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[Codegen][CUDA] Fix codegen of cast among vector bfloat16, fp8 and fp4 #17741

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Merged
merged 1 commit into from
Mar 12, 2025
Merged

[Codegen][CUDA] Fix codegen of cast among vector bfloat16, fp8 and fp4 #17741

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7 changes: 6 additions & 1 deletion python/tvm/runtime/ndarray.py
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Original file line number Diff line number Diff line change
Expand Up @@ -233,7 +233,12 @@ def numpy(self):
if dtype == "int4":
dtype = "int8"
if dtype == "bfloat16":
dtype = "uint16"
if ml_dtypes is not None:
dtype = ml_dtypes.bfloat16
else:
raise RuntimeError(
"ml_dtypes is not installed, cannot convert bfloat16 array to numpy."
)
if dtype == "float8_e4m3fn":
if ml_dtypes is not None:
dtype = ml_dtypes.float8_e4m3fn
Expand Down
58 changes: 38 additions & 20 deletions src/target/source/codegen_cuda.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -194,7 +194,7 @@ std::string CodeGenCUDA::Finish() {
decl_stream << "#include <cuda_fp4.h>\n";
decl_stream << "#endif\n\n";
}
declare_vector_type_extensions(decl_stream, enable_fp16_, enable_fp8_, enable_fp4_);
declare_vector_type_extensions(decl_stream, enable_fp16_, enable_bf16_, enable_fp8_, enable_fp4_);

if (enable_warp_shuffle_) {
decl_stream << _cuda_warp_intrinsic_util;
Expand Down Expand Up @@ -331,8 +331,12 @@ void CodeGenCUDA::PrintType(DataType t, std::ostream& os) { // NOLINT(*)
if (t.is_scalar()) {
os << "nv_bfloat16";
} else if (lanes <= 8) {
ICHECK_EQ(lanes % 2, 0) << "only support even lane for half type";
os << "uint" << lanes / 2;
ICHECK_EQ(lanes % 2, 0) << "only support even lane for bfloat16 type";
if (lanes <= 4) {
os << "nv_bfloat16" << lanes;
} else {
os << "uint" << lanes / 2;
}
} else {
fail = true;
}
Expand Down Expand Up @@ -575,7 +579,11 @@ void CodeGenCUDA::PrintVecElemLoad(const std::string& vec, DataType t, int i,
os << "((half2*)(&(" << vec << "." << access[i / 2] << ")))->" << access[i % 2];
}
} else if (t.is_bfloat16()) {
os << "((nv_bfloat162*)(&(" << vec << "." << access[i / 2] << ")))->" << access[i % 2];
if (t.lanes() <= 4) {
os << vec << "." << access[i];
} else {
os << "((nv_bfloat162*)(&(" << vec << "." << access[i / 2] << ")))->" << access[i % 2];
}
} else if (t.lanes() > 4 && t.lanes() <= 8) {
std::string type_name;
if (t.bits() == 16) {
Expand Down Expand Up @@ -630,8 +638,12 @@ void CodeGenCUDA::PrintVecElemStore(const std::string& vec, DataType t, int i,
}

} else if (t.is_bfloat16()) {
stream << "((nv_bfloat162*)(&(" << vec << "." << access[i / 2] << ")))->" << access[i % 2]
<< " = " << value << ";\n";
if (t.lanes() <= 4) {
stream << vec << "." << access[i] << " = " << value << ";\n";
} else {
stream << "((nv_bfloat162*)(&(" << vec << "." << access[i / 2] << ")))->" << access[i % 2]
<< " = " << value << ";\n";
}
} else if (t.lanes() > 4 && t.lanes() <= 8) {
std::string type_name;
if (t.bits() == 16) {
Expand Down Expand Up @@ -736,9 +748,13 @@ void CodeGenCUDA::VisitExpr_(const CastNode* op, std::ostream& os) {
target_ty.code() == DataType::kFloat4_e2m1fn || from_ty.code() == DataType::kFloat8_e4m3fn ||
from_ty.code() == DataType::kFloat8_e5m2 || from_ty.code() == DataType::kFloat4_e2m1fn) {
std::ostringstream val;
val << "(";
PrintType(target_ty, val);
val << ")(" << PrintExpr(op->value) << ")";
if (target_ty.code() == DataType::kBFloat && target_ty.lanes() == 2) {
val << "cast_to_nv_bfloat162(" << PrintExpr(op->value) << ")";
} else {
val << "(";
PrintType(target_ty, val);
val << ")(" << PrintExpr(op->value) << ")";
}
os << val.str();
return;
}
Expand Down Expand Up @@ -1384,9 +1400,16 @@ void CodeGenCUDA::VisitExpr_(const BroadcastNode* op, std::ostream& os) { // NO
std::string v = PrintExpr(op->value);
PrintVecConstructor(op->dtype, os);
os << '(';
for (int i = 0; i < lanes / 2; ++i) {
if (i != 0) os << ", ";
os << "__pack_nv_bfloat162(" << v << ", " << v << ")";
if (lanes > 4) {
for (int i = 0; i < lanes / 2; ++i) {
if (i != 0) os << ", ";
os << "__pack_nv_bfloat162(" << v << ", " << v << ")";
}
} else {
for (int i = 0; i < lanes; ++i) {
if (i != 0) os << ", ";
os << v;
}
}
os << ')';
return;
Expand Down Expand Up @@ -1660,15 +1683,10 @@ void CodeGenCUDA::PrintVecElemLoadExpr(DataType t, int i, const std::string& val
PrintVecConstructor(t, os);
os << '(';
}
if (i % 2 == 0) {
os << "__pack_nv_bfloat162(" << value;
if (i == t.lanes() - 1) {
os << value << ")";
} else {
os << "," << value << ")";
if (i != t.lanes() - 1) {
os << ",";
} else {
os << ")";
}
os << value << ",";
}
return;
}
Expand Down
151 changes: 108 additions & 43 deletions src/target/source/literal/cuda_half_t.h
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Original file line number Diff line number Diff line change
Expand Up @@ -385,52 +385,70 @@ static constexpr const char* _cuda_warp_intrinsic_util = R"(

