xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUTargetStreamer.cpp (revision f5f40dd63bc7acbb5312b26ac1ea1103c12352a6)
1 //===-- AMDGPUTargetStreamer.cpp - Mips Target Streamer Methods -----------===//
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 provides AMDGPU specific target streamer methods.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "AMDGPUTargetStreamer.h"
14 #include "AMDGPUPTNote.h"
15 #include "AMDKernelCodeT.h"
16 #include "Utils/AMDGPUBaseInfo.h"
17 #include "Utils/AMDKernelCodeTUtils.h"
18 #include "llvm/BinaryFormat/AMDGPUMetadataVerifier.h"
19 #include "llvm/BinaryFormat/ELF.h"
20 #include "llvm/MC/MCAssembler.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCELFStreamer.h"
23 #include "llvm/MC/MCObjectWriter.h"
24 #include "llvm/MC/MCSectionELF.h"
25 #include "llvm/MC/MCSubtargetInfo.h"
26 #include "llvm/Support/AMDGPUMetadata.h"
27 #include "llvm/Support/AMDHSAKernelDescriptor.h"
28 #include "llvm/Support/Casting.h"
29 #include "llvm/Support/FormattedStream.h"
30 #include "llvm/TargetParser/TargetParser.h"
31 
32 using namespace llvm;
33 using namespace llvm::AMDGPU;
34 
35 //===----------------------------------------------------------------------===//
36 // AMDGPUTargetStreamer
37 //===----------------------------------------------------------------------===//
38 
39 bool AMDGPUTargetStreamer::EmitHSAMetadataV3(StringRef HSAMetadataString) {
40   msgpack::Document HSAMetadataDoc;
41   if (!HSAMetadataDoc.fromYAML(HSAMetadataString))
42     return false;
43   return EmitHSAMetadata(HSAMetadataDoc, false);
44 }
45 
46 StringRef AMDGPUTargetStreamer::getArchNameFromElfMach(unsigned ElfMach) {
47   AMDGPU::GPUKind AK;
48 
49   // clang-format off
50   switch (ElfMach) {
51   case ELF::EF_AMDGPU_MACH_R600_R600:      AK = GK_R600;    break;
52   case ELF::EF_AMDGPU_MACH_R600_R630:      AK = GK_R630;    break;
53   case ELF::EF_AMDGPU_MACH_R600_RS880:     AK = GK_RS880;   break;
54   case ELF::EF_AMDGPU_MACH_R600_RV670:     AK = GK_RV670;   break;
55   case ELF::EF_AMDGPU_MACH_R600_RV710:     AK = GK_RV710;   break;
56   case ELF::EF_AMDGPU_MACH_R600_RV730:     AK = GK_RV730;   break;
57   case ELF::EF_AMDGPU_MACH_R600_RV770:     AK = GK_RV770;   break;
58   case ELF::EF_AMDGPU_MACH_R600_CEDAR:     AK = GK_CEDAR;   break;
59   case ELF::EF_AMDGPU_MACH_R600_CYPRESS:   AK = GK_CYPRESS; break;
60   case ELF::EF_AMDGPU_MACH_R600_JUNIPER:   AK = GK_JUNIPER; break;
61   case ELF::EF_AMDGPU_MACH_R600_REDWOOD:   AK = GK_REDWOOD; break;
62   case ELF::EF_AMDGPU_MACH_R600_SUMO:      AK = GK_SUMO;    break;
63   case ELF::EF_AMDGPU_MACH_R600_BARTS:     AK = GK_BARTS;   break;
64   case ELF::EF_AMDGPU_MACH_R600_CAICOS:    AK = GK_CAICOS;  break;
65   case ELF::EF_AMDGPU_MACH_R600_CAYMAN:    AK = GK_CAYMAN;  break;
66   case ELF::EF_AMDGPU_MACH_R600_TURKS:     AK = GK_TURKS;   break;
67   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX600:  AK = GK_GFX600;  break;
68   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX601:  AK = GK_GFX601;  break;
69   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX602:  AK = GK_GFX602;  break;
70   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX700:  AK = GK_GFX700;  break;
71   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX701:  AK = GK_GFX701;  break;
72   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX702:  AK = GK_GFX702;  break;
73   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX703:  AK = GK_GFX703;  break;
74   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX704:  AK = GK_GFX704;  break;
75   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX705:  AK = GK_GFX705;  break;
76   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX801:  AK = GK_GFX801;  break;
77   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX802:  AK = GK_GFX802;  break;
78   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX803:  AK = GK_GFX803;  break;
79   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX805:  AK = GK_GFX805;  break;
80   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX810:  AK = GK_GFX810;  break;
81   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX900:  AK = GK_GFX900;  break;
82   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX902:  AK = GK_GFX902;  break;
83   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX904:  AK = GK_GFX904;  break;
84   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX906:  AK = GK_GFX906;  break;
85   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX908:  AK = GK_GFX908;  break;
86   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX909:  AK = GK_GFX909;  break;
87   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90A:  AK = GK_GFX90A;  break;
88   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90C:  AK = GK_GFX90C;  break;
89   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX940:  AK = GK_GFX940;  break;
90   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX941:  AK = GK_GFX941;  break;
91   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX942:  AK = GK_GFX942;  break;
92   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1010: AK = GK_GFX1010; break;
93   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1011: AK = GK_GFX1011; break;
94   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1012: AK = GK_GFX1012; break;
95   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1013: AK = GK_GFX1013; break;
96   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1030: AK = GK_GFX1030; break;
97   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1031: AK = GK_GFX1031; break;
98   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1032: AK = GK_GFX1032; break;
99   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1033: AK = GK_GFX1033; break;
100   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1034: AK = GK_GFX1034; break;
101   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1035: AK = GK_GFX1035; break;
102   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1036: AK = GK_GFX1036; break;
103   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1100: AK = GK_GFX1100; break;
104   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1101: AK = GK_GFX1101; break;
