This commit is contained in:
2026-01-09 13:34:11 +08:00
parent dfa6476b58
commit b2ef04d792
538 changed files with 105693 additions and 2 deletions

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#pragma once
#ifdef __HIPCC__
#include <hip/hip_runtime.h>
#else
#include <type_traits>
#include <stdint.h>
#include <math.h>
#include <iostream>
#endif
#include "hip_float8_impl.h"
struct alignas(1) hip_fp8
{
struct from_bits_t
{
};
HIP_FP8_HOST_DEVICE static constexpr from_bits_t from_bits() { return from_bits_t(); }
uint8_t data;
hip_fp8() = default;
HIP_FP8_HOST_DEVICE constexpr hip_fp8(const hip_fp8&) = default;
HIP_FP8_HOST_DEVICE constexpr hip_fp8(uint8_t v) = delete;
explicit HIP_FP8_HOST_DEVICE constexpr hip_fp8(uint8_t v, from_bits_t)
: data(v)
{
}
#ifdef __HIP__MI300__
// NOTE: ON-DEVICE... always optimal bias
explicit HIP_FP8_DEVICE hip_fp8(float v)
: data(hip_fp8_impl::to_fp8_from_fp32(v))
{
}
explicit HIP_FP8_DEVICE hip_fp8(_Float16 v)
: hip_fp8(static_cast<float>(v))
{
}
// Host only implementation using s/w simulation
explicit HIP_FP8_HOST
#else // __HIP__MI300__
// both Host and DEVICE for non-MI300 using s/w simulation
explicit HIP_FP8_HOST_DEVICE
#endif // __HIP__MI300__
hip_fp8(float v)
{
data = hip_fp8_impl::to_float8<4, 3, float, true /*negative_zero_nan*/, true /*clip*/>(v);
}
explicit HIP_FP8_HOST_DEVICE hip_fp8(double v)
: hip_fp8(static_cast<float>(v))
{
}
#ifdef __HIP__MI300__
// upcast using device specific intrinsic
explicit inline HIP_FP8_DEVICE operator float() const
{
float fval;
uint32_t i32val = static_cast<uint32_t>(data);
// upcast
asm volatile("v_cvt_f32_fp8 %0, %1 src0_sel:BYTE_0" : "=v"(fval) : "v"(i32val));
return fval;
}
explicit inline HIP_FP8_HOST operator float() const
#else // __HIP__MI300__
explicit inline HIP_FP8_HOST_DEVICE operator float() const
#endif // __HIP__MI300__
{
return hip_fp8_impl::from_float8<4, 3, float, true /*negative_zero_nan*/>(data);
}
};
namespace std
{
inline hip_fp8 sin(hip_fp8 a)
{
return hip_fp8(sinf(float(a)));
}
inline hip_fp8 cos(hip_fp8 a)
{
return hip_fp8(cosf(float(a)));
}
HIP_FP8_HOST_DEVICE constexpr hip_fp8 real(const hip_fp8& a)
{
return a;
}
} // namespace std
// Special operator overloading
inline std::ostream& operator<<(std::ostream& os, const hip_fp8& f8)
{
return os << float(f8);
}
// all + operator overloading with mixed types
// mixed types, always converts to f32, does computation in f32, and returns float
inline HIP_FP8_HOST_DEVICE float operator+(const float fa, hip_fp8 b)
{
return (fa + float(b));
}
inline HIP_FP8_HOST_DEVICE float operator+(hip_fp8 a, const float fb)
{
return (float(a) + fb);
}
inline HIP_FP8_HOST_DEVICE hip_fp8 operator+(hip_fp8 a, hip_fp8 b)
{
return hip_fp8(float(a) + float(b));
}
inline HIP_FP8_HOST_DEVICE hip_fp8& operator+=(hip_fp8& a, hip_fp8 b)
{
return a = hip_fp8(float(a) + float(b));
}
// overloading multiplication, always returns float,
inline HIP_FP8_HOST_DEVICE float operator*(hip_fp8 a, hip_fp8 b)
{
return float(a) * float(b);
}
inline HIP_FP8_HOST_DEVICE float operator*(float a, hip_fp8 b)
{
return (a * float(b));
}
inline HIP_FP8_HOST_DEVICE float operator*(hip_fp8 a, float b)
{
return (float(a) * b);
}
inline HIP_FP8_HOST_DEVICE float operator*(int32_t a, hip_fp8 b)
{
return ((float)a * float(b));
}
inline HIP_FP8_HOST_DEVICE float operator*(double a, hip_fp8 b)
{
return ((float)a * float(b));
}
// overloading for compare
inline HIP_FP8_HOST_DEVICE bool operator==(hip_fp8 a, hip_fp8 b)
{
return (a.data == b.data);
}
inline HIP_FP8_HOST_DEVICE bool operator!=(hip_fp8 a, hip_fp8 b)
{
return (a.data != b.data);
}
inline HIP_FP8_HOST_DEVICE bool operator>=(hip_fp8 a, hip_fp8 b)
{
return static_cast<float>(a) >= static_cast<float>(b);
