1 //===-- X86InstrFMA3Info.cpp - X86 FMA3 Instruction Information -----------===//
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 contains the implementation of the classes providing information
10 // about existing X86 FMA3 opcodes, classifying and grouping them.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "X86InstrFMA3Info.h"
15 #include "X86InstrInfo.h"
16 #include <atomic>
17 #include <cassert>
18 #include <cstdint>
19
20 using namespace llvm;
21
22 #define FMA3GROUP(Name, Suf, Attrs) \
23 { { X86::Name##132##Suf, X86::Name##213##Suf, X86::Name##231##Suf }, Attrs },
24
25 #define FMA3GROUP_MASKED(Name, Suf, Attrs) \
26 FMA3GROUP(Name, Suf, Attrs) \
27 FMA3GROUP(Name, Suf##k, Attrs | X86InstrFMA3Group::KMergeMasked) \
28 FMA3GROUP(Name, Suf##kz, Attrs | X86InstrFMA3Group::KZeroMasked)
29
30 #define FMA3GROUP_MASKED_INT(Name, Suf, Attrs) \
31 FMA3GROUP(Name, Suf##_Int, Attrs) \
32 FMA3GROUP(Name, Suf##k_Int, Attrs | X86InstrFMA3Group::KMergeMasked) \
33 FMA3GROUP(Name, Suf##kz_Int, Attrs | X86InstrFMA3Group::KZeroMasked)
34
35 #define FMA3GROUP_PACKED_WIDTHS_Z(Name, Suf, Attrs) \
36 FMA3GROUP_MASKED(Name, Suf##Z128m, Attrs) \
37 FMA3GROUP_MASKED(Name, Suf##Z128r, Attrs) \
38 FMA3GROUP_MASKED(Name, Suf##Z256m, Attrs) \
39 FMA3GROUP_MASKED(Name, Suf##Z256r, Attrs) \
40 FMA3GROUP_MASKED(Name, Suf##Zm, Attrs) \
41 FMA3GROUP_MASKED(Name, Suf##Zr, Attrs) \
42
43 #define FMA3GROUP_PACKED_WIDTHS_ALL(Name, Suf, Attrs) \
44 FMA3GROUP(Name, Suf##Ym, Attrs) \
45 FMA3GROUP(Name, Suf##Yr, Attrs) \
46 FMA3GROUP_PACKED_WIDTHS_Z(Name, Suf, Attrs) \
47 FMA3GROUP(Name, Suf##m, Attrs) \
48 FMA3GROUP(Name, Suf##r, Attrs)
49
50 #define FMA3GROUP_PACKED_DHS(Name, Attrs) \
51 FMA3GROUP_PACKED_WIDTHS_ALL(Name, PD, Attrs) \
52 FMA3GROUP_PACKED_WIDTHS_Z(Name, PH, Attrs) \
53 FMA3GROUP_PACKED_WIDTHS_ALL(Name, PS, Attrs)
54
55 #define FMA3GROUP_PACKED_BF16(Name, Attrs) \
56 FMA3GROUP_PACKED_WIDTHS_Z(Name, BF16, Attrs)
57
58 #define FMA3GROUP_SCALAR_WIDTHS_Z(Name, Suf, Attrs) \
59 FMA3GROUP(Name, Suf##Zm, Attrs) \
60 FMA3GROUP_MASKED_INT(Name, Suf##Zm, Attrs | X86InstrFMA3Group::Intrinsic) \
61 FMA3GROUP(Name, Suf##Zr, Attrs) \
62 FMA3GROUP_MASKED_INT(Name, Suf##Zr, Attrs | X86InstrFMA3Group::Intrinsic) \
63
64 #define FMA3GROUP_SCALAR_WIDTHS_ALL(Name, Suf, Attrs) \
65 FMA3GROUP_SCALAR_WIDTHS_Z(Name, Suf, Attrs) \
66 FMA3GROUP(Name, Suf##m, Attrs) \
67 FMA3GROUP(Name, Suf##m_Int, Attrs | X86InstrFMA3Group::Intrinsic) \
68 FMA3GROUP(Name, Suf##r, Attrs) \
69 FMA3GROUP(Name, Suf##r_Int, Attrs | X86InstrFMA3Group::Intrinsic)
70
71 #define FMA3GROUP_SCALAR(Name, Attrs) \
