NVPTXRegisterInfo.cpp
4.41 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
//===- NVPTXRegisterInfo.cpp - NVPTX Register Information -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the NVPTX implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "NVPTXRegisterInfo.h"
#include "NVPTX.h"
#include "NVPTXSubtarget.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/MC/MachineLocation.h"
using namespace llvm;
#define DEBUG_TYPE "nvptx-reg-info"
namespace llvm {
std::string getNVPTXRegClassName(TargetRegisterClass const *RC) {
if (RC == &NVPTX::Float32RegsRegClass)
return ".f32";
if (RC == &NVPTX::Float16RegsRegClass)
// Ideally fp16 registers should be .f16, but this syntax is only
// supported on sm_53+. On the other hand, .b16 registers are
// accepted for all supported fp16 instructions on all GPU
// variants, so we can use them instead.
return ".b16";
if (RC == &NVPTX::Float16x2RegsRegClass)
return ".b32";
if (RC == &NVPTX::Float64RegsRegClass)
return ".f64";
if (RC == &NVPTX::Int64RegsRegClass)
// We use untyped (.b) integer registers here as NVCC does.
// Correctness of generated code does not depend on register type,
// but using .s/.u registers runs into ptxas bug that prevents
// assembly of otherwise valid PTX into SASS. Despite PTX ISA
// specifying only argument size for fp16 instructions, ptxas does
// not allow using .s16 or .u16 arguments for .fp16
// instructions. At the same time it allows using .s32/.u32
// arguments for .fp16v2 instructions:
//
// .reg .b16 rb16
// .reg .s16 rs16
// add.f16 rb16,rb16,rb16; // OK
// add.f16 rs16,rs16,rs16; // Arguments mismatch for instruction 'add'
// but:
// .reg .b32 rb32
// .reg .s32 rs32
// add.f16v2 rb32,rb32,rb32; // OK
// add.f16v2 rs32,rs32,rs32; // OK
return ".b64";
if (RC == &NVPTX::Int32RegsRegClass)
return ".b32";
if (RC == &NVPTX::Int16RegsRegClass)
return ".b16";
if (RC == &NVPTX::Int1RegsRegClass)
return ".pred";
if (RC == &NVPTX::SpecialRegsRegClass)
return "!Special!";
return "INTERNAL";
}
std::string getNVPTXRegClassStr(TargetRegisterClass const *RC) {
if (RC == &NVPTX::Float32RegsRegClass)
return "%f";
if (RC == &NVPTX::Float16RegsRegClass)
return "%h";
if (RC == &NVPTX::Float16x2RegsRegClass)
return "%hh";
if (RC == &NVPTX::Float64RegsRegClass)
return "%fd";
if (RC == &NVPTX::Int64RegsRegClass)
return "%rd";
if (RC == &NVPTX::Int32RegsRegClass)
return "%r";
if (RC == &NVPTX::Int16RegsRegClass)
return "%rs";
if (RC == &NVPTX::Int1RegsRegClass)
return "%p";
if (RC == &NVPTX::SpecialRegsRegClass)
return "!Special!";
return "INTERNAL";
}
}
NVPTXRegisterInfo::NVPTXRegisterInfo() : NVPTXGenRegisterInfo(0) {}
#define GET_REGINFO_TARGET_DESC
#include "NVPTXGenRegisterInfo.inc"
/// NVPTX Callee Saved Registers
const MCPhysReg *
NVPTXRegisterInfo::getCalleeSavedRegs(const MachineFunction *) const {
static const MCPhysReg CalleeSavedRegs[] = { 0 };
return CalleeSavedRegs;
}
BitVector NVPTXRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
return Reserved;
}
void NVPTXRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, unsigned FIOperandNum,
RegScavenger *RS) const {
assert(SPAdj == 0 && "Unexpected");
MachineInstr &MI = *II;
int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
MachineFunction &MF = *MI.getParent()->getParent();
int Offset = MF.getFrameInfo().getObjectOffset(FrameIndex) +
MI.getOperand(FIOperandNum + 1).getImm();
// Using I0 as the frame pointer
MI.getOperand(FIOperandNum).ChangeToRegister(NVPTX::VRFrame, false);
MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
}
Register NVPTXRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
return NVPTX::VRFrame;
}