}
inline HIP_FP8_HOST_DEVICE bool operator>(hip_fp8 a, hip_fp8 b)
{
return static_cast<float>(a) > static_cast<float>(b);
}

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#pragma once
#if defined(__HIPCC__) && (defined(__gfx940__) || defined(__gfx941__) || defined(__gfx942__))
#define __HIP__MI300__
#endif
#ifdef __HIPCC__
#define HIP_FP8_HOST_DEVICE __host__ __device__
#define HIP_FP8_HOST __host__
#define HIP_FP8_DEVICE __device__
#else
#define HIP_FP8_HOST_DEVICE
#define HIP_FP8_HOST
#define HIP_FP8_DEVICE
#endif
namespace hip_fp8_impl
{
#ifdef __HIP__MI300__
HIP_FP8_DEVICE uint8_t to_fp8_from_fp32(float v)
{
uint8_t i8data;
union {
float fval;
uint32_t i32val;
uint8_t i8val[4]; // NOTE: not endian independent
} val;
uint32_t ival = 0;
val.fval = v;
if ((val.i32val & 0x7F800000) != 0x7F800000) { /// propagate NAN/INF, no clipping
val.fval = __builtin_amdgcn_fmed3f(val.fval, 240.0, -240.0);
}
ival = __builtin_amdgcn_cvt_pk_fp8_f32(val.fval, val.fval, ival,
false); // false -> WORD0
val.i32val = ival;
i8data = val.i8val[0];
return i8data;
}
#endif // __HIP__MI300__
HIP_FP8_HOST inline int clz(uint32_t x)
{
return __builtin_clz(x);
}
#if defined(__HIPCC__) || defined(__MUSA_ARCH__)
HIP_FP8_DEVICE inline int clz(uint32_t x)
{
return __clz(x);
}
#endif
template <int we, int wm, typename T, bool negative_zero_nan, bool clip>
HIP_FP8_HOST_DEVICE uint8_t to_float8(T _x, bool stoch = false, uint32_t rng = 0)
{
#ifdef __HIPCC__
constexpr bool is_half = std::is_same<T, _Float16>::value;
#else
constexpr bool is_half = false;
#endif
constexpr bool is_float = std::is_same<T, float>::value;
static_assert(wm + we == 7, "wm+we==7");
static_assert(is_half || is_float, "Only half and float can be cast to f8");
const int mfmt = (sizeof(T) == 4) ? 23 : 10;
uint32_t x;
if (sizeof(T) == 4) {
x = reinterpret_cast<uint32_t&>(_x);
} else {
x = reinterpret_cast<uint16_t&>(_x);
}
uint32_t head, mantissa;
int exponent, bias;
uint32_t sign;
if (sizeof(T) == 4) {
head = x & 0xFF800000;
mantissa = x & 0x7FFFFF;
exponent = (head >> 23) & 0xFF;
sign = head >> 31;
bias = 127;
} else {
head = x & 0xFC00;
mantissa = x & 0x3FF;
exponent = (head >> 10) & 0x1F;
sign = head >> 15;
bias = 15;
}
uint32_t signed_inf = (sign << 7) + (((1 << we) - 1) << wm);
// Deal with inf and NaNs
if (negative_zero_nan) {
if (sizeof(T) == 4) {
if ((x & 0x7F800000) == 0x7F800000) {
return 0x80;
}
} else {
// if(__hisinf(x) || __hisnan(x))
if ((x & 0x7C00) == 0x7C00) {
return 0x80;
}
}
} else {
if (sizeof(T) == 4) {
if ((x & 0x7F800000) == 0x7F800000) {
return signed_inf + (mantissa != 0 ? 1 : 0);
}
} else {
if ((x & 0x7C00) == 0x7C00) {
return signed_inf + (mantissa != 0 ? 1 : 0);
}
}
}
if (x == 0) {
return 0;
}
// First need to check if it is normal or denorm as there is a difference of
// implicit 1 Then need to adjust the exponent to align with the F8 exponent,
// in the meanwhile, shift The mantissa. Then for stochastic rounding, add rng
// to mantissa and truncate. And for RNE, no need to add rng. Then probably
// need to check whether there is carry and adjust exponent and mantissa again
// For IEEE bias mode, the bias is 2^(k-1) -1 where k is the width of exponent
// bits
const int f8_bias = (1 << (we - 1)) - 1 + (negative_zero_nan ? 1 : 0);
const int f8_denormal_act_exponent = 1 - f8_bias; // actual exponent of f8 denormal
// act_exponent is the actual exponent of fp32/fp16 (after subtracting bias)
// f8_exponent is the converted f8 exponent with bias encoding
// exponent_diff is the diff between fp32/fp16 exponent and f8 exponent,
// the difference needs to be adjusted and mantissa shifted
int act_exponent, f8_exponent, exponent_diff;
if (exponent == 0) { // fp32/fp16 is in denormal.
