2 * Copyright (c) 2007 MIPS Technologies, Inc.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 * Authors: Korey Sewell
35 #include "cpu/inorder/resources/execution_unit.hh"
36 #include "cpu/inorder/cpu.hh"
37 #include "cpu/inorder/resource_pool.hh"
38 #include "debug/Fault.hh"
39 #include "debug/InOrderExecute.hh"
40 #include "debug/InOrderStall.hh"
43 using namespace ThePipeline
;
45 ExecutionUnit::ExecutionUnit(string res_name
, int res_id
, int res_width
,
46 int res_latency
, InOrderCPU
*_cpu
,
47 ThePipeline::Params
*params
)
48 : Resource(res_name
, res_id
, res_width
, res_latency
, _cpu
),
49 lastExecuteTick(0), lastControlTick(0)
53 ExecutionUnit::regStats()
55 predictedTakenIncorrect
56 .name(name() + ".predictedTakenIncorrect")
57 .desc("Number of Branches Incorrectly Predicted As Taken.");
59 predictedNotTakenIncorrect
60 .name(name() + ".predictedNotTakenIncorrect")
61 .desc("Number of Branches Incorrectly Predicted As Not Taken).");
64 .name(name() + ".executions")
65 .desc("Number of Instructions Executed.");
69 .name(name() + ".mispredicted")
70 .desc("Number of Branches Incorrectly Predicted");
73 .name(name() + ".predicted")
74 .desc("Number of Branches Incorrectly Predicted");
77 .name(name() + ".mispredictPct")
78 .desc("Percentage of Incorrect Branches Predicts")
80 mispredictPct
= (predictedIncorrect
/
81 (predictedCorrect
+ predictedIncorrect
)) * 100;
87 ExecutionUnit::execute(int slot_num
)
89 ResourceRequest
* exec_req
= reqs
[slot_num
];
90 DynInstPtr inst
= reqs
[slot_num
]->inst
;
91 if (inst
->fault
!= NoFault
) {
92 DPRINTF(InOrderExecute
,
93 "[tid:%i]: [sn:%i]: Detected %s fault @ %x. Forwarding to "
94 "next stage.\n", inst
->readTid(), inst
->seqNum
, inst
->fault
->name(),
100 Fault fault
= NoFault
;
101 Tick cur_tick
= curTick();
102 unsigned stage_num
= exec_req
->getStageNum();
103 ThreadID tid
= inst
->readTid();
105 InstSeqNum seq_num
= inst
->seqNum
;
108 switch (exec_req
->cmd
)
113 DPRINTF(InOrderExecute
, "[tid:%i] [sn:%i] [PC:%s] Ignoring execution"
114 "of %s.\n", inst
->readTid(), seq_num
, inst
->pcState(),
120 DPRINTF(InOrderExecute
, "[tid:%i] Executing [sn:%i] [PC:%s] %s.\n",
121 inst
->readTid(), seq_num
, inst
->pcState(), inst
->instName());
124 if (cur_tick
!= lastExecuteTick
) {
125 lastExecuteTick
= cur_tick
;
128 //@todo: handle address generation here
129 assert(!inst
->isMemRef());
131 if (inst
->isControl()) {
132 if (lastControlTick
== cur_tick
) {
133 DPRINTF(InOrderExecute
, "Can not Execute More than One Control "
134 "Inst Per Cycle. Blocking Request.\n");
135 exec_req
->done(false);
138 lastControlTick
= curTick();
141 fault
= inst
->execute();
143 // Should unconditional control , pc relative count as an
144 // execution??? Probably not.
147 if (fault
== NoFault
) {
150 if (inst
->mispredicted()) {
151 assert(inst
->isControl());
153 // Set up Squash Generated By this Misprediction
154 TheISA::PCState pc
= inst
->pcState();
155 TheISA::advancePC(pc
, inst
->staticInst
);
156 inst
->setPredTarg(pc
);
157 inst
->setSquashInfo(stage_num
);
158 setupSquash(inst
, stage_num
, tid
);
160 DPRINTF(InOrderExecute
, "[tid:%i]: [sn:%i] Squashing from "
161 "stage %i. Redirecting fetch to %s.\n", tid
,
162 inst
->seqNum
, stage_num
, pc
);
163 DPRINTF(InOrderStall
, "STALL: [tid:%i]: Branch"
164 " misprediction at %s\n", tid
, inst
->pcState());
166 if (inst
->predTaken()) {
167 predictedTakenIncorrect
++;
168 DPRINTF(InOrderExecute
, "[tid:%i] [sn:%i] %s ..."
169 "PC %s ... Mispredicts! "
170 "(Prediction: Taken)\n",
172 inst
->staticInst
->disassemble(
176 predictedNotTakenIncorrect
++;
177 DPRINTF(InOrderExecute
, "[tid:%i] [sn:%i] %s ..."
178 "PC %s ... Mispredicts! "
179 "(Prediction: Not Taken)\n",
181 inst
->staticInst
->disassemble(
185 predictedIncorrect
++;
187 DPRINTF(InOrderExecute
, "[tid:%i]: [sn:%i]: Prediction"
188 "Correct.\n", inst
->readTid(), seq_num
);
194 DPRINTF(Fault
, "[tid:%i]:[sn:%i]: Fault %s found\n",
195 inst
->readTid(), inst
->seqNum
, fault
->name());
200 // Regular ALU instruction
201 fault
= inst
->execute();
204 if (fault
== NoFault
) {
208 for (int didx
= 0; didx
< inst
->numDestRegs(); didx
++)
209 if (inst
->resultType(didx
) == InOrderDynInst::Float
||
210 inst
->resultType(didx
) == InOrderDynInst::FloatBits
||
211 inst
->resultType(didx
) == InOrderDynInst::Double
)
212 DPRINTF(InOrderExecute
, "[tid:%i]: [sn:%i]: Dest result %i "
213 "of FP execution is %08f (%x).\n", inst
->readTid(),
214 seq_num
, didx
, inst
->readFloatResult(didx
),
215 inst
->readFloatBitsResult(didx
));
217 DPRINTF(InOrderExecute
, "[tid:%i]: [sn:%i]: Dest result %i "
218 "of Int execution is 0x%x.\n", inst
->readTid(),
219 seq_num
, didx
, inst
->readIntResult(didx
));
223 // The Syscall might change the PC, so conservatively
224 // squash everything behing it
225 if (inst
->isSyscall()) {
226 inst
->setSquashInfo(stage_num
);
227 setupSquash(inst
, stage_num
, tid
);
231 DPRINTF(InOrderExecute
, "[tid:%i]: [sn:%i]: had a %s "
232 "fault.\n", inst
->readTid(), seq_num
, fault
->name());
233 DPRINTF(Fault
, "[tid:%i]:[sn:%i]: Fault %s found\n",
234 inst
->readTid(), inst
->seqNum
, fault
->name());
244 fatal("Unrecognized command to %s", resName
);