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Disable loop vectorization for gfortran on ARM #1165

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Merged
langou merged 2 commits into from
Nov 14, 2025
Merged

Disable loop vectorization for gfortran on ARM #1165

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Disable loop vectorization for GNU Fortran 14.0-14.4 and 15.0-15.2 on…
ACSimon33 Nov 14, 2025
54726b8
Format message better.
ACSimon33 Nov 14, 2025
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16 changes: 16 additions & 0 deletions CMAKE/CheckLAPACKCompilerFlags.cmake
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Original file line number Diff line number Diff line change
Expand Up @@ -59,6 +59,22 @@ macro(CheckLAPACKCompilerFlags)
add_compile_definitions("$<$<COMPILE_LANGUAGE:C>:FORTRAN_STRLEN=int>")
endif()

# Disabling loop vectorization for GNU Fortran versions affected by
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122408. See issue
# https://github.com/Reference-LAPACK/lapack/issues/1160 as well.
if(CMAKE_HOST_SYSTEM_PROCESSOR MATCHES "arm|arm64|aarch64")
if((CMAKE_Fortran_COMPILER_VERSION VERSION_GREATER_EQUAL "14.0" AND
CMAKE_Fortran_COMPILER_VERSION VERSION_LESS_EQUAL "14.4") OR
(CMAKE_Fortran_COMPILER_VERSION VERSION_GREATER_EQUAL "15.0" AND
CMAKE_Fortran_COMPILER_VERSION VERSION_LESS_EQUAL "15.2"))
message(WARNING
"Disabling loop vectorization for GNU Fortran (14.0-14.4, 15.0-15.2) on ARM "
"due to a compiler bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122408). "
"For full performance, consider changing to a different compiler or compiler version.")
add_compile_options("$<$<COMPILE_LANGUAGE:Fortran>:-fno-tree-loop-vectorize>")
endif()
endif()

# Intel Fortran
elseif(CMAKE_Fortran_COMPILER_ID MATCHES "Intel")
set(FPE_EXIT_FLAG "[-/]fpe(-all=|)0")
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