1 //===-- ABIX86.cpp --------------------------------------------------------===//
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 #include "ABIMacOSX_i386.h"
10 #include "ABISysV_i386.h"
11 #include "ABISysV_x86_64.h"
12 #include "ABIWindows_x86_64.h"
13 #include "ABIX86.h"
14 #include "lldb/Core/PluginManager.h"
15 #include "lldb/Target/Process.h"
16 #include <optional>
17 
18 using namespace lldb;
19 using namespace lldb_private;
20 
21 LLDB_PLUGIN_DEFINE(ABIX86)
22 
23 void ABIX86::Initialize() {
24   ABIMacOSX_i386::Initialize();
25   ABISysV_i386::Initialize();
26   ABISysV_x86_64::Initialize();
27   ABIWindows_x86_64::Initialize();
28 }
29 
30 void ABIX86::Terminate() {
31   ABIMacOSX_i386::Terminate();
32   ABISysV_i386::Terminate();
33   ABISysV_x86_64::Terminate();
34   ABIWindows_x86_64::Terminate();
35 }
36 
37 namespace {
38 enum RegKind {
39   GPR32,
40   GPR16,
41   GPR8h,
42   GPR8,
43   MM,
44   YMM_YMMh,
45   YMM_XMM,
46 
47   RegKindCount
48 };
49 }
50 
51 struct RegData {
52   RegKind subreg_kind;
53   llvm::StringRef subreg_name;
54   std::optional<uint32_t> base_index;
55 };
56 
57 static void
58 addPartialRegisters(std::vector<DynamicRegisterInfo::Register> &regs,
59                     llvm::ArrayRef<RegData *> subregs, uint32_t base_size,
60                     lldb::Encoding encoding, lldb::Format format,
61                     uint32_t subreg_size, uint32_t subreg_offset = 0) {
62   for (const RegData *subreg : subregs) {
63     assert(subreg);
64     uint32_t base_index = *subreg->base_index;
65     DynamicRegisterInfo::Register &full_reg = regs[base_index];
66     if (full_reg.byte_size != base_size)
67       continue;
68 
69     lldb_private::DynamicRegisterInfo::Register new_reg{
70         lldb_private::ConstString(subreg->subreg_name),
71         lldb_private::ConstString(),
72         lldb_private::ConstString("supplementary registers"),
73         subreg_size,
74         LLDB_INVALID_INDEX32,
75         encoding,
76         format,
77         LLDB_INVALID_REGNUM,
78         LLDB_INVALID_REGNUM,
79         LLDB_INVALID_REGNUM,
80         LLDB_INVALID_REGNUM,
81         {base_index},
82         {},
83         subreg_offset};
84 
85     addSupplementaryRegister(regs, new_reg);
86   }
87 }
88 
89 static void
90 addCombinedRegisters(std::vector<DynamicRegisterInfo::Register> &regs,
91                      llvm::ArrayRef<RegData *> subregs1,
92                      llvm::ArrayRef<RegData *> subregs2, uint32_t base_size,
93                      lldb::Encoding encoding, lldb::Format format) {
94   for (auto it : llvm::zip(subregs1, subregs2)) {
95     RegData *regdata1, *regdata2;
96     std::tie(regdata1, regdata2) = it;
97     assert(regdata1);
98     assert(regdata2);
99 
100     // verify that we've got matching target registers
101     if (regdata1->subreg_name != regdata2->subreg_name)
102       continue;
103 
104     uint32_t base_index1 = *regdata1->base_index;
105     uint32_t base_index2 = *regdata2->base_index;
106     if (regs[base_index1].byte_size != base_size ||
107         regs[base_index2].byte_size != base_size)
108       continue;
109 
110     lldb_private::DynamicRegisterInfo::Register new_reg{
111         lldb_private::ConstString(regdata1->subreg_name),
112         lldb_private::ConstString(),
113         lldb_private::ConstString("supplementary registers"),
114         base_size * 2,
115         LLDB_INVALID_INDEX32,
116         encoding,
117         format,
118         LLDB_INVALID_REGNUM,
119         LLDB_INVALID_REGNUM,
120         LLDB_INVALID_REGNUM,
121         LLDB_INVALID_REGNUM,
122         {base_index1, base_index2},
123         {}};
124 
125     addSupplementaryRegister(regs, new_reg);
126   }
127 }
128 
129 typedef llvm::SmallDenseMap<llvm::StringRef, llvm::SmallVector<RegData, 4>, 64>
130     BaseRegToRegsMap;
131 
132 #define GPRh(l)                                                                \
133   {                                                                            \
134     is64bit ? BaseRegToRegsMap::value_type("r" l "x",                          \
135                                            {{GPR32, "e" l "x", std::nullopt},  \
136                                             {GPR16, l "x", std::nullopt},      \
137                                             {GPR8h, l "h", std::nullopt},      \
138                                             {GPR8, l "l", std::nullopt}})      \
139             : BaseRegToRegsMap::value_type("e" l "x",                          \
140                                            {{GPR16, l "x", std::nullopt},      \
141                                             {GPR8h, l "h", std::nullopt},      \
142                                             {GPR8, l "l", std::nullopt}})      \
143   }
144 
145 #define GPR(r16)                                                               \
146   {                                                                            \
147     is64bit ? BaseRegToRegsMap::value_type("r" r16,                            \
148                                            {{GPR32, "e" r16, std::nullopt},    \