/* fp32 denormal is below 2^-127 so it is usually not a concern here, we
mostly concern fp16 here. In this case, f8 is usually in denormal. But there
could be exceptions. fp16 denormal has exponent bias 15 while bf8 with NANOO has
exponent bias 16. It means that there are some numbers in fp16 denormal but they
are bf8 (NANOO) normals - smallest bf8 (NANOO) normal is 2^-15. fp16 numbers
where exponent==0 (actual exponent -14) and highest bit of mantissa is 1 are bf8
(NANOO) normal. In this case, the fp16 mantissa should be shift left by 1 */
act_exponent = exponent - bias + 1;
exponent_diff = f8_denormal_act_exponent - act_exponent; // actual exponent is exponent-bias+1 as it is denormal
} else { // fp32/fp16 is normal with implicit 1
act_exponent = exponent - bias;
if (act_exponent <= f8_denormal_act_exponent) {
/* This is the case where fp32/fp16 is normal but it is in f8 denormal
range. For example fp8 nanoo mode, denormal exponent is -7, but if the
fp32/fp16 actual exponent is -7, it is actually larger due to the implicit 1,
Therefore it needs to be adjust to -6 and mantissa shift right by 1.
So for fp32/fp16, exponent -8 is the cut point to convert to fp8 nanoo */
exponent_diff = f8_denormal_act_exponent - act_exponent;
} else { // both fp32/fp16 and f8 are in normal range
exponent_diff = 0; // exponent_diff=0 does not mean there is no difference
// for this case,
// act_exponent could be larger. Just that it does not need shift mantissa
}
mantissa += (1 << mfmt); // Add the implicit 1 into mantissa
}
bool midpoint = (mantissa & ((1 << (mfmt - wm + exponent_diff)) - 1)) ==
static_cast<uint32_t>(1 << (mfmt - wm + exponent_diff - 1));
/* This part is a bit tricky. The judgment of whether it is a tie needs to be
done before we shift right as shift right could rip off some residual part
and make something not midpoint look like midpoint. For example, the fp16
number 0x1002 (0 00100 0000000010), it is larger than midpoint, but after
shift right by 4 bits, it would look like midpoint.
*/
if (exponent_diff > 0) {
mantissa >>= exponent_diff;
} else if (exponent_diff == -1) {
mantissa <<= -exponent_diff;
}
bool implicit_one = mantissa & (1 << mfmt);
// if there is no implicit 1, it means the f8 is denormal and need to adjust
// to denorm exponent
f8_exponent = (act_exponent + exponent_diff) /*actual f8 exponent*/ + f8_bias - (implicit_one ? 0 : 1);
// Now we have the exponent and mantissa adjusted
uint32_t drop_mask = (1 << (mfmt - wm)) - 1;
bool odd = mantissa & (1 << (mfmt - wm)); // if the least significant bit that
// is not truncated is 1
mantissa += (stoch ? rng : (midpoint ? (odd ? mantissa : mantissa - 1) : mantissa)) & drop_mask;
// Now we deal with overflow
if (f8_exponent == 0) {
if ((1 << mfmt) & mantissa) {
f8_exponent = 1; // denormal overflow to become normal, promote exponent
}
} else {
if ((1 << (mfmt + 1)) & mantissa) {
mantissa >>= 1;
f8_exponent++;
}
}
mantissa >>= (mfmt - wm);
// above range: quantize to maximum possible float of the same sign
const int max_exp = (1 << we) - (negative_zero_nan ? 1 : 2);
if (f8_exponent > max_exp) {
if (clip) {
mantissa = (1 << wm) - 1;
f8_exponent = max_exp;
} else {
return signed_inf;
}
}
if (f8_exponent == 0 && mantissa == 0) {
return negative_zero_nan ? 0 : (sign << 7);
}
mantissa &= (1 << wm) - 1;
return (sign << 7) | (f8_exponent << wm) | mantissa;
}
template <int we, int wm, typename T = float, bool negative_zero_nan = true>
inline HIP_FP8_HOST_DEVICE T from_float8(uint8_t x)
{
#ifdef __HIPCC__
constexpr bool is_half = std::is_same<T, _Float16>::value;
#else
constexpr bool is_half = false;
#endif
constexpr bool is_float = std::is_same<T, float>::value;
static_assert(is_half || is_float, "only half and float are supported");
constexpr int weo = is_half ? 5 : 8;
