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| author | Allan Sandfeld Jensen <allan.jensen@qt.io> | 2021-04-20 12:19:53 +0200 |
|---|---|---|
| committer | Allan Sandfeld Jensen <allan.jensen@qt.io> | 2021-04-21 15:01:13 +0200 |
| commit | ed82e1304d327bd663926be6301aae28b02323c0 (patch) | |
| tree | df668a44c3351d65a67a74d024f7bc70c4e49a6c /src/corelib/global/qsimd.cpp | |
| parent | 8179d7edf6cb2b06666634d0cafddbca974931e1 (diff) | |
Cleanup qsimd ARM code
Switch to using getauxval.
Change-Id: I1a55cf24e3cacbbca1f57ad6f74a80df80fe60cf
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'src/corelib/global/qsimd.cpp')
| -rw-r--r-- | src/corelib/global/qsimd.cpp | 70 |
1 files changed, 26 insertions, 44 deletions
diff --git a/src/corelib/global/qsimd.cpp b/src/corelib/global/qsimd.cpp index f76c6820ead..093ca877908 100644 --- a/src/corelib/global/qsimd.cpp +++ b/src/corelib/global/qsimd.cpp @@ -57,6 +57,10 @@ #elif defined(Q_OS_LINUX) && (defined(Q_PROCESSOR_ARM) || defined(Q_PROCESSOR_MIPS_32)) #include "private/qcore_unix_p.h" +#if QT_CONFIG(getauxval) +# include <sys/auxv.h> +#endif + // the kernel header definitions for HWCAP_* // (the ones we need/may need anyway) @@ -134,54 +138,32 @@ static inline quint64 detectProcessorFeatures() { quint64 features = 0; -#if defined(Q_OS_LINUX) -# if defined(Q_PROCESSOR_ARM_V8) && defined(Q_PROCESSOR_ARM_64) - features |= CpuFeatureNEON; // NEON is always available on ARMv8 64bit. -# endif - int auxv = qt_safe_open("/proc/self/auxv", O_RDONLY); - if (auxv != -1) { - unsigned long vector[64]; - int nread; - while (features == 0) { - nread = qt_safe_read(auxv, (char *)vector, sizeof vector); - if (nread <= 0) { - // EOF or error - break; - } - - int max = nread / (sizeof vector[0]); - for (int i = 0; i < max; i += 2) { - if (vector[i] == AT_HWCAP) { -# if defined(Q_PROCESSOR_ARM_V8) && defined(Q_PROCESSOR_ARM_64) - // For Aarch64: - if (vector[i+1] & HWCAP_CRC32) - features |= CpuFeatureCRC32; - if (vector[i+1] & HWCAP_AES) - features |= CpuFeatureAES; -# endif - // Aarch32, or ARMv7 or before: - if (vector[i+1] & HWCAP_NEON) - features |= CpuFeatureNEON; - } -# if defined(Q_PROCESSOR_ARM_32) - // For Aarch32: - if (vector[i] == AT_HWCAP2) { - if (vector[i+1] & HWCAP2_CRC32) - features |= CpuFeatureCRC32; - if (vector[i+1] & HWCAP2_AES) - features |= CpuFeatureAES; - } +#if QT_CONFIG(getauxval) + unsigned long auxvHwCap = getauxval(AT_HWCAP); + if (auxvHwCap != 0) { +# if defined(Q_PROCESSOR_ARM_64) + // For Aarch64: + features |= CpuFeatureNEON; // NEON is always available + if (auxvHwCap & HWCAP_CRC32) + features |= CpuFeatureCRC32; + if (auxvHwCap & HWCAP_AES) + features |= CpuFeatureAES; +# else + // For ARM32: + if (auxvHwCap & HWCAP_NEON) + features |= CpuFeatureNEON; + auxvHwCap = getauxval(AT_HWCAP2); + if (auxvHwCap & HWCAP2_CRC32) + features |= CpuFeatureCRC32; + if (auxvHwCap & HWCAP2_AES) + features |= CpuFeatureAES; # endif - } - } - - qt_safe_close(auxv); return features; } - // fall back if /proc/self/auxv wasn't found -#endif + // fall back to compile-time flags if getauxval failed +#endif // QT_CONFIG(getauxval) -#if defined(__ARM_NEON__) +#if defined(__ARM_NEON__) || defined(__ARM_NEON) features |= CpuFeatureNEON; #endif #if defined(__ARM_FEATURE_CRC32) |