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Compile bug: error: call to undeclared function '_mm512_storeu_si512'; in ggml.c (icx/clang in MSVC compat mode)

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
68/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Active
Tech stack
c, cmake, cpp
Domain
build-system

Research direction

Start with the AVX512BF16 conditional in ggml/src/ggml.c around the reported intrinsic declarations and compare how compiler modes include immintrin.h. Reproduce the Windows IntelLLVM clang-cl build using the supplied flags, then check the BF16 conversion path. Done when the build succeeds in MSVC-compatible clang mode and the existing supported compiler paths remain valid.

Written by the indexing model from the issue text.

Description

bug-unconfirmed
Git commit

3cf03257f219afbe7334045ff7c6a06ac68c627d

Operating systems

Windows

GGML backends

SYCL

Problem description & steps to reproduce

I'm trying to compile Strata using -march=znver4 on a Zen 4 CPU (Ryzen 7600). It has this project as a dependency, currently using the specified pinned revision.

The issue is BF16 support (AVX512BF16) while icx/clang is running in MSVC-compatible modes. In this case the following code fails because _MSC_VER is set but the relevant intrinsic isn't defined:

// Needed for ggml_fp32_to_bf16_row()
#if defined(__AVX512BF16__)
#if defined(_MSC_VER)
#define m512i(p) p
#else
#include <immintrin.h>
#define m512i(p) (__m512i)(p)
#endif // defined(_MSC_VER)
#endif // defined(__AVX512BF16__)

You might need something like #if defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER) instead.

First Bad Commit

No response

Compile command
cmake -B build-sycl -S . -G Ninja -DCMAKE_BUILD_TYPE=Release -DSTRATA_ENABLE_SYCL=ON -DSTRATA_SYCL_AOT=bmg-g21 -DSTRATA_SYCL_PARITY=OFF -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDLL -DCMAKE_CXX_FLAGS="/EHsc -Qunused-arguments -Qmkl=sequential /clang:-O3 /clang:-march=znver4" -DCMAKE_C_FLAGS="-Qunused-arguments -Qmkl=sequential /clang:-O3 /clang:-march=znver4" -DCMAKE_EXE_LINKER_FLAGS="-Qmkl=sequential"

cmake --build build-sycl --target strata

With /clang:-mno-avx512bf16 or /clang:-includeimmintrin.h set in -DCMAKE_CXX_FLAGS and -DCMAKE_C_FLAGS, the error does not occur.

Relevant log output
-- The CXX compiler identification is IntelLLVM 2026.1.0 with MSVC-like command-line
-- Check for working C compiler: C:/Program Files (x86)/Intel/oneAPI/compiler/latest/bin/icx.exe - skipped
-- The ASM compiler identification is IntelLLVM
-- Found assembler: C:/Program Files (x86)/Intel/oneAPI/compiler/latest/bin/icx.exe
-- Adding CPU backend variant ggml-cpu: /arch:AVX512 GGML_AVX512
-- ggml version: 0.24.0
-- ggml commit:  3cf03257f

[1/134] Building C object ggml\src\CMakeFiles\ggml-base.dir\ggml.c.obj
FAILED: [code=1] ggml/src/CMakeFiles/ggml-base.dir/ggml.c.obj
C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\icx.exe  /nologo -DGGML_SCHED_MAX_COPIES=4 -DSTRATA_Q6K_EXPERTS=1 -DSTRATA_VERSION=\"0.1.49.2\" -DSTRATA_XMX_SG16=1 -D_CRT_SECURE_NO_WARNINGS -D_XOPEN_SOURCE=600 -IC:\Users\GreenReaper\strata\build-sycl\_deps\strata_llamacpp-src\ggml\src\. -IC:\Users\GreenReaper\strata\build-sycl\ggml\src -IC:\Users\GreenReaper\strata\build-sycl\_deps\strata_llamacpp-src\ggml\src\..\include -Qunused-arguments -Qmkl=sequential /clang:-O3 /clang:-march=znver4 /O2 /Ob2 /DNDEBUG -Qstd:c11 -MD -fp-model=precise -Wno-unused-parameter -Wno-unused-variable -Wno-deprecated-declarations /wd4005 /wd4244 /wd4267 /wd4305 /wd4566 /wd4996 /wd4702 /utf-8 -QMD -QMT ggml\src\CMakeFiles\ggml-base.dir\ggml.c.obj -QMF ggml\src\CMakeFiles\ggml-base.dir\ggml.c.obj.d /Foggml\src\CMakeFiles\ggml-base.dir\ggml.c.obj /Fdggml\src\CMakeFiles\ggml-base.dir\ggml-base.pdb -c C:\Users\GreenReaper\strata\build-sycl\_deps\strata_llamacpp-src\ggml\src\ggml.c
icx: warning: unknown argument ignored in clang-cl: '-fp-model=precise' [-Wunknown-argument]
C:\Users\GreenReaper\strata\build-sycl\_deps\strata_llamacpp-src\ggml\src\ggml.c(500,9): error: call to undeclared function '_mm512_storeu_si512'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
  500 |         _mm512_storeu_si512(
      |         ^
C:\Users\GreenReaper\strata\build-sycl\_deps\strata_llamacpp-src\ggml\src\ggml.c(501,14): error: use of undeclared identifier '__m512i'
  501 |             (__m512i *)(y + i),
      |              ^~~~~~~
C:\Users\GreenReaper\strata\build-sycl\_deps\strata_llamacpp-src\ggml\src\ggml.c(501,23): error: expected expression
  501 |             (__m512i *)(y + i),
      |                       ^
C:\Users\GreenReaper\strata\build-sycl\_deps\strata_llamacpp-src\ggml\src\ggml.c(502,19): error: call to undeclared function '_mm512_cvtne2ps_pbh'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
  502 |             m512i(_mm512_cvtne2ps_pbh(_mm512_loadu_ps(x + i + 16),
      |                   ^
C:\Users\GreenReaper\strata\build-sycl\_deps\strata_llamacpp-src\ggml\src\ggml.c(502,39): error: call to undeclared function '_mm512_loadu_ps'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
  502 |             m512i(_mm512_cvtne2ps_pbh(_mm512_loadu_ps(x + i + 16),
      |                                       ^
5 errors generated.
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