72 FMA3GROUP_SCALAR_WIDTHS_ALL(Name, SD, Attrs) \
73 FMA3GROUP_SCALAR_WIDTHS_Z(Name, SH, Attrs) \
74 FMA3GROUP_SCALAR_WIDTHS_ALL(Name, SS, Attrs)
75
76 #define FMA3GROUP_FULL(Name, Attrs) \
77 FMA3GROUP_PACKED_BF16(Name, Attrs) \
78 FMA3GROUP_PACKED_DHS(Name, Attrs) \
79 FMA3GROUP_SCALAR(Name, Attrs)
80
81 static const X86InstrFMA3Group Groups[] = {
82 FMA3GROUP_FULL(VFMADD, 0)
83 FMA3GROUP_PACKED_DHS(VFMADDSUB, 0)
84 FMA3GROUP_FULL(VFMSUB, 0)
85 FMA3GROUP_PACKED_DHS(VFMSUBADD, 0)
86 FMA3GROUP_FULL(VFNMADD, 0)
87 FMA3GROUP_FULL(VFNMSUB, 0)
88 };
89
90 #define FMA3GROUP_PACKED_AVX512_WIDTHS(Name, Type, Suf, Attrs) \
91 FMA3GROUP_MASKED(Name, Type##Z128##Suf, Attrs) \
92 FMA3GROUP_MASKED(Name, Type##Z256##Suf, Attrs) \
93 FMA3GROUP_MASKED(Name, Type##Z##Suf, Attrs)
94
95 #define FMA3GROUP_PACKED_AVX512_ALL(Name, Suf, Attrs) \
96 FMA3GROUP_PACKED_AVX512_WIDTHS(Name, BF16, Suf, Attrs) \
97 FMA3GROUP_PACKED_AVX512_WIDTHS(Name, PD, Suf, Attrs) \
98 FMA3GROUP_PACKED_AVX512_WIDTHS(Name, PH, Suf, Attrs) \
99 FMA3GROUP_PACKED_AVX512_WIDTHS(Name, PS, Suf, Attrs)
100
101 #define FMA3GROUP_PACKED_AVX512_DHS(Name, Suf, Attrs) \
102 FMA3GROUP_PACKED_AVX512_WIDTHS(Name, PD, Suf, Attrs) \
103 FMA3GROUP_PACKED_AVX512_WIDTHS(Name, PH, Suf, Attrs) \
104 FMA3GROUP_PACKED_AVX512_WIDTHS(Name, PS, Suf, Attrs)
105
106 #define FMA3GROUP_PACKED_AVX512_ROUND(Name, Suf, Attrs) \
107 FMA3GROUP_MASKED(Name, PDZ##Suf, Attrs) \
108 FMA3GROUP_MASKED(Name, PHZ##Suf, Attrs) \
109 FMA3GROUP_MASKED(Name, PSZ##Suf, Attrs)
110
111 #define FMA3GROUP_SCALAR_AVX512_ROUND(Name, Suf, Attrs) \
112 FMA3GROUP(Name, SDZ##Suf, Attrs) \
113 FMA3GROUP_MASKED_INT(Name, SDZ##Suf, Attrs) \
114 FMA3GROUP(Name, SHZ##Suf, Attrs) \
115 FMA3GROUP_MASKED_INT(Name, SHZ##Suf, Attrs) \
116 FMA3GROUP(Name, SSZ##Suf, Attrs) \
117 FMA3GROUP_MASKED_INT(Name, SSZ##Suf, Attrs)
118
119 static const X86InstrFMA3Group BroadcastGroups[] = {
120 FMA3GROUP_PACKED_AVX512_ALL(VFMADD, mb, 0)
121 FMA3GROUP_PACKED_AVX512_DHS(VFMADDSUB, mb, 0)
122 FMA3GROUP_PACKED_AVX512_ALL(VFMSUB, mb, 0)
123 FMA3GROUP_PACKED_AVX512_DHS(VFMSUBADD, mb, 0)
124 FMA3GROUP_PACKED_AVX512_ALL(VFNMADD, mb, 0)
125 FMA3GROUP_PACKED_AVX512_ALL(VFNMSUB, mb, 0)
126 };
127
128 static const X86InstrFMA3Group RoundGroups[] = {
129 FMA3GROUP_PACKED_AVX512_ROUND(VFMADD, rb, 0)
130 FMA3GROUP_SCALAR_AVX512_ROUND(VFMADD, rb, X86InstrFMA3Group::Intrinsic)
131 FMA3GROUP_PACKED_AVX512_ROUND(VFMADDSUB, rb, 0)
132 FMA3GROUP_PACKED_AVX512_ROUND(VFMSUB, rb, 0)
133 FMA3GROUP_SCALAR_AVX512_ROUND(VFMSUB, rb, X86InstrFMA3Group::Intrinsic)
