1 //===---------------------- MicroOpQueueStage.cpp ---------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 /// \file
9 ///
10 /// This file defines the MicroOpQueueStage.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/MCA/Stages/MicroOpQueueStage.h"
15 
16 namespace llvm {
17 namespace mca {
18 
19 #define DEBUG_TYPE "llvm-mca"
20 
21 Error MicroOpQueueStage::moveInstructions() {
22   InstRef IR = Buffer[CurrentInstructionSlotIdx];
23   while (IR && checkNextStage(IR)) {
24     if (llvm::Error Val = moveToTheNextStage(IR))
25       return Val;
26 
27     Buffer[CurrentInstructionSlotIdx].invalidate();
28     unsigned NormalizedOpcodes = getNormalizedOpcodes(IR);
29     CurrentInstructionSlotIdx += NormalizedOpcodes;
30     CurrentInstructionSlotIdx %= Buffer.size();
31     AvailableEntries += NormalizedOpcodes;
32     IR = Buffer[CurrentInstructionSlotIdx];
33   }
34 
35   return llvm::ErrorSuccess();
36 }
37 
38 MicroOpQueueStage::MicroOpQueueStage(unsigned Size, unsigned IPC,
39                                      bool ZeroLatencyStage)
40     : NextAvailableSlotIdx(0), CurrentInstructionSlotIdx(0), MaxIPC(IPC),
41       CurrentIPC(0), IsZeroLatencyStage(ZeroLatencyStage) {
42   Buffer.resize(Size ? Size : 1);
43   AvailableEntries = Buffer.size();
44 }
45 
46 Error MicroOpQueueStage::execute(InstRef &IR) {
47   Buffer[NextAvailableSlotIdx] = IR;
48   unsigned NormalizedOpcodes = getNormalizedOpcodes(IR);
49   NextAvailableSlotIdx += NormalizedOpcodes;
50   NextAvailableSlotIdx %= Buffer.size();
51   AvailableEntries -= NormalizedOpcodes;
52   ++CurrentIPC;
53   return llvm::ErrorSuccess();
54 }
55 
56 Error MicroOpQueueStage::cycleStart() {
57   CurrentIPC = 0;
58   if (!IsZeroLatencyStage)
59     return moveInstructions();
60   return llvm::ErrorSuccess();
61 }
62 
63 Error MicroOpQueueStage::cycleEnd() {
64   if (IsZeroLatencyStage)
65     return moveInstructions();
66   return llvm::ErrorSuccess();
67 }
68 
69 } // namespace mca
70 } // namespace llvm
71