105   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1102: AK = GK_GFX1102; break;
106   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1103: AK = GK_GFX1103; break;
107   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1150: AK = GK_GFX1150; break;
108   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1151: AK = GK_GFX1151; break;
109   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1200: AK = GK_GFX1200; break;
110   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1201: AK = GK_GFX1201; break;
111   case ELF::EF_AMDGPU_MACH_NONE:           AK = GK_NONE;    break;
112   default:                                 AK = GK_NONE;    break;
113   }
114   // clang-format on
115 
116   StringRef GPUName = getArchNameAMDGCN(AK);
117   if (GPUName != "")
118     return GPUName;
119   return getArchNameR600(AK);
120 }
121 
122 unsigned AMDGPUTargetStreamer::getElfMach(StringRef GPU) {
123   AMDGPU::GPUKind AK = parseArchAMDGCN(GPU);
124   if (AK == AMDGPU::GPUKind::GK_NONE)
125     AK = parseArchR600(GPU);
126 
127   // clang-format off
128   switch (AK) {
129   case GK_R600:    return ELF::EF_AMDGPU_MACH_R600_R600;
130   case GK_R630:    return ELF::EF_AMDGPU_MACH_R600_R630;
131   case GK_RS880:   return ELF::EF_AMDGPU_MACH_R600_RS880;
132   case GK_RV670:   return ELF::EF_AMDGPU_MACH_R600_RV670;
133   case GK_RV710:   return ELF::EF_AMDGPU_MACH_R600_RV710;
134   case GK_RV730:   return ELF::EF_AMDGPU_MACH_R600_RV730;
135   case GK_RV770:   return ELF::EF_AMDGPU_MACH_R600_RV770;
136   case GK_CEDAR:   return ELF::EF_AMDGPU_MACH_R600_CEDAR;
137   case GK_CYPRESS: return ELF::EF_AMDGPU_MACH_R600_CYPRESS;
138   case GK_JUNIPER: return ELF::EF_AMDGPU_MACH_R600_JUNIPER;
139   case GK_REDWOOD: return ELF::EF_AMDGPU_MACH_R600_REDWOOD;
140   case GK_SUMO:    return ELF::EF_AMDGPU_MACH_R600_SUMO;
141   case GK_BARTS:   return ELF::EF_AMDGPU_MACH_R600_BARTS;
142   case GK_CAICOS:  return ELF::EF_AMDGPU_MACH_R600_CAICOS;
143   case GK_CAYMAN:  return ELF::EF_AMDGPU_MACH_R600_CAYMAN;
144   case GK_TURKS:   return ELF::EF_AMDGPU_MACH_R600_TURKS;
145   case GK_GFX600:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX600;
146   case GK_GFX601:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX601;
147   case GK_GFX602:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX602;
148   case GK_GFX700:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX700;
149   case GK_GFX701:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX701;
150   case GK_GFX702:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX702;
151   case GK_GFX703:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX703;
152   case GK_GFX704:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX704;
153   case GK_GFX705:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX705;
154   case GK_GFX801:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX801;
155   case GK_GFX802:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX802;
156   case GK_GFX803:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX803;
157   case GK_GFX805:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX805;
158   case GK_GFX810:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX810;
159   case GK_GFX900:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX900;
160   case GK_GFX902:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX902;
161   case GK_GFX904:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX904;
162   case GK_GFX906:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX906;
163   case GK_GFX908:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX908;
164   case GK_GFX909:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX909;
165   case GK_GFX90A:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX90A;
166   case GK_GFX90C:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX90C;
167   case GK_GFX940:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX940;
168   case GK_GFX941:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX941;
169   case GK_GFX942:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX942;
170   case GK_GFX1010: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1010;
171   case GK_GFX1011: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1011;
172   case GK_GFX1012: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1012;
173   case GK_GFX1013: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1013;
174   case GK_GFX1030: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1030;
175   case GK_GFX1031: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1031;
176   case GK_GFX1032: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1032;
177   case GK_GFX1033: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1033;
178   case GK_GFX1034: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1034;
179   case GK_GFX1035: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1035;
180   case GK_GFX1036: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1036;
181   case GK_GFX1100: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1100;
182   case GK_GFX1101: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1101;
183   case GK_GFX1102: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1102;
184   case GK_GFX1103: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1103;
185   case GK_GFX1150: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1150;
186   case GK_GFX1151: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1151;
187   case GK_GFX1200: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1200;
188   case GK_GFX1201: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1201;
189   case GK_NONE:    return ELF::EF_AMDGPU_MACH_NONE;
190   }
191   // clang-format on
192 
193   llvm_unreachable("unknown GPU");
194 }
195 
196 //===----------------------------------------------------------------------===//
197 // AMDGPUTargetAsmStreamer
198 //===----------------------------------------------------------------------===//
199 
200 AMDGPUTargetAsmStreamer::AMDGPUTargetAsmStreamer(MCStreamer &S,
201                                                  formatted_raw_ostream &OS)
202     : AMDGPUTargetStreamer(S), OS(OS) { }
203 
204 // A hook for emitting stuff at the end.