149                                             {GPR16, r16, std::nullopt},        \
150                                             {GPR8, r16 "l", std::nullopt}})    \
151             : BaseRegToRegsMap::value_type(                                    \
152                   "e" r16,                                                     \
153                   {{GPR16, r16, std::nullopt}, {GPR8, r16 "l", std::nullopt}}) \
154   }
155 
156 #define GPR64(n)                                                               \
157   {                                                                            \
158     BaseRegToRegsMap::value_type("r" #n, {{GPR32, "r" #n "d", std::nullopt},   \
159                                           {GPR16, "r" #n "w", std::nullopt},   \
160                                           {GPR8, "r" #n "l", std::nullopt}})   \
161   }
162 
163 #define STMM(n)                                                                \
164   { BaseRegToRegsMap::value_type("st" #n, {{MM, "mm" #n, std::nullopt}}) }
165 
166 #define YMM(n)                                                                 \
167   {BaseRegToRegsMap::value_type("ymm" #n "h",                                  \
168                                 {{YMM_YMMh, "ymm" #n, std::nullopt}})},        \
169   {                                                                            \
170     BaseRegToRegsMap::value_type("xmm" #n,                                     \
171                                  {{YMM_XMM, "ymm" #n, std::nullopt}})          \
172   }
173 
174 BaseRegToRegsMap makeBaseRegMap(bool is64bit) {
175   BaseRegToRegsMap out{
176       {// GPRs common to amd64 & i386
177        GPRh("a"), GPRh("b"), GPRh("c"), GPRh("d"), GPR("si"), GPR("di"),
178        GPR("bp"), GPR("sp"),
179 
180        // ST/MM registers
181        STMM(0), STMM(1), STMM(2), STMM(3), STMM(4), STMM(5), STMM(6), STMM(7),
182 
183        // lower YMM registers (common to amd64 & i386)
184        YMM(0), YMM(1), YMM(2), YMM(3), YMM(4), YMM(5), YMM(6), YMM(7)}};
185 
186   if (is64bit) {
187     BaseRegToRegsMap amd64_regs{{// GPRs specific to amd64
188                                  GPR64(8), GPR64(9), GPR64(10), GPR64(11),
189                                  GPR64(12), GPR64(13), GPR64(14), GPR64(15),
190 
191                                  // higher YMM registers (specific to amd64)
192                                  YMM(8), YMM(9), YMM(10), YMM(11), YMM(12),
193                                  YMM(13), YMM(14), YMM(15)}};
194     out.insert(amd64_regs.begin(), amd64_regs.end());
195   }
196 
197   return out;
198 }
199 
200 void ABIX86::AugmentRegisterInfo(
201     std::vector<DynamicRegisterInfo::Register> &regs) {
202   MCBasedABI::AugmentRegisterInfo(regs);
203 
204   ProcessSP process_sp = GetProcessSP();
205   if (!process_sp)
206     return;
207 
208   uint32_t gpr_base_size =
209       process_sp->GetTarget().GetArchitecture().GetAddressByteSize();
210 
211   // primary map from a base register to its subregisters
212   BaseRegToRegsMap base_reg_map = makeBaseRegMap(gpr_base_size == 8);
213   // set used for fast matching of register names to subregisters
214   llvm::SmallDenseSet<llvm::StringRef, 64> subreg_name_set;
215   // convenience array providing access to all subregisters of given kind,
216   // sorted by base register index
217   std::array<llvm::SmallVector<RegData *, 16>, RegKindCount> subreg_by_kind;
218 
219   // prepare the set of all known subregisters
220   for (const auto &x : base_reg_map) {
221     for (const auto &subreg : x.second)
222       subreg_name_set.insert(subreg.subreg_name);
223   }
224 
225   // iterate over all registers
226   for (const auto &x : llvm::enumerate(regs)) {
227     llvm::StringRef reg_name = x.value().name.GetStringRef();
228     // abort if at least one sub-register is already present
229     if (llvm::is_contained(subreg_name_set, reg_name))
230       return;
231 
232     auto found = base_reg_map.find(reg_name);
233     if (found == base_reg_map.end())
234       continue;
235 
236     for (auto &subreg : found->second) {
237       // fill in base register indices
238       subreg.base_index = x.index();
239       // fill subreg_by_kind map-array
240       subreg_by_kind[static_cast<size_t>(subreg.subreg_kind)].push_back(
241           &subreg);
242     }
243   }
244 
245   // now add registers by kind
246   addPartialRegisters(regs, subreg_by_kind[GPR32], gpr_base_size, eEncodingUint,
247                       eFormatHex, 4);
248   addPartialRegisters(regs, subreg_by_kind[GPR16], gpr_base_size, eEncodingUint,
249                       eFormatHex, 2);
250   addPartialRegisters(regs, subreg_by_kind[GPR8h], gpr_base_size, eEncodingUint,
251                       eFormatHex, 1, 1);
252   addPartialRegisters(regs, subreg_by_kind[GPR8], gpr_base_size, eEncodingUint,
253                       eFormatHex, 1);
254 
255   addPartialRegisters(regs, subreg_by_kind[MM], 10, eEncodingUint, eFormatHex,
256                       8);
257 
258   addCombinedRegisters(regs, subreg_by_kind[YMM_XMM], subreg_by_kind[YMM_YMMh],
259                        16, eEncodingVector, eFormatVectorOfUInt8);
260 }
261