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[Backport to 15] Add __builtin_spirv_ internal builtins (KhronosGroup#3374)
Way they are implemented is described in: KhronosGroup#3221 The PR also adds SPV_EXT_float8 extension and packed conversions for SPV_INTEL_int4 Currently only conversion instructions (and internal builtins) are covered. TODO: in the following PR Saturation decoration will be added. Signed-off-by: Sidorov, Dmitry <[email protected]> --------- Signed-off-by: Sidorov, Dmitry <[email protected]>
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14 files changed

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-12
lines changed

14 files changed

+1056
-12
lines changed

‎include/LLVMSPIRVExtensions.inc‎

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -79,5 +79,7 @@ EXT(SPV_INTEL_ternary_bitwise_function)
7979
EXT(SPV_INTEL_int4)
8080
EXT(SPV_INTEL_function_variants)
8181
EXT(SPV_INTEL_16bit_atomics)
82+
EXT(SPV_INTEL_shader_atomic_bfloat16)
83+
EXT(SPV_EXT_float8)
8284
EXT(SPV_INTEL_predicated_io)
8385
EXT(SPV_INTEL_sigmoid)

‎lib/SPIRV/SPIRVInternal.h‎

Lines changed: 83 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -394,6 +394,7 @@ const static char ConvertHandleToImageINTEL[] = "ConvertHandleToImageINTEL";
394394
const static char ConvertHandleToSamplerINTEL[] = "ConvertHandleToSamplerINTEL";
395395
const static char ConvertHandleToSampledImageINTEL[] =
396396
"ConvertHandleToSampledImageINTEL";
397+
const static char InternalBuiltinPrefix[] = "__builtin_spirv_";
397398
} // namespace kSPIRVName
398399

399400
namespace kSPIRVPostfix {
@@ -694,7 +695,7 @@ Op getSPIRVFuncOC(StringRef Name, SmallVectorImpl<std::string> *Dec = nullptr);
694695
bool getSPIRVBuiltin(const std::string &Name, spv::BuiltIn &Builtin);
695696

696697
/// \param Name LLVM function name
697-
/// \param DemangledName demanged name of the OpenCL built-in function
698+
/// \param DemangledName demangled name of the OpenCL built-in function
698699
/// \returns true if Name is the name of the OpenCL built-in function,
699700
/// false for other functions
700701
bool oclIsBuiltin(StringRef Name, StringRef &DemangledName, bool IsCpp = false);
@@ -771,6 +772,9 @@ CallInst *addCallInst(Module *M, StringRef FuncName, Type *RetTy,
771772
StringRef InstName = SPIR_TEMP_NAME_PREFIX_CALL,
772773
bool TakeFuncName = true);
773774

