From 58855d08c21baca953b9958c4b2a2b71bd5a2e47 Mon Sep 17 00:00:00 2001 From: Talha Can Havadar Date: Tue, 17 Feb 2026 12:22:46 +0100 Subject: [PATCH] ggml: ggml-cpu: force-no-lto-for-cpu-feats (llama/19609) When LTO enabled in build environments it forces all builds to have LTO in place. But feature detection logic is fragile, and causing Illegal instruction errors with lto. This disables LTO for the feature detection code to prevent cross-module optimization from inlining architecture-specific instructions into the score function. Without this, LTO can cause SIGILL when loading backends on older CPUs (e.g., loading power10 backend on power9 crashes before feature check runs). --- ggml/src/ggml-cpu/CMakeLists.txt | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/ggml/src/ggml-cpu/CMakeLists.txt b/ggml/src/ggml-cpu/CMakeLists.txt index 43d6f7f5..3dc948e4 100644 --- a/ggml/src/ggml-cpu/CMakeLists.txt +++ b/ggml/src/ggml-cpu/CMakeLists.txt @@ -9,6 +9,11 @@ function(ggml_add_cpu_backend_features cpu_name arch) target_compile_definitions(${GGML_CPU_FEATS_NAME} PRIVATE ${ARGN}) target_compile_definitions(${GGML_CPU_FEATS_NAME} PRIVATE GGML_BACKEND_DL GGML_BACKEND_BUILD GGML_BACKEND_SHARED) set_target_properties(${GGML_CPU_FEATS_NAME} PROPERTIES POSITION_INDEPENDENT_CODE ON) + # Disable LTO for the feature detection code to prevent cross-module optimization + # from inlining architecture-specific instructions into the score function. + # Without this, LTO can cause SIGILL when loading backends on older CPUs + # (e.g., loading power10 backend on power9 crashes before feature check runs). + target_compile_options(${GGML_CPU_FEATS_NAME} PRIVATE -fno-lto) target_link_libraries(${cpu_name} PRIVATE ${GGML_CPU_FEATS_NAME}) endfunction()