constexpr int wmo = is_half ? 10 : (is_float ? 23 : 7);
T fInf, fNegInf, fNaN, fNeg0;
#ifdef __HIPCC__
if (is_half) {
const uint16_t ihInf = 0x7C00;
const uint16_t ihNegInf = 0xFC00;
const uint16_t ihNaN = 0x7C01;
const uint16_t ihNeg0 = 0x8000;
fInf = reinterpret_cast<const _Float16&>(ihInf);
fNegInf = reinterpret_cast<const _Float16&>(ihNegInf);
fNaN = reinterpret_cast<const _Float16&>(ihNaN);
fNeg0 = reinterpret_cast<const _Float16&>(ihNeg0);
} else
#endif
if (is_float) {
const uint32_t ifInf = 0x7F800000;
const uint32_t ifNegInf = 0xFF800000;
const uint32_t ifNaN = 0x7F800001;
const uint32_t ifNeg0 = 0x80000000;
fInf = reinterpret_cast<const float&>(ifInf);
fNegInf = reinterpret_cast<const float&>(ifNegInf);
fNaN = reinterpret_cast<const float&>(ifNaN);
fNeg0 = reinterpret_cast<const float&>(ifNeg0);
}
if (x == 0) {
return 0;
}
uint32_t sign = x >> 7;
uint32_t mantissa = x & ((1 << wm) - 1);
int exponent = (x & 0x7F) >> wm;
if (negative_zero_nan) {
if (x == 0x80) {
return fNaN;
}
} else {
if (x == 0x80) {
return fNeg0;
}
if (exponent == ((1 << we) - 1)) {
return (mantissa == 0) ? (sign ? fNegInf : fInf) : fNaN;
}
}
typename std::conditional<sizeof(T) == 2, uint16_t, uint32_t>::type retval;
if (we == 5 && is_half && !negative_zero_nan) {
retval = x << 8;
return reinterpret_cast<const T&>(retval);
}
const int exp_low_cutoff = (1 << (weo - 1)) - (1 << (we - 1)) + 1 - (negative_zero_nan ? 1 : 0);
// subnormal input
if (exponent == 0) {
// guaranteed mantissa!=0 since cases 0x0 and 0x80 are handled above
int sh = 1 + clz(mantissa) - (32 - wm);
mantissa <<= sh;
exponent += 1 - sh;
mantissa &= ((1 << wm) - 1);
}
exponent += exp_low_cutoff - 1;
mantissa <<= wmo - wm;
// subnormal output (occurs when T=half, we=5, negative_zero_nan=true)
if (exponent <= 0) {
mantissa |= 1 << wmo;
mantissa >>= 1 - exponent;
exponent = 0;
}
if (sizeof(T) == 2) {
retval = (sign << 15) | (exponent << 10) | mantissa;
} else {
retval = (sign << 31) | (exponent << 23) | mantissa;
}
return reinterpret_cast<const T&>(retval);
}
} // namespace hip_fp8_impl

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#pragma once
#include "hip_float8.h"
#include <hip/hip_fp16.h>
#include <hip/hip_bf16.h>
#include <hip/hip_bfloat16.h>
#include "../../../attention/dtype_float32.cuh"
#include "../../../attention/dtype_bfloat16.cuh"
namespace vllm
{
namespace fp8_e4m3 {
template <typename Tout, typename Tin>
__inline__ __device__ Tout vec_conversion(const Tin& x)
{
return x;
}
template <typename Tout, typename Tin>
__inline__ __device__ Tout scaled_vec_conversion(const Tin& x, const float scale)
{
return x;
}
// fp8 -> half
template <>
__inline__ __device__ uint16_t vec_conversion<uint16_t, uint8_t>(const uint8_t& a)
{
hip_fp8 f8{a, hip_fp8::from_bits()};
__half_raw res;
res.data = static_cast<float>(f8);
return res.x;
}
// fp8x2 -> half2
template <>
__inline__ __device__ uint32_t vec_conversion<uint32_t, uint16_t>(const uint16_t& a)
{
#if defined(__HIP__MI300__) && defined(__HIP_FP8_EXPERIMENTAL_BULK_CONVERT__)
const auto& f2 = __builtin_amdgcn_cvt_pk_f32_fp8(a, 0);
union {
__half2_raw h2r;
uint32_t ui32;
} tmp;
tmp.h2r.x.data = f2[0];
tmp.h2r.y.data = f2[1];
return tmp.ui32;
#else
union {
uint16_t u16[2];
uint32_t u32;
} tmp;
tmp.u16[0] = vec_conversion<uint16_t, uint8_t>(static_cast<uint8_t>(a));
tmp.u16[1] = vec_conversion<uint16_t, uint8_t>(static_cast<uint8_t>(a >> 8U));
return tmp.u32;
#endif
}
// fp8x4 -> half2x2
template <>
__inline__ __device__ uint2 vec_conversion<uint2, uint32_t>(const uint32_t& a)
{
union {
uint2 u32x2;
uint32_t u32[2];
} tmp;
tmp.u32[0] = vec_conversion<uint32_t, uint16_t>((uint16_t)a);
tmp.u32[1] = vec_conversion<uint32_t, uint16_t>((uint16_t)(a >> 16U));
return tmp.u32x2;
}
// fp8x8 -> half2x4
template <>
__inline__ __device__ uint4 vec_conversion<uint4, uint2>(const uint2& a)
{