205 // We use it for emitting the accumulated PAL metadata as directives.
206 // The PAL metadata is reset after it is emitted.
207 void AMDGPUTargetAsmStreamer::finish() {
208   std::string S;
209   getPALMetadata()->toString(S);
210   OS << S;
211 
212   // Reset the pal metadata so its data will not affect a compilation that
213   // reuses this object.
214   getPALMetadata()->reset();
215 }
216 
217 void AMDGPUTargetAsmStreamer::EmitDirectiveAMDGCNTarget() {
218   OS << "\t.amdgcn_target \"" << getTargetID()->toString() << "\"\n";
219 }
220 
221 void AMDGPUTargetAsmStreamer::EmitDirectiveAMDHSACodeObjectVersion(
222     unsigned COV) {
223   AMDGPUTargetStreamer::EmitDirectiveAMDHSACodeObjectVersion(COV);
224   OS << "\t.amdhsa_code_object_version " << COV << '\n';
225 }
226 
227 void
228 AMDGPUTargetAsmStreamer::EmitAMDKernelCodeT(const amd_kernel_code_t &Header) {
229   OS << "\t.amd_kernel_code_t\n";
230   dumpAmdKernelCode(&Header, OS, "\t\t");
231   OS << "\t.end_amd_kernel_code_t\n";
232 }
233 
234 void AMDGPUTargetAsmStreamer::EmitAMDGPUSymbolType(StringRef SymbolName,
235                                                    unsigned Type) {
236   switch (Type) {
237     default: llvm_unreachable("Invalid AMDGPU symbol type");
238     case ELF::STT_AMDGPU_HSA_KERNEL:
239       OS << "\t.amdgpu_hsa_kernel " << SymbolName << '\n' ;
240       break;
241   }
242 }
243 
244 void AMDGPUTargetAsmStreamer::emitAMDGPULDS(MCSymbol *Symbol, unsigned Size,
245                                             Align Alignment) {
246   OS << "\t.amdgpu_lds " << Symbol->getName() << ", " << Size << ", "
247      << Alignment.value() << '\n';
248 }
249 
250 bool AMDGPUTargetAsmStreamer::EmitISAVersion() {
251   OS << "\t.amd_amdgpu_isa \"" << getTargetID()->toString() << "\"\n";
252   return true;
253 }
254 
255 bool AMDGPUTargetAsmStreamer::EmitHSAMetadata(
256     msgpack::Document &HSAMetadataDoc, bool Strict) {
257   HSAMD::V3::MetadataVerifier Verifier(Strict);
258   if (!Verifier.verify(HSAMetadataDoc.getRoot()))
259     return false;
260 
261   std::string HSAMetadataString;
262   raw_string_ostream StrOS(HSAMetadataString);
263   HSAMetadataDoc.toYAML(StrOS);
264 
265   OS << '\t' << HSAMD::V3::AssemblerDirectiveBegin << '\n';
266   OS << StrOS.str() << '\n';
267   OS << '\t' << HSAMD::V3::AssemblerDirectiveEnd << '\n';
268   return true;
269 }
270 
271 bool AMDGPUTargetAsmStreamer::EmitCodeEnd(const MCSubtargetInfo &STI) {
272   const uint32_t Encoded_s_code_end = 0xbf9f0000;
273   const uint32_t Encoded_s_nop = 0xbf800000;
274   uint32_t Encoded_pad = Encoded_s_code_end;
275 
276   // Instruction cache line size in bytes.
277   const unsigned Log2CacheLineSize = AMDGPU::isGFX11Plus(STI) ? 7 : 6;
278   const unsigned CacheLineSize = 1u << Log2CacheLineSize;
279 
280   // Extra padding amount in bytes to support prefetch mode 3.