775+
/// Check if an LLVM type is spirv.CooperativeMatrixKHR.
776+
bool isLLVMCooperativeMatrixType(llvm::Type *Ty);
777+
774778
/// Add a call instruction for SPIR-V builtin function.
775779
CallInst *addCallInstSPIRV(Module *M, StringRef FuncName, Type *RetTy,
776780
ArrayRef<Value *> Args, AttributeList *Attrs,
@@ -1124,6 +1128,84 @@ MetadataAsValue *map2MDString(LLVMContext &C, SPIRVValue *V);
11241128
/// The return value is undefined if the input is larger than the largest power
11251129
/// of two representable in SPIRVWord.
11261130
[[nodiscard]] SPIRVWord bitCeil(SPIRVWord Value);
1131+
1132+
/// \param MangledName LLVM function name.
1133+
/// \param DemangledName demangled name of the input function if it is the
1134+
/// translator's internal built-in function.
1135+
/// \returns true if MangledName is the name of the translator's internal
1136+
/// built-in function, false for other functions.
1137+
/// Used for 'mini'-floats conversion functions
1138+
bool isInternalSPIRVBuiltin(StringRef MangledName, std::string &DemangledName);
1139+
1140+
// Wrapper around SPIR-V 1.6.4 FP Encoding to be used in the conversion
1141+
// descriptor
1142+
enum FPEncodingWrap {
1143+
Integer = FPEncoding::FPEncodingMax - 1,
1144+
IEEE754 = FPEncoding::FPEncodingMax,
1145+
BF16 = FPEncoding::FPEncodingBFloat16KHR,
1146+
E4M3 = FPEncoding::FPEncodingFloat8E4M3EXT,
1147+
E5M2 = FPEncoding::FPEncodingFloat8E5M2EXT,
1148+
};
1149+
1150+
// Structure describing non-trivial conversions (FP8 and int4)
1151+
struct FPConversionDesc {
1152+
FPEncodingWrap SrcEncoding;
1153+
FPEncodingWrap DstEncoding;
1154+
SPIRVWord ConvOpCode;
1155+
1156+
// To use as a key in std::map
1157+
bool operator==(const FPConversionDesc &Other) const {
1158+
return SrcEncoding == Other.SrcEncoding &&
1159+
DstEncoding == Other.DstEncoding && ConvOpCode == Other.ConvOpCode;
1160+
}
1161+
1162+
bool operator<(const FPConversionDesc &Other) const {
1163+
if (ConvOpCode != Other.ConvOpCode)
1164+
return ConvOpCode < Other.ConvOpCode;
1165+
if (SrcEncoding != Other.SrcEncoding)
1166+
return SrcEncoding < Other.SrcEncoding;
1167+
return DstEncoding < Other.DstEncoding;
1168+
}
1169+
};
1170+
1171+
// Maps internal builtin name to conversion descriptor
1172+
typedef SPIRVMap<llvm::StringRef, FPConversionDesc> FPConvertToEncodingMap;
1173+
1174+
// clang-format off
1175+
template <> inline void FPConvertToEncodingMap::init() {
1176+
// 8-bit conversions
1177+
add("ConvertE4M3ToFP16EXT",
1178+
{FPEncodingWrap::E4M3, FPEncodingWrap::IEEE754, OpFConvert});
1179+
add("ConvertE5M2ToFP16EXT",
1180+
{FPEncodingWrap::E5M2, FPEncodingWrap::IEEE754, OpFConvert});
1181+
add("ConvertE4M3ToBF16EXT",
1182+
{FPEncodingWrap::E4M3, FPEncodingWrap::BF16, OpFConvert});
1183+
add("ConvertE5M2ToBF16EXT",
1184+
{FPEncodingWrap::E5M2, FPEncodingWrap::BF16, OpFConvert});
1185+
add("ConvertFP16ToE4M3EXT",
1186+
{FPEncodingWrap::IEEE754, FPEncodingWrap::E4M3, OpFConvert});
1187+
add("ConvertFP16ToE5M2EXT",
1188+
{FPEncodingWrap::IEEE754, FPEncodingWrap::E5M2, OpFConvert});
1189+
add("ConvertBF16ToE4M3EXT",
1190+
{FPEncodingWrap::BF16, FPEncodingWrap::E4M3, OpFConvert});
1191+
add("ConvertBF16ToE5M2EXT",
1192+
{FPEncodingWrap::BF16, FPEncodingWrap::E5M2, OpFConvert});
1193+
1194+
add("ConvertInt4ToE4M3INTEL",
1195+
{FPEncodingWrap::Integer, FPEncodingWrap::E4M3, OpConvertSToF});
1196+
add("ConvertInt4ToE5M2INTEL",
1197+
{FPEncodingWrap::Integer, FPEncodingWrap::E5M2, OpConvertSToF});
1198+
add("ConvertInt4ToFP16INTEL",
1199+
{FPEncodingWrap::Integer, FPEncodingWrap::IEEE754, OpConvertSToF});
1200+
add("ConvertInt4ToBF16INTEL",
1201+
{FPEncodingWrap::Integer, FPEncodingWrap::BF16, OpConvertSToF});
1202+
add("ConvertFP16ToInt4INTEL",
1203+
{FPEncodingWrap::IEEE754, FPEncodingWrap::Integer, OpConvertFToS});
1204+
add("ConvertBF16ToInt4INTEL",
1205+
{FPEncodingWrap::BF16, FPEncodingWrap::Integer, OpConvertFToS});
1206+
}
1207+
1208+
// clang-format on
11271209
} // namespace SPIRV
11281210

11291211
#endif // SPIRV_SPIRVINTERNAL_H

‎lib/SPIRV/SPIRVReader.cpp‎

Lines changed: 116 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -310,6 +310,9 @@ llvm::Optional<uint64_t> SPIRVToLLVM::getAlignment(SPIRVValue *V) {
310310