union {
uint4 u64x2;
uint2 u64[2];
} tmp;
tmp.u64[0] = vec_conversion<uint2, uint32_t>(a.x);
tmp.u64[1] = vec_conversion<uint2, uint32_t>(a.y);
return tmp.u64x2;
}
using __mt_bfloat16 = __hip_bfloat16;
// fp8 -> __nv_bfloat16
template <>
__inline__ __device__ __mt_bfloat16 vec_conversion<__mt_bfloat16, uint8_t>(const uint8_t& a)
{
hip_fp8 f8{a, hip_fp8::from_bits()};
float f{f8};
return __float2bfloat16(f);
}
using __mt_bfloat162 = __hip_bfloat162;
// fp8x2 -> __nv_bfloat162
template <>
__inline__ __device__ __mt_bfloat162 vec_conversion<__mt_bfloat162, uint16_t>(const uint16_t& a)
{
__mt_bfloat162 res;
res.x = vec_conversion<__mt_bfloat16, uint8_t>((uint8_t)a);
res.y = vec_conversion<__mt_bfloat16, uint8_t>((uint8_t)(a >> 8U));
return res;
}
// fp8x4 -> bf16_4_t
template <>
__inline__ __device__ bf16_4_t vec_conversion<bf16_4_t, uint32_t>(const uint32_t& a)
{
bf16_4_t res;
res.x = vec_conversion<__mt_bfloat162, uint16_t>((uint16_t)a);
res.y = vec_conversion<__mt_bfloat162, uint16_t>((uint16_t)(a >> 16U));
return res;
}
// fp8x8 -> bf16_8_t
template <>
__inline__ __device__ bf16_8_t vec_conversion<bf16_8_t, uint2>(const uint2& a)
{
bf16_4_t tmp1, tmp2;
tmp1 = vec_conversion<bf16_4_t, uint32_t>(a.x);
tmp2 = vec_conversion<bf16_4_t, uint32_t>(a.y);
bf16_8_t res;
res.x = tmp1.x;
res.y = tmp1.y;
res.z = tmp2.x;
res.w = tmp2.y;
return res;
}
// fp8 -> float
template <>
__inline__ __device__ float vec_conversion<float, uint8_t>(const uint8_t& a)
{
hip_fp8 fp8{a, hip_fp8::from_bits()};
return static_cast<float>(fp8);
}
// fp8x2 -> float2
template <>
__inline__ __device__ float2 vec_conversion<float2, uint16_t>(const uint16_t& a)
{
#if defined(__HIP__MI300__) && defined(__HIP_FP8_EXPERIMENTAL_BULK_CONVERT__)
float2 res;
const auto& f2 = __builtin_amdgcn_cvt_pk_f32_fp8(a, 0);
res.x = f2[0];
res.y = f2[1];
return res;
#else
float2 res;
res.x = vec_conversion<float, uint8_t>(static_cast<uint8_t>(a));
res.y = vec_conversion<float, uint8_t>(static_cast<uint8_t>(a >> 8U));
return res;
#endif
}
// fp8x4 -> float4
template <>
__inline__ __device__ Float4_ vec_conversion<Float4_, uint32_t>(const uint32_t& a)
{
Float4_ res;
res.x = vec_conversion<float2, uint16_t>((uint16_t)a);
res.y = vec_conversion<float2, uint16_t>((uint16_t)(a >> 16U));
return res;
}
// fp8x8 -> float8
template <>
__inline__ __device__ Float8_ vec_conversion<Float8_, uint2>(const uint2& a)
{
Float4_ tmp1, tmp2;
tmp1 = vec_conversion<Float4_, uint32_t>(a.x);
tmp2 = vec_conversion<Float4_, uint32_t>(a.y);
Float8_ res;
res.x = tmp1.x;
res.y = tmp1.y;
res.z = tmp2.x;
res.w = tmp2.y;
return res;
}
// half -> fp8
template <>
__inline__ __device__ uint8_t vec_conversion<uint8_t, uint16_t>(const uint16_t& a)
{
__half_raw tmp;
tmp.x = a;
hip_fp8 f8{static_cast<float>(tmp.data)};
return f8.data;
}
// bf16 -> fp8
template <>
__inline__ __device__ uint8_t vec_conversion<uint8_t, __mt_bfloat16>(const __mt_bfloat16& a)
{
hip_fp8 res{__bfloat162float(a)};
return res.data;
}
// float -> fp8
template <>
__inline__ __device__ uint8_t vec_conversion<uint8_t, float>(const float& a)
{
hip_fp8 f8(a);
return f8.data;
}
// fp8x4 -> float4
template <>
__inline__ __device__ float4 vec_conversion<float4, uint32_t>(const uint32_t& a)
{
Float4_ tmp = vec_conversion<Float4_, uint32_t>(a);
float4 res = make_float4(tmp.x.x, tmp.x.y, tmp.y.x, tmp.y.y);
return res;
}
// float2 -> half2
template <>
__inline__ __device__ uint32_t vec_conversion<uint32_t, float2>(const float2& a)
{
union {
half2 float16;
uint32_t uint32;
};
float16 = __float22half2_rn(a);
return uint32;
}
// Float4 -> half2x2
template <>
__inline__ __device__ uint2 vec_conversion<uint2, Float4_>(const Float4_& a)
{
uint2 b;
float2 val;
val.x = a.x.x;
val.y = a.x.y;
b.x = vec_conversion<uint32_t, float2>(val);
val.x = a.y.x;
val.y = a.y.y;
