1 //===------ llvm/MC/MCInstrDesc.cpp- Instruction Descriptors --------------===//
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 // This file defines methods on the MCOperandInfo and MCInstrDesc classes, which
10 // are used to describe target instructions and their operands.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/MC/MCInstrDesc.h"
15 #include "llvm/MC/MCInst.h"
16 #include "llvm/MC/MCRegisterInfo.h"
17 #include "llvm/MC/MCSubtargetInfo.h"
18 
19 using namespace llvm;
20 
21 bool MCInstrDesc::getDeprecatedInfo(MCInst &MI, const MCSubtargetInfo &STI,
22                                     std::string &Info) const {
23   if (ComplexDeprecationInfo)
24     return ComplexDeprecationInfo(MI, STI, Info);
25   if (DeprecatedFeature != -1 && STI.getFeatureBits()[DeprecatedFeature]) {
26     // FIXME: it would be nice to include the subtarget feature here.
27     Info = "deprecated";
28     return true;
29   }
30   return false;
31 }
32 bool MCInstrDesc::mayAffectControlFlow(const MCInst &MI,
33                                        const MCRegisterInfo &RI) const {
34   if (isBranch() || isCall() || isReturn() || isIndirectBranch())
35     return true;
36   unsigned PC = RI.getProgramCounter();
37   if (PC == 0)
38     return false;
39   if (hasDefOfPhysReg(MI, PC, RI))
40     return true;
41   return false;
42 }
43 
44 bool MCInstrDesc::hasImplicitDefOfPhysReg(unsigned Reg,
45                                           const MCRegisterInfo *MRI) const {
46   if (const MCPhysReg *ImpDefs = ImplicitDefs)
47     for (; *ImpDefs; ++ImpDefs)
48       if (*ImpDefs == Reg || (MRI && MRI->isSubRegister(Reg, *ImpDefs)))
49         return true;
50   return false;
51 }
52 
53 bool MCInstrDesc::hasDefOfPhysReg(const MCInst &MI, unsigned Reg,
54                                   const MCRegisterInfo &RI) const {
55   for (int i = 0, e = NumDefs; i != e; ++i)
56     if (MI.getOperand(i).isReg() &&
57         RI.isSubRegisterEq(Reg, MI.getOperand(i).getReg()))
58       return true;
59   if (variadicOpsAreDefs())
60     for (int i = NumOperands - 1, e = MI.getNumOperands(); i != e; ++i)
61       if (MI.getOperand(i).isReg() &&
62           RI.isSubRegisterEq(Reg, MI.getOperand(i).getReg()))
63         return true;
64   return hasImplicitDefOfPhysReg(Reg, &RI);
65 }
66