Skip to content

[BugFix] Correct direct copy from bf16 to fp8 #1090

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 21 commits into from
Oct 29, 2025
+61 −18
Merged

[BugFix] Correct direct copy from bf16 to fp8 #1090

Show file tree
Hide file tree
Changes from 11 commits
Commits
Show all changes
21 commits
Select commit Hold shift + click to select a range
9923cd8
[BugFix] Correct direct copy from bf16 to fp8
Oct 21, 2025
d2e495f
Merge branch 'main' into fix_1046
Oct 21, 2025
cb907dd
fix lint
Oct 21, 2025
8281b05
implement overloaded cast codegen for type conversion
Oct 21, 2025
3051cf4
fix lint
Oct 22, 2025
37804b3
remove test
Oct 22, 2025
999e74e
fix lint
Oct 22, 2025
900ae67
trigger CI
Oct 22, 2025
5c25147
Overload fp8 for implicit conversion
Oct 23, 2025
c49edee
format
Oct 23, 2025
cda16d5
Merge branch 'main' into fix_1046
Oct 23, 2025
0aad651
new format
Oct 23, 2025
e448754
fix: Reinterpret types to cute types in GEMM
Oct 23, 2025
dad541c
new format
Oct 23, 2025
76c0b1a
fix lint
Oct 23, 2025
4741fd6
Merge branch 'main' into fix_1046
Oct 23, 2025
6d885a4
new format
Oct 23, 2025
7f1a507
fix lint
Oct 25, 2025
19e8a7d
Merge branch 'main' into fix_1046
Cunxiao2002 Oct 29, 2025
521c0bb
format
Oct 29, 2025
e9b9501
trigger ci
Oct 29, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 24 additions & 0 deletions src/tl_templates/cuda/common.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,9 @@
#include <cutlass/numeric_types.h>
#include <math_constants.h>

#include <cutlass/bfloat16.h>
#include <cutlass/float8.h>

Comment on lines +13 to +15
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🟡 Minor

Explicitly include cuda_bf16.h to guarantee __nv_bfloat16 availability.

Avoid relying on transitive includes; add the CUDA header so host/RTC builds consistently see __nv_bfloat16.

Apply this diff near the existing cuda_runtime include:

 #ifndef __CUDACC_RTC__
 #include <cuda_runtime.h>
+#include <cuda_bf16.h>
 #endif

Committable suggestion skipped: line range outside the PR's diff.

🤖 Prompt for AI Agents 
In src/tl_templates/cuda/common.h around lines 13 to 15, the file relies on
transitive includes for the CUDA bfloat16 type (__nv_bfloat16); explicitly add
the CUDA header cuda_bf16.h (near the existing cuda_runtime include) to
guarantee __nv_bfloat16 is available for host and RTC builds, avoiding
transitive-include fragility.

using cutlass::bfloat16_t;
using cutlass::half_t;
using cutlass::tfloat32_t;
Expand Down Expand Up @@ -318,6 +321,27 @@ TL_DEVICE void increase_descriptor_offset(GmmaDescriptor &descriptor,
descriptor.reg32_[0] += (offset >> 4);
}

// and add the desired implicit conversion from bfloat16_t.
struct float_e4m3_t : public cutlass::float_e4m3_t {
using cutlass::float_e4m3_t::float_e4m3_t;
CUTLASS_HOST_DEVICE
float_e4m3_t() = default;

CUTLASS_HOST_DEVICE
explicit float_e4m3_t(__nv_bfloat16 x)
: float_e4m3_t(static_cast<float>(x)) {}
};

struct float_e5m2_t : public cutlass::float_e5m2_t {
using cutlass::float_e5m2_t::float_e5m2_t;
CUTLASS_HOST_DEVICE
float_e5m2_t() = default;

CUTLASS_HOST_DEVICE
explicit float_e5m2_t(__nv_bfloat16 x)
: float_e5m2_t(static_cast<float>(x)) {}
};

} // namespace tl

namespace cutlass {
Expand Down
5 changes: 3 additions & 2 deletions src/tl_templates/cuda/cuda_fp8.h
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,10 +1,11 @@
#pragma once

#include "common.h"
#include <cuda_fp8.h>
#include <cute/numeric/numeric_types.hpp>

using fp8_e4_t = cute::float_e4m3_t;
using fp8_e5_t = cute::float_e5m2_t;
using fp8_e4_t = tl::float_e4m3_t;
using fp8_e5_t = tl::float_e5m2_t;

struct __CUDA_ALIGN__(2) fp8_e4_2_t {
fp8_e4_t x;
Expand Down
Loading