b.y = vec_conversion<uint32_t, float2>(val);
return b;
}
// Float4 -> float4
template <>
__inline__ __device__ float4 vec_conversion<float4, Float4_>(const Float4_& a)
{
float4 b;
b.x = a.x.x;
b.y = a.x.y;
b.z = a.y.x;
b.w = a.y.y;
return b;
}
// Float8 -> half2x4
template <>
__inline__ __device__ uint4 vec_conversion<uint4, Float8_>(const Float8_& a)
{
uint4 b;
b.x = vec_conversion<uint32_t, float2>(a.x);
b.y = vec_conversion<uint32_t, float2>(a.y);
b.z = vec_conversion<uint32_t, float2>(a.z);
b.w = vec_conversion<uint32_t, float2>(a.w);
return b;
}
// float2 -> bfloat162
template <>
__inline__ __device__ __mt_bfloat162 vec_conversion<__mt_bfloat162, float2>(const float2& a)
{
__mt_bfloat162 b = __float22bfloat162_rn(a);
return b;
}
// Float4 -> bfloat162x2
template <>
__inline__ __device__ bf16_4_t vec_conversion<bf16_4_t, Float4_>(const Float4_& a)
{
bf16_4_t b;
b.x = __float22bfloat162_rn(a.x);
b.y = __float22bfloat162_rn(a.y);
return b;
}
// Float8 -> bfloat162x4
template <>
__inline__ __device__ bf16_8_t vec_conversion<bf16_8_t, Float8_>(const Float8_& a)
{
bf16_8_t b;
b.x = __float22bfloat162_rn(a.x);
b.y = __float22bfloat162_rn(a.y);
b.z = __float22bfloat162_rn(a.z);
b.w = __float22bfloat162_rn(a.w);
return b;
}
/* Scaled and vectorized conversions, for data exchange between high and low precision domains
Convention of the scale in API, e.g: FP8_data = Quantization( High_Precision_data / scale )
s.t.
Quantize(HP / scale) => FP8
Dequant(FP8) * scale => HP
*/
// fp8 -> half
template <>
__inline__ __device__ uint16_t scaled_vec_conversion<uint16_t, uint8_t>(const uint8_t& a, const float scale)
{
hip_fp8 f8{a, hip_fp8::from_bits()};
__half_raw res;
res.data = static_cast<float>(f8) * scale;
return res.x;
}
// fp8x2 -> half2
template <>
__inline__ __device__ uint32_t scaled_vec_conversion<uint32_t, uint16_t>(const uint16_t& a, const float scale)
{
#if defined(__HIP__MI300__) && defined(__HIP_FP8_EXPERIMENTAL_BULK_CONVERT__)
const auto& f2 = __builtin_amdgcn_cvt_pk_f32_fp8(a, 0);
union {
__half2_raw h2r;
uint32_t ui32;
} tmp;
tmp.h2r.x.data = f2[0] * scale;
tmp.h2r.y.data = f2[1] * scale;
return tmp.ui32;
#else
union {
uint16_t u16[2];
uint32_t u32;
} tmp;
tmp.u16[0] = scaled_vec_conversion<uint16_t, uint8_t>(static_cast<uint8_t>(a), scale);
tmp.u16[1] = scaled_vec_conversion<uint16_t, uint8_t>(static_cast<uint8_t>(a >> 8U), scale);
return tmp.u32;
#endif
}
// fp8x4 -> half2x2
template <>
__inline__ __device__ uint2 scaled_vec_conversion<uint2, uint32_t>(const uint32_t& a, const float scale)
{
union {
uint2 u32x2;
uint32_t u32[2];
} tmp;
tmp.u32[0] = scaled_vec_conversion<uint32_t, uint16_t>((uint16_t)a, scale);
tmp.u32[1] = scaled_vec_conversion<uint32_t, uint16_t>((uint16_t)(a >> 16U), scale);
return tmp.u32x2;
}
// fp8x8 -> half2x4
template <>
__inline__ __device__ uint4 scaled_vec_conversion<uint4, uint2>(const uint2& a, const float scale)
{
union {
uint4 u64x2;
uint2 u64[2];
} tmp;
tmp.u64[0] = scaled_vec_conversion<uint2, uint32_t>(a.x, scale);
tmp.u64[1] = scaled_vec_conversion<uint2, uint32_t>(a.y, scale);
return tmp.u64x2;
}
using __mt_bfloat16 = __hip_bfloat16;
// fp8 -> __nv_bfloat16
template <>
__inline__ __device__ __mt_bfloat16 scaled_vec_conversion<__mt_bfloat16, uint8_t>(const uint8_t& a, const float scale)
{
hip_fp8 f8{a, hip_fp8::from_bits()};
float f{f8};
return __float2bfloat16(f * scale);
}
using __mt_bfloat162 = __hip_bfloat162;
// fp8x2 -> __nv_bfloat162
template <>
__inline__ __device__ __mt_bfloat162 scaled_vec_conversion<__mt_bfloat162, uint16_t>(const uint16_t& a, const float scale)
{
__mt_bfloat162 res;
res.x = scaled_vec_conversion<__mt_bfloat16, uint8_t>((uint8_t)a, scale);
res.y = scaled_vec_conversion<__mt_bfloat16, uint8_t>((uint8_t)(a >> 8U), scale);
return res;
}
// fp8x4 -> bf16_4_t
template <>
