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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
//===-- X86InstComments.cpp - Generate verbose-asm comments for instrs ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This defines functionality used to emit comments about X86 instructions to
// an output stream for -fverbose-asm.
//
//===----------------------------------------------------------------------===//
#include "X86InstComments.h"
#include "X86GenInstrNames.inc"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Vector Mask Decoding
//===----------------------------------------------------------------------===//
enum {
SM_SentinelZero = ~0U
};
static void DecodeINSERTPSMask(unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
// Defaults the copying the dest value.
ShuffleMask.push_back(0);
ShuffleMask.push_back(1);
ShuffleMask.push_back(2);
ShuffleMask.push_back(3);
// Decode the immediate.
unsigned ZMask = Imm & 15;
unsigned CountD = (Imm >> 4) & 3;
unsigned CountS = (Imm >> 6) & 3;
// CountS selects which input element to use.
unsigned InVal = 4+CountS;
// CountD specifies which element of destination to update.
ShuffleMask[CountD] = InVal;
// ZMask zaps values, potentially overriding the CountD elt.
if (ZMask & 1) ShuffleMask[0] = SM_SentinelZero;
if (ZMask & 2) ShuffleMask[1] = SM_SentinelZero;
if (ZMask & 4) ShuffleMask[2] = SM_SentinelZero;
if (ZMask & 8) ShuffleMask[3] = SM_SentinelZero;
}
static void DecodeSHUFPSMask(unsigned NElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
// Part that reads from dest.
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(Imm % NElts);
Imm /= NElts;
}
// Part that reads from src.
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(Imm % NElts + NElts);
Imm /= NElts;
}
}
static void DecodePSHUFMask(unsigned NElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts; ++i) {
ShuffleMask.push_back(Imm % NElts);
Imm /= NElts;
}
}
/// DecodeUNPCKLPMask - This decodes the shuffle masks for unpcklps/unpcklpd
/// etc. NElts indicates the number of elements in the vector allowing it to
/// handle different datatypes and vector widths.
static void DecodeUNPCKLPMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i); // Reads from dest
ShuffleMask.push_back(i+NElts); // Reads from src
}
}
//===----------------------------------------------------------------------===//
// Top Level Entrypoint
//===----------------------------------------------------------------------===//
/// EmitAnyX86InstComments - This function decodes x86 instructions and prints
/// newline terminated strings to the specified string if desired. This
/// information is shown in disassembly dumps when verbose assembly is enabled.
void llvm::EmitAnyX86InstComments(const MCInst *MI, raw_ostream &OS,
const char *(*getRegName)(unsigned)) {
// If this is a shuffle operation, the switch should fill in this state.
SmallVector<unsigned, 8> ShuffleMask;
const char *DestName = 0, *Src1Name = 0, *Src2Name = 0;
switch (MI->getOpcode()) {
case X86::INSERTPSrr:
Src1Name = getRegName(MI->getOperand(1).getReg());
Src2Name = getRegName(MI->getOperand(2).getReg());
DecodeINSERTPSMask(MI->getOperand(3).getImm(), ShuffleMask);
break;
case X86::PSHUFDri:
Src1Name = getRegName(MI->getOperand(1).getReg());
// FALL THROUGH.
case X86::PSHUFDmi:
DestName = getRegName(MI->getOperand(0).getReg());
DecodePSHUFMask(4, MI->getOperand(MI->getNumOperands()-1).getImm(),
ShuffleMask);
break;
case X86::SHUFPDrri:
DecodeSHUFPSMask(2, MI->getOperand(3).getImm(), ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
Src2Name = getRegName(MI->getOperand(2).getReg());
break;
case X86::SHUFPSrri:
DecodeSHUFPSMask(4, MI->getOperand(3).getImm(), ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
Src2Name = getRegName(MI->getOperand(2).getReg());
break;
case X86::UNPCKLPSrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::UNPCKLPSrm:
DecodeUNPCKLPMask(4, ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
break;
}
// If this was a shuffle operation, print the shuffle mask.
if (!ShuffleMask.empty()) {
if (DestName == 0) DestName = Src1Name;
OS << (DestName ? DestName : "mem") << " = ";
// If the two sources are the same, canonicalize the input elements to be
// from the first src so that we get larger element spans.
if (Src1Name == Src2Name) {
for (unsigned i = 0, e = ShuffleMask.size(); i != e; ++i) {
if ((int)ShuffleMask[i] >= 0 && // Not sentinel.
ShuffleMask[i] >= e) // From second mask.
ShuffleMask[i] -= e;
}
}
// The shuffle mask specifies which elements of the src1/src2 fill in the
// destination, with a few sentinel values. Loop through and print them
// out.
for (unsigned i = 0, e = ShuffleMask.size(); i != e; ++i) {
if (i != 0)
OS << ',';
if (ShuffleMask[i] == SM_SentinelZero) {
OS << "zero";
continue;
}
// Otherwise, it must come from src1 or src2. Print the span of elements
// that comes from this src.
bool isSrc1 = ShuffleMask[i] < ShuffleMask.size();
const char *SrcName = isSrc1 ? Src1Name : Src2Name;
OS << (SrcName ? SrcName : "mem") << '[';
bool IsFirst = true;
while (i != e &&
(int)ShuffleMask[i] >= 0 &&
(ShuffleMask[i] < ShuffleMask.size()) == isSrc1) {
if (!IsFirst)
OS << ',';
else
IsFirst = false;
OS << ShuffleMask[i] % ShuffleMask.size();
++i;
}
OS << ']';
--i; // For loop increments element #.
}
//MI->print(OS, 0);
OS << "\n";
}
}
|
