# Copyright (c) 2021 Google LLC.
#
# Use of this source code is governed by a BSD-style license
# that can be found in the LICENSE file in the root of the source
# tree. An additional intellectual property rights grant can be found
# in the file PATENTS. All contributing project authors may
# be found in the AUTHORS file in the root of the source tree.
# Check for SIMD extensions.
include(CMakePushCheckState)
function(webp_check_compiler_flag WEBP_SIMD_FLAG ENABLE_SIMD)
if(NOT ENABLE_SIMD)
message(STATUS "Disabling ${WEBP_SIMD_FLAG} optimization.")
set(WEBP_HAVE_${WEBP_SIMD_FLAG} 0 PARENT_SCOPE)
return()
endif()
unset(WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG} CACHE)
cmake_push_check_state()
set(CMAKE_REQUIRED_INCLUDES ${CMAKE_CURRENT_SOURCE_DIR})
check_c_source_compiles(
"
#include \"${CMAKE_CURRENT_LIST_DIR}/../src/dsp/dsp.h\"
int main(void) {
#if !defined(WEBP_USE_${WEBP_SIMD_FLAG})
this is not valid code
#endif
return 0;
}
"
WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG})
cmake_pop_check_state()
if(WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG})
set(WEBP_HAVE_${WEBP_SIMD_FLAG} 1 PARENT_SCOPE)
else()
set(WEBP_HAVE_${WEBP_SIMD_FLAG} 0 PARENT_SCOPE)
endif()
endfunction()
# those are included in the names of WEBP_USE_* in c++ code.
set(WEBP_SIMD_FLAGS "SSE41;SSE2;MIPS32;MIPS_DSP_R2;NEON;MSA")
set(WEBP_SIMD_FILE_EXTENSIONS
"_sse41.c;_sse2.c;_mips32.c;_mips_dsp_r2.c;_neon.c;_msa.c")
if(MSVC AND CMAKE_C_COMPILER_ID STREQUAL "MSVC")
# With at least Visual Studio 12 (2013)+ /arch is not necessary to build SSE2
# or SSE4 code unless a lesser /arch is forced. MSVC does not have a SSE4
# flag, but an AVX one. Using that with SSE4 code risks generating illegal
# instructions when used on machines with SSE4 only. The flags are left for
# older (untested) versions to avoid any potential compatibility issues.
if(MSVC_VERSION GREATER_EQUAL 1800 AND NOT CMAKE_C_FLAGS MATCHES "/arch:")
set(SIMD_ENABLE_FLAGS)
else()
set(SIMD_ENABLE_FLAGS "/arch:AVX;/arch:SSE2;;;;")
endif()
set(SIMD_DISABLE_FLAGS)
else()
set(SIMD_ENABLE_FLAGS "-msse4.1;-msse2;-mips32;-mdspr2;-mfpu=neon;-mmsa")
set(SIMD_DISABLE_FLAGS "-mno-sse4.1;-mno-sse2;;-mno-dspr2;;-mno-msa")
endif()
set(WEBP_SIMD_FILES_TO_INCLUDE)
set(WEBP_SIMD_FLAGS_TO_INCLUDE)
if(ANDROID AND ANDROID_ABI)
if(${ANDROID_ABI} STREQUAL "armeabi-v7a")
# This is because Android studio uses the configuration "-march=armv7-a
# -mfloat-abi=softfp -mfpu=vfpv3-d16" that does not trigger neon
# optimizations but should (as this configuration does not exist anymore).
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=neon ")
endif()
endif()
list(LENGTH WEBP_SIMD_FLAGS WEBP_SIMD_FLAGS_LENGTH)
math(EXPR WEBP_SIMD_FLAGS_RANGE "${WEBP_SIMD_FLAGS_LENGTH} - 1")
foreach(I_SIMD RANGE ${WEBP_SIMD_FLAGS_RANGE})