311311
Type *SPIRVToLLVM::transFPType(SPIRVType *T) {
312312
switch (T->getFloatBitWidth()) {
313+
case 8:
314+
// No LLVM IR counter part for FP8 - map it on i8
315+
return Type::getIntNTy(*Context, 8);
313316
case 16:
314317
if (T->isTypeFloat(16, FPEncodingBFloat16KHR))
315318
return Type::getBFloatTy(*Context);
@@ -1156,6 +1159,22 @@ Value *SPIRVToLLVM::transConvertInst(SPIRVValue *BV, Function *F,
11561159
CastInst::CastOps CO = Instruction::BitCast;
11571160
bool IsExt =
11581161
Dst->getScalarSizeInBits() > Src->getType()->getScalarSizeInBits();
1162+
1163+
auto GetFPEncoding = [](SPIRVType *Ty) -> FPEncodingWrap {
1164+
if (Ty->isTypeFloat()) {
1165+
unsigned Enc =
1166+
static_cast<SPIRVTypeFloat *>(Ty)->getFloatingPointEncoding();
1167+
return static_cast<FPEncodingWrap>(Enc);
1168+
}
1169+
if (Ty->isTypeInt())
1170+
return FPEncodingWrap::Integer;
1171+
return FPEncodingWrap::IEEE754;
1172+
};
1173+
1174+
auto IsFP8Encoding = [](FPEncodingWrap Encoding) -> bool {
1175+
return Encoding == FPEncodingWrap::E4M3 || Encoding == FPEncodingWrap::E5M2;
1176+
};
1177+
11591178
switch (BC->getOpCode()) {
11601179
case OpPtrCastToGeneric:
11611180
case OpGenericCastToPtr:
@@ -1177,10 +1196,84 @@ Value *SPIRVToLLVM::transConvertInst(SPIRVValue *BV, Function *F,
11771196
case OpUConvert:
11781197
CO = IsExt ? Instruction::ZExt : Instruction::Trunc;
11791198
break;
1180-
case OpFConvert:
1181-
CO = IsExt ? Instruction::FPExt : Instruction::FPTrunc;
1199+
case OpConvertSToF:
1200+
case OpConvertFToS:
1201+
case OpConvertUToF:
1202+
case OpConvertFToU:
1203+
case OpFConvert: {
1204+
const auto OC = BC->getOpCode();
1205+
{
1206+
auto SPVOps = BC->getOperands();
1207+
auto *SPVSrcTy = SPVOps[0]->getType();
1208+
auto *SPVDstTy = BC->getType();
1209+
1210+
auto GetEncodingAndUpdateType =
1211+
[GetFPEncoding](SPIRVType *&SPVTy) -> FPEncodingWrap {
1212+
if (SPVTy->isTypeVector()) {
1213+
SPVTy = SPVTy->getVectorComponentType();
1214+
} else if (SPVTy->isTypeCooperativeMatrixKHR()) {
1215+
auto *MT = static_cast<SPIRVTypeCooperativeMatrixKHR *>(SPVTy);
1216+
SPVTy = MT->getCompType();
1217+
}
1218+
return GetFPEncoding(SPVTy);
1219+
};
1220+
1221+
FPEncodingWrap SrcEnc = GetEncodingAndUpdateType(SPVSrcTy);
1222+
FPEncodingWrap DstEnc = GetEncodingAndUpdateType(SPVDstTy);
1223+
if (IsFP8Encoding(SrcEnc) || IsFP8Encoding(DstEnc) ||
1224+
SPVSrcTy->isTypeInt(4) || SPVDstTy->isTypeInt(4)) {
1225+
FPConversionDesc FPDesc = {SrcEnc, DstEnc, BC->getOpCode()};
1226+
auto Conv = SPIRV::FPConvertToEncodingMap::rmap(FPDesc);
1227+
std::vector<Value *> Ops = {Src};
1228+
std::vector<Type *> OpsTys = {Src->getType()};
1229+
1230+
std::string BuiltinName =
1231+
kSPIRVName::InternalBuiltinPrefix + std::string(Conv);
1232+
BuiltinFuncMangleInfo Info;
1233+
std::string MangledName;
1234+
// Translate additional Ops for stochastic conversions.
1235+
if (OC == internal::OpStochasticRoundFToFINTEL ||
1236+
OC == internal::OpClampStochasticRoundFToFINTEL ||
1237+
OC == internal::OpClampStochasticRoundFToSINTEL) {
1238+
// Seed.
1239+
