LLVM 20.0.0git
AArch64PostCoalescerPass.cpp
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1//===- AArch64PostCoalescerPass.cpp - AArch64 Post Coalescer pass ---------===//
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//===----------------------------------------------------------------------===//
9
10#include "AArch64InstrInfo.h"
15
16using namespace llvm;
17
18#define DEBUG_TYPE "aarch64-post-coalescer-pass"
19
20namespace {
21
22struct AArch64PostCoalescer : public MachineFunctionPass {
23 static char ID;
24
25 AArch64PostCoalescer() : MachineFunctionPass(ID) {
27 }
28
29 LiveIntervals *LIS;
31
32 bool runOnMachineFunction(MachineFunction &MF) override;
33
34 StringRef getPassName() const override {
35 return "AArch64 Post Coalescer pass";
36 }
37
38 void getAnalysisUsage(AnalysisUsage &AU) const override {
39 AU.setPreservesAll();
42 }
43};
44
45char AArch64PostCoalescer::ID = 0;
46
47} // end anonymous namespace
48
49INITIALIZE_PASS_BEGIN(AArch64PostCoalescer, "aarch64-post-coalescer-pass",
50 "AArch64 Post Coalescer Pass", false, false)
52INITIALIZE_PASS_END(AArch64PostCoalescer, "aarch64-post-coalescer-pass",
53 "AArch64 Post Coalescer Pass", false, false)
54
55bool AArch64PostCoalescer::runOnMachineFunction(MachineFunction &MF) {
56 if (skipFunction(MF.getFunction()))
57 return false;
58
59 AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
60 if (!FuncInfo->hasStreamingModeChanges())
61 return false;
62
63 MRI = &MF.getRegInfo();
64 LIS = &getAnalysis<LiveIntervalsWrapperPass>().getLIS();
65 bool Changed = false;
66
67 for (MachineBasicBlock &MBB : MF) {
69 switch (MI.getOpcode()) {
70 default:
71 break;
72 case AArch64::COALESCER_BARRIER_FPR16:
73 case AArch64::COALESCER_BARRIER_FPR32:
74 case AArch64::COALESCER_BARRIER_FPR64:
75 case AArch64::COALESCER_BARRIER_FPR128: {
76 Register Src = MI.getOperand(1).getReg();
77 Register Dst = MI.getOperand(0).getReg();
78 if (Src != Dst)
79 MRI->replaceRegWith(Dst, Src);
80
81 // MI must be erased from the basic block before recalculating the live
82 // interval.
83 LIS->RemoveMachineInstrFromMaps(MI);
84 MI.eraseFromParent();
85
86 LIS->removeInterval(Src);
87 LIS->createAndComputeVirtRegInterval(Src);
88
89 Changed = true;
90 break;
91 }
92 }
93 }
94 }
95
96 return Changed;
97}
98
100 return new AArch64PostCoalescer();
101}
unsigned const MachineRegisterInfo * MRI
aarch64 post coalescer pass
MachineBasicBlock & MBB
IRTranslator LLVM IR MI
#define INITIALIZE_PASS_DEPENDENCY(depName)
Definition: PassSupport.h:55
#define INITIALIZE_PASS_END(passName, arg, name, cfg, analysis)
Definition: PassSupport.h:57
#define INITIALIZE_PASS_BEGIN(passName, arg, name, cfg, analysis)
Definition: PassSupport.h:52
register Register Coalescer
register coalescer
AArch64FunctionInfo - This class is derived from MachineFunctionInfo and contains private AArch64-spe...
Represent the analysis usage information of a pass.
AnalysisUsage & addRequired()
void setPreservesAll()
Set by analyses that do not transform their input at all.
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:310
MachineFunctionPass - This class adapts the FunctionPass interface to allow convenient creation of pa...
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.
virtual bool runOnMachineFunction(MachineFunction &MF)=0
runOnMachineFunction - This method must be overloaded to perform the desired machine code transformat...
Representation of each machine instruction.
Definition: MachineInstr.h:69
MachineRegisterInfo - Keep track of information for virtual and physical registers,...
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
Pass interface - Implemented by all 'passes'.
Definition: Pass.h:94
virtual StringRef getPassName() const
getPassName - Return a nice clean name for a pass.
Definition: Pass.cpp:81
Wrapper class representing virtual and physical registers.
Definition: Register.h:19
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
unsigned ID
LLVM IR allows to use arbitrary numbers as calling convention identifiers.
Definition: CallingConv.h:24
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
void initializeAArch64PostCoalescerPass(PassRegistry &)
FunctionPass * createAArch64PostCoalescerPass()
iterator_range< early_inc_iterator_impl< detail::IterOfRange< RangeT > > > make_early_inc_range(RangeT &&Range)
Make a range that does early increment to allow mutation of the underlying range without disrupting i...
Definition: STLExtras.h:656