)";

void declare_vector_type_extensions(std::ostringstream& stream, bool enable_fp16, bool enable_fp8,
bool enable_fp4) {
if (enable_fp16 || enable_fp8 || enable_fp4) {
void declare_vector_type_extensions(std::ostringstream& stream, bool enable_fp16, bool enable_bf16,
bool enable_fp8, bool enable_fp4) {
if (enable_fp16 || enable_bf16) {
stream << R"(
struct __align__(8) half4 {
__half x, y, z, w;
__host__ __device__ half4() : x(__half(0)), y(__half(0)), z(__half(0)), w(__half(0)) {}
__host__ __device__ half4(__half x, __half y, __half z, __half w) : x(x), y(y), z(z), w(w) {}
#include <type_traits>
template <typename T, typename TVec2>
struct __align__(8) half4_bfloat164 {
T x, y, z, w;
__host__ __device__ half4_bfloat164() : x(T(0)), y(T(0)), z(T(0)), w(T(0)) {}
__host__ __device__ half4_bfloat164(T x, T y, T z, T w) : x(x), y(y), z(z), w(w) {}
)";
if (enable_fp8) {
stream << R"(
__host__ __device__ explicit half4(const __nv_fp8x4_e4m3& fp8x4) {
__nv_fp8x2_e4m3 lo_part, hi_part;
lo_part.__x = static_cast<__nv_fp8x2_storage_t>(fp8x4.__x & 0xFFFF);
hi_part.__x = static_cast<__nv_fp8x2_storage_t>((fp8x4.__x >> 16) & 0xFFFF);
__half2 lo_half2 = static_cast<__half2>(lo_part);
__half2 hi_half2 = static_cast<__half2>(hi_part);
x = reinterpret_cast<__half*>(&lo_half2)[0];
y = reinterpret_cast<__half*>(&lo_half2)[1];
z = reinterpret_cast<__half*>(&hi_half2)[0];
w = reinterpret_cast<__half*>(&hi_half2)[1];
__host__ __device__ explicit half4_bfloat164(const __nv_fp8x4_e4m3& fp8x4) {
if constexpr (std::is_same_v<T, __half>) {
__nv_fp8x2_e4m3 lo_part, hi_part;
lo_part.__x = static_cast<__nv_fp8x2_storage_t>(fp8x4.__x & 0xFFFF);
hi_part.__x = static_cast<__nv_fp8x2_storage_t>((fp8x4.__x >> 16) & 0xFFFF);
TVec2 lo_half2 = static_cast<TVec2>(lo_part);
TVec2 hi_half2 = static_cast<TVec2>(hi_part);
x = reinterpret_cast<T*>(&lo_half2)[0];
y = reinterpret_cast<T*>(&lo_half2)[1];
z = reinterpret_cast<T*>(&hi_half2)[0];
w = reinterpret_cast<T*>(&hi_half2)[1];
} else {
__nv_fp8_storage_t elem0_raw = static_cast<__nv_fp8_storage_t>(fp8x4.__x & 0xFF);
__nv_fp8_storage_t elem1_raw = static_cast<__nv_fp8_storage_t>((fp8x4.__x >> 8) & 0xFF);
__nv_fp8_storage_t elem2_raw = static_cast<__nv_fp8_storage_t>((fp8x4.__x >> 16) & 0xFF);
__nv_fp8_storage_t elem3_raw = static_cast<__nv_fp8_storage_t>((fp8x4.__x >> 24) & 0xFF);
__nv_fp8_e4m3 elem0, elem1, elem2, elem3;
elem0.__x = elem0_raw;
elem1.__x = elem1_raw;
elem2.__x = elem2_raw;
elem3.__x = elem3_raw;
x = T(elem0);
y = T(elem1);
z = T(elem2);
w = T(elem3);
}
}
__host__ __device__ explicit operator __nv_fp8x4_e4m3() const {
__nv_fp8x4_e4m3 result;
__half2 lo_half2 = *reinterpret_cast<const __half2*>(&x);
__half2 hi_half2 = *reinterpret_cast<const __half2*>(&z);
TVec2 lo_half2 = *reinterpret_cast<const TVec2*>(&x);