Ops.emplace_back(transValue(SPVOps[1], F, BB, true));
1240+
OpsTys.emplace_back(Ops[1]->getType());
1241+
constexpr unsigned MaxOpsSize = 3;
1242+
if (SPVOps.size() == MaxOpsSize) {
1243+
// New Seed.
1244+
Ops.emplace_back(transValue(SPVOps[2], F, BB, true));
1245+
1246+
// The following mess is needed to create a function with correct
1247+
// mangling.
1248+
SPIRVType *PtrTy = SPVOps[2]->getType();
1249+
const unsigned AS =
1250+
SPIRSPIRVAddrSpaceMap::rmap(PtrTy->getPointerStorageClass());
1251+
Type *ElementTy = transType(PtrTy->getPointerElementType());
1252+
// LLVM 15 uses typed pointers natively
1253+
OpsTys.emplace_back(PointerType::get(ElementTy, AS));
1254+
MangledName = mangleBuiltin(BuiltinName, OpsTys, &Info);
1255+
}
1256+
}
1257+
1258+
if (MangledName.empty())
1259+
MangledName = mangleBuiltin(BuiltinName, OpsTys, &Info);
1260+
1261+
FunctionType *FTy = FunctionType::get(Dst, OpsTys, false);
1262+
FunctionCallee Func = M->getOrInsertFunction(MangledName, FTy);
1263+
return CallInst::Create(Func, Ops, "", BB);
1264+
}
1265+
}
1266+
1267+
if (OC == OpFConvert) {
1268+
CO = IsExt ? Instruction::FPExt : Instruction::FPTrunc;
1269+
break;
1270+
}
1271+
CO = static_cast<CastInst::CastOps>(OpCodeMap::rmap(OC));
11821272
break;
1273+
}
11831274
case OpBitcast:
1275+
if (!Dst->isPointerTy() && Dst == Src->getType())
1276+
return Src;
11841277
// OpBitcast need to be handled as a special-case when the source is a
11851278
// pointer and the destination is not a pointer, and where the source is not
11861279
// a pointer and the destination is a pointer. This is supported by the
@@ -2979,10 +3072,29 @@ Value *SPIRVToLLVM::transValueWithoutDecoration(SPIRVValue *BV, Function *F,
29793072
if (isCvtOpCode(OC) && OC != OpGenericCastToPtrExplicit) {
29803073
auto BI = static_cast<SPIRVInstruction *>(BV);
29813074
Value *Inst = nullptr;
2982-
if (BI->hasFPRoundingMode() || BI->isSaturatedConversion())
3075+
if (BI->hasFPRoundingMode() || BI->isSaturatedConversion()) {
29833076
Inst = transSPIRVBuiltinFromInst(BI, BB);
2984-
else
3077+
} else if (BI->getType()->isTypeCooperativeMatrixKHR()) {
3078+
// For cooperative matrix conversions generate __builtin_spirv
3079+
// conversions instead of __spirv_FConvert in case of mini-float
3080+
// type element type.
3081+
auto *OutMatrixElementTy =
3082+
static_cast<SPIRVTypeCooperativeMatrixKHR *>(BI->getType())
3083+
->getCompType();
3084+
auto *InMatrixElementTy =
3085+
static_cast<SPIRVTypeCooperativeMatrixKHR *>(
3086+
static_cast<SPIRVUnary *>(BI)->getOperand(0)->getType())
3087+
->getCompType();
3088+
if (OutMatrixElementTy->isTypeFloat(8, FPEncodingFloat8E4M3EXT) ||
3089+
OutMatrixElementTy->isTypeFloat(8, FPEncodingFloat8E5M2EXT) ||
3090+
InMatrixElementTy->isTypeFloat(8, FPEncodingFloat8E4M3EXT) ||
3091+
InMatrixElementTy->isTypeFloat(8, FPEncodingFloat8E5M2EXT))
3092+
Inst = transConvertInst(BV, F, BB);
3093+
else
3094+
Inst = transSPIRVBuiltinFromInst(BI, BB);
3095+
} else {
29853096
Inst = transConvertInst(BV, F, BB);
3097+
}
29863098
return mapValue(BV, Inst);
29873099
}
29883100
return mapValue(