# With Emscripten 2.0.9 -msimd128 -mfpu=neon will enable NEON, but the source
# will fail to compile.
if(EMSCRIPTEN AND ${I_SIMD} GREATER_EQUAL 2)
break()
endif()
list(GET WEBP_SIMD_FLAGS ${I_SIMD} WEBP_SIMD_FLAG)
# First try with no extra flag added as the compiler might have default flags
# (especially on Android).
unset(WEBP_HAVE_${WEBP_SIMD_FLAG} CACHE)
cmake_push_check_state()
set(CMAKE_REQUIRED_FLAGS)
webp_check_compiler_flag(${WEBP_SIMD_FLAG} ${WEBP_ENABLE_SIMD})
if(NOT WEBP_HAVE_${WEBP_SIMD_FLAG})
list(GET SIMD_ENABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
if(EMSCRIPTEN)
set(SIMD_COMPILE_FLAG "-msimd128 ${SIMD_COMPILE_FLAG}")
endif()
set(CMAKE_REQUIRED_FLAGS ${SIMD_COMPILE_FLAG})
webp_check_compiler_flag(${WEBP_SIMD_FLAG} ${WEBP_ENABLE_SIMD})
else()
if(MSVC AND SIMD_ENABLE_FLAGS)
# The detection for SSE2/SSE4 support under MSVC is based on the compiler
# version so e.g., clang-cl will require flags to enable the assembly.
list(GET SIMD_ENABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
else()
set(SIMD_COMPILE_FLAG " ")
endif()
endif()
# Check which files we should include or not.
list(GET WEBP_SIMD_FILE_EXTENSIONS ${I_SIMD} WEBP_SIMD_FILE_EXTENSION)
file(GLOB SIMD_FILES
"${CMAKE_CURRENT_LIST_DIR}/../sharpyuv/*${WEBP_SIMD_FILE_EXTENSION}"
"${CMAKE_CURRENT_LIST_DIR}/../src/dsp/*${WEBP_SIMD_FILE_EXTENSION}")
if(WEBP_HAVE_${WEBP_SIMD_FLAG})
# Memorize the file and flags.
foreach(FILE ${SIMD_FILES})
list(APPEND WEBP_SIMD_FILES_TO_INCLUDE ${FILE})
list(APPEND WEBP_SIMD_FLAGS_TO_INCLUDE ${SIMD_COMPILE_FLAG})
endforeach()
else()
# Remove the file from the list.
foreach(FILE ${SIMD_FILES})
list(APPEND WEBP_SIMD_FILES_NOT_TO_INCLUDE ${FILE})
endforeach()
# Explicitly disable SIMD.
if(SIMD_DISABLE_FLAGS)
list(GET SIMD_DISABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
include(CheckCCompilerFlag)
if(SIMD_COMPILE_FLAG)
# Between 3.17.0 and 3.18.2 check_cxx_compiler_flag() sets a normal
# variable at parent scope while check_cxx_source_compiles() continues
# to set an internal cache variable, so we unset both to avoid the
# failure / success state persisting between checks. See
# https://gitlab.kitware.com/cmake/cmake/-/issues/21207.
unset(HAS_COMPILE_FLAG)
unset(HAS_COMPILE_FLAG CACHE)
check_c_compiler_flag(${SIMD_COMPILE_FLAG} HAS_COMPILE_FLAG)
if(HAS_COMPILE_FLAG)
# Do one more check for Clang to circumvent CMake issue 13194.
if(COMMAND check_compiler_flag_common_patterns)
# Only in CMake 3.0 and above.
check_compiler_flag_common_patterns(COMMON_PATTERNS)
else()
set(COMMON_PATTERNS)
endif()
set(CMAKE_REQUIRED_DEFINITIONS ${SIMD_COMPILE_FLAG})
check_c_source_compiles(
"int main(void) {return 0;}" FLAG_${SIMD_COMPILE_FLAG} FAIL_REGEX
"warning: argument unused during compilation:" ${COMMON_PATTERNS})
if(NOT FLAG_${SIMD_COMPILE_FLAG})
unset(HAS_COMPILE_FLAG)
unset(HAS_COMPILE_FLAG CACHE)
endif()
endif()
if(HAS_COMPILE_FLAG)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SIMD_COMPILE_FLAG}")
endif()
endif()
endif()
endif()
cmake_pop_check_state()
endforeach()