TVec2 hi_half2 = *reinterpret_cast<const TVec2*>(&z);
__nv_fp8x2_e4m3 lo_part(lo_half2), hi_part(hi_half2);
result.__x =
(static_cast<__uint32_t>(lo_part.__x) | (static_cast<__uint32_t>(hi_part.__x) << 16));
return result;
}
__host__ __device__ explicit half4(const __nv_fp8x4_e5m2& fp8x4) {
__nv_fp8x2_e5m2 lo_part, hi_part;
lo_part.__x = static_cast<__nv_fp8x2_storage_t>(fp8x4.__x & 0xFFFF);
hi_part.__x = static_cast<__nv_fp8x2_storage_t>((fp8x4.__x >> 16) & 0xFFFF);
__half2 lo_half2 = static_cast<__half2>(lo_part);
__half2 hi_half2 = static_cast<__half2>(hi_part);
x = reinterpret_cast<__half*>(&lo_half2)[0];
y = reinterpret_cast<__half*>(&lo_half2)[1];
z = reinterpret_cast<__half*>(&hi_half2)[0];
w = reinterpret_cast<__half*>(&hi_half2)[1];
__host__ __device__ explicit half4_bfloat164(const __nv_fp8x4_e5m2& fp8x4) {
__nv_fp8x2_e5m2 lo_part, hi_part;
lo_part.__x = static_cast<__nv_fp8x2_storage_t>(fp8x4.__x & 0xFFFF);
hi_part.__x = static_cast<__nv_fp8x2_storage_t>((fp8x4.__x >> 16) & 0xFFFF);
TVec2 lo_half2 = static_cast<TVec2>(lo_part);
TVec2 hi_half2 = static_cast<TVec2>(hi_part);
x = reinterpret_cast<T*>(&lo_half2)[0];
y = reinterpret_cast<T*>(&lo_half2)[1];
z = reinterpret_cast<T*>(&hi_half2)[0];
w = reinterpret_cast<T*>(&hi_half2)[1];
}
__host__ __device__ explicit operator __nv_fp8x4_e5m2() const {
__nv_fp8x4_e5m2 result;
__half2 lo_half2 = *reinterpret_cast<const __half2*>(&x);
__half2 hi_half2 = *reinterpret_cast<const __half2*>(&z);
TVec2 lo_half2 = *reinterpret_cast<const TVec2*>(&x);
TVec2 hi_half2 = *reinterpret_cast<const TVec2*>(&z);
__nv_fp8x2_e5m2 lo_part(lo_half2), hi_part(hi_half2);
result.__x =
(static_cast<__uint32_t>(lo_part.__x) | (static_cast<__uint32_t>(hi_part.__x) << 16));
Expand Down Expand Up @@ -460,31 +478,70 @@ struct __align__(8) half4 {
}
if (enable_fp4) {
stream << R"(
__host__ __device__ explicit half4(const __nv_fp4x4_e2m1& fp4x4) {
__nv_fp4x2_storage_t lo_part, hi_part;
lo_part = static_cast<__nv_fp4x2_storage_t>(fp4x4.__x & 0xFF);
hi_part = static_cast<__nv_fp4x2_storage_t>((fp4x4.__x >> 8) & 0xFF);
__half2 lo_half2 = __half2(__nv_cvt_fp4x2_to_halfraw2(lo_part, __NV_E2M1));
__half2 hi_half2 = __half2(__nv_cvt_fp4x2_to_halfraw2(hi_part, __NV_E2M1));
x = reinterpret_cast<__half*>(&lo_half2)[0];
y = reinterpret_cast<__half*>(&lo_half2)[1];
z = reinterpret_cast<__half*>(&hi_half2)[0];
w = reinterpret_cast<__half*>(&hi_half2)[1];
__host__ __device__ explicit half4_bfloat164(const __nv_fp4x4_e2m1& fp4x4) {
if constexpr (std::is_same_v<T, __half>) {
__nv_fp4x2_storage_t lo_part = static_cast<__nv_fp4x2_storage_t>(fp4x4.__x & 0xFF);
__nv_fp4x2_storage_t hi_part = static_cast<__nv_fp4x2_storage_t>((fp4x4.__x >> 8) & 0xFF);
TVec2 lo_half2 = __half2(__nv_cvt_fp4x2_to_halfraw2(lo_part, __NV_E2M1));