281   unsigned FillSize = 3 * CacheLineSize;
282 
283   if (AMDGPU::isGFX90A(STI)) {
284     Encoded_pad = Encoded_s_nop;
285     FillSize = 16 * CacheLineSize;
286   }
287 
288   OS << "\t.p2alignl " << Log2CacheLineSize << ", " << Encoded_pad << '\n';
289   OS << "\t.fill " << (FillSize / 4) << ", 4, " << Encoded_pad << '\n';
290   return true;
291 }
292 
293 void AMDGPUTargetAsmStreamer::EmitAmdhsaKernelDescriptor(
294     const MCSubtargetInfo &STI, StringRef KernelName,
295     const amdhsa::kernel_descriptor_t &KD, uint64_t NextVGPR, uint64_t NextSGPR,
296     bool ReserveVCC, bool ReserveFlatScr) {
297   IsaVersion IVersion = getIsaVersion(STI.getCPU());
298 
299   OS << "\t.amdhsa_kernel " << KernelName << '\n';
300 
301 #define PRINT_FIELD(STREAM, DIRECTIVE, KERNEL_DESC, MEMBER_NAME, FIELD_NAME)   \
302   STREAM << "\t\t" << DIRECTIVE << " "                                         \
303          << AMDHSA_BITS_GET(KERNEL_DESC.MEMBER_NAME, FIELD_NAME) << '\n';
304 
305   OS << "\t\t.amdhsa_group_segment_fixed_size " << KD.group_segment_fixed_size
306      << '\n';
307   OS << "\t\t.amdhsa_private_segment_fixed_size "
308      << KD.private_segment_fixed_size << '\n';
309   OS << "\t\t.amdhsa_kernarg_size " << KD.kernarg_size << '\n';
310 
311   PRINT_FIELD(OS, ".amdhsa_user_sgpr_count", KD,
312               compute_pgm_rsrc2,
313               amdhsa::COMPUTE_PGM_RSRC2_USER_SGPR_COUNT);
314 
315   if (!hasArchitectedFlatScratch(STI))
316     PRINT_FIELD(
317         OS, ".amdhsa_user_sgpr_private_segment_buffer", KD,
318         kernel_code_properties,
319         amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_PRIVATE_SEGMENT_BUFFER);
320   PRINT_FIELD(OS, ".amdhsa_user_sgpr_dispatch_ptr", KD,
321               kernel_code_properties,
322               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_DISPATCH_PTR);
323   PRINT_FIELD(OS, ".amdhsa_user_sgpr_queue_ptr", KD,
324               kernel_code_properties,
325               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_QUEUE_PTR);
326   PRINT_FIELD(OS, ".amdhsa_user_sgpr_kernarg_segment_ptr", KD,
327               kernel_code_properties,
328               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_KERNARG_SEGMENT_PTR);
329   PRINT_FIELD(OS, ".amdhsa_user_sgpr_dispatch_id", KD,
330               kernel_code_properties,
331               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_DISPATCH_ID);
332   if (!hasArchitectedFlatScratch(STI))
333     PRINT_FIELD(OS, ".amdhsa_user_sgpr_flat_scratch_init", KD,
334                 kernel_code_properties,
335                 amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_FLAT_SCRATCH_INIT);
336   if (hasKernargPreload(STI)) {
337     PRINT_FIELD(OS, ".amdhsa_user_sgpr_kernarg_preload_length ", KD,
338                 kernarg_preload, amdhsa::KERNARG_PRELOAD_SPEC_LENGTH);
339     PRINT_FIELD(OS, ".amdhsa_user_sgpr_kernarg_preload_offset ", KD,
340                 kernarg_preload, amdhsa::KERNARG_PRELOAD_SPEC_OFFSET);
341   }
342   PRINT_FIELD(OS, ".amdhsa_user_sgpr_private_segment_size", KD,
343               kernel_code_properties,
344               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_PRIVATE_SEGMENT_SIZE);
345   if (IVersion.Major >= 10)
346     PRINT_FIELD(OS, ".amdhsa_wavefront_size32", KD,
347                 kernel_code_properties,
348                 amdhsa::KERNEL_CODE_PROPERTY_ENABLE_WAVEFRONT_SIZE32);
349   if (CodeObjectVersion >= AMDGPU::AMDHSA_COV5)
350     PRINT_FIELD(OS, ".amdhsa_uses_dynamic_stack", KD, kernel_code_properties,
351                 amdhsa::KERNEL_CODE_PROPERTY_USES_DYNAMIC_STACK);
352   PRINT_FIELD(OS,
353               (hasArchitectedFlatScratch(STI)
354                    ? ".amdhsa_enable_private_segment"
355                    : ".amdhsa_system_sgpr_private_segment_wavefront_offset"),
356               KD, compute_pgm_rsrc2,
357               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_PRIVATE_SEGMENT);
358   PRINT_FIELD(OS, ".amdhsa_system_sgpr_workgroup_id_x", KD,
359               compute_pgm_rsrc2,
360               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_SGPR_WORKGROUP_ID_X);
361   PRINT_FIELD(OS, ".amdhsa_system_sgpr_workgroup_id_y", KD,
362               compute_pgm_rsrc2,
363               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_SGPR_WORKGROUP_ID_Y);
364   PRINT_FIELD(OS, ".amdhsa_system_sgpr_workgroup_id_z", KD,
365               compute_pgm_rsrc2,
366               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_SGPR_WORKGROUP_ID_Z);
367   PRINT_FIELD(OS, ".amdhsa_system_sgpr_workgroup_info", KD,
368               compute_pgm_rsrc2,
369               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_SGPR_WORKGROUP_INFO);
370   PRINT_FIELD(OS, ".amdhsa_system_vgpr_workitem_id", KD,
371               compute_pgm_rsrc2,
372               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_VGPR_WORKITEM_ID);
373 
374   // These directives are required.
