1 //===-- TargetInstrInfo.cpp - Target Instruction Information --------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the TargetInstrInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/Target/TargetInstrInfo.h"
15 #include "llvm/Target/TargetRegisterInfo.h"
16 #include "llvm/MC/MCAsmInfo.h"
17 #include "llvm/MC/MCInstrItineraries.h"
18 #include "llvm/Support/ErrorHandling.h"
19 #include <cctype>
20 using namespace llvm;
21
22 //===----------------------------------------------------------------------===//
23 // TargetInstrInfo
24 //===----------------------------------------------------------------------===//
25
~TargetInstrInfo()26 TargetInstrInfo::~TargetInstrInfo() {
27 }
28
29 const TargetRegisterClass*
getRegClass(const MCInstrDesc & MCID,unsigned OpNum,const TargetRegisterInfo * TRI) const30 TargetInstrInfo::getRegClass(const MCInstrDesc &MCID, unsigned OpNum,
31 const TargetRegisterInfo *TRI) const {
32 if (OpNum >= MCID.getNumOperands())
33 return 0;
34
35 short RegClass = MCID.OpInfo[OpNum].RegClass;
36 if (MCID.OpInfo[OpNum].isLookupPtrRegClass())
37 return TRI->getPointerRegClass(RegClass);
38
39 // Instructions like INSERT_SUBREG do not have fixed register classes.
40 if (RegClass < 0)
41 return 0;
42
43 // Otherwise just look it up normally.
44 return TRI->getRegClass(RegClass);
45 }
46
47 unsigned
getNumMicroOps(const InstrItineraryData * ItinData,const MachineInstr * MI) const48 TargetInstrInfo::getNumMicroOps(const InstrItineraryData *ItinData,
49 const MachineInstr *MI) const {
50 if (!ItinData || ItinData->isEmpty())
51 return 1;
52
53 unsigned Class = MI->getDesc().getSchedClass();
54 unsigned UOps = ItinData->Itineraries[Class].NumMicroOps;
55 if (UOps)
56 return UOps;
57
58 // The # of u-ops is dynamically determined. The specific target should
59 // override this function to return the right number.
60 return 1;
61 }
62
63 int
getOperandLatency(const InstrItineraryData * ItinData,const MachineInstr * DefMI,unsigned DefIdx,const MachineInstr * UseMI,unsigned UseIdx) const64 TargetInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
65 const MachineInstr *DefMI, unsigned DefIdx,
66 const MachineInstr *UseMI, unsigned UseIdx) const {
67 if (!ItinData || ItinData->isEmpty())
68 return -1;
69
70 unsigned DefClass = DefMI->getDesc().getSchedClass();
71 unsigned UseClass = UseMI->getDesc().getSchedClass();
72 return ItinData->getOperandLatency(DefClass, DefIdx, UseClass, UseIdx);
73 }
74
getInstrLatency(const InstrItineraryData * ItinData,const MachineInstr * MI,unsigned * PredCost) const75 int TargetInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
76 const MachineInstr *MI,
77 unsigned *PredCost) const {
78 if (!ItinData || ItinData->isEmpty())
79 return 1;
80
81 return ItinData->getStageLatency(MI->getDesc().getSchedClass());
82 }
83
hasLowDefLatency(const InstrItineraryData * ItinData,const MachineInstr * DefMI,unsigned DefIdx) const84 bool TargetInstrInfo::hasLowDefLatency(const InstrItineraryData *ItinData,
85 const MachineInstr *DefMI,
86 unsigned DefIdx) const {
87 if (!ItinData || ItinData->isEmpty())
88 return false;
89
90 unsigned DefClass = DefMI->getDesc().getSchedClass();
91 int DefCycle = ItinData->getOperandCycle(DefClass, DefIdx);
92 return (DefCycle != -1 && DefCycle <= 1);
93 }
94
95 /// insertNoop - Insert a noop into the instruction stream at the specified
96 /// point.
insertNoop(MachineBasicBlock & MBB,MachineBasicBlock::iterator MI) const97 void TargetInstrInfo::insertNoop(MachineBasicBlock &MBB,
98 MachineBasicBlock::iterator MI) const {
99 llvm_unreachable("Target didn't implement insertNoop!");
100 }
101
102
103 /// Measure the specified inline asm to determine an approximation of its
104 /// length.
105 /// Comments (which run till the next SeparatorString or newline) do not
106 /// count as an instruction.
107 /// Any other non-whitespace text is considered an instruction, with
108 /// multiple instructions separated by SeparatorString or newlines.
109 /// Variable-length instructions are not handled here; this function
110 /// may be overloaded in the target code to do that.
getInlineAsmLength(const char * Str,const MCAsmInfo & MAI) const111 unsigned TargetInstrInfo::getInlineAsmLength(const char *Str,
112 const MCAsmInfo &MAI) const {
113
114
115 // Count the number of instructions in the asm.
116 bool atInsnStart = true;
117 unsigned Length = 0;
118 for (; *Str; ++Str) {
119 if (*Str == '\n' || strncmp(Str, MAI.getSeparatorString(),
120 strlen(MAI.getSeparatorString())) == 0)
121 atInsnStart = true;
122 if (atInsnStart && !std::isspace(*Str)) {
123 Length += MAI.getMaxInstLength();
124 atInsnStart = false;
125 }
126 if (atInsnStart && strncmp(Str, MAI.getCommentString(),
127 strlen(MAI.getCommentString())) == 0)
128 atInsnStart = false;
129 }
130
131 return Length;
132 }
133