TVec2 hi_half2 = __half2(__nv_cvt_fp4x2_to_halfraw2(hi_part, __NV_E2M1));
x = reinterpret_cast<T*>(&lo_half2)[0];
y = reinterpret_cast<T*>(&lo_half2)[1];
z = reinterpret_cast<T*>(&hi_half2)[0];
w = reinterpret_cast<T*>(&hi_half2)[1];
} else {
__nv_fp4_e2m1 elem0, elem1, elem2, elem3;
elem0.__x = static_cast<__nv_fp4_storage_t>(fp4x4.__x & 0xF);
elem1.__x = static_cast<__nv_fp4_storage_t>((fp4x4.__x >> 4) & 0xF);
elem2.__x = static_cast<__nv_fp4_storage_t>((fp4x4.__x >> 8) & 0xF);
elem3.__x = static_cast<__nv_fp4_storage_t>((fp4x4.__x >> 12) & 0xF);
x = T(elem0);
y = T(elem1);
z = T(elem2);
w = T(elem3);
}
}
__host__ __device__ explicit operator __nv_fp4x4_e2m1() const {
__half2 lo_half2 = *reinterpret_cast<const __half2*>(&x);
__half2 hi_half2 = *reinterpret_cast<const __half2*>(&z);
TVec2 lo_half2 = *reinterpret_cast<const TVec2*>(&x);
TVec2 hi_half2 = *reinterpret_cast<const TVec2*>(&z);
return __nv_fp4x4_e2m1(lo_half2, hi_half2);
}
)";
}
stream << R"(
};
)";
}
if (enable_fp16) {
stream << R"(
using half4 = half4_bfloat164<__half, __half2>;
__host__ __device__ half4 make_half4(__half x, __half y, __half z, __half w) {
return half4(x, y, z, w);
}
)";
}
if (enable_bf16) {
stream << R"(
using nv_bfloat164 = half4_bfloat164<nv_bfloat16, nv_bfloat162>;
__host__ __device__ nv_bfloat164 make_nv_bfloat164(nv_bfloat16 x, nv_bfloat16 y, nv_bfloat16 z, nv_bfloat16 w) {
return nv_bfloat164(x, y, z, w);
}
__host__ __device__ nv_bfloat162 make_nv_bfloat162(nv_bfloat16 x, nv_bfloat16 y) {
return nv_bfloat162(x, y);
}
)";
if (enable_fp8) {
stream << R"(
__host__ __device__ nv_bfloat162 cast_to_nv_bfloat162(const __nv_fp8x2_e4m3& fp8x2) {
__nv_fp8_e4m3 elem0, elem1;
elem0.__x = static_cast<__nv_fp8_storage_t>(fp8x2.__x & 0xFF);
elem1.__x = static_cast<__nv_fp8_storage_t>((fp8x2.__x >> 8) & 0xFF);
nv_bfloat16 x = nv_bfloat16(elem0);
nv_bfloat16 y = nv_bfloat16(elem1);
return nv_bfloat162(x, y);
}
)";
}
}
if (enable_fp4) {
stream << R"(
__device__ __nv_fp4x2_e2m1 make___nv_fp4x2_e2m1(__nv_fp4_e2m1 x, __nv_fp4_e2m1 y) {
Expand All @@ -497,6 +554,14 @@ __device__ __nv_fp4x4_e2m1 make___nv_fp4x4_e2m1(__nv_fp4_e2m1 a, __nv_fp4_e2m1 b
result.__x = (static_cast<__nv_fp4x4_storage_t>(a.__x)) | (static_cast<__nv_fp4x4_storage_t>(b.__x) << 4) | (static_cast<__nv_fp4x4_storage_t>(c.__x) << 8) | (static_cast<__nv_fp4x4_storage_t>(d.__x) << 12);
return result;
}
__host__ __device__ nv_bfloat162 cast_to_nv_bfloat162(const __nv_fp4x2_e2m1& fp4x2) {
__nv_fp4_e2m1 elem0, elem1;
elem0.__x = static_cast<__nv_fp4_storage_t>(fp4x2.__x & 0xF);
elem1.__x = static_cast<__nv_fp4_storage_t>((fp4x2.__x >> 4) & 0xF);
nv_bfloat16 x = nv_bfloat16(elem0);
nv_bfloat16 y = nv_bfloat16(elem1);
return nv_bfloat162(x, y);
}
)";
}
}
Expand Down
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