375   OS << "\t\t.amdhsa_next_free_vgpr " << NextVGPR << '\n';
376   OS << "\t\t.amdhsa_next_free_sgpr " << NextSGPR << '\n';
377 
378   if (AMDGPU::isGFX90A(STI))
379     OS << "\t\t.amdhsa_accum_offset " <<
380       (AMDHSA_BITS_GET(KD.compute_pgm_rsrc3,
381                        amdhsa::COMPUTE_PGM_RSRC3_GFX90A_ACCUM_OFFSET) + 1) * 4
382       << '\n';
383 
384   if (!ReserveVCC)
385     OS << "\t\t.amdhsa_reserve_vcc " << ReserveVCC << '\n';
386   if (IVersion.Major >= 7 && !ReserveFlatScr && !hasArchitectedFlatScratch(STI))
387     OS << "\t\t.amdhsa_reserve_flat_scratch " << ReserveFlatScr << '\n';
388 
389   switch (CodeObjectVersion) {
390   default:
391     break;
392   case AMDGPU::AMDHSA_COV4:
393   case AMDGPU::AMDHSA_COV5:
394     if (getTargetID()->isXnackSupported())
395       OS << "\t\t.amdhsa_reserve_xnack_mask " << getTargetID()->isXnackOnOrAny() << '\n';
396     break;
397   }
398 
399   PRINT_FIELD(OS, ".amdhsa_float_round_mode_32", KD,
400               compute_pgm_rsrc1,
401               amdhsa::COMPUTE_PGM_RSRC1_FLOAT_ROUND_MODE_32);
402   PRINT_FIELD(OS, ".amdhsa_float_round_mode_16_64", KD,
403               compute_pgm_rsrc1,
404               amdhsa::COMPUTE_PGM_RSRC1_FLOAT_ROUND_MODE_16_64);
405   PRINT_FIELD(OS, ".amdhsa_float_denorm_mode_32", KD,
406               compute_pgm_rsrc1,
407               amdhsa::COMPUTE_PGM_RSRC1_FLOAT_DENORM_MODE_32);
408   PRINT_FIELD(OS, ".amdhsa_float_denorm_mode_16_64", KD,
409               compute_pgm_rsrc1,
410               amdhsa::COMPUTE_PGM_RSRC1_FLOAT_DENORM_MODE_16_64);
411   if (IVersion.Major < 12) {
412     PRINT_FIELD(OS, ".amdhsa_dx10_clamp", KD, compute_pgm_rsrc1,
413                 amdhsa::COMPUTE_PGM_RSRC1_GFX6_GFX11_ENABLE_DX10_CLAMP);
414     PRINT_FIELD(OS, ".amdhsa_ieee_mode", KD, compute_pgm_rsrc1,
415                 amdhsa::COMPUTE_PGM_RSRC1_GFX6_GFX11_ENABLE_IEEE_MODE);
416   }
417   if (IVersion.Major >= 9)
418     PRINT_FIELD(OS, ".amdhsa_fp16_overflow", KD,
419                 compute_pgm_rsrc1,
420                 amdhsa::COMPUTE_PGM_RSRC1_GFX9_PLUS_FP16_OVFL);
421   if (AMDGPU::isGFX90A(STI))
422     PRINT_FIELD(OS, ".amdhsa_tg_split", KD,
423                 compute_pgm_rsrc3,
424                 amdhsa::COMPUTE_PGM_RSRC3_GFX90A_TG_SPLIT);
425   if (IVersion.Major >= 10) {
426     PRINT_FIELD(OS, ".amdhsa_workgroup_processor_mode", KD,
427                 compute_pgm_rsrc1,
428                 amdhsa::COMPUTE_PGM_RSRC1_GFX10_PLUS_WGP_MODE);
429     PRINT_FIELD(OS, ".amdhsa_memory_ordered", KD,
430                 compute_pgm_rsrc1,
431                 amdhsa::COMPUTE_PGM_RSRC1_GFX10_PLUS_MEM_ORDERED);
432     PRINT_FIELD(OS, ".amdhsa_forward_progress", KD,
433                 compute_pgm_rsrc1,
434                 amdhsa::COMPUTE_PGM_RSRC1_GFX10_PLUS_FWD_PROGRESS);
435   }
436   if (IVersion.Major >= 10 && IVersion.Major < 12) {
437     PRINT_FIELD(OS, ".amdhsa_shared_vgpr_count", KD, compute_pgm_rsrc3,
438                 amdhsa::COMPUTE_PGM_RSRC3_GFX10_GFX11_SHARED_VGPR_COUNT);
439   }
440   if (IVersion.Major >= 12)
441     PRINT_FIELD(OS, ".amdhsa_round_robin_scheduling", KD, compute_pgm_rsrc1,
442                 amdhsa::COMPUTE_PGM_RSRC1_GFX12_PLUS_ENABLE_WG_RR_EN);
443   PRINT_FIELD(
444       OS, ".amdhsa_exception_fp_ieee_invalid_op", KD,
445       compute_pgm_rsrc2,
446       amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_INVALID_OPERATION);
447   PRINT_FIELD(OS, ".amdhsa_exception_fp_denorm_src", KD,
448               compute_pgm_rsrc2,
449               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_FP_DENORMAL_SOURCE);
450   PRINT_FIELD(
451       OS, ".amdhsa_exception_fp_ieee_div_zero", KD,
452       compute_pgm_rsrc2,
453       amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_DIVISION_BY_ZERO);
454   PRINT_FIELD(OS, ".amdhsa_exception_fp_ieee_overflow", KD,
455               compute_pgm_rsrc2,
456               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_OVERFLOW);
457   PRINT_FIELD(OS, ".amdhsa_exception_fp_ieee_underflow", KD,
458               compute_pgm_rsrc2,
459               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_UNDERFLOW);
460   PRINT_FIELD(OS, ".amdhsa_exception_fp_ieee_inexact", KD,
461               compute_pgm_rsrc2,
462               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_INEXACT);
463   PRINT_FIELD(OS, ".amdhsa_exception_int_div_zero", KD,
464               compute_pgm_rsrc2,
465               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_INT_DIVIDE_BY_ZERO);
466 #undef PRINT_FIELD
467 
468   OS << "\t.end_amdhsa_kernel\n";
469 }
470 
471 //===----------------------------------------------------------------------===//
472 // AMDGPUTargetELFStreamer
473 //===----------------------------------------------------------------------===//
474 
475 AMDGPUTargetELFStreamer::AMDGPUTargetELFStreamer(MCStreamer &S,
476                                                  const MCSubtargetInfo &STI)
477     : AMDGPUTargetStreamer(S), STI(STI), Streamer(S) {}
478 
479 MCELFStreamer &AMDGPUTargetELFStreamer::getStreamer() {
480   return static_cast<MCELFStreamer &>(Streamer);
481 }
482 
483 // A hook for emitting stuff at the end.