‎lib/SPIRV/SPIRVUtil.cpp‎

Lines changed: 66 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -38,6 +38,11 @@
3838
///
3939
//===----------------------------------------------------------------------===//
4040

41+
// This file needs to be included before anything that declares
42+
// llvm::PointerType to avoid a compilation bug on MSVC.
43+
#include "llvm/Demangle/Demangle.h"
44+
#include "llvm/Demangle/ItaniumDemangle.h"
45+
4146
#include "FunctionDescriptor.h"
4247
#include "ManglingUtils.h"
4348
#include "NameMangleAPI.h"
@@ -50,7 +55,6 @@
5055

5156
#include "llvm/ADT/StringSwitch.h"
5257
#include "llvm/Bitcode/BitcodeWriter.h"
53-
#include "llvm/Demangle/Demangle.h"
5458
#include "llvm/IR/IRBuilder.h"
5559
#include "llvm/IR/IntrinsicInst.h"
5660
#include "llvm/IR/Metadata.h"
@@ -345,6 +349,11 @@ bool isSYCLBfloat16Type(llvm::Type *Ty) {
345349
return false;
346350
}
347351

352+
bool isLLVMCooperativeMatrixType(llvm::Type *Ty) {
353+
// TargetExtType doesn't exist in LLVM 15, so cooperative matrices are not supported in this form
354+
return false;
355+
}
356+
348357
Function *getOrCreateFunction(Module *M, Type *RetTy, ArrayRef<Type *> ArgTypes,
349358
StringRef Name, BuiltinFuncMangleInfo *Mangle,
350359
AttributeList *Attrs, bool TakeName) {
@@ -544,7 +553,7 @@ bool getSPIRVBuiltin(const std::string &OrigName, spv::BuiltIn &B) {
544553
return getByName(R.str(), B);
545554
}
546555

547-
// Demangled name is a substring of the name. The DemangledName is updated only
556+
// DemangledName is a substring of Name. The DemangledName is updated only
548557
// if true is returned
549558
bool oclIsBuiltin(StringRef Name, StringRef &DemangledName, bool IsCpp) {
550559
if (Name == "printf") {
@@ -583,6 +592,61 @@ bool oclIsBuiltin(StringRef Name, StringRef &DemangledName, bool IsCpp) {
583592
return true;
584593
}
585594

595+
// DemangledName is a substring of Name. The DemangledName is updated only
596+
// if true is returned.
597+
bool isInternalSPIRVBuiltin(StringRef Name, std::string &DemangledName) {
598+
if (!Name.startswith("_Z"))
599+
return false;
600+
constexpr unsigned DemangledNameLenStart = 2;
601+
size_t Start = Name.find_first_not_of("0123456789", DemangledNameLenStart);
602+
if (!Name.substr(Start).startswith(kSPIRVName::InternalBuiltinPrefix))
603+
return false;
604+
// LLVM 16 doesn't have itaniumDemangle(const char*, bool) overload
605+
// Try using the C-style API first, but it may fail for types like bfloat (DF16b)
606+
// that LLVM 16's demangler doesn't recognize
607+
char *Demangled = llvm::itaniumDemangle(Name.data(), nullptr, nullptr, nullptr);
608+
609+
if (Demangled) {
610+
// Demangling succeeded - extract function name from demangled string
611+
std::string FullDemangled(Demangled);
612+
std::free(Demangled);
613+
if (!StringRef(FullDemangled).startswith(kSPIRVName::InternalBuiltinPrefix))
614+
return false;
615+
// Remove the __builtin_spirv_ prefix
616+
std::string WithoutPrefix = FullDemangled.substr(strlen(kSPIRVName::InternalBuiltinPrefix));
617+
// Extract just the function name (before the opening parenthesis)
618+
size_t ParenPos = WithoutPrefix.find('(');
619+
if (ParenPos != std::string::npos)
620+
DemangledName = WithoutPrefix.substr(0, ParenPos);
621+
else
622+
DemangledName = WithoutPrefix;
623+
} else {
624+
// Demangling failed (e.g., for bfloat types in LLVM 16)
625+
// Fall back to extracting function name directly from the mangled name
626+
// Format: _Z<len>__builtin_spirv_<FunctionName><TypeEncoding>
627+
// All conversion function names end with "EXT" or "INTEL"
628+
StringRef AfterPrefix = Name.substr(Start + strlen(kSPIRVName::InternalBuiltinPrefix));
629+
630+
size_t ExtPos = AfterPrefix.find("EXT");
631+
size_t IntelPos = AfterPrefix.find("INTEL");
632+
size_t FuncNameEnd = StringRef::npos;
633+
634+
if (ExtPos != StringRef::npos && IntelPos != StringRef::npos)
635+
FuncNameEnd = std::min(ExtPos + 3, IntelPos + 5); // +3 for "EXT", +5 for "INTEL"
636+
else if (ExtPos != StringRef::npos)
637+
FuncNameEnd = ExtPos + 3;
638+
else if (IntelPos != StringRef::npos)
639+
FuncNameEnd = IntelPos + 5;
640+
641+
if (FuncNameEnd == StringRef::npos)
642+
DemangledName = AfterPrefix.str();
643+
else
644+
DemangledName = AfterPrefix.substr(0, FuncNameEnd).str();
645+
}
646+
647+
return true;
648+
}
649+
586650
// Check if a mangled type Name is unsigned
587651
bool isMangledTypeUnsigned(char Mangled) {
588652
return Mangled == 'h' /* uchar */

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