134 FMA3GROUP_PACKED_AVX512_ROUND(VFMSUBADD, rb, 0)
135 FMA3GROUP_PACKED_AVX512_ROUND(VFNMADD, rb, 0)
136 FMA3GROUP_SCALAR_AVX512_ROUND(VFNMADD, rb, X86InstrFMA3Group::Intrinsic)
137 FMA3GROUP_PACKED_AVX512_ROUND(VFNMSUB, rb, 0)
138 FMA3GROUP_SCALAR_AVX512_ROUND(VFNMSUB, rb, X86InstrFMA3Group::Intrinsic)
139 };
140
verifyTables()141 static void verifyTables() {
142 #ifndef NDEBUG
143 static std::atomic<bool> TableChecked(false);
144 if (!TableChecked.load(std::memory_order_relaxed)) {
145 assert(llvm::is_sorted(Groups) && llvm::is_sorted(RoundGroups) &&
146 llvm::is_sorted(BroadcastGroups) && "FMA3 tables not sorted!");
147 TableChecked.store(true, std::memory_order_relaxed);
148 }
149 #endif
150 }
151
152 /// Returns a reference to a group of FMA3 opcodes to where the given
153 /// \p Opcode is included. If the given \p Opcode is not recognized as FMA3
154 /// and not included into any FMA3 group, then nullptr is returned.
getFMA3Group(unsigned Opcode,uint64_t TSFlags)155 const X86InstrFMA3Group *llvm::getFMA3Group(unsigned Opcode, uint64_t TSFlags) {
156
157 // FMA3 instructions have a well defined encoding pattern we can exploit.
158 uint8_t BaseOpcode = X86II::getBaseOpcodeFor(TSFlags);
159 bool IsFMA3Opcode = ((BaseOpcode >= 0x96 && BaseOpcode <= 0x9F) ||
160 (BaseOpcode >= 0xA6 && BaseOpcode <= 0xAF) ||
161 (BaseOpcode >= 0xB6 && BaseOpcode <= 0xBF));
162 bool IsFMA3Encoding = ((TSFlags & X86II::EncodingMask) == X86II::VEX &&
163 (TSFlags & X86II::OpMapMask) == X86II::T8) ||
164 ((TSFlags & X86II::EncodingMask) == X86II::EVEX &&
165 ((TSFlags & X86II::OpMapMask) == X86II::T8 ||
166 (TSFlags & X86II::OpMapMask) == X86II::T_MAP6));
167 bool IsFMA3Prefix = (TSFlags & X86II::OpPrefixMask) == X86II::PD ||
168 (TSFlags & X86II::OpPrefixMask) == 0; // X86II::PS
169 if (!IsFMA3Opcode || !IsFMA3Encoding || !IsFMA3Prefix)
170 return nullptr;
171
172 verifyTables();
173
174 ArrayRef<X86InstrFMA3Group> Table;
175 if (TSFlags & X86II::EVEX_RC)
176 Table = ArrayRef(RoundGroups);
177 else if (TSFlags & X86II::EVEX_B)
178 Table = ArrayRef(BroadcastGroups);
179 else
180 Table = ArrayRef(Groups);
181
182 // FMA 132 instructions have an opcode of 0x96-0x9F
183 // FMA 213 instructions have an opcode of 0xA6-0xAF
184 // FMA 231 instructions have an opcode of 0xB6-0xBF
185 unsigned FormIndex = ((BaseOpcode - 0x90) >> 4) & 0x3;
186
187 auto I = partition_point(Table, [=](const X86InstrFMA3Group &Group) {
188 return Group.Opcodes[FormIndex] < Opcode;
189 });
190 assert(I != Table.end() && I->Opcodes[FormIndex] == Opcode &&
191 "Couldn't find FMA3 opcode!");
192 return I;
193 }
194