484 // We use it for emitting the accumulated PAL metadata as a .note record.
485 // The PAL metadata is reset after it is emitted.
486 void AMDGPUTargetELFStreamer::finish() {
487   MCAssembler &MCA = getStreamer().getAssembler();
488   MCA.setELFHeaderEFlags(getEFlags());
489   MCA.getWriter().setOverrideABIVersion(
490       getELFABIVersion(STI.getTargetTriple(), CodeObjectVersion));
491 
492   std::string Blob;
493   const char *Vendor = getPALMetadata()->getVendor();
494   unsigned Type = getPALMetadata()->getType();
495   getPALMetadata()->toBlob(Type, Blob);
496   if (Blob.empty())
497     return;
498   EmitNote(Vendor, MCConstantExpr::create(Blob.size(), getContext()), Type,
499            [&](MCELFStreamer &OS) { OS.emitBytes(Blob); });
500 
501   // Reset the pal metadata so its data will not affect a compilation that
502   // reuses this object.
503   getPALMetadata()->reset();
504 }
505 
506 void AMDGPUTargetELFStreamer::EmitNote(
507     StringRef Name, const MCExpr *DescSZ, unsigned NoteType,
508     function_ref<void(MCELFStreamer &)> EmitDesc) {
509   auto &S = getStreamer();
510   auto &Context = S.getContext();
511 
512   auto NameSZ = Name.size() + 1;
513 
514   unsigned NoteFlags = 0;
515   // TODO Apparently, this is currently needed for OpenCL as mentioned in
516   // https://reviews.llvm.org/D74995
517   if (isHsaAbi(STI))
518     NoteFlags = ELF::SHF_ALLOC;
519 
520   S.pushSection();
521   S.switchSection(
522       Context.getELFSection(ElfNote::SectionName, ELF::SHT_NOTE, NoteFlags));
523   S.emitInt32(NameSZ);                                        // namesz
524   S.emitValue(DescSZ, 4);                                     // descz
525   S.emitInt32(NoteType);                                      // type
526   S.emitBytes(Name);                                          // name
527   S.emitValueToAlignment(Align(4), 0, 1, 0);                  // padding 0
528   EmitDesc(S);                                                // desc
529   S.emitValueToAlignment(Align(4), 0, 1, 0);                  // padding 0
530   S.popSection();
531 }
532 
533 unsigned AMDGPUTargetELFStreamer::getEFlags() {
534   switch (STI.getTargetTriple().getArch()) {
535   default:
536     llvm_unreachable("Unsupported Arch");
537   case Triple::r600:
538     return getEFlagsR600();
539   case Triple::amdgcn:
540     return getEFlagsAMDGCN();
541   }
542 }
543 
544 unsigned AMDGPUTargetELFStreamer::getEFlagsR600() {
545   assert(STI.getTargetTriple().getArch() == Triple::r600);
546 
547   return getElfMach(STI.getCPU());
548 }
549 
550 unsigned AMDGPUTargetELFStreamer::getEFlagsAMDGCN() {
551   assert(STI.getTargetTriple().getArch() == Triple::amdgcn);
552 
553   switch (STI.getTargetTriple().getOS()) {
554   default:
555     // TODO: Why are some tests have "mingw" listed as OS?
556     // llvm_unreachable("Unsupported OS");
557   case Triple::UnknownOS:
558     return getEFlagsUnknownOS();
559   case Triple::AMDHSA:
560     return getEFlagsAMDHSA();
561   case Triple::AMDPAL:
562     return getEFlagsAMDPAL();
563   case Triple::Mesa3D:
564     return getEFlagsMesa3D();
565   }
566 }
567 
568 unsigned AMDGPUTargetELFStreamer::getEFlagsUnknownOS() {
569   // TODO: Why are some tests have "mingw" listed as OS?
570   // assert(STI.getTargetTriple().getOS() == Triple::UnknownOS);
571 
572   return getEFlagsV3();
573 }
574 
575 unsigned AMDGPUTargetELFStreamer::getEFlagsAMDHSA() {
576   assert(isHsaAbi(STI));
577 
578   return getEFlagsV4();
579 }
580 
581 unsigned AMDGPUTargetELFStreamer::getEFlagsAMDPAL() {
582   assert(STI.getTargetTriple().getOS() == Triple::AMDPAL);
583 
584   return getEFlagsV3();
585 }
586 
587 unsigned AMDGPUTargetELFStreamer::getEFlagsMesa3D() {
588   assert(STI.getTargetTriple().getOS() == Triple::Mesa3D);
589 
590   return getEFlagsV3();
591 }
592 
593 unsigned AMDGPUTargetELFStreamer::getEFlagsV3() {
594   unsigned EFlagsV3 = 0;
595 
596   // mach.
597   EFlagsV3 |= getElfMach(STI.getCPU());
598 
599   // xnack.
600   if (getTargetID()->isXnackOnOrAny())
601     EFlagsV3 |= ELF::EF_AMDGPU_FEATURE_XNACK_V3;
602   // sramecc.