__inline__ __device__ bf16_4_t scaled_vec_conversion<bf16_4_t, uint32_t>(const uint32_t& a, const float scale)
{
bf16_4_t res;
res.x = scaled_vec_conversion<__mt_bfloat162, uint16_t>((uint16_t)a, scale);
res.y = scaled_vec_conversion<__mt_bfloat162, uint16_t>((uint16_t)(a >> 16U), scale);
return res;
}
// fp8x8 -> bf16_8_t
template <>
__inline__ __device__ bf16_8_t scaled_vec_conversion<bf16_8_t, uint2>(const uint2& a, const float scale)
{
bf16_4_t tmp1, tmp2;
tmp1 = scaled_vec_conversion<bf16_4_t, uint32_t>(a.x, scale);
tmp2 = scaled_vec_conversion<bf16_4_t, uint32_t>(a.y, scale);
bf16_8_t res;
res.x = tmp1.x;
res.y = tmp1.y;
res.z = tmp2.x;
res.w = tmp2.y;
return res;
}
// fp8 -> float
template <>
__inline__ __device__ float scaled_vec_conversion<float, uint8_t>(const uint8_t& a, const float scale)
{
hip_fp8 fp8{a, hip_fp8::from_bits()};
return static_cast<float>(fp8) * scale;
}
// fp8x2 -> float2
template <>
__inline__ __device__ float2 scaled_vec_conversion<float2, uint16_t>(const uint16_t& a, const float scale)
{
#if defined(__HIP__MI300__) && defined(__HIP_FP8_EXPERIMENTAL_BULK_CONVERT__)
float2 res;
const auto& f2 = __builtin_amdgcn_cvt_pk_f32_fp8(a, 0);
res.x = f2[0] * scale;
res.y = f2[1] * scale;
return res;
#else
float2 res;
res.x = scaled_vec_conversion<float, uint8_t>(static_cast<uint8_t>(a), scale);
res.y = scaled_vec_conversion<float, uint8_t>(static_cast<uint8_t>(a >> 8U), scale);
return res;
#endif
}
// fp8x4 -> float4
template <>
__inline__ __device__ Float4_ scaled_vec_conversion<Float4_, uint32_t>(const uint32_t& a, const float scale)
{
Float4_ res;
res.x = scaled_vec_conversion<float2, uint16_t>((uint16_t)a, scale);
res.y = scaled_vec_conversion<float2, uint16_t>((uint16_t)(a >> 16U), scale);
return res;
}
// fp8x8 -> float8
template <>
__inline__ __device__ Float8_ scaled_vec_conversion<Float8_, uint2>(const uint2& a, const float scale)
{
Float4_ tmp1, tmp2;
tmp1 = scaled_vec_conversion<Float4_, uint32_t>(a.x, scale);
tmp2 = scaled_vec_conversion<Float4_, uint32_t>(a.y, scale);
Float8_ res;
res.x = tmp1.x;
res.y = tmp1.y;
res.z = tmp2.x;
res.w = tmp2.y;
return res;
}
/* Quantize(HP / scale) => FP8 */
// TODO(Hai): vectorized to add
// half -> fp8
template <>
__inline__ __device__ uint8_t scaled_vec_conversion<uint8_t, uint16_t>(const uint16_t& a, const float scale)
{
__half_raw tmp;
tmp.x = a;
hip_fp8 f8{static_cast<float>(tmp.data)/scale};
return f8.data;
}
// bf16 -> fp8
template <>
__inline__ __device__ uint8_t scaled_vec_conversion<uint8_t, __mt_bfloat16>(const __mt_bfloat16& a, const float scale)
{
hip_fp8 res{__bfloat162float(a)/scale};
return res.data;
}
// float -> fp8
template <>
__inline__ __device__ uint8_t scaled_vec_conversion<uint8_t, float>(const float& a, const float scale)
{
hip_fp8 f8(a/scale);
return f8.data;
}
// fp8x4 -> float4
template <>
__inline__ __device__ float4 scaled_vec_conversion<float4, uint32_t>(const uint32_t& a, const float scale)
{
Float4_ tmp = scaled_vec_conversion<Float4_, uint32_t>(a, scale);
float4 res = make_float4(tmp.x.x, tmp.x.y, tmp.y.x, tmp.y.y);
return res;
}
}
} // namespace vllm

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@@ -0,0 +1,126 @@
#include "torch_musa/csrc/aten/musa/MUSAContext.h"
#include <torch/extension.h>
#include "torch_musa/csrc/core/MUSAGuard.h"
#include <cmath>
#include "musa_compat.h"
#include "dispatch_utils.h"
namespace vllm {
__device__ __forceinline__ float atomicMaxFloat(float* addr, float value) {
float old;
old = (value >= 0) ? __int_as_float(atomicMax((int*)addr, __float_as_int(value))) :
__uint_as_float(atomicMin((unsigned int*)addr, __float_as_uint(value)));
return old;
}
// Compute the absolute maximum m of the input tensor and store
// m / float8_e4m3::max() in *scale. Each thread block performs a
// reduction tree and the memory in scale is atomically updated.
