computeUnit->shader->coissue_return)
w->computeUnit->wfWait.at(m->pipeId).set(m->time);
}
void
GlobalMemPipeline::regStats()
{
loadVrfBankConflictCycles
.name(name() + ".load_vrf_bank_conflict_cycles")
.desc("total number of cycles GM data are delayed before updating "
"the VRF")
;
}
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