603   if (getTargetID()->isSramEccOnOrAny())
604     EFlagsV3 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_V3;
605 
606   return EFlagsV3;
607 }
608 
609 unsigned AMDGPUTargetELFStreamer::getEFlagsV4() {
610   unsigned EFlagsV4 = 0;
611 
612   // mach.
613   EFlagsV4 |= getElfMach(STI.getCPU());
614 
615   // xnack.
616   switch (getTargetID()->getXnackSetting()) {
617   case AMDGPU::IsaInfo::TargetIDSetting::Unsupported:
618     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_XNACK_UNSUPPORTED_V4;
619     break;
620   case AMDGPU::IsaInfo::TargetIDSetting::Any:
621     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_XNACK_ANY_V4;
622     break;
623   case AMDGPU::IsaInfo::TargetIDSetting::Off:
624     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_XNACK_OFF_V4;
625     break;
626   case AMDGPU::IsaInfo::TargetIDSetting::On:
627     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_XNACK_ON_V4;
628     break;
629   }
630   // sramecc.
631   switch (getTargetID()->getSramEccSetting()) {
632   case AMDGPU::IsaInfo::TargetIDSetting::Unsupported:
633     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_UNSUPPORTED_V4;
634     break;
635   case AMDGPU::IsaInfo::TargetIDSetting::Any:
636     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_ANY_V4;
637     break;
638   case AMDGPU::IsaInfo::TargetIDSetting::Off:
639     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_OFF_V4;
640     break;
641   case AMDGPU::IsaInfo::TargetIDSetting::On:
642     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_ON_V4;
643     break;
644   }
645 
646   return EFlagsV4;
647 }
648 
649 void AMDGPUTargetELFStreamer::EmitDirectiveAMDGCNTarget() {}
650 
651 void
652 AMDGPUTargetELFStreamer::EmitAMDKernelCodeT(const amd_kernel_code_t &Header) {
653 
654   MCStreamer &OS = getStreamer();
655   OS.pushSection();
656   OS.emitBytes(StringRef((const char*)&Header, sizeof(Header)));
657   OS.popSection();
658 }
659 
660 void AMDGPUTargetELFStreamer::EmitAMDGPUSymbolType(StringRef SymbolName,
661                                                    unsigned Type) {
662   MCSymbolELF *Symbol = cast<MCSymbolELF>(
663       getStreamer().getContext().getOrCreateSymbol(SymbolName));
664   Symbol->setType(Type);
665 }
666 
667 void AMDGPUTargetELFStreamer::emitAMDGPULDS(MCSymbol *Symbol, unsigned Size,
668                                             Align Alignment) {
669   MCSymbolELF *SymbolELF = cast<MCSymbolELF>(Symbol);
670   SymbolELF->setType(ELF::STT_OBJECT);
671 
672   if (!SymbolELF->isBindingSet()) {
673     SymbolELF->setBinding(ELF::STB_GLOBAL);
674     SymbolELF->setExternal(true);
675   }
676 
677   if (SymbolELF->declareCommon(Size, Alignment, true)) {
678     report_fatal_error("Symbol: " + Symbol->getName() +
679                        " redeclared as different type");
680   }
681 
682   SymbolELF->setIndex(ELF::SHN_AMDGPU_LDS);
683   SymbolELF->setSize(MCConstantExpr::create(Size, getContext()));
684 }
685 
686 bool AMDGPUTargetELFStreamer::EmitISAVersion() {
687   // Create two labels to mark the beginning and end of the desc field
688   // and a MCExpr to calculate the size of the desc field.
689   auto &Context = getContext();
690   auto *DescBegin = Context.createTempSymbol();
691   auto *DescEnd = Context.createTempSymbol();
692   auto *DescSZ = MCBinaryExpr::createSub(
693     MCSymbolRefExpr::create(DescEnd, Context),
694     MCSymbolRefExpr::create(DescBegin, Context), Context);
695 
696   EmitNote(ElfNote::NoteNameV2, DescSZ, ELF::NT_AMD_HSA_ISA_NAME,
697            [&](MCELFStreamer &OS) {
698              OS.emitLabel(DescBegin);
699              OS.emitBytes(getTargetID()->toString());
700              OS.emitLabel(DescEnd);
701            });
702   return true;
703 }
704 
705 bool AMDGPUTargetELFStreamer::EmitHSAMetadata(msgpack::Document &HSAMetadataDoc,
706                                               bool Strict) {
707   HSAMD::V3::MetadataVerifier Verifier(Strict);
708   if (!Verifier.verify(HSAMetadataDoc.getRoot()))
709     return false;
710 
711   std::string HSAMetadataString;
712   HSAMetadataDoc.writeToBlob(HSAMetadataString);
713 
714   // Create two labels to mark the beginning and end of the desc field
715   // and a MCExpr to calculate the size of the desc field.
