From 6a6a05289ef9bdbef646b2b8e6d998444212bcfa Mon Sep 17 00:00:00 2001 From: Ben Avison Date: Thu, 24 Oct 2019 21:12:08 -0400 Subject: [PATCH] ARM: Create configure option --enable-arm-simd to govern assembly optimizations --- configure.ac | 37 +++++++++++++++++++++++++ include/SDL_config.h.in | 1 + include/SDL_cpuinfo.h | 5 ++++ src/cpuinfo/SDL_cpuinfo.c | 57 ++++++++++++++++++++++++++++++++++++++- 4 files changed, 99 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 13c3b0268..e9f62dfcf 100644 --- a/configure.ac +++ b/configure.ac @@ -1303,6 +1303,42 @@ AS_HELP_STRING([--enable-libsamplerate-shared], [dynamically load libsamplerate fi } +dnl Check for ARM instruction support using gas syntax +CheckARM() +{ + AC_ARG_ENABLE(arm-simd, +AC_HELP_STRING([--enable-arm-simd], [use SIMD assembly blitters on ARM [[default=yes]]]), + enable_arm_simd=$enableval, enable_arm_simd=yes) + if test x$enable_video = xyes -a x$enable_assembly = xyes -a x$enable_arm_simd = xyes; then + save_CFLAGS="$CFLAGS" + have_arm_simd=no + CFLAGS="-x assembler-with-cpp $CFLAGS" + + AC_MSG_CHECKING(for ARM SIMD) + AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ + .text + .arch armv6 + .object_arch armv4 + .arm + .altmacro + #ifndef __ARM_EABI__ + #error EABI is required (to be sure that calling conventions are compatible) + #endif + pld [r0] + uqadd8 r0, r0, r0 + ]])], have_arm_simd=yes) + AC_MSG_RESULT($have_arm_simd) + + CFLAGS="$save_CFLAGS" + + if test x$have_arm_simd = xyes; then + AC_DEFINE(SDL_ARM_SIMD_BLITTERS) +dnl SOURCES="$SOURCES $srcdir/src/video/arm/pixman-arm-simd*.c" + SOURCES="$SOURCES $srcdir/src/video/arm/pixman-arm-simd*.S" + fi + fi +} + dnl See if GCC's -fvisibility=hidden is supported (gcc4 and later, usually). dnl Details of this flag are here: http://gcc.gnu.org/wiki/Visibility CheckVisibilityHidden() @@ -3396,6 +3432,7 @@ case "$host" in CheckDiskAudio CheckDummyAudio CheckDLOPEN + CheckARM CheckOSS CheckALSA CheckPulseAudio diff --git a/include/SDL_config.h.in b/include/SDL_config.h.in index c263e17d8..376552273 100644 --- a/include/SDL_config.h.in +++ b/include/SDL_config.h.in @@ -407,6 +407,7 @@ /* Enable assembly routines */ #undef SDL_ASSEMBLY_ROUTINES #undef SDL_ALTIVEC_BLITTERS +#undef SDL_ARM_SIMD_BLITTERS /* Enable ime support */ #undef SDL_USE_IME diff --git a/include/SDL_cpuinfo.h b/include/SDL_cpuinfo.h index efbf6ff07..2d094e88c 100644 --- a/include/SDL_cpuinfo.h +++ b/include/SDL_cpuinfo.h @@ -186,6 +186,11 @@ extern DECLSPEC SDL_bool SDLCALL SDL_HasAVX2(void); */ extern DECLSPEC SDL_bool SDLCALL SDL_HasAVX512F(void); +/** + * This function returns true if the CPU has ARM SIMD (ARMv6) features. + */ +extern DECLSPEC SDL_bool SDLCALL SDL_HasARMSIMD(void); + /** * This function returns true if the CPU has NEON (ARM SIMD) features. */ diff --git a/src/cpuinfo/SDL_cpuinfo.c b/src/cpuinfo/SDL_cpuinfo.c index 00670407f..5f86acff9 100644 --- a/src/cpuinfo/SDL_cpuinfo.c +++ b/src/cpuinfo/SDL_cpuinfo.c @@ -96,6 +96,7 @@ #define CPU_HAS_AVX2 (1 << 10) #define CPU_HAS_NEON (1 << 11) #define CPU_HAS_AVX512F (1 << 12) +#define CPU_HAS_ARM_SIMD (1 << 13) #if SDL_ALTIVEC_BLITTERS && HAVE_SETJMP && !__MACOSX__ && !__OpenBSD__ /* This is the brute force way of detecting instruction sets... @@ -325,7 +326,50 @@ CPU_haveAltiVec(void) return altivec; } -#if defined(__LINUX__) && defined(__ARM_ARCH) && !defined(HAVE_GETAUXVAL) +#ifdef __linux__ + +#include +#include +#include +#include +#include + +static SDL_bool +CPU_haveARMSIMD(void) +{ + int arm_simd = 0; + int fd; + + fd = open("/proc/self/auxv", O_RDONLY); + if (fd >= 0) + { + Elf32_auxv_t aux; + while (read(fd, &aux, sizeof aux) == sizeof aux) + { + if (aux.a_type == AT_PLATFORM) + { + const char *plat = (const char *) aux.a_un.a_val; + arm_simd = strncmp(plat, "v6l", 3) == 0 || + strncmp(plat, "v7l", 3) == 0; + } + } + close(fd); + } + return arm_simd; +} + +#else + +static SDL_bool +CPU_haveARMSIMD(void) +{ +#warning SDL_HasARMSIMD is not implemented for this ARM platform. Write me. + return 0; +} + +#endif + +#if (defined(__LINUX__) || defined(__ANDROID__)) && defined(__ARM_ARCH) && !defined(HAVE_GETAUXVAL) static int readProcAuxvForNeon(void) { @@ -668,6 +712,10 @@ SDL_GetCPUFeatures(void) SDL_CPUFeatures |= CPU_HAS_AVX512F; SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 64); } + if (CPU_haveARMSIMD()) { + SDL_CPUFeatures |= CPU_HAS_ARM_SIMD; + SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16); + } if (CPU_haveNEON()) { SDL_CPUFeatures |= CPU_HAS_NEON; SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16); @@ -749,6 +797,12 @@ SDL_HasAVX512F(void) return CPU_FEATURE_AVAILABLE(CPU_HAS_AVX512F); } +SDL_bool +SDL_HasARMSIMD(void) +{ + return CPU_FEATURE_AVAILABLE(CPU_HAS_ARM_SIMD); +} + SDL_bool SDL_HasNEON(void) { @@ -870,6 +924,7 @@ main() printf("AVX: %d\n", SDL_HasAVX()); printf("AVX2: %d\n", SDL_HasAVX2()); printf("AVX-512F: %d\n", SDL_HasAVX512F()); + printf("ARM SIMD: %d\n", SDL_HasARMSIMD()); printf("NEON: %d\n", SDL_HasNEON()); printf("RAM: %d MB\n", SDL_GetSystemRAM()); return 0;