// So to get the right answer, *scale needs to be initialized to
// a value <= 0.0 and we need to wait for all thread blocks to
// finish before consuming *scale.
template<typename scalar_t>
__global__ void segmented_max_reduction(
float* __restrict__ scale,
const scalar_t* __restrict__ input,
int64_t num_elems) {
__shared__ float cache[1024];
int i = blockDim.x * blockIdx.x + threadIdx.x;
// First store maximum for all values processes by
// the current thread in cache[threadIdx.x]
scalar_t tmp = 0.0;
while (i < num_elems) {
float x = static_cast<float>(input[i]);
tmp = max(tmp, fabs(x));
i += blockDim.x * gridDim.x;
}
cache[threadIdx.x] = tmp;
__syncthreads();
// Now perform parallel reduction within the thread block
int ib = blockDim.x / 2;
while (ib != 0) {
if (threadIdx.x < ib && cache[threadIdx.x + ib] > cache[threadIdx.x]) {
cache[threadIdx.x] = cache[threadIdx.x + ib];
}
__syncthreads();
ib /= 2;
}
// Finally, since cache[0] contains the maximum for this thread block,
// atomically write the max to the target location
if (threadIdx.x == 0) {
atomicMaxFloat(scale, cache[0] / std::numeric_limits<c10::Float8_e4m3fn>::max());
}
}
template<typename scalar_t>
__global__ void scaled_fp8_quant_kernel(
c10::Float8_e4m3fn* __restrict__ out,
const scalar_t* __restrict__ input,
const float* __restrict__ scale,
int64_t num_elems) {
int i = blockDim.x * blockIdx.x + threadIdx.x;
while (i < num_elems) {
out[i] = static_cast<c10::Float8_e4m3fn>(input[i] / *scale);
i += blockDim.x * gridDim.x;
}
}
} // namespace vllm
void static_scaled_fp8_quant(
torch::Tensor& out, // [..., d]
torch::Tensor& input, // [..., d]
torch::Tensor& scale) // [1]
{
int64_t num_tokens = input.numel() / input.size(-1);
int64_t num_elems = input.numel();
dim3 grid(num_tokens);
dim3 block(1024);
const at::musa::OptionalMUSAGuard device_guard(device_of(input));
const musaStream_t stream = at::musa::getCurrentMUSAStream();
VLLM_DISPATCH_FLOATING_TYPES(
input.scalar_type(),
"scaled_fp8_quant_kernel",
[&] {
vllm::scaled_fp8_quant_kernel<scalar_t><<<grid, block, 0, stream>>>(
out.data_ptr<c10::Float8_e4m3fn>(),
input.data_ptr<scalar_t>(),
scale.data_ptr<float>(),
num_elems);
});
}
void dynamic_scaled_fp8_quant(
torch::Tensor& out, // [..., d]
torch::Tensor& input, // [..., d]
torch::Tensor& scale) // [1]
{
int64_t num_tokens = input.numel() / input.size(-1);
int64_t num_elems = input.numel();
dim3 grid(num_tokens);
dim3 block(1024);
const at::musa::OptionalMUSAGuard device_guard(device_of(input));
const musaStream_t stream = at::musa::getCurrentMUSAStream();
VLLM_DISPATCH_FLOATING_TYPES(
input.scalar_type(),
"scaled_fp8_quant_kernel",
[&] {
vllm::segmented_max_reduction<scalar_t><<<grid, block, 0, stream>>>(
scale.data_ptr<float>(),
input.data_ptr<scalar_t>(),
num_elems);
vllm::scaled_fp8_quant_kernel<scalar_t><<<grid, block, 0, stream>>>(
out.data_ptr<c10::Float8_e4m3fn>(),
input.data_ptr<scalar_t>(),
scale.data_ptr<float>(),
num_elems);
});
}