716   auto &Context = getContext();
717   auto *DescBegin = Context.createTempSymbol();
718   auto *DescEnd = Context.createTempSymbol();
719   auto *DescSZ = MCBinaryExpr::createSub(
720       MCSymbolRefExpr::create(DescEnd, Context),
721       MCSymbolRefExpr::create(DescBegin, Context), Context);
722 
723   EmitNote(ElfNote::NoteNameV3, DescSZ, ELF::NT_AMDGPU_METADATA,
724            [&](MCELFStreamer &OS) {
725              OS.emitLabel(DescBegin);
726              OS.emitBytes(HSAMetadataString);
727              OS.emitLabel(DescEnd);
728            });
729   return true;
730 }
731 
732 bool AMDGPUTargetAsmStreamer::EmitKernargPreloadHeader(
733     const MCSubtargetInfo &STI) {
734   for (int i = 0; i < 64; ++i) {
735     OS << "\ts_nop 0\n";
736   }
737   return true;
738 }
739 
740 bool AMDGPUTargetELFStreamer::EmitKernargPreloadHeader(
741     const MCSubtargetInfo &STI) {
742   const uint32_t Encoded_s_nop = 0xbf800000;
743   MCStreamer &OS = getStreamer();
744   for (int i = 0; i < 64; ++i) {
745     OS.emitInt32(Encoded_s_nop);
746   }
747   return true;
748 }
749 
750 bool AMDGPUTargetELFStreamer::EmitCodeEnd(const MCSubtargetInfo &STI) {
751   const uint32_t Encoded_s_code_end = 0xbf9f0000;
752   const uint32_t Encoded_s_nop = 0xbf800000;
753   uint32_t Encoded_pad = Encoded_s_code_end;
754 
755   // Instruction cache line size in bytes.
756   const unsigned Log2CacheLineSize = AMDGPU::isGFX11Plus(STI) ? 7 : 6;
757   const unsigned CacheLineSize = 1u << Log2CacheLineSize;
758 
759   // Extra padding amount in bytes to support prefetch mode 3.
760   unsigned FillSize = 3 * CacheLineSize;
761 
762   if (AMDGPU::isGFX90A(STI)) {
763     Encoded_pad = Encoded_s_nop;
764     FillSize = 16 * CacheLineSize;
765   }
766 
767   MCStreamer &OS = getStreamer();
768   OS.pushSection();
769   OS.emitValueToAlignment(Align(CacheLineSize), Encoded_pad, 4);
770   for (unsigned I = 0; I < FillSize; I += 4)
771     OS.emitInt32(Encoded_pad);
772   OS.popSection();
773   return true;
774 }
775 
776 void AMDGPUTargetELFStreamer::EmitAmdhsaKernelDescriptor(
777     const MCSubtargetInfo &STI, StringRef KernelName,
778     const amdhsa::kernel_descriptor_t &KernelDescriptor, uint64_t NextVGPR,
779     uint64_t NextSGPR, bool ReserveVCC, bool ReserveFlatScr) {
780   auto &Streamer = getStreamer();
781   auto &Context = Streamer.getContext();
782 
783   MCSymbolELF *KernelCodeSymbol = cast<MCSymbolELF>(
784       Context.getOrCreateSymbol(Twine(KernelName)));
785   MCSymbolELF *KernelDescriptorSymbol = cast<MCSymbolELF>(
786       Context.getOrCreateSymbol(Twine(KernelName) + Twine(".kd")));
787 
788   // Copy kernel descriptor symbol's binding, other and visibility from the
789   // kernel code symbol.
790   KernelDescriptorSymbol->setBinding(KernelCodeSymbol->getBinding());
791   KernelDescriptorSymbol->setOther(KernelCodeSymbol->getOther());
792   KernelDescriptorSymbol->setVisibility(KernelCodeSymbol->getVisibility());
793   // Kernel descriptor symbol's type and size are fixed.
794   KernelDescriptorSymbol->setType(ELF::STT_OBJECT);
795   KernelDescriptorSymbol->setSize(
796       MCConstantExpr::create(sizeof(KernelDescriptor), Context));
797 
798   // The visibility of the kernel code symbol must be protected or less to allow
799   // static relocations from the kernel descriptor to be used.
800   if (KernelCodeSymbol->getVisibility() == ELF::STV_DEFAULT)
801     KernelCodeSymbol->setVisibility(ELF::STV_PROTECTED);
802 
803   Streamer.emitLabel(KernelDescriptorSymbol);
804   Streamer.emitInt32(KernelDescriptor.group_segment_fixed_size);
805   Streamer.emitInt32(KernelDescriptor.private_segment_fixed_size);
806   Streamer.emitInt32(KernelDescriptor.kernarg_size);
807 
808   for (uint8_t Res : KernelDescriptor.reserved0)
809     Streamer.emitInt8(Res);
810 
811   // FIXME: Remove the use of VK_AMDGPU_REL64 in the expression below. The
812   // expression being created is:
813   //   (start of kernel code) - (start of kernel descriptor)
814   // It implies R_AMDGPU_REL64, but ends up being R_AMDGPU_ABS64.
815   Streamer.emitValue(MCBinaryExpr::createSub(
816       MCSymbolRefExpr::create(
817           KernelCodeSymbol, MCSymbolRefExpr::VK_AMDGPU_REL64, Context),
818       MCSymbolRefExpr::create(
819           KernelDescriptorSymbol, MCSymbolRefExpr::VK_None, Context),
820       Context),
821       sizeof(KernelDescriptor.kernel_code_entry_byte_offset));
822   for (uint8_t Res : KernelDescriptor.reserved1)
823     Streamer.emitInt8(Res);
824   Streamer.emitInt32(KernelDescriptor.compute_pgm_rsrc3);
825   Streamer.emitInt32(KernelDescriptor.compute_pgm_rsrc1);
826   Streamer.emitInt32(KernelDescriptor.compute_pgm_rsrc2);
827   Streamer.emitInt16(KernelDescriptor.kernel_code_properties);
828   Streamer.emitInt16(KernelDescriptor.kernarg_preload);
829   for (uint8_t Res : KernelDescriptor.reserved3)
830     Streamer.emitInt8(Res);
831 }
832